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Tropical Cyclone Report

Hurricane Ivan

2 - 24 September 2004

Stacy R. Stewart
National Hurricane Center
16 December 2004
(updated 27 May 2005)

Ivan was a classical, long-lived Cape Verde hurricane that reached Category 5 strength three times on the Saffir-Simpson Hurricane Scale (SSHS). It was also the strongest hurricane on record that far south east of the Lesser Antilles. Ivan caused considerable damage and loss of life as it passed through the Caribbean Sea.

a. Synoptic History

Ivan developed from a large tropical wave that moved off the west coast of Africa on 31 August. Although the wave was accompanied by a surface pressure system and an impressive upper-level outflow pattern, associated convection was limited and not well organized. However, by early on 1 September, convective banding began to develop around the low-level center and Dvorak satellite classifications were initiated later that day. Favorable upper-level outflow and low shear environment was conducive for the formation of vigorous deep convection to develop and persist near the center, and it is estimated that a tropical depression formed around 1800 UTC 2 September. Figure 1 depicts the "best track" of the tropical cyclone's path. The wind and pressure histories are shown in Figure 2a and Figure 3a, respectively. Table 1 is a listing of the best track positions and intensities.

Despite a relatively low latitude (9.7°N), development continued and it is estimated that the cyclone became Tropical Storm Ivan just 12 h later at 0600 UTC 3 September. Ivan continued on a generally westward motion south of 10°N latitude and steadily strengthened, becoming a hurricane at 0600 UTC 5 September centered about 1000 n mi east of Tobago in the southern Windward Islands. After reaching hurricane strength, the rate of intensification increased dramatically and Ivan underwent an 18 h period of rapid intensification (rate > 30 kt/24 h). Satellite intensity estimates suggest that the intensity increased 50 kt while the central pressure decreased 39 mb during that time and Ivan reached its first peak intensity of 115 kt at 0000 UTC 6 September. This made Ivan the southernmost major hurricane on record. However, almost as quickly as Ivan strengthened it also weakened -- as much 20 kt over the following 24 h. Conventional and microwave satellite data indicated the probable cause of the rapid weakening was due to mid-level dry air that got wrapped into the center of the hurricane and eroded the eyewall convection.

Immediately following the 24 h weakening period, Ivan began a second strengthening phase (Figure 2b) that also contained a 12 h period of rapid intensification. During that time, Ivan was under surveillance by U.S. Air Force Reserve reconnaissance aircraft as the hurricane approached the southern Windward Islands. Reports from the aircrew indicated that Ivan had strengthened to a strong category 3 (SSHS) hurricane as the center passed about 6 n mi south-southwest of Grenada. The eye diameter at that time was about 10 n mi, and the strongest winds raked the southern portion of the island.

After passing Grenada and into the southeastern Caribbean Sea, the hurricane's intensity leveled off until 1800 UTC on 8 September when another brief period of rapid intensification ensued. Reconnaissance aircraft data indicated Ivan reached its second peak intensity -- 140 kt and category 5 strength (SSHS) -- just 12 h later. This was the first of three occasions that Ivan reached the category 5 level. The previous west-northwestward motion of 14-15 kt gradually decreased while Ivan moved across the central Caribbean Sea toward Jamaica. Although a large subtropical ridge to the north remained intact, steering currents weakened and Ivan's forward speed decreased to less than 10 kt on 11 September while the hurricane made a turn to the west, keeping the center at least 20 n mi offshore the southern coast of the island. As Ivan passed south of Jamaica it weakened to category 4 strength, in part, due to an eyewall replacement or concentric eyewall cycle (Figure 4a). The combination of the westward turn and weakening kept the strongest winds offshore.

Later that day Ivan began moving west-northwestward away from Jamaica. Ivan rapidly intensified to category 5 strength a second time while it remained in a low vertical shear environment, and reached its third peak intensity at 1800 UTC 11 September. However, Ivan only maintained its maximum intensity of 145 kt and category 5 status for 6 h before it weakened back to a category 4 hurricane on 12 September. The weakening trend was short-lived and Ivan re-strengthened to category 5 for its third and final time when it was about 80 n mi west of Grand Cayman Island. Although Ivan was weakening while the center passed south of Grand Cayman on 12 September, the hurricane still brought sustained winds just below category 5 strength (Table 3) to the island. This resulted in widespread wind damage, and a storm surge that completely over swept the island except for the extreme northeastern portion.

On 13 September, Ivan approached a weakness in the subtropical ridge over the central Gulf of Mexico and turned northwestward at a slower speed of 8-10 kt. As Ivan moved over the northwestern Caribbean Sea, the combination of the impressive upper-tropospheric outflow that was being enhanced by the south-southwesterly upper-level flow ahead of an approaching trough and the very warm water in that region probably helped the hurricane maintain category 5 strength for an unusually long 30 h. Once again major land areas were spared the full force of the hurricane because the 20 n mi diameter eye and strongest winds passed through the Yucatan channel just off the extreme western tip of Cuba (Figure 4b). Hurricane force conditions were reported across portions of western Cuba, but the effects were far less than what occurred on Grenada, Jamaica, and Grand Cayman when Ivan passed those areas.

Shortly after emerging over the southern Gulf of Mexico early on 14 September, Ivan turned north-northwestward and then northward. A steady weakening trend also ensued as moderate southwesterly flow on the east side of a large mid- to upper-level trough over the central United States and northeastern Mexico gradually caused the vertical shear to increase across the hurricane. As Ivan neared the northern U.S. Gulf coast, the upper-level wind flow ahead of the trough became more westerly and strengthened to more than 30 kt, which helped to increase the shear even more and advect dry air into the inner core region. Despite the unfavorable environmental conditions, the presence of cooler shelf water just offshore and eyewall replacement cycles, Ivan weakened only slowly and made landfall as a 105 kt hurricane (category 3 on the SSHS; see Figure 2c and Figure 3b.) at approximately 0650 UTC 16 September, just west of Gulf Shores, Alabama. By this time, the eye diameter had increased to 40-50 n mi (Figure 4c), which resulted in some of the strongest winds occurring over a narrow area near the southern Alabama-western Florida panhandle border.

After Ivan moved across the barrier islands of Alabama, the hurricane turned north-northeastward across eastern Mobile Bay and weakened into a tropical storm 12 h later over central Alabama. A gradual turn to the northeast occurred shortly thereafter and Ivan became a tropical depression by 0000 UTC 17 September over northeast Alabama. A northeastward motion at 10-14 kt continued for the next 36 h before Ivan merged with a frontal system and became an extratropical low over the DelMarVa peninsula around 1800 UTC 18 September. However, even as a weak tropical depression, Ivan was a prodigious rain and tornado producer causing flash floods and tornado damage across much of the southeastern United States.

Even as an extratropical low, the remnant circulation of Ivan was identifiable in both surface and upper-air data. Over the next 3 days, the low moved south and southwestward and eventually crossed the southern Florida peninsula from the Atlantic the morning of 21 September and emerged over the southeastern Gulf of Mexico later that afternoon. As Ivan moved westward across the warm water of the Gulf, the low began to re-acquire warm core, tropical characteristics as showers and thunderstorms started developing near the well-defined low-level circulation center. During the morning of 22 September, Ivan completed a large anticyclonic loop and by 1800 UTC reconnaissance aircraft reports indicated that it had become a tropical depression again over the central Gulf of Mexico. Ivan regained tropical strength 6 h later when it was located about 120 n mi south of the mouth of the Mississippi River. Tropical Storm Ivan turned northwestward and made landfall as a tropical depression in extreme southwestern Louisiana around 0200 UTC 24 September. After landfall, Ivan quickly dissipated later that morning over the upper Texas coastal area about 20 n mi northwest of Beaumont. Including its extratropical phase, Ivan existed for 22.5 days and produced a track more than 5600 n mi long.

b. Meteorological Statistics

Observations in Ivan (Figure 2 and Figure 3) include satellite-based Dvorak technique intensity estimates from the Tropical Analysis and Forecast Branch (TAFB), the Satellite Analysis Branch (SAB) and the U. S. Air Force Weather Agency (AFWA), as well as flight-level and dropwindsonde observations from flights of the 53rd Weather Reconnaissance Squadron of the U. S. Air Force Reserve Command (AFRES), and flight-level and stepped frequency microwave radiometer (SFMR) observations from the NOAA Aircraft Operations Center. Microwave satellite imagery from NOAA polar-orbiting satellites, the NASA Tropical Rainfall Measuring Mission (TRMM), the NASA QuikSCAT, and Defense Meteorological Satellite Program (DMSP) satellites were also helpful in monitoring Ivan. In addition, National Weather Service Doppler radars (Slidell, LA, Mobile, AL, and Elgin AFB, FL) were extremely useful for tracking this tropical cyclone. An example is seen in Figure 4, a reflectivity image of Ivan shortly after the time of landfall on 16 September from the Mobile WSR-88D Doppler radar, which shows the large eye of the hurricane inland over extreme southern Alabama.

A total of 112 reconnaissance center investigations were made in Ivan - 95 by the U.S. Air Force Reserve and 17 by the NOAA Hurricane Hunters. In addition, the NOAA Gulfstream-IV jet aircraft conducted 12 synoptic surveillance flights around the periphery of the hurricane. The maximum flight-level (700 mb) wind observed was 161 kt at 1917 UTC 11 September, when Ivan was located about 45 n mi west-southwest of the western tip of Jamaica. However, during Ivan's traversal across the Caribbean Sea, there were 12 additional flight-level wind reports of 150 kt or greater. The lowest aircraft measured pressure was 910 mb at 0005 UTC 12 September, less than 5 h after the maximum flight-level wind was observed, and also at 2053 UTC 13 September, which was about 2 h after flight-level winds of 157 kt were measured on two separate flight legs. Several research flights were made by NOAA aircraft when Ivan was moving over the Gulf of Mexico. The maximum SFMR surface wind observed was 99 kt at 0135 UTC 16 September about 58 n mi south of the Alabama coast. In the Caribbean Sea area, the maximum observed wind over land was sustained 130 kt with a gust to 149 kt on Grand Cayman Island at 1345 UTC 12 September. A 10-min average wind of 116 kt was reported at Pedro Bank, which is about 50 n mi southwest of Kingston. This was also the upper limit of reporting range of the wind observing equipment. Doppler radar velocity data indicated wind speeds as high as 97 kt may have affected much of Jamaica, especially over the higher elevations. In the United States, the strongest winds measured were an unofficial report from a storm chaser near Gulf Shores, Alabama of sustained 77 kt with a gust to 99 kt at 0602 UTC 16 September. Also, an unofficial wind gust of 126 kt at approximately 0600 UTC 16 September was observed by the sailboat Odalisque anchored in Wolf Bay north of Orange Beach, Alabama. The highest official wind report was 76 kt sustained with a gust to 93 kt at the Pensacola Naval Air Station, Florida at 0629 UTC 16 September.

The lowest pressures observed during Ivan's first U.S. landfall were unofficial reports 943.1 mb and 947.9 mb, which came from storm chasers based in Fairhope, Alabama. In addition, an automated weather observing station (AWOS) on the oil drilling platform Ram Powell-VJ956, located about 70 n mi south of Mobile Bay, Alabama (Table 3) reported a sustained wind of 102 kt with a gust to 135 kt at 2256 UTC 15 September at an elevation of 400 ft ASL. The instrument failed immediately after this report was obtained and remained inoperable for the next 4 days. Aircraft reconnaissance reports around that time suggest that the oil rig was located north-northeast of Ivan's center and just outside the radius of maximum winds.

Although Ivan was weakening as it made its first U.S. landfall, it is estimated to have been a category 3 hurricane when it reached the Alabama coast. As Ivan neared the U.S. Gulf coast on 15 and 16 September, the hurricane came under the surveillance of National Weather Service (NWS) WSR-88D Doppler radars located in Slidell, LA, Mobile, AL, and Eglin AFB, FL There was a robust and persistent velocity maximum located within vigorous convection in the northeastern quadrant of the outermost concentric eyewall as Ivan was coming ashore. For several hours prior to landfall, the velocities were actually higher in this area than in the vicinity of the inner eyewall. Within the outer eyewall existed several 1-2 n mi2 patches of 120-122 kt inbound Doppler velocities (some individual gates contained 123.4 kt velocities) at around 6,000 ft ASL. Using 122 kt as being representative of a smoothed peak and applying a reduction factor of 0.85 (standard reconnaissance flight-level reduction for 6000 ft) yields a surface estimate of 104 kt. In addition to the Doppler radar velocity data, a 700 mb flight-level wind of 120-kt was observed just south of Gulf Shores, AL at 0724 UTC 16 September (Figure 2c) in the same general area where the aforementioned maximum Doppler radar velocities were observed. The 120-kt flight-level wind converts to approximately a 108-kt surface wind using the standard 0.90 reduction factor from the 700 mb-level. A blend of those two equivalent surface wind values yields an intensity of 105 kt Ivan's first U.S. landfall. This intensity estimate is also consistent with the 99-kt SFMR surface wind data that was collected by a NOAA WP-3 aircraft more than 6 h before landfall. In addition, assuming a typical outward slope to the eyewall, the narrow band of strongest winds at landfall likely occurred over Perdido Key and Perdido Bay, which would have been to the west of the Pensacola Naval Air Station and to the east of the Florida Coastal Monitoring Program portable wind tower at Gulf Shores, Alabama.

Ship reports of winds of tropical storm force associated with Ivan are given in Table 2, and selected surface observations from land stations and data buoys are given in Table 3, Table 4, and Table 5. With the exception of a couple of ships that had sought shelter in the harbors around Grenada, the majority of ships remained clear of Ivan's strong winds.

Heavy rainfall exceeding 10 inches occurred on several of the Caribbean Islands (Table 3 and Table 5) and caused extensive freshwater flooding and/or mud slides. Some peak rainfall totals are 16.20 in from Tobago, 13.33 in from western Cuba, and 12.14 in from Grand Cayman. Across Jamaica, several locations received more than 25 in (635 mm) of rainfall. A few of the largest rainfall totals were 28.37 in (720.8 mm) at Ritchies, 27.92 in (709.4 mm) at Mavis Bank, and 26.83 in (681.5 mm) at both Craighead and Worthy Park. The Meteorological Service of Jamaica also "noted that rainfall data representative of a number of stations in southern parishes were lost due to damage done to rain gages by Hurricane Ivan." In the United States, rainfall totals generally ranged from 3-7 in along a large swath from Alabama and the Florida panhandle northeastward across the eastern Tennessee Valley and into the New England area (Figure 6) In fact, when Ivan was an extratropical low pressure system, it produced rainfall totals in excess of 7 in as far north as New Hampshire and as far south as the Florida east coast. Even as a weakening tropical depression, Ivan produced rainfall amounts exceeding 7 in across eastern Texas. However, there were two isolated extreme rainfall reports exceeding 15 in -- 15.75 in at television station WEAR-TV3 in Pensacola, Florida and 17.00 in at Cruso, North Carolina. Widespread flooding resulted from Ivan's rains, which fell on already saturated ground caused by Tropical Storm Bonnie and Hurricane Frances that traversed much of the same area in August and early September.

An outbreak of 117 tornadoes -- with the bulk of the tornadoes on 17 September -- developed over a 3 day period in the United States, including 37 in Virginia, 25 in Georgia, 18 in Florida, 9 in Pennsylvania, 8 in Alabama, 7 in South Carolina, 6 in Maryland, 4 in North Carolina, and 3 in West Virginia. There were 26 tornadoes reported on 15 September, 32 tornadoes on 16 September, 57 tornadoes on 17 September, and 2 tornadoes (in Maryland) on 18 September. At least 8 people were killed and 17 injured by the tornadoes. On 15 September, some of the more significant tornado events occurred -- an F2 tornado occurred near Panama City Beach (Bay Co.), FL resulting in 1 death and 7 injuries; a second F2 tornado occurred near Blountstown (Calhoun Co.), FL resulting in 4 deaths and 1 injury; a third tornado (intensity undetermined) killed 2 people in Panama City, FL a little more than 1 h after the F2 tornado had struck the area.

Storm surge of 10-15 ft occurred along the coasts from Destin in the Florida panhandle westward to Mobile Bay/Baldwin County, Alabama. Storm surge values of 6-9 ft were observed from Destin eastward to St. Marks in the Florida Big Bend region. Lesser values of storm surge continued east and southward along the Florida west coast with 3.5 ft reported in Hillsborough Bay/Tampa Bay. There was also a possible record observed wave height of 52.5 ft reported by the NOAA Buoy 42040 located in the north central Gulf of Mexico south of Alabama. In addition, severe storm surge flooding of 8-10 ft with 20-30 ft waves caused more than 5-8 ft of water to cover Grand Cayman Island at times. This resulted in the airport and numerous homes being completely inundated by sea water.

c. Casualty and Damage Statistics

The forces of Ivan were directly responsible for 92 deaths - 39 in Grenada, 25 in United States, 17 in Jamaica, 4 in Dominican Republic, 3 in Venezuela, 2 in Cayman Islands, and 1 each in Tobago and Barbados. Concerning the deaths in the United States, 14 occurred in Florida, 8 in North Carolina, 2 in Georgia, and 1 in Mississippi. The breakdown of U.S. deaths by cause is as follows: tornado (7), storm surge (5), fresh water floods (4), mud slides (4), wind (3), and surf (2). Ivan was also indirectly responsible for 32 deaths in the United States.

Ivan caused extensive damage to coastal and inland areas of the United States. Portions of the Interstate 10 bridge system across Pensacola Bay, Florida were severely damaged in several locations as a result of severe wave action on top of the 10-15 ft storm surge. As much as a quarter-mile of the bridge collapsed into the bay. The U.S Highway 90 Causeway across the northern part of the bay was also heavily damaged. To the south of Pensacola, Florida, Perdido Key bore the brunt of Ivan's fury and was essentially leveled. Along the Alabama coast, high surf and wind caused extensive damage to Innerarity Point and Orange Beach. In the Alabama and Florida panhandle areas, widespread over wash occurred along much of the coastal highway system. In addition, extensive beach erosion caused severe damage to or the destruction of numerous beachfront homes, as well as apartment and condominium buildings. Some buildings collapsed due to scouring of the sand from underneath the foundations caused by the inundating wave action. Thousands of homes the three-county coastal area of Baldwin, Escambia, and Santa Rosa were damaged or destroyed. Cleanup efforts alone in Escambia County resulted in debris piles that were more than three-quarters of a mile long and 70 feet high. In all, Ivan was the most destructive hurricane to affect this area in more than 100 years. Strong winds also spread well inland damaging homes, and downing tress and power lines. At one point, more than 1.8 million people were without power in nine states.

In addition to the damaged homes and businesses, Ivan also destroyed millions of acres of woodlands and forests. The Alabama Forestry Commission found damaged timber valued at about $610 million on 2.7 million acres. These figures include

  • Pine pulpwood: 7.5 million cubic feet
  • Hardwood pulpwood: 2.6 million cubic feet
  • Pine sawtimber: 351.5 million board feet
  • Hardwood sawtimber: 493 million board feet.

In the 200,000-acre Blackwater Forest, just east of Pensacola in the western Florida panhandle, more than 1.5 million board feet of timber were downed across 185,000 acres.

Ivan's effects were not just limited to coastal and inland areas. Offshore oil industry operations in the Gulf of Mexico were severely disrupted, and several oil drilling platforms and pipelines sustained varying degrees of damage. The normal daily flow of 475,000 barrels of oil and 1.8 billion cubic feet of natural gas, plus refining operations, were disrupted for more than 4 weeks. A total of 12 large pipelines and 6 drilling platforms sustained major damage; another 7 platforms were completely destroyed.

A total of 686,700 claims were filed and the American Insurance Services Group estimates (14 December 2004 re-survey) that insured losses in the United States from Hurricane Ivan totaled $7.11 billion, of which more than $4 billion occurred in Florida alone. Using a two-to-one ratio of insured damages yields an estimated U.S. loss of approximately $14.2 billion. In addition to the insured losses that occurred, the U.S. Naval Air Station at Pensacola, Florida sustained damage losses of $800-$900 million.

In the Caribbean region, extensive damage occurred to homes, buildings and other structures. The following are brief synopses of the reports received from some of the Caribbean islands:

Barbados
More than 176 homes completely destroyed; many homes lost their roofs; most coastal roads severely damaged due to erosion caused by the storm surge and wave action.
Cayman
95 percent of the homes and other buildings (which generally follow South Florida's building codes) were damaged or destroyed.
Cuba
Roofs were torn off homes in extreme western Pinar del Rio Province; flooding damaged houses, and fishing and farm installations; mud slides cut off at least two towns.
Grenada
At least 80 percent of the 100,000 residents were without power; more than 14,000 homes were damaged or destroyed; 80 percent of the nutmeg trees were destroyed; a 17th century prison was also damaged allowing many of the inmates to briefly escape during the height of the storm; Ivan was the worst hurricane to strike the island since Hurricane Janet in 1955.
Jamaica
At least 47,000 homes were damaged, of which 5,600 were completely destroyed; most of the islands utilities were damaged.
St. Vincent/Grenadines
50 homes severely damaged with 2 homes washed away into the sea; more than two-thirds of residents lost power.
Tobago
At least 1 home collapsed and fell into the ocean; at least 45 homes lost their roofs; numerous trees and utility were blown down; 20 villages suffered various forms of damage

In the Caribbean Sea region, the Caribbean Development Bank (CDB) estimates the damage at more than US$3 billion -- US$1.85 billion in the Cayman Islands, US$815 million in Grenada, US$360 million in Jamaica, US$40 million in St. Vincent and the Grenadines, and US$2.6 million in St Lucia. No damage estimates were available from any of the other Windward Islands countries, Venezuela, or Cuba.

d. Forecast and Warning Critique

Average official track errors (with the number of cases in parentheses) for Ivan were 24 (63), 47 (61), 79 (59), 108 (56), 161 (52), 222 (48), and 289 (44) n mi for the 12, 24, 36, 48, 72, 96, and 120 h forecasts, respectively. In comparison, the longer-term average official track errors for the 10-yr period 1994-2003[1] are 44, 78, 112, 146, 217, 248, and 319 n mi. Table 6 contains the average errors from various numerical track forecast models for Ivan. The average NHC official track forecast (OFCL) errors for Ivan were better than the 10-yr average throughout the 120 h forecast cycle, especially through 72 h. However, most of the various numerical track forecast models, like the UKMET and FSU Superensemble (FSSE) models outperformed the NHC official track forecast at most times. On average, the FSSE model significantly outperformed the NHC official forecast at all times. Average official intensity errors were 9, 12, 13, 12, 15, 24 and 36 kt for the 12, 24, 36, 48, 72, 96, and 120 h forecasts, respectively. For comparison, the average official intensity errors over the 10-yr period 1994-2003 are 6, 10, 12, 15, 19, 20, and 21 kt, respectively. These intensity errors were greater than average at 96 and 120 h due to rapid intensification and greater than forecast intensities that occurred over the Caribbean Sea. Synoptic-scale analyses produced by the NOAA Global Forecast System (GFS) indicate that Ivan essentially remained underneath a 200 mb ridge axis as the hurricane traversed the Caribbean Sea. This resulted in implied relatively low 850-200 mb vertical wind shear values ( < 10 kt in many times periods) over the inner core region and also provided favorable upper-level outflow channels to the north and south. However, the Statistical Hurricane Intensity Prediction Scheme (SHIPS) model failed to capture both the early rapid intensification period and the lengthy period of category 4 and 5 strength. This may be due to the way the SHIPS model assesses the vertical shear across a tropical cyclone. During the period 7-14 September when significant intensification occurred, the SHIPS model assessed the vertical shear on numerous occasions to be 15-20 kt from a westerly direction. Typically when alleged westerly shear of this magnitude is present, little or no strengthening occurs and, more often, weakening transpires. The westerly vertical shear calculated by the SHIPS model may have been due, in part, to its inability to separate the strong upper-level outflow from the environmental flow in which the cyclone was embedded.

Official track forecasts had, in general, a persistent right-of-track bias for the first 11 days of Ivan's existence as a tropical cyclone (Figure 5a). The official track forecasts relied heavily on the global model forecasts, which prematurely eroded the large and strong subtropical ridge to the north of Ivan that extended well westward across the Bahamas, Florida, and into the Gulf of Mexico. In fact, several of the GFS model forecast cycles consistently eroded the ridge across Bahamas and took Ivan well to the east of Florida, even as the hurricane was approaching Jamaica. The westward jog that Ivan made on 11 September appears to be, at least in part, the result of a mid- to upper-level cold low to the north of Hispaniola that moved slowly southwestward rather than weakening and lifting out to the northeast as some of the models had been forecasting. Despite the early right bias, once Ivan moved into the northwestern Caribbean Sea, the track forecasts gradually narrowed down the likely landfall region of the western Florida panhandle and Alabama coasts (Figure 5b). Table 7 lists all of the watches and warnings issued for Ivan.

A hurricane watch was issued for the central U.S. Gulf coast more than 51 h prior to landfall on the Alabama coast. A hurricane warning was issued for the same area less than 42 h prior to landfall. Over the 72 h period leading up to the first U.S. landfall, there was a spread of only 95 n mi between the westernmost and easternmost forecast tracks. In fact, more than 75% of those forecasts targeted the Alabama coast as the most likely area where landfall was expected to occur. The result of these forecasts was that Ivan made landfall well within the area covered by the hurricane watch and warning.

Acknowledgments

NWS/WFOs Houston/Galveston, Huntsville, Jacksonville, Key West, Lake Charles, Mobile, New Orleans (Slidell), Tallahassee, and Tampa Bay, and the NOAA Hydrometeorological Prediction Center and the NOAA Southeast River Forecast Center contributed many of the observations contained in this report. Amateur Radio (HAM) operators throughout the Caribbean region and those working as part of the National Hurricane Center's WX4NHC Hurricane WatchNet team ( http://www.fiu.edu/orgs/w4ehw/) were indispensable in providing critical reports as Ivan moved through the Windward Islands and across the Caribbean Sea.

[1]Errors given for the 96 and 120 h periods are averages over the three-year period 2001-3.



Table 1: Best track for Hurricane Ivan, 2-24 September 2004.
Date/Time
(UTC)
PositionPressure
(mb)
Wind Speed
(kt)
Stage
Lat.
(°N)
Lon.
(°W)
 02 / 1800 9.7 27.6 1009 25 tropical depression
 03 / 0000 9.7 28.7 1007 30 "
 03 / 0600 9.7 30.3 1005 35 tropical storm
 03 / 1200 9.5 32.1 1003 40 "
 03 / 1800 9.3 33.6 1000 45 "
 04 / 0000 9.1 35.0 999 45 "
 04 / 0600 8.9 36.5 997 50 "
 04 / 1200 8.9 38.2 997 50 "
 04 / 1800 9.0 39.9 994 55 "
 05 / 0000 9.3 41.4 991 60 "
 05 / 0600 9.5 43.4 987 65 hurricane
 05 / 1200 9.8 45.1 977 85 "
 05 / 1800 10.2 46.8 955 110 "
 06 / 0000 10.6 48.5 948 115 "
 06 / 0600 10.8 50.5 950 110 "
 06 / 1200 11.0 52.5 955 110 "
 06 / 1800 11.3 54.4 969 90 "
 07 / 0000 11.2 56.1 964 90 "
 07 / 0600 11.3 57.8 965 95 "
 07 / 1200 11.6 59.4 963 100 "
 07 / 1800 11.8 61.1 956 105 "
 08 / 0000 12.0 62.6 950 115 "
 08 / 0600 12.3 64.1 946 120 "
 08 / 1200 12.6 65.5 955 120 "
 08 / 1800 13.0 67.0 950 120 "
 09 / 0000 13.3 68.3 938 130 "
 09 / 0600 13.7 69.5 925 140 "
 09 / 1200 14.2 70.8 919 140 "
 09 / 1800 14.7 71.9 921 130 "
 10 / 0000 15.2 72.8 923 130 "
 10 / 0600 15.7 73.8 930 125 "
 10 / 1200 16.2 74.7 934 125 "
 10 / 1800 16.8 75.8 940 120 "
 11 / 0000 17.3 76.5 926 135 "
 11 / 0600 17.4 77.6 923 130 "
 11 / 1200 17.7 78.4 925 125 "
 11 / 1800 18.0 79.0 920 145 "
 12 / 0000 18.2 79.6 910 145 "
 12 / 0600 18.4 80.4 915 135 "
 12 / 1200 18.8 81.2 919 135 "
 12 / 1800 19.1 82.1 920 130 "
 13 / 0000 19.5 82.8 916 140 "
 13 / 0600 19.9 83.5 920 140 "
 13 / 1200 20.4 84.1 915 140 "
 13 / 1800 20.9 84.7 912 140 "
 14 / 0000 21.6 85.1 914 140 "
 14 / 0600 22.4 85.6 924 140 "
 14 / 1200 23.0 86.0 930 125 "
 14 / 1800 23.7 86.5 931 120 "
 15 / 0000 24.7 87.0 928 120 "
 15 / 0600 25.6 87.4 935 120 "
 15 / 1200 26.7 87.9 939 115 "
 15 / 1800 27.9 88.2 937 115 "
 16 / 0000 28.9 88.2 931 110 "
 16 / 0600 30.0 87.9 943 105 "
 16 / 1200 31.4 87.7 965 70 "
 16 / 1800 32.5 87.4 975 50 tropical storm
 17 / 0000 33.8 86.5 986 30 tropical depression
 17 / 0600 34.7 85.7 991 25 "
 17 / 1200 35.4 84.0 994 20 "
 17 / 1800 36.2 82.3 996 20 "
 18 / 0000 37.0 80.5 999 20 "
 18 / 0600 37.7 78.5 998 15 "
 18 / 1200 38.4 76.7 1000 15 "
 18 / 1800 38.0 75.5 1002 25 extratropical
 19 / 0000 37.5 74.0 1003 35 "
 19 / 0600 36.0 74.0 1005 35 "
 19 / 1200 34.5 74.5 1008 35 "
 19 / 1800 32.8 75.8 1008 35 "
 20 / 0000 31.0 77.5 1008 35 "
 20 / 0600 29.0 78.5 1008 35 "
 20 / 1200 27.5 78.7 1009 30 "
 20 / 1800 26.4 79.1 1009 25 "
 21 / 0000 26.1 79.7 1009 25 "
 21 / 0600 25.9 80.6 1009 25 "
 21 / 1200 25.8 81.7 1009 25 "
 21 / 1800 25.2 82.8 1010 25 low
 22 / 0000 24.8 84.1 1010 25 "
 22 / 0600 25.1 86.1 1010 25 "
 22 / 1200 26.0 87.3 1010 25 "
 22 / 1800 26.5 88.6 1008 30 tropical depression
 23 / 0000 27.1 89.5 1007 35 tropical storm
 23 / 0600 27.9 91.0 1007 35 "
 23 / 1200 28.9 92.2 998 50 "
 23 / 1800 29.2 92.7 1003 40 "
 24 / 0000 29.6 93.2 1003 30 tropical depression
 24 / 0600 30.1 94.2 1009 25 "
 24 / 1200     dissipated inland
 12 / 0000 18.2 79.6 910 145 minimum pressure
 13 / 2100 21.2 84.8 910 140 minimum pressure
 07 / 2130 11.9 61.8 952 110 closest point of approach, 6 n mi south-southwest of Prickly Point, Grenada
 11 / 0330 17.4 77.2 924 130 closest point of approach, 20 n mi south of Portland Point, Jamaica
 12 / 1415 18.9 81.5 920 130 closest point of approach, 22 n mi south-southwest of Georgetown, GCI
 14 / 0100 21.7 85.2 916 140 closest point of approach, 15 n mi southwest of Cabo San Antonio, Cuba
 16 / 0650 30.2 87.9 946 105 1st U.S. landfall near Pine Beach, AL, or 9 n mi west-southwest of Gulf Shores, AL
 24 / 0200 29.8 83.6 1004 30 2nd U.S. landfall near Holly Beach, LA, or 10 n mi west of Cameron, LA


Table 2: Selected ship and drifting buoy reports with winds of at least 34 kt for Hurricane Ivan, 2-24 September 2004.
Ship Name or Call SignDate/Time (UTC)Lat.
(°N)
Lon.
(°W)
Wind dir/speed (deg/kt)Pressure (mb)
1300904 / 11008.038.0- - - / 36 - - - 
MV Son Monoy08 / 035910.766.2320 / 40G50 - - - 
ZCDE408 / 120011.662.7120 / 47 1007.2 
WDA40611 / 060015.977.5230 / 37 1002.1 
ATPN12 / 040016.880.2010 / 46 1005.0 
P3JA812 / 150017.781.8250 / 53 997.5 
A8CO213 / 180018.385.5260 / 35 1006.8 
A8CO213 / 210018.384.9250 / 35 1005.9 
C6DM214 / 000017.986.8280 / 44 1002.0 
LAZK414 / 100022.688.8020 / 44 999.0 
WPPO14 / 140025.584.2090 / 45 1004.0 
HZRX14 / 150024.583.3110 / 52 1004.3 
WPPO14 / 170025.383.9120 / 47 1004.0 
HZRX14 / 180024.182.7120 / 52 1004.4 
WPPO14 / 230024.783.4140 / 52 1004.2 
H3SM15 / 090027.190.2020 / 39 999.7 
LANT515 / 120024.285.1180 / 43 1005.0 
H3SM15 / 150027.090.0360 / 50 963.0 
H3SM15 / 180027.090.2330 / 43 963.7 
SPLL115 / 180028.990.5010 / 39 1002.2 
H3SM15 / 210027.090.2320 / 46 998.0 
H3SM16 / 000027.090.2290 / 42 1001.3 
C6YC19 / 060037.574.5010 / 37 1010.5 
DHBN19 / 120040.470.7020 / 35 1016.0 
A8CF220 / 060034.772.3020 / 37 1017.0 
VRXL620 / 060033.473.0200 / 35 1015.5 
WGXO20 / 060029.579.6040 / 37 1011.0 


Table 3: Selected surface observations for Hurricane Ivan, 2-24 September 2004.
Minimum
Sea-level
Pressure
Maximum Surface Wind Speed
(kt)
LocationDate/
Time
(UTC)
Press.
(mb)
Date/
Timea
(UTC)
Sust.
Windb
(kts)
Peak
Gust (kts)
Storm
Surgec
(ft)
Storm
Tided
(ft)
Rain
(storm total)
(in)
Windward Islands
Dominica
Hewanorra (TLPL)  07/1700+ 37     
Grenada
Point Salines (TGPY)  07/2000 45 81    
  07/2100 64 101    
  07/2300 49 67    
Jamaica
Craighead       26.83 
Kingston (MKJP)11/0129 991.5 11/0217* 55     
Mavis Bank       27.92 
Negril Point11/???? 986.8       
Pedro Bank11/???? 979.5 11/???? 116     
Ritchies       28.37 
Rose Hill       25.80 
South Central coastal areas     4-6   
Worthy Park       26.83 
Cayman Islands
Cayman Brac12/0300 997.0 12/0200 44 58   4.92 
Grand Cayman12/1345 970.0 12/1500 130 149 8-10  12.14 
Cuba
Cabo de San Antonio  14/0050# 96 104    
Cuba - Francia (78309)14/0000 1001.6 14/0043 45 56   10.16 
La Fe (78321)13/1850 1001.0 13/1248 51 64   6.26 
La Palma (78316)14/0100 1000.3 14/0620 49 61   4.43 
Isabel Rubio (78313)14/0200 990.1 14/0200 61 76   13.33 
Nueva Gerona (Isle of Youth)13/1800 1000.1 13/1457 55 69   5.66 
Pinar del Rio (78315)13/2310 997.7 14/0140 54 67   7.69 
Pinar del Rio Prov. (s. coast)     6-12   
P.R.S. Diego (78317)13/2340 1001.5 14/0140 42 52   5.55 
Punta del Este (78324)13/2200 1000.7 14/0030 49 61   4.75 
San Juan y Martinez (78314)14/0100 996.0 13/2340 47 59   5.69 
Santa Lucia (78312)14/0200 994.7 14/0220 61 76   6.00 
Alabama
Alabaster (KEET)17/0053 991.7      6.00 
Alberta       6.85 
Alexander City (KALX)  16/1500  36    
Andalusia (HAM Radio)       9.96 
Anniston (ANNA1)       7.64 
Anniston (KANB)17/0053 991.5       
Ariton Co-op (ARTA1)       5.32 
Baldwin County     10-15   
Bellwood Co-op (BELA1)       5.48 
Bessie       5.81 
Birmingham (KBHM)17/0053 989.6 16/1653  42   9.81 
Blakely (Co-op (BLKG1)       6.50 
Blount Springs       5.29 
Brookley / Mobile (KBFM)16/0656 956.0       
Coden       6.30 
Cullman (K3A1)  16/1740+  39    
Daleville Co-op (DALA1)       5.82 
Daphne       7.50 
Dothan (KDHN)16/0752 1000.6 16/1900 38 47   5.94 
Elba Co-op (EBBA1)       5.48 
Evergreen (EVRA1)       7.55 
Fairhope (awis)  16/0418  63    
Flat Rock (FLRA1)       8.04 
Florence (C0168)  17/0050+  37    
Fort Payne 6NE (LRWA1)       7.30 
Fort Payne (K4A9)  16/1920  45    
Gadsden (KGAD)  16/1735  37    
Geneva Co-op (GVAA1)       8.20 
Grand Bay (awis)  16/0517  62    
Helena       4.72 
Huntsville (KHSV)16/2353 994.3 16/2153  40    
Huntsville (KMDQ)  16/2242+  35    
Jackson Shoals       4.05 
Ketona       9.69 
Lauderdale (RLDM6)  16/1113  47    
Lower Bryant Landing (NOS)     3.4   
Manchester       4.35 
Maxwell AFB (KMXF)16/1755 989.9 16/1257 31 57   9.78 
Millers Ferry (MRFA1)       11.66 
Mobile (KMOB)16/0725 964.4 16/0644 51 65   5.56 
Mobile (2S KMOB)       9.90 
Mobile (3S KMOB)       6.30 
Mobile (7S KMOB)       6.53 
Mobile (10S KMOB)       8.00 
Mobile County     6-9   
Montgomery (KMGM)16/1753 989.5 16/1353 32 50    
Muscle Shoals (KMSL)16/2253 998.7 16/2110  40    
Newton Co-op (NEWA1)       5.47 
Ozark / Ft. Rucker (KOZR)16/1055 999.8 16/0955  38   6.10 
Ram Powell VK-956 Oil Rig - 400 ft elev. (29.05°N 88.10°W)15/2256* 952.6 15/2256* 102 135    
Robertsdale       9.35 
Selma (SELA1)       8.87 
Semmes (awis)16/0830 967.5 16/0500 49 51   5.00 
Silverhill (3S)       10.16 
Spanish Fort  16/0800  51   8.00 
Talladega       5.60 
Tannehill       9.76 
Troy (KTOI)16/1755 994.7 16/1128+  37    
Trussville (TRSA1)       8.97 
Tuscaloosa (KTCL)16/1353 996.7 16/1453+  43    
Valley Head (VYHA1)       8.27 
Wing 6NE (OPNA1)  16/1022+  58    
Wedowee       5.20 
Florida
Apalachicola (KAAF)       4.11 
Baker (BAKF1)       10.41 
Bay County     8-10   
Big Pine Key       2.12 
Bristol Co-op (BRLF1)       7.00 
Bruce Co-op (BRUF1)       7.05 
Chipley Co-op (CHPF1)       5.42 
Crestview (CRVF1)       7.68 
Crestview (HAM radio)       8.40 
Cross City (KCTY)  16/1918  31    
Dixie County       
Eglin AFB (KVPS)16/0755 991.6 16/0755 46 70   7.43 
Escambia County     10-15   
Franklin County     3-5   
Ft. Walton (HAM radio)       6.06 
Gulf County (St. Joseph State Park)     4-6   
Hillsborough Co. (Hills. Bay)     3.5   
Huntsville (KHSV)       3.73 
Jefferson County       
Key West (KEYW)  14/0903 36 46   1.11 
Key West (KEYW - Atlantic)     1.0   
Levy County (Cedar Key)     1.91   
Lowry Mill Co-op (LOWA1)       7.33 
Marianna Co-op (MALF1)       5.28 
Mayport Naval Stn. (KNRB)  21/0355+  34    
Milligan (MLGF1)       11.31 
Mossy Head Co-op (MHDF1)       9.26 
Munson       6.50 
Nettles Island (NETF1)       7.62 
Niceville       6.55 
Okaloosa County     6-9   
Panama City (KPFN)16/0853 999.9 16/1700 30 60    
Pensacola (KPNS)16/0645 970.2 16/0650 67 87    
Pensacola NAS (KNPA)16/0656 965.8 16/0629 76 93   8.00 
Pensacola (WEAR-TV)       15.79 
Perry (K40J)  16/1749  41    
Saint Augustine (KSGJ)  21/0300  36    
Santa Rosa County     10-15   
Sarasota (KSRQ)  16/1255  30    
Seminole 5NE       8.10 
Tallahassee (KTLH)  16/1605 33 47    
Taylor County       
Walton County     8-10   
Wakulla County     4-5   
Georgia
Albany (KABY)  16/1803  36    
Athens (KAHN)  16/2333  39    
Atlanta - Falcon (KFFC)  17/0122  34    
Atlanta - Hatrsfield (KATL)  16/2357  39    
Atlanta - McCollum (KRYY)  16/2347  35    
Atlanta - Peachtree (KPDK)  16/2125  38    
Byromville (BYRG1)  16/2105  34    
Canton / Cherokee Co. (K47A)  16/2122  35    
Chickamauga (FTOG1)       7.75 
Clayton 4NE (TULG1)  18/0206  43    
Clayton 10W (TCLG1)       7.87 
Columbus (KCSG)16/2151 997.1 16/2227+  39    
Elberton (K27A)  17/0101  37    
Ellijay 7NW (MTNG1)       7.24 
Fort Benning AAF (KLSF)  16/2355  36    
Gainesville (KGVL)  16/2253  39    
Helen (HELG1)       8.57 
Helen 7N (BRSG1)  17/0306  61    
Hurst 3SE (HSTG1)       8.42 
Lafayette 5SW (LFYG1)       7.28 
Lagrange (KLGC)  16/2140  34    
Lawrenceville (KLZU)  16/2150  40    
Mountain City 2N (MTCG1)       7.10 
Nacoochee (NACG1)       9.20 
Pine Mountain (PIMG1)       7.80 
Preston Co-op (PRSG1)       5.57 
Rome (KRMG)17/0553 994.5       
Suches 6NW (TCCG1)  17/0005  39    
Tallula Falls (TLUG1)       7.88 
Thomaston - Upson (KOPN)  16/2101  38    
Titus (TUSG1)       9.27 
Valdosta (KVLD)  16/1907  37    
Washington 5NW (WSNG1)  17/202  35    
Winder (KWDR)  16/2240  39    
Kentucky
Greenup (GNUK2)       6.26 
Louisiana
Barataria Bay  15/1700  44    
Bootheville (KBVE)  15/1551 31 42    
Bootheville - LSU Citrus AG  16/0000  52   1.05 
Buras       2.50 
Calcasieu Pass - East Jetty     1.7   
Cameron Heliport (K7R5)  23/2325  34    
Cameron Prairie NWR       4.14 
Cocodrie  16/0000  36    
Deridder       3.00 
Elmer 2SW       3.75 
Franklin 3NW       3.04 
Hackberry 8SSW (HAKL1)  24/0140  36    
Galliano - Little Lake  15/2300  41    
Grand Isle - East Point     1.7   
Laffitte - Lake Salvador  16/0300  34    
Lake Charles (KLCH)23/2346 1012.5 24/0217 23 30   1.16 
Lake Pontchartrain - Mandeville  16/0030 30 33    
Lake Pontchartrain - mid lake  16/0330 35 46    
Marco Polo GC608 Oil Rig - 300 ft elev. (27.36°N 90.19°W)  15/2100& 54     
New Orleans (KNEW)16/0125 994.2 16/0206 41 48   0.08 
New Orleans (KMSY)16/0644 998.0 15/2138 33 40   Trace 
Pointe a la Hache - northeast Bay Gardene  16/0400  60    
Rockefeller NWR       3.22 
Slidell (KASD)16/0147 994.2 16/0011 32 37   0.26 
SW Pass (NOS)     3.0   
Maryland
AP259 APRSWXNET (39.0°N 76.3°W)  18/1700  36    
Patuxent NAS (KNHK)  18/2355  35    
Mississippi
Biloxi Bay - NOAA/NOS     3.2   
Biloxi Harbor - Pointe Cadet  16/0245 47 68    
Columbus (KGTR)  16/1815+  46    
Columbus AFB (KCBM)16/1955 995.8 16/1855  35    
Gautier - U.S. Hwy 90  16/0700*  51    
Gholson 8W (GHLM6)       5.35 
Gulfport (KGPT)16/0703* 983.7 16/0059* 40 53   1.70 
Keesler AFB (KBIX)16/0655 982.9 16/0644 42 62   3.28 
NAS Meridian (KNMM)16/1555 992.0 16/1255 30 51    
Ocean Springs - Ft. Bayou  16/0415  43    
Orange Grove - Interstate 10  16/0715  46    
Pascagoula 3NNE       5.70 
Pascagoula / Jackson Co. EOC (top of 2-story building)  16/0600  76   6.29 
Pascagoula (KPQL)16/0536* 975.6 15/2349* 37 51   1.15 
Pass Christian - USCG Merril Shell Bank Lighthouse  16/0500  64    
Van Cleave (BCVM6)       3.73 
Waveland - NOAA/NOS  16/0242 34 49 3.4   
Waveland - Hancock Co. EOC  16/0430  53    
New Hampshire
Jaffrey (AFN)       7.30 
New Jersey
Columbia (CMBN4)       5.50 
New York
Deposit (DEPN6)       5.37 
Fishs Eddy (FSHN6)       5.40 
Stuyvesant 5N (STYN6)       5.11 
Windham (WDMN6)       5.45 
North Carolina
Andrew - Murphy (KRHP)  17/0524  39    
AP341 RAWS (36.1°N 81.9°W)  17/0330  41    
Asheville (KAVL)  17/0535+  42    
Black Mtn (MMTN7)       9.05 
Boone (KTNB)  17/0801  45    
Burgaw 11E (BKIN7)  17/2213  36    
Burlington (KBUY)  17/1727  44    
C1587 RAWS (35.8°N 78.9°W)  17/1746  39    
Canton 10 SSW (SNBN7)       8.92 
Charlotte Int'l (KCLT)  17/0851  35    
Cruso       17.00 
Cullowhee (CUWN7)  17/0610+  42    
Daniel Ridge (DNRN7)       8.25 
Elizabeth City (KECG)  18/0254  36    
Fayetteville 11WNW (FBRN7)  17/2007+  36    
Fayetteville (KFAY)  17/2023+  41    
Guion Farms AFS (GUIN7)  17/0610  44    
H0002 RAWS (36.4°N 81.5°W)  17/0510  37    
Hawk - IFLOWS (HAKN7)       7.12 
Highlands (C0930)  17/0155  41    
Highlands - IFLOWS (HILN7)       8.16 
Highlands (TVA)       11.83 
Hogback (IHBN7)       8.92 
Jacksonville (KOAJ)  17/1835  35    
Jefferson (KGEV)  18/0441+  41    
Jonas Ridge (JSRN7)       8.95 
Kill Devil Hills (KFFA)  19/0900  38    
Kure Beach 3W (SUNN7)  18/0058  39    
Laurel Springs (LRLN7)  17/0810*  51    
Mackall AAF (KHFF)  17/1555  34    
Manteo (KMQI)  18/1100+  37    
New Bern (KEWN)  18/0107+  35    
Plumtree (PLMN7)       8.08 
Purlear 2N (RVZN7)  18/0810+  42    
Raleigh - Durham (KRDU)  17/1951  36    
Rich Mountain (RCMN7)       8.08 
Rosman 6E (CFFN7)       7.83 
Shallotte 7NE (NATN7)  17/2259  38    
Shelby (KEHO)  17/0720  35    
Spruce Pine 3SE (SPPN7)       7.20 
TS156 RAWS (35.8°N 82.7°W)  17/0908  42    
Whiteville (WHIN7)  17/2045  35    
Yancey (YNCN7)       7.50 
Ohio
Albany (ABNO1)       8.53 
Pennsylvania
Acmetonia (ACMP1)       7.51 
Ansonville (ANSP1)       7.29 
Blakeslee (TBYP1)       8.20 
Cristy Manor 2SE (CRCP1)       7.15 
Elimsport (ELIP1)       7.60 
Fort Indiantown Gap (FIGP1)       7.90 
Hugos Corners (HGCP1)       7.40 
Loyalsockville (LOYP1)       5.40 
Pine Grove 1SW (PGVP1)       7.70 
Scrub Oak (SCBP1)       8.32 
South Carolina
Anderson (KAND)  17/0040  38    
Greenville (KGMU)  17/0253  37    
Greenwood (KGRD)  17/0556  34    
Greer (KGSP)  17/0303  40    
North Myrtle Beach (KCRE)  17/2208  38    
Tennessee
Crossville (CSST1)  17/0606  34    
Burns (BURT1)  17/0406+*  56    
Charleston (CHTT1)       7.39 
Chattanooga (KCHA)17/0853 994.7       
Chickamauga Dam (CKDT1)       7.63 
Coker Creek (CCKT1)  17/06744+  42    
Dayton (DAYT1)       7.65 
Decatur (DECT1)       7.86 
Lenoir City 5NW (LCLT1)  17/0505  39    
Lewisburg (LSBT1)  17/0106  35    
McDonald       11.03 
Morristown 3NNE (HCOT1)  17/0505  36    
Pikeville 7NW (BLDT1)  17/0105  41    
Sweetwater (SWET1)       8.99 
Watts Bardam (WBOT1)       7.52 
Whitwell 7SE (PCFT1)  16/2106  51    
Texas
Beaumont (KBPT)24/0425 1008.8 24/0339 23 30   1.05 
Beckville (BEKT2)       7.86 
Bon Weir       2.70 
Eagle Point - Galveston Bay     1.7   
Galveston Pier 21     1.6   
Houston Hobby (KHOU)23/2156 1012.9 23/2344  23   0.62 
Jamaica Bch Co-op (JBHT2)23/2230 1012.7 22/0932  29   Trace 
Matagorda Island (MIRT2)  24/0512  47    
Sabine Pass North     1.4   
Sam Rayburn Reservoir       3.49 
Silsbee 4N       2.00 
Steinhagen Lake (TBLT2)       7.07 
Toledo Bend Reservoir       2.34 
Weches - Houston Co.       1.92 
Virginia
Big Meadows (BGMV2)       5.72 
Dulles / Wash. Int'l (KIAD)  17/2212+  37    
Hillsville (KHLX)  17/0900  42    
Hot Springs (KHSP)  18/0500  34    
Langley AFB (KLFI)  19/0155  36    
Leesburg (KJYO)  18/1541  36    
Manassas (KHEF)  18/1955  38    
Martinsville (KMTV)  18/0520  34    
Meadows of Dan (AP852)  18/1815  41    
Melfa (KMFV)  18/0420  37    
Norfolk Int'l (KORF)  19/0351+  35    
Norfolk Naval Stn (KNGU)  19/0755 30 38    
Oceana NAS (KNTU)  18/2256  37    
Reagan / Wash. Int'l (KDCA)  18/2051+  35    
Richmond Int'l (KRIC)  18/0012+  35    
Stafford (KRMN)  18/1720  37    
Strasburg (STGV2)       5.50 
TS121 RAWS (37.9°N 81.9°W)  17/2214  34    
West Virginia
Buckhannon (KW22)  18/0200+  42    
Charleston (KCRW)  17/2154  32    
Clarksburg (KCKB)  18/0053+  37    
Gallipois Dam (GALW2)       5.94 
Moundsville (MOUW2)       7.68 
dStorm tide is water height above National Geodetic Vertical Datum (1929 mean sea level).
aDate/time is for sustained wind when both sustained and gust are listed.
bExcept as noted, sustained wind averaging periods for C-MAN and land-based ASOS reports are 2 min; buoy averaging periods are 8 min.
cStorm surge is water height above normal astronomical tide level.
dStorm tide is water height above National Geodetic Vertical Datum (1929 mean sea level).
+Last of several occurrences
#Approximate time
*Instrument failed after report
&30-minute averaging period


Table 4: Selected fixed buoy and C-MAN observations for Hurricane Ivan, 2-24 September 2004.
Minimum
Sea-level
Pressure
Maximum Surface Wind Speed
(kt)
LocationDate/
Time
(UTC)
Press.
(mb)
Date/
Timea
(UTC)
Sust.
Windb
(kts)
Peak
Gust (kts)
Storm
Surgec
(ft)
Storm
Tided
(ft)
Rain
(storm total)
(in)
C-MAN
BURL1 (28.9°N 89.4°W)15/2300 983.6 15/2310 72 87    
  16/0000 69     
  15/2300 68     
23/0500 1013.8 23/0300 35     
  23/0500 35     
CDRF1 (29.1°N 83.0°W)  16/1217  31    
CLKN7 (34.6°N 76.5°W)  18/0228  34    
CHLV2 (36.9°N 75.7°W)18/0400 1001.8 18/0350 38 48    
  18/2230 39 45    
  19/0500 39 45    
DPIA1 (30.2°N 88.1°W)16/0705 952.7 16/0405 63 89    
  16/0505 63     
DUCN7 (36.2°N 75.7°W)  18/0330 33 47    
19/0300 1011.4 19/0400 38     
GDIL1 (29.3°N 90.0°W)16/0000 994.2 15/2310 46 61    
  16/0200 43     
GLPT2 (29.3°N 94.8°W)23/2200 1012.2 22/0900  32 1.6   
ILDL1 (29.0°N 90.5°W)23/0900 1013.7 23/0900 35     
MRSL1 (29.4°N 92.1°W)23/1200 1012.0 23/1200 32 38    
SANF1 (24.5°N 81.9°W)13/1200 1010.9 13/1200 36 42    
SAUF1 (29.9°N 81.3°W)  20/0130 30 38    
  20/1950 31 41    
SGOF1 (29.4°N 84.9°W)15/2100 1005.2 15/2200 49 62    
SHPF1 (30.1°N 84.3°W)  16/1454  31    
SIPM6 (30.3°N 89.0°W)15/2300# 997.4 15/2300# 38     
SPLL1 (28.9°N 90.5°W)16/0200 999.6 16/0200 42     
23/0700 1011.9 23/0700 36     
TPLM2 (38.9°N 76.4°W)  18/0332  35    
  18/1740 34 41    
TYBG1 (31.6°N 79.9°W)21/0726 1016.6 21/0726 35     
Buoys
41012 (30.0°N 80.6°W)  20/1750 29 39    
42001 (25.8°N 89.7°W)15/1050 995.2 15/0950 37     
42003 (26.0°N 85.9°W)15/0750 993.5 15/0230 55 72    
42007 (30.1°N 88.8°W)16/0350# 976.0 16/0350 49 68    
  16/0530 49*     
42035 (29.3°N 94.4°W)23/2250 1012.2 16/0900  30    
42036 (28.5°N 84.5°W)  15/2020 34 49    
42039 (28.8°N 86.1°W)15/2350 995.1 15/2150 45 62    
  15/2350 45     
42040 (29.2°N 88.2°W)16/0150 955.3 15/2300 55 73    
  16/0950 54     
16/0050 956.3       
42041 (27.5°N 90.5°W)15/1950 997.6 15/1950 35*     
44017 (40.7°N 72.0°W)18/1650 1006.9 18/1650 35     
a Date/time is for sustained wind when both sustained and gust are listed.
b Except as noted, sustained wind averaging periods for C-MAN and land-based ASOS reports are 2 min; buoy averaging periods are 8 min.
cStorm surge is water height above normal astronomical tide level.
d Storm tide is water height above National Geodetic Vertical Datum (1929 mean sea level).
*Last of several occurrences
#Instrument failed after report


Table 5: Unofficial observations for Hurricane Ivan, 2-24 September 2004.
Minimum
Sea-level
Pressure
Maximum Surface Wind Speed
(kt)
LocationDate/
Time
(UTC)
Press.
(mb)
Date/
Timea
(UTC)
Sust.
Windb
(kts)
Peak
Gust (kts)
Storm
Surgec
(ft)
Storm
Tided
(ft)
Rain
(storm total)
(in)
Windward Islands
Grenada
Calivigny Island07/1955 969.0 07/1955 80 100    
4 SE Princkly Bay  07/2230 70     
St. Georges Harbour07/1950 978.0 07/2230 60     
Tobago
HAM Radio 9Y4PDE       16.20 
Trinidad
HAM radio VE7KSN07/2159 980.0       
Jamaica
2W Kingston (HAM rpt)  10/2300 39 59    
Kingston (HAM rpt)  11/0055  57    
Kingston Downtown (HAM rpt)  10/2350 est. 74 est. 109    
3W Montego Bay (HAM rpt)  11/0139 est. 87     
Cuba
Cabo de San Antonio  14/???? est. 116 est. 146    
Punta del Holandes  14/???? est. 100 est. 116    
Mexico
Cancun (HAM rpt)  13/0225 44     
Isla Mujeres (HAM rpt)  13/2200 38     
Alabama
Fairhope (storm chaser)16/???? 943.1       
Fairhope - WEMITE 2(30.5N 87.89W)  16/0342 42 62    
Fairhope - Florida Coastal Monitoring Program (FCMP) - Tower 2 (30.48N 87.87W)  16/0644 59 77    
FCMP Tower2 - Fairhope (30.48°N 87.88°W)  16/0644 59 77    
Gulf Shores Arpt - DOW3 (30.29°N 87.67°W)  16/???? 73 95    
Gulf Shores Arpt - WEMITE 1 (30.3°N 87.66°W)  16/0615 70 89    
Gulf Shores - Mark Sudduth / HIRT (30.25°N 87.75°W)15/2017 1003.9 15/2017 32 57    
16/0647 947.2 16/0602* 77 99    
Mobile (Wallace Tunnel)  16/0940  51    
Mobile (WKRG-TV)  16/0604  64    
Mobile Bay (USNS Fisher - ship in dry dock)16/0830 957.0       
USS Alabama (battleship)  16/0635*  91    
Sailboat Odalisque anchored in Wolf Bay / Orange Beach, AL (72 ft)  16/0600#  126    
Wolf Field Airport - MIPS (30.35°N 87.54°W)  16/0515 66 87    
Florida
Carabelle Beach (HAM rpt)15/2216 999.0 15/2216 28 37    
Cudjoe Key - SKYWARN  13/1348  36    
Destin Arpt - SBCCOM / CR5000 (30.4°N 86.48°W)  16/0652 60 77    
Eglin AFB Sensors        
5 S Harold16/0850 981.4       
10 S Harold16/0740 982.1 16/0710  78   5.72 
10 N Mary Esther16/0820 986.8 16/0730  75    
5 NE Seminole16/0920 992.1 16/0940  75   8.10 
5 SW Mossy Head16/0900 991.0       
8 SW Mossy Head  16/0710  60    
10 S Mossy Head16/0900 994.2      8.92 
2 SW Mary Esther (200 ft)  16/0850  103    
Molino Volunteer Fire Dept.  16/0855  70    
Pensacola - Florida Coastal Monitoring Program (FCMP) Tower 1 (30.48°N 87.19°W)  16/0649 69 92    
Pensacola P.D. (70 ft)  16/0644  108   13.50 
  16/0312  97    
  16/0700  92    
St. George Island (HAM rpt)16/0150 1005 16/0150 39     
West Pensacola  16/????  84    
Georgia
Greenville (HAM rpt)  16/1730  48    
Newnan16/2215 963.1 17/0011  45    
Mississippi
Gulfport Arpt - SBCCOM / CR23X (30.4°N 80.1°W)  16/0415 44 62    
Pascagoula EOC (on 2-story bldg)  16/0600  76    
aDate/time is for sustained wind when both sustained and gust are listed.
bExcept as noted, sustained wind averaging periods for C-MAN and land-based ASOS reports are 2 min; buoy averaging periods are 8 min.
cStorm surge is water height above normal astronomical tide level.
dStorm tide is water height above National Geodetic Vertical Datum (1929 mean sea level).
*Instrument failed afterwards.
#Approximate time.


Table 6: Preliminary forecast evaluation (heterogeneous sample) for Hurricane Ivan, 9-14 August 2004. Forecast errors (n mi) are followed by the number of forecasts in parentheses. Errors smaller than the NHC official forecasts are shown in bold-face type. Verification includes the depression stage.
Forecast TechniquePeriod (hours)
122436487296120
CLP525 (62) 51 (60) 86 (58) 121 (55) 175 (51) 229 (47) 296 (44) 
GFNI27 (57) 57 (55) 95 (55) 134 (53) 219 (49) 325 (45) 443 (41) 
GFDI28 (60) 52 (58) 77 (57)94 (55)147 (51)204 (47)261 (43)
GFDL29 (61) 52 (59) 76 (57)92 (56)136 (52)195 (48)252 (44)
GFDN29 (56) 51 (54) 79 (53) 118 (53) 198 (49) 298 (45) 412 (41) 
GFSI29 (60) 55 (58) 79 (57) 100 (55)154 (51)212 (47)285 (43)
GFSO32 (63) 56 (61) 80 (58) 99 (56)147 (52)198 (48)268 (43)
AEMI27 (60) 49 (58) 73 (57)95 (55)151 (51)203 (47)252 (43)
NGPI26 (59) 54 (57) 86 (56) 119 (54) 200 (50) 304 (46) 449 (42) 
NGPS29 (61) 52 (59) 82 (56) 109 (54) 186 (50) 278 (46) 413 (42) 
UKMI24 (58) 47 (56) 72 (55)92 (53)147 (49)214 (45)286 (41)
UKM26 (30) 44 (29)66 (28)87 (28)133 (26)189 (24)279 (22)
A98E27 (61) 43 (59)72 (57)103 (55)179 (51)248 (47) 349 (44) 
A9UK27 (28) 43 (27)71 (26)95 (25)149 (23)   
BAMD31 (61) 54 (59) 78 (57)96 (55)147 (51)219 (47)300 (44) 
BAMM32 (61) 53 (59) 86 (57) 116 (55) 172 (51) 214 (47)283 (44)
BAMS48 (61) 93 (59) 142 (57) 179 (55) 236 (51) 251 (47) 286 (44)
CONU22 (60)47 (58) 74 (57)97 (55)154 (51)224 (47) 307 (43) 
GUNA22 (58)45 (56)71 (55)92 (53)147 (49)213 (45)289 (41) 
FSSE21 (53)38 (51)58 (51)81 (51)126 (47)171 (43)199 (38)
OFCL24 (63) 47 (61) 79 (59) 108 (56) 161 (52) 222 (48) 289 (44) 
NHC Official, 1994 - 2003 mean (number of cases)44 (3172) 78 (2894) 112 (2636) 146 (2368) 217 (1929) 248 (421) 319 (341) 


Table 7: Watch and warning summary for Hurricane Ivan. 2-24 September 2004.
Date/TimeActionLocation
5/2100Hurricane Watch IssuedBarbados 
6/0000Tropical Storm Watch IssuedGrenada and Dependencies 
6/0300Hurricane Watch IssuedSt. Lucia 
6/1200Tropical Storm Warning IssuedSt. Vincent and Grenadines 
6/1200Hurricane Watch IssuedMartinique 
6/1200Tropical Storm Warning IssuedTobago, Grenada and Dependencies 
6/1500Hurricane Warning IssuedBarbados, St. Vincent, Grenadines, St. Lucia, Tobago, Grenada and Dependencies 
6/1500Tropical Storm Warning IssuedTrinidad 
7/0300Tropical Storm Warning IssuedMartinique 
7/0600Tropical Storm Warning IssuedSt. Lucia, St. Vincent, Grenadines, Grenada and Dependencies 
7/0900Tropical Storm Warning IssuedBarbados 
7/1500Hurricane Watch IssuedBonaire, Curacao, Aruba 
7/2100Tropical Storm Warning IssuedTobago, Bonaire, Curacao, Aruba 
7/2100Hurricane Watch and Tropical Storm Warning IssuedGuajira Peninsula Northern Coast of Venezuela 
7/2245Tropical Storm Warning DiscontinuedMartinique 
8/0000Tropical Storm Warning DiscontinuedTrinidad, Tobago 
8/0300Hurricane Warning IssuedBonaire, Curacao, Aruba 
8/0300Tropical Storm Warning DiscontinuedSt. Lucia 
8/0900Tropical Storm Warning DiscontinuedBarbados, St. Vincent, Grenadines, Grenada and Dependencies 
8/0900Tropical Storm Watch IssuedSanto Domingo to D.R. / Haiti Border 
8/1500Hurricane Watch IssuedD.R. / Haiti Border to Port-Au-Prince 
8/2100Hurricane Watch IssuedJamaica 
9/0300Hurricane Watch IssuedCayman Islands 
9/0300Tropical Storm Warning IssuedD.R. / Haiti Border to Port-Au-Prince 
9/1500Hurricane Warning IssuedJamaica 
9/1500Hurricane Watch IssuedBarahona to D.R. / Haiti Border 
9/1500Hurricane Warning DiscontinuedBonaire, Curacao, Aruba 
9/1500Hurricane Watch and Tropical Storm Warning DiscontinuedGuajira Peninsula Northern Coast of Venezuela 
9/1500Hurricane Watch IssuedMatanzas eastward 
9/2100Hurricane Warning IssuedCayman Islands 
10/1500Hurricane WatchAll Cuba and Isle of Youth 
10/1500Tropical Storm Warning IssuedCabo Cruz to Santiago De Cuba 
10/1500All Watches/Warnings DiscontinuedDominican Republic 
11/0900Tropical Storm Warning Extended WestCabo Cruz to Cienfuegos 
11/0900Tropical Storm Warning DiscontinuedHaiti 
11/1500Hurricane Warning IssuedCiago De Avila to Pinar Del Rioand Isle of Youth 
12/0300Tropical Storm Warning IssuedJamaica 
12/1500Tropical Storm Warning DiscontinuedJamaica 
12/1500Tropical Storm Watch Issued7 Mile Bridge to Dry Tortugas 
12/2100Hurricane Watch and Tropical Storm Warning IssuedTulum to Progreso (Yucatan) 
13/0900Hurricane Warning IssuedTulum to Progreso 
13/1500Hurricane Warning DiscontinuedCayman Islands 
14/0000Hurricane Warning AdjustedHavana east to Pinar Del Rio and Isle of Youth 
14/0300Hurricane Watch IssuedMorgan City, LA to St. Marks, FL 
14/1500Tropical Storm Warning IssuedTulum to Progreso (Yucatan) 
14/1800Tropical Storm Warning IssuedHavana east to Pinar Del Rio and Isle of Youth 
14/2100Hurricane Warning IssuedGrand Isle, LA to Apalachicola , FL 
14/2100Hurricane Watch IssuedMorgan City, LA to Grand Isle, LA 
14/2100Tropical Storm Warning IssuedIntracoastal City, LA to Grand Isle, LA Apalachicola, FL to Yankeetown, FL 
14/2100All Watches/Warnings DiscontinuedYucatan, Cuba 
15/0300Tropical Storm Watch Discontinued7 Mile Bridge to Dry Tortugas 
15/2100Tropical Storm Warning DiscontinuedMorgan City, LA to Intracoastal City, LA 
16/0900All Watches and Warnings DiscontinuedWest of Grand Isle, LA 
16/0900Tropical Storm Warning IssuedMouth of Pearl River, LA to Grand Isle, LA 
16/1200Tropical Storm Warning DiscontinuedApalachicola, FL to Yankeetown, FL 
16/1500Tropical Storm Warning IssuedMouth of Pearl River, LA to Apalachicola, FL 
16/1500Tropical Storm Warning DiscontinuedGrand Isle, LA to Mouth of Pearl River, LA 
16/1800Tropical Storm Warning DiscontinuedWest of MS/LA Border 
16/2100Tropical Storm Warning DiscontinuedMS/LA Border to Apalachicola , FL 
22/2300Tropical Storm Warning IssuedMouth of MS River to Sargent, TX 
23/1500Tropical Storm Warning DiscontinuedMouth of MS River to Morgan City, LA 
23/2100Tropical Storm Warning DiscontinuedSan Luis Pass, TX to Sargent, TX 
24/0300All Warnings DiscontinuedRemaining Coastal (San Luis Pass, TX to Morgan City, LA) 

Best track positions for Hurricane Ivan

Figure 1: Best track positions for Hurricane Ivan, 2-24 September 2004.

Selected wind observations and best track maximum sustained surface wind speed curve for Hurricane Ivan

Figure 2a: Selected wind observations and best track maximum sustained surface wind speed curve for Hurricane Ivan, 2-24 September 2004. Aircraft observations have been adjusted for elevation using 90%, 80%, and 80% reduction factors for observations from 700 mb, 850 mb, and 1500 ft, respectively.

Selected wind observations and best track maximum sustained surface wind speed curve for Hurricane Ivan

Figure 2b: Selected wind observations and best track maximum sustained surface wind speed curve for Hurricane Ivan during the peak intensity period of 9-16 September 2004.

Selected wind observations and best track maximum sustained surface wind speed curve for Hurricane Ivan

Figure 2c: Selected wind observations and best track maximum sustained surface wind speed curve for Hurricane Ivan approximately 24h prior to and 18 h after landfall (15-17 September 2004) along the Alabama coast. The highest surface winds occurred along the extreme western Florida panhandle coastal areas, well east of where the center actually made landfall along the Alabama coast.

Pressure observations and minimum central pressure curve for Hurricane Ivan

Figure 3a: Pressure observations and minimum central pressure curve for Hurricane Ivan, 2-24 September 2004.

Pressure observations and minimum central pressure curve for Hurricane Ivan

Figure 3b: Pressure observations and minimum central pressure curve for Hurricane Ivan during its period of greatest intensity (9-16 September 2004).

Radar reflectivity image from Kingston, Jamaica

Figure 4a: Radar reflectivity image from Kingston, Jamaica at 1444 UTC 10 September 2004 as Ivan was approaching the island from the southeast. Ivan had weakened from a category 5 hurricane down to category 4 hurricane with sustained winds of 125 kt at this time. Note the two concentric eyewalls that likely were the cause of the short term weakening (image courtesy of the Jamaica Meteorological Service).

Radar reflectivity image from Cancun, Mexico

Figure 4b: Radar reflectivity image from Cancun, Mexico at 2342 UTC 13 September 2004. Ivan was a category 5 hurricane with sustained winds of 140 kt and a pressure of 914 mb at this time (image courtesy of the National Meteorological Service of Mexico).

Reflectivity image of Hurricane Ivan from Mobile, AL

Figure 4c: Reflectivity image of Hurricane Ivan from the Mobile, AL National Weather Service Forecast Office WSR-88D Doppler radar at 0702 UTC 16 September 2004 -- less than 15 min after the time of landfall along the Alabama coast. The center of the broad eye of the hurricane was inland over extreme southern Alabama at this time. An Air Force Reserve reconnaissance aircraft reported flight-level winds of 120 just offshore in the strong convective band (red 50 dBZ areas) southwest of Pensacola, Florida at about 20 min after the time of this image. Peak Doppler radar velocities ranged from 120-123 kt at 6,000 ft ASL as Ivan moved onshore.

NHC Official forecast tracks (OFCL) for Hurricane Ivan

Figure 5a: NHC Official forecast tracks (OFCL) for Hurricane Ivan during the period 1800 UTC 02 through 0600 UTC16 September 2004 (1stU.S.landfall). Note the persistent right-of-track bias from the outset as a result of most of the global models prematurely eroding the subtropical ridge to the north of the hurricane.

NHC Official forecast tracks (OFCL) for Hurricane Ivan

Figure 5b: NHC Official forecast tracks (OFCL) for Hurricane Ivan during the period 0600 UTC 13 September to 0000 UTC 16 September 2004. Note the small spread in the forecast tracks (from 72 h through 6 h prior to landfall), which targeted the Alabama and extreme western Florida panhandle coastal areas as the most likely region where landfall would occur.

United States rainfall totals for Hurricane Ivan

Figure 6: United States rainfall totals for Hurricane Ivan (image courtesy of NOAA Hydrometeorological Prediction Center).



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