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Preliminary Report
Hurricane Dennis
24 August - 7 September 1999

Jack Beven
National Hurricane Center
11 January 2000

Tropical Storm Arlene
Tropical Depression Two
Hurricane Bret
Hurricane Cindy
Hurricane Dennis
Tropical Storm Emily
Tropical Depression Seven
Hurricane Floyd
Hurricane Gert
Tropical Storm Harvey
Tropical Depression Eleven
Tropical Depression Twelve
Hurricane Irene
Hurricane Jose
Tropical Storm Katrina
Hurricane Lenny

[1999 Atlantic Hurricane Season]

Dennis was a larger-than-average western Atlantic hurricane that was erratic in both track and intensity. Although it never made landfall as a hurricane, it affected the North Carolina coast with hurricane force winds, heavy rains, prolonged high surf, and beach erosion. Dennis also produced tropical storm force winds over portions of the Bahamas.

a. Synoptic History

The origin of Dennis can be traced to a tropical wave that moved off the coast of Africa on 17 August. The system moved westward with little significant weather until 21 August, when associated shower activity increased a few hundred miles northeast of the Leeward Islands. A low- level circulation developed over the next two days as convective organization increased. An investigative flight by the Air Force Reserve Hurricane Hunters failed to find a surface circulation on the 23rd. However, the aircraft data indicated a circulation was present at 850 mb. Later surface observations showed a closed circulation, and it is estimated that Tropical Depression Five formed at 0000 UTC 24 August about 190 n mi east of Turks Island (Table 1 and Figure 1). Reconnaissance data and ship reports indicated further intensification, and the depression became Tropical Storm Dennis at 1200 UTC the same day.

The initial structure was unusual. Dennis was at the east-southeast end of an elongated trough that extended to southern Florida. This and upper-level westerly shear caused an asymmetric pattern of convection and tropical storm force winds, with both confined to the eastern semicircle on 24-25 August. Despite the shear, the cyclone intensified unsteadily and reached hurricane strength early on the 26th.

The unusual structure may have also affected the cyclone's motion. Dennis initially moved at 9 to 12 kt, but slowed to an erratic 3 kt on 25 August as steering currents weakened due to a mid-latitude trough passing to the north. At one time that day, the center appeared to re-form eastward along the trough axis. Once Dennis reached hurricane strength, it began a more steady northwestward motion near or over the eastern Bahamas. This motion continued into the 28th.

Westerly shear persisted, preventing significant strengthening until late on 27 August. After the shear decreased, Dennis reached a peak intensity of 90 kt on the 28th and maintained that intensity until early on the 30th. Even at peak intensity, Dennis never consolidated into a classic tightly-wound hurricane. The eye was 30 to 40 miles wide, and on several center fixes the Hurricane Hunters did not report an eye. The radius of maximum winds was as large as 70 to 85 nm on the 29th and 30th.

A second mid-latitude trough caused Dennis to turn gradually northward on 28-29 August, which was followed by acceleration to the east-northeast on 30th and 31th. This turn kept the center about 60 miles south of the North Carolina coast. The east-northeast motion continued until the trough passed Dennis on the 31st. At that time, steering current collapsed and the cyclone slowed to an erratic drift about 110 n mi east of Cape Hatteras, NC. The erratic motion would last into 2 September.

During this time, Dennis became involved with the cold front associated with the mid-latitude trough. A combination of vertical shear and cool dry air entraining into the circulation decreased the convection and weakened the cyclone. Dennis weakened to a tropical storm on 1 September, and on the 1st and 2nd may have been as much a subtropical or extratropical cyclone as a tropical cyclone. Despite the lack of convection, surface observations indicate maximum sustained winds were near 45 kt during 2 September. Some of these winds were due to the combination of Dennis and a strong surface ridge north of the front, which caused 34 kt or greater winds as far north as the New Jersey coast.

A large westerly ridge over the eastern United States forced Dennis southward late on 2 September. This motion toward warmer water probably aided a deep convective burst on the next day. Later that day, Dennis turned northwest toward the North Carolina coast as the ridge moved east into the Atlantic. This motion continued on the 4th along with re-intensification. Dennis was just below hurricane strength when it made landfall over the Cape Lookout National Seashore just east of Harkers Island, NC at 2100 UTC that day. Dennis continued inland and weakened to a depression on the 5th over central North Carolina. Even in dissipation, Dennis continued to move erratically. Figure 1 shows that the cyclone followed a zig-zag course northward for the rest of its life. Dennis became extratropical on the 7th and was absorbed into a larger low on the 9th.

b. Meteorological Statistics

Table 1 shows the best track positions and intensities for Dennis, with the track plotted in Figure 1. Figure 2 and Figure 3 depict the curves of minimum central sea-level pressure and maximum sustained one-minute average "surface" (10 m above ground level) winds, respectively, as a function of time. These figures also contain the data on which the curves are based: aircraft reconnaissance and dropsonde data from the Air Force Reserve Hurricane Hunter and NOAA, satellite-based Dvorak technique intensity estimates from the Tropical Analysis and Forecast Branch (TAFB), the Synoptic Analysis Branch (SAB) of the National Environmental Satellite Data and Information Service (NESDIS), and the Air Force Weather Agency, and estimates from synoptic data.

1. Wind and Pressure Data

The Hurricane Hunters flew 24 missions into Dennis and made 81 center fixes, and NOAA research aircraft provided three additional fixes during various research missions. The maximum reported wind was 110 kt (at 700 mb) at 2002 UTC 28 August. While taking 90% of this wind would suggest a maximum sustained surface wind of 99 kt, dropsonde observations at that time do not support that high of a surface wind. The minimum observed central pressure observed from dropsondes was 962 mb at 0350 and 0543 UTC on 30 August. A 959 mb pressure was estimated from 700 mb data at 1017 UTC on the 30th, (Figure 2), but is believed to be too low. The Hurricane Hunters also measured 71 kt winds (at 850 mb) and a 984 mb pressure just before Dennis made landfall on 4 September. These data indicate Dennis was a 60 kt tropical storm at landfall.

Dennis's path brought it near the eastern Bahamas on 27-28 August. The only official report of tropical storm force winds in the Bahamas was from the Coastal Marine Automated Network (C-MAN) station at Settlement Point, Grand Bahama, which reported 34 kt sustained winds with gusts to 46 kt at 0030 UTC 29 August. (This and other available surface observations are summarized in Table 2.) However, reports relayed to the NHC through amateur radio operators indicated sustained winds of up to 60 to 65 mph with gusts of 70 to 75 mph in the Abaco island group. Reported pressures were as low as 976 mb as the western part of the eye passed over the Abacos around 0700 to 1000 UTC on the 28th. While these observations are significant, their reliability is uncertain. Therefore, they are not included in Table 2.

Dennis tracked parallel to the Florida and Georgia coasts, with tropical storm force winds remaining mostly offshore. The only reported tropical storm force wind was a 41 kt gust at the St. Augustine, FL C-MAN station. The core of Dennis passed just east of NOAA buoy 41010 on 29 August, which reported 57 kt sustained winds with gusts to 72 kt at 0500 UTC and a minimum pressure of 980.2 mb at 0750 UTC.

Dennis's first pass near the coast of the Carolinas on 30 August caused sustained tropical storm force winds with gusts to hurricane force in coastal North Carolina and gusts to tropical storm force in coastal South Carolina from Charleston northward. The maximum reported sustained winds were 53 kt with gusts to 77 kt at Oregon Inlet at 2030 UTC. It is not clear whether sustained hurricane force winds affected the coast. There are no observations of such winds, and analyses from the Hurricane Research Division suggests they stayed offshore. However, gusts to 96 kt at Wrightsville Beach and 85 kt at Hatteras Village (Table 2) suggest that sustained hurricane force winds may have occurred along the coasts of New Hanover and Dare counties. Sustained hurricane force winds of 81 kt with gusts to 97 kt were measured at the Frying Pan Shoals C-MAN station (145 ft elevation) at 0945 UTC 30 August, with a minimum pressure of 977.2 mb at 0900 UTC.

The landfall of Dennis on 4 September produced tropical storm force winds over portions of eastern North Carolina and coastal southeastern Virginia. Langley Air Force Base VA, reported 45 kt sustained winds with gusts to 66 kt at 2330 UTC, while Cherry Point Marine Corp Air Station NC, reported 41 kt sustained winds with gusts to 53 kt at 2005 UTC.

The large circulation of Dennis also affected shipping over a portion of the western Atlantic. Table 2a shows the available ship observations of tropical storm force or greater winds. The maximum ship-observed winds were 65 kt from the Zim U.S.A. at 0900 UTC 30 August, while the lowest observed pressure was 987.3 mb from the Hoegh Dene at 1800 UTC 4 September. Observations from the Sealand Crusader on 24 August were important in determining that the pre-Dennis wave had developed into a depression.

2. Storm Surge Data

Few detailed observations of storm surge are available from areas affected by Dennis (Table 2). Storm tides of 3 to 5 ft above normal were reported along much of the North Carolina coast on both 30 August and 4 September. Areas along the Neuse River reported tides of 8 to 10 ft above normal tide level on 30 August, while areas along the Pamlico River reported similar values on 4 September. Portions of the South Carolina and southeastern Virginia coast experienced 2 to 4 ft above normal tides during Dennis, while amateur radio reports from the Bahamas indicate tides 1 to 3 ft above normal as the eye passed over the Abacos.

Since Dennis meandered off the North Carolina coast for several days, the above normal tides were unusually prolonged. This led to extensive beach erosion along portions of the North Carolina and southeastern Virginia coasts.

3. Rainfall data

Dennis affected the mid-Atlantic states twice within a week, and other weather systems affected the region during the same period. This makes determination of storm total rainfall in that area difficult. Table 2 shows the storm total rainfalls for Dennis, including the best estimates in North Carolina and Virginia. The maximum reported total was 19.13 inches at Ocracoke NC, with 6 to 10 inches reported elsewhere over portions of eastern North Carolina. Rainfalls of 3 to 6 inches occurred elsewhere over eastern North Carolina, extreme eastern South Carolina, and over portions of southeastern Virginia. Rainfalls were generally 1 to 3 inches elsewhere over eastern South Carolina and less than an inch in Florida and Georgia.

Dennis and the other weather systems contributed to a wet period over portions of the mid-Atlantic states. Table 2b shows 11-day rainfall totals of 6 inches or more ending at 1200 UTC 8 September. The heaviest rainfalls were observed over eastern North Carolina and central Virginia. While this rainfall broke a prolonged dry spell in the area, it also set the stage for the severe flooding caused by Hurricane Floyd two weeks later.

Official rainfall data from the Bahamas indicates a maximum total of 4.00 inches at Cat Island. Heavier amounts likely occurred on Eleuthera and in the Abaco group near the eye of Dennis.

4. Tornadoes

One tornado was reported with Dennis on 4 September. This F2 tornado in Hampton VA caused an estimated $7 million damage and 15 injuries, 6 of them serious.

c. Casualty and Damage Statistics

Four deaths reported in Florida were related to high surf spawned by the hurricane. No deaths are known due to winds, rains, storm tides or tornadoes associated with Dennis.

In the United States, the Property Claims Services Division of the Insurance Services Office reports insured losses due to Dennis totaled $60 million in North Carolina and Virginia. To determine the total property damage, a two to one ratio is applied to the insured property damage based on comparisons done in historical hurricanes. Press reports indicate that agricultural losses in North Carolina and Virginia were $37 million. Combining these reports gives a total estimated damage from Dennis of $157 million.

There are no damage reports available from the Bahamas as of this time.

d. Forecast and warning critique

Table 3 shows the track forecast errors during Dennis for the official NHC track forecast and a selection of objective guidance models. The official forecasts were generally quite good with errors of about 60% to 70% of the long term average. The official forecasts also were better than the objective guidance with two exceptions: The United Kingdom Meteorological Office global model (UKM) was slightly better than the official forecast at all time periods, and the barotropic model LBAR was slightly better at 12 and 24 hours. It should the noted that the UKMI, which is the interpolated UKM track forecast available to hurricane forecasters in real time, was slightly worse than the official forecast at all time periods. There were two periods with worse than average official track forecasts. The first was on 24 August, as the poorly-organized Dennis consistently moved slower than forecast. The second on was 28 August, when the motion parallel to the coast on 30-31 August was poorly forecast.

While intensity forecast errors were also better than the long term average, there was a significant positive bias which is counter to the 10-year average. This occurred due to forecasts on 28-30 August which predicted Dennis to remain a hurricane when it actually weakened to a tropical storm. Three consecutive forecasts during this time overforecasted the 72 hour intensity by 50 kt.

Table 4 shows the watches and warnings that were issued for Dennis. Due to the somewhat erratic motion near the Bahamas, hurricane warnings were issued for Eleuthera and the Abacos 40 hours before the eye passed over the Abacos. While tropical-storm force winds did not occur over land south of Charleston, SC, they were present over the Florida, Georgia, and South Carolina coastal waters. Hurricane warnings for the North Carolina coast on 29 August had less than the normally-desired 24 hour lead time. However, these were issued in anticipation that Dennis' large size and track just offshore would cause hurricane conditions along the coast and not in anticipation of a landfall. Hurricane warnings were also issued for the North Carolina coast on 4 September in anticipation of Dennis regaining hurricane strength before landfall. These proved to be unnecessary.


Much of the data in this report was provided by the local National Weather Service forecast offices in Miami, Melbourne, Jacksonville, Charleston, Wilmington, Morehead City, and Wakefield. Buoy and C-MAN station data was provided by the National Data Buoy Center. James Franklin created the wind and pressure plots.

Figure 1. Best track for Hurricane Dennis, 24 August - 7 September 1999.

Figure 2. Best track minimum central pressure curve for Hurricane Dennis, 24 August - 7 September 1999.

Figure 3. Best track maximum sustained 1-minute 10 meter wind speed curve for Hurricane Dennis, 24 August - 7 September, 1999.

Table 1. Best track, Hurricane Dennis, 24 August - 7 September 1999
Position Pressure
Wind Speed
Lat. (°N)Lon. (°W)
24/000021.5 67.71009 30tropical depression
24/060022.0 68.91009 30"
24/120022.4 70.01009 35tropical storm
24/180022.7 70.91009 40"
25/000022.8 71.51008 40"
25/060023.0 71.91007 40"
25/120023.2 72.11004 45"
25/180023.4 72.31000 55"
26/000023.6 72.5 998 60"
26/060023.8 73.1 995 65hurricane
26/120024.1 73.6 995 65"
26/180024.4 74.0 990 70"
27/000024.8 74.4 993 65"
27/060025.2 75.0 988 65"
27/120025.6 75.5 988 65"
27/180025.9 75.9 987 65"
28/000026.1 76.2 982 70"
28/060026.5 76.7 976 75"
28/120027.1 77.0 973 85"
28/180027.7 77.3 969 90"
29/000028.3 77.7 969 90"
29/060029.0 77.9 970 90"
29/120029.9 78.4 971 90"
29/180030.8 78.4 967 90"
30/000031.9 78.1 964 90"
30/060032.8 77.6 962 90"
30/120033.6 76.5 965 85"
30/180034.3 74.8 966 85"
31/000034.9 73.6 971 80"
31/060035.1 72.9 977 80"
31/120035.2 72.8 983 75"
31/180035.1 73.3 984 70"
01/000035.2 73.6 986 60tropical storm
01/060035.0 73.4 987 55"
01/120035.4 73.5 989 50"
01/180035.5 73.8 988 50"
02/000035.4 73.7 988 50"
02/060035.2 73.6 989 45"
02/120035.1 73.7 989 45 "
02/180034.8 73.9 990 45"
03/000034.2 74.0 989 45"
03/060033.6 74.1 989 45"
03/120033.2 73.9 988 45"
03/180033.0 73.8 987 50"
04/000033.1 74.0 987 50"
04/060033.3 74.5 986 55"
04/120033.9 75.3 986 55"
04/180034.5 76.0 986 60"
05/000035.0 76.8 985 50"
05/060035.5 77.7 989 35"
05/120036.1 78.8 994 30tropical depression
05/180036.2 79.4 998 25"
06/000036.2 79.91000 25"
06/060036.4 80.11004 20"
06/120037.0 79.91005 20"
06/180037.7 79.51008 20"
07/000038.5 78.51009 20"
07/060040.8 77.01008 20"
07/120042.7 77.71007 20"
07/180043.5 77.71006 20extratropical
08/000043.5 76.51006 20"
08/060044.0 75.81006 20"
08/120044.9 74.81006 20"
08/180045.5 75.61005 20"
09/0000    lost identity
30 /060032.8 77.6 96290minimum pressure
28/070026.6 76.8 976 75Abaco Islands, Bahamas
04/210034.8 76.5 984 60 Cape Lookout National Seashore, NC

Table 2. Hurricane Dennis selected surface observations, 24 August - 7 September 1999. (Incomplete pending further data from NDBC)
Maximum surface wind speed
Location Pressure
(kts) a
gust (kts)
(storm total)
Cat Island       4.00
North Carolina
Alligator Bridge#  485630/1100   
Atlantic (Texas Tech tower, 30 ft)992.630/1351487530/1532   
Beaufort (Texas Tech tower, 33 ft)992.830/1302527530/1103   
Blockade Runner   72    
Brunswick Cnty Airport   6130/0810   
Brunswick Power Plant  50g 30/0456   
Calabash   35   1.57
Carolina Beach   6630/0710   
Castle Hayne (Oxychem)   5430/1100   
Castle Hayne (SW)  356730/0900   
Cherry Point MCAS986.504/2355415304/2005  9.24
Delco  285730/1200   
East Waccamaw   3430/1100  0.98
Elizabeth City1003.804/2313344530/1654  7.01
Elizabethtown   37    
Flemington  396830/0900   
Greenville   4305/0140   
Harkers Island Bridge   7630/1230   
Hatteras Inlet  50$6430/1930   
Hatteras Village   8530/1515   
Jacksonville994.205/0235 4130/0835   
Kingston   3704/2250   
Kure Beach   5830/0740   
Kure Beach (Federal Point)   7130/0530   
Manteo   5230/1635   
New Bern986.805/0000354630/1056  3.35
New River993.904/2126335030/0956  5.75
Newport985.104/2115 5430/1204  9.89
North Topsail Beach  44$6530/1240   
Oak Island  466230/0800   
Ocean Isle   4930/0559   
Ocean Isle (Tubbs Inlet)   4630/0753   
Ocracoke Island#995.131/074035$5831/0220  19.13
Oregon Inlet  53$7730/2030   
Oriental      6-8 
St. James       6.00
Shallotte   6030/0700  
Shallotte Inlet   6030/0730   
Southport (Elementary)   49   9.01
Southport (Marina)       13.50
Southport (Pilot Boat Dispatch)   6030/0743   
Washington   4130/1520   
Whiteville   37   1.97
Wilmington Airport996.10953425330/0607  4.73
Wilmington (Battleship North Carolina)   6630/0530  6.70
Wilmington (College RD/Oleander DR)   46   8.75
Wilmington (Corning)   6030/1200   
Wilmington (Eastwood RD/Military Cutoff)   4430/0650  6.60
Wilmington (Masonboro Loop)   37    
Wilmington (New Hanover EOC)  517630/0800   
Wilmington (WECT-TV)   46   5.07
Wrightsville Beach   9630/0444   
Wrightsville Beach Fire Dept.   7330/0630   
South Carolina
Charleston Harbor      2.0 
Charleston WFO  294029/2050  1.22
Murrells Inlet       2.88
Myrtle Beach (Pavilion)   4530/0600   
N. Myrtle Beach  294230/0732  1.65
John Kerr Dam       3.38
Norfolk Airport1006.105/0551374630/1651  3.30
Langely AFB1007.1 456604/2332   
Newport News1006.5 283904/2332  3.32
Norfolk NAS1006.5      2.85
Oceana NAS1006.5      2.90
Portsmouth       5.75
Richmond1006.505/0754     2.18
Roanoke Rapids  273530/1214   
Sewells Point      3.0 
Wakefield       4.59
Wallops Island  334030/1717   
NOAA Buoys and C-MAN Stations
Buoy 41001976.031/040048$6330/2300   
Buoy 41002997.630/110043$59    
Buoy 41004990.530/030054$7230/0330   
Buoy 410081003.929/2000314329/1700   
Buoy 41009#1001.329/0900293729/0700   
Buoy 41010980.229/0750577229/0500   
Buoy 440141002.330/2000435330/2100   
Drifting Buoy 41650#1009.827/000045 27/1200   
Drifting Buoy 41651#1010.825/210042 25/2100   
Cape Lookout NC (CKLN7)986.504/2000607930/1400   
Chesapeake Bay VA (CHLV2)1006.205/060049$5630/2100   
Duck NC (DUCN7)1005.604/2300566530/2000   
Folly Beach SC (FBIS1)1001.630/0100243530/0000   
Frying Pan Shoals NC (FPSN7)977.230/090081$9730/0945   
Settlement Point, BI (SPGF1)1002.628/220034$4629/0030   
St. Augustine FL (SAUF1)1004.929/1100274129/1355   

aStandard NWS ASOS and C-MAN averaging period is 2 minutes; buoys are 8 minutes.
bDate/time is for sustained wind when both sustained and gust are listed.
cStorm surge is water height above normal astronomical tide level.
dStorm tide is water height above NGVD.
$10 min average.
g100 ft tower, 15 min average.
#Incomplete record.

Table 2a. Ship observations of tropical storm or greater winds associated with Hurricane Dennis, 24 August - 7 September 1999.
Ship Date/Time
Lat. (°N) Lon. (°W) Wind
Sealand Crusader24/060021.067.0130/351011.5
Iver Express24/180023.274.6010/391012.0
Jo Sypress26/150025.973.0120/391012.5
Star Hidra28/210030.177.5050/401005.0
Torm Freya29/000030.275.5100/351005.0
Nedlloyd Holland29/000027.879.2340/421002.0
Star Hidra29/000030.077.0050/411004.0
Nedlloyd Holland29/030028.779.9340/391002.2
Star Hidra29/030029.576.4090/551001.0
Torm Freya29/060029.574.8150/481005.0
Star Hidra29/060029.876.5120/56999.3
Star Hidra29/090029.776.4150/56999.5
Star Hidra29/120029.676.2160/551000.5
Star Hidra29/150029.376.1180/461003.0
Torm Freya29/180028.374.9190/461007.0
Zim U.S.A.29/210032.075.0140/381006.0
Star Hidra29/210028.877.1210/371005.5
Zim U.S.A.30/000032.075.1160/401004.0
Zim U.S.A.30/030032.075.3160/501002.0
Zim U.S.A.30/060031.875.5180/65999.0
OOCL Fair30/060033.474.3150/401005.0
Zim U.S.A.30/090032.375.0180/651000.0
OOCL Fair30/090032.774.3180/501002.0
Zim U.S.A.30/120031.475.7250/501002.5
Zim U.S.A.30/150031.576.3270/501006.0
OOCL Fair30/150032.174.6210/501002.0
OOCL Fair30/180032.075.0260/551006.0
Barbet Arrow31/120032.571.5240/401009.2
Stonewall Jackson31/120033.571.7230/551003.5
Barbet Arrow31/180032.472.3250/401015.0
Edyth L.31/180034.875.1310/551005.7
Stonewall Jackson31/180033.472.7250/451007.0
Sealand Performance31/180033.769.8230/401009.5
Stonewall Jackson02/000033.575.1300/361010.0
Trojan Star02/000036.870.7110/381010.1
Shanghai Senator02/090037.675.1040/351011.0
OOCL Friendship02/180034.174.7300/45999.2
OOCL Friendship02/210034.173.5200/45993.6
Chemical Pioneer03/150034.376.3320/401004.7
Chemical Pioneer03/180034.775.8340/351004.7
Hoegh Dene04/060033.177.3100/391005.3
Hoegh Dene04/120033.876.4360/371000.0
Hoegh Dene04/150034.176.0110/39992.5
Hoegh Dene04/180034.475.6150/40987.3
Mette Maersk04/180035.474.4110/451002.9
Mette Maersk04/210035.873.6120/37N/A
Hoegh Dene05/000035.575.0140/351003.8

Table 2b. Eleven day rainfall totals ending at 1200 UTC 8 September 1999. Data courtesy of the National Climatic Data Center
Station Rainfall (in) Station Rainfall (in)
North Carolina
Cherry Point10.18Wilsonville7.11
Elizabeth City8.17Rocky Mount6.53
Goldsboro (GSB)8.04Butner6.50
Neuse7.72New Bern6.09
South Carolina
Myrtle Beach6.02  
Allisonia13.82Fincastle (DAEV2)7.03
Front Royal (HOGV2)12.86Lovingston (LOVV2)6.87
Roanoke (WITV2)10.33Front Royal (LIMV2)6.76
Montebello9.40Lovingston (BRNV2)6.68
Copper Hill (COPV2)8.31Strasburg6.57
Fincastle (TIKV2)7.63Waynesboro6.52
Copper Hill (COHV2)7.62Springcreek6.50
Alberta7.49Roanoke (FOTV2)6.44
Winterpock7.33South Boston6.41
Mathews7.10Pedlar Mills6.20

Table 3. Preliminary track forecast evaluation for Hurricane Dennis - heterogeneous sample. Errors in nautical miles for tropical storm and hurricane stages with number of forecasts in parentheses. Numbers in boldface represent forecast which were better than the official forecast.
Forecast Technique Period (hours)
CLIP44 (46)92 (44)150 (42)209 (40)360 (36)
GFDI40 (38)75 (36)110 (34)148 (32)213 (29)
GFDL*40 (36)69 (34)100 (32)136 (30)209 (27)
LBAR31 (46)61 (44)99 (42)137 (40)217 (36)
AVNI53 (42)100 (40)139 (38)175 (35)220 (26)
AVNO*46 (40)93 (37)134 (35)163 (32)213 (22)
BAMD35 (45)65 (44)102 (41)144 (39)212 (35)
BAMM43 (46)84 (44)128 (42)168 (40)260 (36)
BAMS56 (46)111 (44)169 (42)230 (40)343 (36)
NGPI48 (44)76 (42)108 (40)133 (38)184 (30)
NGPS*46 (23)77 (22)100 (21)133 (20)173 (16)
UKMI41 (41)68 (39)96 (38)118 (37)161 (33)
UKM*33 (23)61 (22)82 (21)106 (20)147 (18)
A90E39 (45)73 (43)100 (41)138 (39)228 (35)
A98E38 (40)73 (38)110 (36)151 (34)240 (30)
A9UK37 (22)73 (21)108 (20)147 (19 )274 (17)
NHC Official34 (46)63 (44)90 (42)112 (40)160 (36)
NHC Official 10-Year Average (1989-1998)48 (2005)89 (1790)128 (1595)164 (1410)242 (1107)

*Output from these models was unavailable at time of forecast issuance.

Table 4. Watch and warning summary, Hurricane Dennis, 24 August- 7 September 1999.
Action Location
24/1500Tropical Storm Warning issuedBahamas...Turks and Caicos Islands and SE Bahamas
24/1500Tropical Storm Watch issuedCentral Bahamas.
25/0900Hurricane Watch and Tropical Storm Warning issuedCentral Bahamas.
25/0900Hurricane Watch issuedNorthwest Bahamas.
26/0900Tropical Storm Warning discontinuedBahamas...Turks and Caicos Islands and
SE Bahamas.
26/1500Hurricane Warning issuedCentral Bahamas.
Northwest Bahamas...Eleuthera and the Abacos.
27/0300Tropical Storm Warning issuedNorthwest Bahamas...New Providence, Grand Bahama, and the Berry Islands.
27/0900Hurricane Warning issuedNorthwest Bahamas...remainder.
27/1500Hurricane Watch issuedFlorida....Sebastian Inlet to Fernandina Beach.
27/1500Hurricane Warning discontinuedCentral Bahamas...including Andros and New Providence Islands.
27/2100Tropical Storm Warning issuedFlorida...Sebastian Inlet to Flagler Beach.
28/0900Hurricane Warning discontinuedBahamas...Eleuthera and the Berry Islands.
28/2100Hurricane Warning discontinuedBahamas...Abacos and Grand Bahama Islands.
29/0300Hurricane Watch issuedN of Savannah, GA to Surf City, NC.
29/0300Hurricane Watch discontinuedFlorida...Sebastian Inlet to Fernandina Beach.
29/0900Tropical Storm Warning issuedN of Savannah, GA to Surf City, NC.
29/0900Hurricane Watch issuedNorth Carolina...Surf City to Cape Hatteras.
29/1500Tropical Storm Warning issuedNorth Carolina...Surf City to Cape Hatteras.
29/1500Tropical Storm Watch issuedN of Cape Hatteras to Cape Charles Light, VA.
29/2100Hurricane Watch upgraded to Hurricane WarningLittle River Inlet, SC to Oregon Inlet, NC...including Pamlico Sound.
29/2100Tropical Storm Warning issuedOregon Inlet, NC to Chincoteague, VA...including Abermarle Sound and southern Chesapeake Bay south of New Point Comfort.
30/0300Hurricane Watch and Tropical Storm Warning discontinuedEdisto Beach, SC to Savannah, GA.
30/0900Hurricane Watch upgraded to Hurricane WarningOregon Inlet, NC to North Carolina/Virginia border.
30/0900Gale Warning issuedChincoteague, VA to Cape Henlopen, DE.
30/0900Hurricane Watch and Tropical Storm Warning discontinuedN of Savannah, GA to Little River Inlet, SC.
30/2100Hurricane Warning discontinued South of Cape Lookout, NC to Little River Inlet, SC.
31/0300Hurricane Warning downgraded to Tropical Storm WarningCape Lookout, NC to NC/VA border.
31/0900Gale Warning issuedCape Henlopen, DE to Great Egg Inlet, NJ.
01/0300Tropical Storm Warning and a Hurricane Watch issuedSurf City, NC to Chincoteague, VA...including Pamlico and Ablemarle Sounds and southern Chesapeake Bay south of New Point Comfort.
01/1500Hurricane Watch discontinuedSurf City, NC to Chincoteague, VA...including Pamlico and Ablemarle Sounds and southern Chesapeake Bay south of New Point Comfort.
02/0600Gale Warning discontinuedFenwick Island, DE to Cape Henlopen, DE.
02/0600Gale Warning issuedChincoteague, VA to Fenwick Island, DE.
02/1500Tropical Storm Warning discontinuedNorth of Cape Charles Light, VA to Chincoteague, VA
South of Cape Lookout, NC to Surf City, NC.
02/2100Tropical Storm Warning discontinuedSouthern Chesapeake Bay south of New Point Comfort.
03/0300Tropical Storm Warning discontinuedCape Charles Light, VA to NC/VA border.
03/0900 Tropical Storm Warning discontinuedOregon Inlet, NC to NC/VA border.
03/2100Tropical Storm Watch issuedOregon Inlet, NC to NC/VA border...including Ablemarle Sound.
Cape Lookout, NC to Surf City, NC.
04/0900Tropical Storm Warning issuedN of Oregon Inlet, NC to the NC/VA border...including Ablemarle Sound.
S of Cape Lookout, NC to Surf City, NC.
04/1500Tropical Storm Warning upgraded to Hurricane WarningNC/VA border to Surf City, NC...including Pamlico and Ablemarle Sounds.
04/1500Tropical Storm Warning issuedN of NC/VA border to Chincoteague, VA...including Chesapeake Bay south of Smith Point.
04/2100Tropical Storm Warning issuedEntire Chesapeake Bay...including the Tidal Potomac.
04/2100Gale Warning issuedN of Chincoteague, VA to Great Egg Inlet, NJ.
05/0100Hurricane Warning downgraded to Tropical Storm WarningNC/VA border to Surf City, NC...including Pamlico and Ablemarle Sounds.
05/0900Tropical Storm Warning discontinuedNC/VA border to Surf City, NC...including Pamlico and Ablemarle Sounds.


Last updated February 2, 2000