Tropical Storm Harvey, which formed in the eastern Gulf of Mexico and moved across southern Florida, produced heavy rainfall over portions of southwest Florida.
a. Synoptic History
The tropical wave that produced Harvey moved off the west coast of Africa late on 4 September with little fanfare. From the 4th through the 14th, the wave's trek across the tropical Atlantic into the eastern Caribbean Sea was uneventful. This was due, in part, to the disruptive effects of the upper-level outflow from Hurricane Floyd. By 16 September, with the influence of Floyd's circulation abating, convective activity in association with the wave began to increase over the western Caribbean Sea and a broad area of low pressure formed. Upper-air observations from the northwest Caribbean showed an associated mid-level circulation near the Cayman Islands. The system drifted northwestward during the next two days and by the morning of the 18th, the broad area of low pressure was over the south central Gulf of Mexico. Early on the 19th, satellite imagery showed increasing deep convection near and east of the broad surface circulation center. This, coupled with a sustained 30 knot wind report from the National Data Buoy Center (NDBC) buoy 42003, located in the eastern Gulf of Mexico, is the basis for initiating Tropical Depression Ten at 0600 UTC 19 September, at which time the circulation center was located about 350 n mi west-southwest of St. Petersburg, Florida as shown in the post-storm "best track" in Table 1 and Figure 1.
Upper-tropospheric outflow improved over the depression throughout the 19th, indicative of gradual strengthening . Surface observations and reconnaissance data from the U.S. Air Force Reserve "Hurricane Hunters" (USAFR) indicated that by 0000 UTC 20 September surface winds were near 40 knots and the system became Tropical Storm Harvey, while located about 300 n mi west-southwest of St. Petersburg, Florida. Over the next 24 hours, Harvey's central pressure dropped a modest 7 mb and the storm is estimated to have reached a peak intensity of 50 knots from 1800 UTC 20 September to 1800 UTC 21 September. Satellite images showed that the system did not become better organized during this period because of westerly vertical wind shear. Data from the NOAA G-IV synoptic flow mission over the Gulf of Mexico on the afternoon of the 20th showed 25 to 35 knot westerly upper-level winds over the cyclone. This resulted in the displacement of Harvey's center to the northwest edge of the deep convection along with restricted outflow over the western semicircle. Satellite imagery also suggested that dry air was being entrained into the circulation from the northwest.
After turning from a north to a northeast heading on the afternoon of the 19th, Harvey moved slowly eastward on the 20th. By early on the 21st, the system turned southeast and the forward speed increased to 9 knots in response to mid-level northwesterly flow depicted in NOAA G-IV synoptic flow data. Harvey's track bent back to the east by mid morning of the 21st and the cyclone accelerated in advance of a mid-latitude trough approaching from the west. Harvey made landfall near Everglades City, Florida around 1700 UTC 21 September with maximum sustained winds of 50 knots and a minimum central pressure of 999 mb. Later that afternoon, the center of Harvey became elongated while becoming absorbed by a developing extratropical cyclone located just off the coast of South Carolina with an associated front extending into south Florida. Harvey lost its identity over the western Atlantic early on the 22nd as it merged with the extratropical cyclone.
b. Meteorological Statistics
The best-track curves of minimum central sea-level pressure and maximum sustained one-minute average "surface" (10 meters above ground level) wind speed are shown in Figure 2a. This figure also contains the data upon which the curves are based: USAFR reconnaissance data, 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 (AFGWC in the figures).
1. Wind and Pressure Data
The USAFR Hurricane Hunters flew five reconnaissance missions into Harvey and made 14 center fixes. The highest wind speed reported in Harvey was 58 knots, at 1500 feet, at 1554 UTC 21 September; the lowest central pressure was 994 mb at 0813 UTC 21 September.The maximum sustained wind of 50 knots at 1800 UTC 20 September was based on an observation of 47 knots from ship WCOB; The C-MAN buoy at Molasses Reef (MLRF1) recorded a maximum wind of 47 knots, with a gust to 59 knots, at 1743 UTC 21 September while Fowey Rocks Light (FWYF1) reported 45 knots sustained winds, with a gust to 51 knots at 1800 UTC, and the aircraft data, all support the continuation of the 50-knot maximum sustained wind speed in the best track through 1800 UTC 21 September. These reports, along with other buoys and ship reports of 34 knot winds or higher, are listed in Table 2.
Table 3 lists a selection of surface observations from land stations. The highest official sustained surface wind observed over land was 32 knots at the Key West Airport at 1956 UTC 21 September. The Turkey Point Nuclear Power Plant recorded a 10-minute 46 knot wind, at a 9 meter elevation, at 1610 UTC 21 September while the highest gust, 48 knots, was recorded at Tenraw in the Everglades in Dade County (25.6N/81.9W) at 1700 UTC. The lowest pressure observed in south Florida was 999.4 mb at the Fort Lauderdale Airport at 1953 UTC 21 September.
A Carnival Cruise Line vessel provided two observations on 20 September of tropical storm-force winds. These reports were used to help define the tropical storm-force wind and the 12-foot sea radii.
2. Rainfall Data
The highest storm-total rainfall recorded in Harvey was 10.03 inches at the Naples Conservancy in Collier County. Naples Lakewood measured 10 inches of rainfall while Naples/Collier County Emergency Management estimated a similar amount at their operations center. These measurements are consistent with NWS doppler radar estimates. Substantial street flooding was reported in the Naples area. Street flooding was also reported in portions of Lee County, with two homes flooded in Bonita Springs. Rainfall totals of 5.53 and 6.72 inches were observed at Immokalee and Everglades City, respectively. Storm total rainfall across Miami-Dade, Broward, and Palm Beach counties ranged from 0.75 inches (West Palm Beach Airport) to 2.85 inches (Coral Springs).
3. Storm Surge Data
The maximum recorded storm surge was 2.41 feet at Fort Myers with estimates of 2 to 3 feet common elsewhere in Charlotte County. Storm surge values ranged from 1 to 2 feet elsewhere in southwest Florida and in the Florida Keys. Tidal flooding was reported in Everglades City including the county airport where a portion of the runway was flooded resulting in the closure of the airport. Minor coastal flooding was also reported along the south-facing portions of the Florida Keys and the west-facing shores of Florida Bay. Sections of Highway A1A in the Keys were closed due to the flooding. The combined effect of wave action and the storm surge resulted in minor beach erosion in Sarasota County, along the south-facing shores of the Keys, and in the back country of Everglades National Park.
Harvey resulted in two confirmed tornadoes. One tornado, an F0, touched down briefly in Collier County near Paradise Point taking the roof off one house, while the other touched down in Dade County with no reported damage.
c. Casualty and Damage Statistics
No reports of casualties due to Harvey have been received at the National Hurricane Center.
Property damage estimates supplied by the Property Claims Services Division of the American Insurance Services Group indicate that Harvey caused about $7.5 million in insured losses in southern Florida. This estimate excludes storm surge damage. To determine the total estimated damage, a ratio of 2:1 is applied to the insured property damage; this is based on comparisons done in historical hurricanes. Thus, the total estimated damage from Harvey is $15 million.
d. Forecast and Warning Critique
The incipient disturbance that was to become Harvey was first identified as a candidate for development in NHC's Tropical Weather Outlook about two and a half days before it became a tropical depression.
There were only nine forecasts issued while Harvey was a tropical storm with only one verifying at 48 hours and none at 72 hours. This number of cases is too small to obtain a meaningful quantitative evaluation of forecast accuracy. However, Harvey was forecast to move across central Florida by most of the computer guidance as well as the official forecasts, and instead moved through south Florida.
Table 4 lists the various watches and warnings that were issued for Harvey. The formation of Harvey in the eastern Gulf of Mexico prompted the issuance of a tropical storm watch for the west coast of Florida, from the mouth of the Swannee River to Bonita Beach, with the first advisory. A tropical storm warning and a hurricane watch were issued six hours later with the warning extended southward to east Cape Sable at 2100 UTC 20 September. This was 20 hours prior to Harvey's landfall in southwest Florida near Everglades City. By early on the 21st, Harvey turned southeast and the forward speed increased, necessitating the extension of tropical storm warnings at 0900 UTC 21 September from Cape Sable to Boca Raton, including the Florida Keys.
Some of the data in this report was provided by the National Weather Service Forecast Offices in Tampa, Melbourne, Key West, and Miami . James Franklin produced the wind and pressure plots.
Figure 1. Best track positions for Tropical Storm Harvey, 19-21 September 1999.
Figure 2a. Best track minimum central pressure curve for Tropical Storm Harvey, 19-22 September 1999.
Figure 2b. Best track maximum sustained 1-minute 10 meter wind speed curve for Tropical Storm Harvey, 19 - 22 September 1999.
Table 1. Preliminary Best Track - Tropical Storm Harvey, 19 - 21 September 1999. Date/Time
Stage Lat. (°N) Lon. (°W) 19/0600 25.0 87.8 1005 30 Tropical Depression 19/1200 25.5 87.8 1004 30 " 19/1800 26.0 87.8 1003 30 " 20/0000 26.3 87.4 1002 40 Tropical Storm 20/0600 26.6 86.9 1001 40 " 20/1200 27.0 86.3 998 40 " 20/1800 27.0 85.5 998 50 " 21/0000 27.1 84.6 995 50 " 21/0600 26.5 83.9 995 50 " 21/1200 26.0 82.8 996 50 " 21/1800 25.9 81.5 999 50 " 22/0000 26.9 78.6 1000 40 " 22/0600 Merged with Low 21/0800 26.3 83.7 994 50 Minimum Pressure 21/1700 25.9 81.7 999 50 Landfall near Everglades City, FL
Table 2. Tropical Storm Harvey selected National Buoy Data Center (NBDC) and ship observations, September 1999. Minimum
Maximum surface wind speed
CMAN Stations Lake Worth, FL (LKWF1) 1010.0 25/1100 30 35 25/1400 Fowey Rocks, FL (FWYF1) 45 51 21/1800 Molasses Reef, FL ( MLRF1) 1001.5 21/1800 47 59 21/1743 Long Key, FL (LONF1) 1003.1 21/1800 28 40 21/1200 Sombrero Key, FL (SMKF1) 21/1600 36 41 21/1400 Sand Key, FL (SANF1) 1002.9 21/1700 35 40 21/1305 Dry Tortugas, FL (DRYF1) 25 31 21/1200 NBDC Buoys 42003 (25.9N / 89.9W) 1001.6 20/2200 34 42 20/0400 42036 (28.5N / 84.5W) 1003.5 20/2200 26 32 20/1800 34-Knot Ship Reports WCPU (25.6N / 86.7W) 1004.0 19/2300 40 19/2300 23.0 PFFV (25.3N / 85.8W) 1003.2 20/1200 40 20/1200 16.0 WCHF (25.0N / 84.8W) 1004.8 20/1500 40 20/1500 15.0 WCOB (25.7N / 85.2W) 1003.0 20/1800 47 20/1800 18.0 Carnival Cruise Line (26.2N/83.6W) 20/2200 40 12.0 Carnival Cruise Line (26.0N/83.3W) 21/0000 35 10.0 ELXB9 (24.3N / 83.2W) 1007.0 21/0000 35 ELBM9 (25.7N / 83.6W) 21/0600 40 21/0600 WCOB (25.5N / 79.7W) 1000.5 21/1800 45 21/1800 16.4
aStandard NWS C-MAN averaging period is 2 min; buoys are 8 min.
bDate/time is for sustained wind when both sustained and gust are listed.
Table 3. Tropical Storm Harvey selected surface observations, September 1999. Minimum
Maximum surface wind speed
Florida Key West Airport 1004.1 21/1956 32 37 21/1404 0.33 Tavernier 1.13 Marathon 0.04 Key West 0.8 Vaca Key 1.0 Homestead 0.96 Turkey Pt. Nuclear Plant 46* 21/1800 Tamiami Aprt (KTMB) 25 36 21/1909 1.26 Miami Int. Aprt (KMIA) 23 36 21/1925 1.52 NWSFO Miami 29.6 21/1930 Hollywood 3.29 Ft. Lauderdale 6.62 Ft. Lauderdale Beach 3.88 Ft. Lauderdale (KFLL) 999.4 21/1953 23 33 21/1904 1.87 Ft. Lauderdale (KFXE) 999.5 21/1953 Pompano Beach (KPMP) 999.5 21/1950 W. Palm Beach (KPBI) 0.73 Tenraw WIMS (Dade) 28 48 21/1700 1.61 Naples/Collier EM 29.6 21/1445 34 21/XXXX 10.00 Immokalee (Collier) 5.53 Everglades City (Collier) 6.72 Naples Conserv (Collier) 10.03 Naples Lkwd (Collier) 10.00 Ochopee WIMS (Collier) 2.06 Coral Springs (Broward) 2.85 Sarsota Aprt (KSRQ) 1003.1 21/1053 25 31 21/0410 1.80 Sunshine Skywy (Hillsb) 31 21/0006 Venice Dardc (Sarsota) 21 21/2000 St Petersburg (KPIE) 1003.1 21/1053 14 19 21/0117 Tampa Arpt (KTPA) 1004.5 21/0956 11 17 20/0320 1.79 Fort Myers (KFMY) 1004.0 21/1053 14 20 21/0853 2.41 Levy County 1-2 Citrus County 1-2 Hernando County 1-2 Pasco County 1-2 Pinellas County 1-2 Hillsborough County 1-2 Manatee County 1-2 Sarasota County 1-2 Charlotte County 2-3
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 minute/9 meter wind
XXXX - time unknown
Table 4. Watch and warning summary, Tropical Storm Harvey, September 1999. Date/Time
Action Location 19/0300 Tropical Storm Watch Issued Florida West Coast: Bonita Beach Florida to the mouth of the Suwannee River 20/1500 Tropical Storm Warning and Hurricane Watch Issued Florida West Coast: Bonita Beach Florida to the mouth of the Suwannee River 20/1500 Tropical Storm Watch Issued Florida East Coast: North of Jupiter Inlet to just south of Flagler Beach...including Lake Okeechobee 20/2100 Tropical Storm Warning Extended Florida West Coast: East Cape Sable to the mouth of the Suwannee River 20/2100 Tropical Storm Watch Extended Florida East Coast: Florida City to just south of Flagler Beach... including Lake Okeechobee 21/0000 Tropical Storm Watch Issued Northwest Bahamas: Grand Bahama Island and the Abacos 21/0300 Tropical Storm Warning Extended Florida East Coast: south of Flagler Beach to Boca Raton... including Lake Okeechobee 21/0900 Tropical Storm Warning Issued Northwest Bahamas: Grand Bahama Island and the Abacos 21/0900 Tropical Storm Warning Extended Boca Raton to East Cape Sable including the Florida Keys... the Dry Tortugas... Florida Bay and the Florida Straits 21/0900 Tropical Storm Warning Discontinued Florida East Coast: North of Sebastian Inlet
Florida West Coast: North of Longboat Key
21/0900 Hurricane Watch Discontinued Florida West Coast: Bonita Beach to the mouth of the Suwannee River 21/1500 Tropical Storm Warning Discontinued Florida East Coast: North of Jupiter Inlet to just south of Flagler Beach ...including Lake Okeechobee
Florida West Coast: Bonita Beach to the mouth of the Suwannee River
21/2100 Tropical Storm Warning Discontinued South of Bonita beach southward through the Florida Keys to just west of Craig Key...including the Dry Tortugas 22/0000 Tropical Storm Warning Discontinued Florida East Coast: Craig Key to Jupiter Inlet...including Florida bay and the Florida Straits 22/0300 Tropical Storm Warning Discontinued Northwest Bahamas: Grand Bahama Island and the Abacos