HURRICANE GEORGES 1998

Hurricane Georges 1998

Preliminary Report
Hurricane Georges
15 September - 01 October 1998


1998 PRELIMINARY REPORTS

Tropical Storm Alex (TS)
Hurricane Bonnie (3)
Tropical Storm Charley (TS)
Hurricane Danielle (2)
Hurricane Earl (2)
Tropical Storm Frances (TS)
Hurricane Georges (4)
Tropical Storm Hermine (TS)
Hurricane Ivan (1)
Hurricane Jeanne (2)
Hurricane Karl (2)
Hurricane Lisa (1)
Hurricane Mitch (5)
Hurricane Nicole (1)



Georges (pronounced Zhorzh) was the second deadliest and second strongest hurricane within the Atlantic basin during the 1998 season. Its 17 day journey resulted in seven landfalls, extending from the northeastern Caribbean to the coast of Mississippi, and 602 fatalities -- mainly in the Dominican Republic and Haiti.

 

a. Synoptic History

Georges originated from a tropical wave, observed by satellite and upper-air data, which crossed the west coast of Africa late on 13 September. Rawinsonde data from Dakar, Senegal showed an attendant 40 to 52 mph easterly jet between 550 and 650 millibars (mb). On the 14th, visible satellite imagery depicted a large, well-defined cloud system in association with the wave and meteorologists at the Tropical Prediction Center/National Hurricane Center (NHC) Tropical Analysis and Forecast Branch (TAFB), the Satellite Analysis Branch (SAB) of the National Environmental Satellite, Data, and Information Service, and the Air Force Weather Agency (AFGWC) began satellite-based Dvorak intensity classifications. By early on the 15th, ship reports indicated the presence of a closed surface circulation in this system and it is estimated that a tropical depression formed at 1200 UTC, centered about 300 nautical miles south-southwest of the Cape Verde Islands in the far eastern Atlantic, as shown in the post-storm "best-track". During the next 24 hours the tropical depression continued to become better organized as banding features developed and deep convection formed over the center. The system became a tropical storm at 1200 UTC on 16 September while centered about 620 nautical miles west-southwest of the Cape Verde Islands. Georges moved on a persistent west-northwest course for the next ten days, a classic Cape Verde-type track, in response to a mid- to upper-level tropospheric ridge which strengthened with height.

Georges continued to gradually strengthen over the next several days, reaching hurricane intensity around 1800 UTC on 17 September when a banding-type eye feature became evident in satellite imagery. By the 19th, an upper-level anticyclone was well-established over Georges and satellite pictures suggested that the hurricane was beginning to strengthen rapidly, as indicated by the cooling cloud tops, increased symmetry of the deep convection, and the warming and contracting of the well-defined eye.

By early afternoon on the 19th, the first U.S. Air Force Reserve (USAFR) reconnaissance aircraft reached the hurricane and measured maximum flight-level winds of 168 mph and a minimum central pressure of 938 mb - confirming the intensification trend noted in satellite imagery. Georges' winds were increased to 144 mph at 1800 UTC on the 19th making it a category four hurricane on the Saffir-Simpson Hurricane Scale.

Several Global Positioning System (GPS) dropwinsondes were deployed within the eye-wall region of the hurricane during these reconnaissance missions. Near-surface (below 200 feet) wind estimates from these drops indicate maximum winds from 154 mph to 173 mph. On this basis, Georges is estimated to have reached a peak intensity of 155 mph at 0600 UTC on the 20th while located about 285 nautical miles east of Guadeloupe in the Lesser Antilles. Although GPS Dropwinsondes data is still being evaluated by scientists at the National Oceanic and Atmospheric Administration (NOAA) Hurricane Research Division, preliminary research suggests that the observed near-surface winds approximate 1-minute values.

Shortly after 0600 UTC 20 September, the hurricane began a marked weakening trend with the eye becoming indiscernible in satellite pictures, or to aerial reconnaissance by that afternoon. Examination of water vapor satellite imagery and satellite-derived wind analyses from the Cooperative Institute for Meteorological Satellite Studies at the University of Wisconsin suggest that one possible factor responsible for the weakening could have been upper-level northerly vertical wind shear induced by an upper-level anticyclone located over the eastern Caribbean. By the evening of the 20th, the central pressure had risen 26 mb and Georges weakened. It then made the first two of its seven landfalls in the Lesser Antilles, first in Antigua then in St. Kitts and Nevis, early on the 21st with maximum sustained surface winds of 115 mph.

By mid-morning of the 21st an upper-level low over Cuba, denoted in water vapor imagery, was moving westward away from Georges thereby reducing the possibility of Georges moving to the northwest, away from Puerto Rico. Later in the afternoon, the shear appeared to diminish and the outflow aloft improved but Georges never fully recovered due in part to the circulation's interaction with Puerto Rico. Georges made landfall in southeast Puerto Rico with sustained surface winds of 115 mph on the evening of the 21st. The hurricane moved inland over Puerto Rico and weakened slightly and then moved into the Mona Passage early on the 22nd. Georges began to re-intensify while over the Mona Passage and made landfall later that morning in the Dominican Republic, about 75 nautical miles east of Santo Domingo with estimated sustained surface winds of 121 mph.

During the next 21 hours Georges weakened as it moved slowly across the mountainous terrain of the Dominican Republic and Haiti, where it produced copious rains resulting in deadly flash floods and mud slides. The system emerged into the Windward Passage on the morning of the 23rd with 75 mph maximum winds. Georges changed little before making landfall in eastern Cuba later that afternoon, about 25 nautical miles east of Guantanamo Bay. The system retained hurricane status while moving slowly west-northwestward across the northern coast of Cuba, exiting the northern coast by late afternoon on the 24th. Satellite imagery showed that the system retained a fairly impressive upper-level outflow pattern during its crossing of both Hispaniola and Cuba.

Once back over water, the hurricane began to re-intensify. Satellite pictures showed that a band of deep convection developed east of the center early on the 25th which expanded throughout the morning. Georges made landfall during mid-morning of the 25th in Key West, Florida with a minimum central pressure of 981 mb and maximum winds of 104 mph. After moving away from Key West, Georges turned more to the northwest, then north-northwest, and gradually slowed down on the 26th and 27th. This occurred in response to the mid-tropospheric anticyclone north of the hurricane shifting eastward into the southeastern United States. The hurricane made landfall near Biloxi, Mississippi on the morning of the 28th with estimated maximum sustained 1-minute winds of 104 mph and a minimum central pressure of 964 mb. After landfall, the system meandered around southern Mississippi and was downgraded to a tropical storm on the afternoon of the 28th.

Georges became quasi-stationary for the next 6 to 12 hours moving in a cyclonic loop over southern Mississippi. The tropical storm began moving in a generally northeast to east direction early on the 29th and was downgraded to a tropical depression by mid-morning while located about 30 nautical miles north-northeast of Mobile, Alabama. Georges continued to move eastward at 6 to 12 mph on the 29th and 30th. By early morning of 1 October, the system dissipated near the northeast Florida/southeast Georgia coast, although a very weak remnant low did emerge over the western Atlantic during the day. However, the remnant circulation merged with a frontal zone by late on the 1st.


b. Meteorological Statistics

The best-track intensities in were obtained from the data in which depict the curves of minimum central sea-level pressure and maximum sustained 1-minute average "surface" (10 meters above ground level) wind speed, respectively, as a function of time. These figures also contain data upon which the curves are based: USAFR and NOAA aircraft reconnaissance data, satellite-based Dvorak-technique intensity estimates from TAFB, SAB, and AFGWC, and estimates from synoptic data analyses after landfall.


1. Storm Surge Data

The storm surge was estimated to be near 10 feet in Fajardo, Puerto Rico while values of 4 to 6 feet were typical in the Florida Keys. Preliminary storm surge estimates along the central and east Gulf Coast range from 5 to 9 feet in Louisiana and Mississippi (maximum of 8.9 feet at Point A La Hache, LA and Point Cadet, Biloxi, MS) to 5 to 12 feet in Alabama (5 to 10 feet in Mobile County and 7 to 12 feet in Baldwin County). The two highest values received from Alabama are 9.3 feet which occurred in west Mobile Bay, and 11.9 feet in Fort Morgan. In the Florida Panhandle, the storm surge in Escambia, Santa Rosa, and Okaloosa Counties was estimated to be 5 to 10 feet. Of course breaking waves superimposed on the storm surge will result in even higher water marks. At the time of this writing, official United States Corps of Engineers/Geological Survey (USCE/USGS) storm surge site survey values have not been received.


2. Rainfall Data

Georges was a substantial rain-producer in portions of the Caribbean and the central/eastern Gulf of Mexico coast. In the U.S. Virgin islands, rainfall totals were generally between 3 and 8 inches. In Puerto Rico, the maximum official two-day USGS rain gage measurement was 24.62 IN in Lago El Guineo near Villalba while the maximum Cooperative Observer (CO-OP) two-day total reported was 28.36 inches in Jayuya. Figure 4 shows the USGS rainfall analysis for Puerto Rico in 5-inch isohyets - of particular interest is the large swath of 10-15 inch values.

No surface-based rainfall estimates are available from the Dominican Republic or Haiti, two of the hardest-hit countries. Satellite-derived rainfall estimates suggest that as much as 39 inches of rain may have fallen over portions of the Dominican Republic and Haiti over a 24-hour period ending around 1200 UTC on the 23rd. Over Cuba, the Instituto de Meteorologica reported a maximum storm total of 24.41 inches in Limonar.

Rainfall in the Florida Keys was considerably less than what was seen over Cuba or Hispaniola, with Key West recording 8.38 inches. In contrast, storm totals along the Gulf Coast were noticeably higher owing to the hurricane's marked deceleration. The maximum rainfall total from an official observation site was 24.24 inches at Eglin AFB (KVPS) in the Florida Panhandle while the highest storm total was 29.66 inches from a CO-OP in Bay Minette, AL. Rainfall totals generally ranged from 10 to 20 inches over most of southern Mississippi and Alabama, and the Florida Panhandle - see Figure 5. In response to the heavy rains, widespread river flooding occurred in southern Mississippi from 30 September through 2 October flooding homes and forcing evacuations. The Tchoutacabouffa River at D'Iberbville, MS set a record crest of 19 feet at 0200 UTC 30 September.


3. Tornadoes

Most of the reported tornado activity associated with Georges occurred in Florida and Alabama with a total of 28 tornadoes estimated to have touched down, mostly in northwest Florida. No deaths were directly attributible to these tornadoes. Two tornadoes were also reported in Puerto Rico.


c. Casualty and Damage Statistics

There were 602 deaths attributed to Georges; 380 in Dominican Republic, 209 in Haiti, 6 in Cuba, 4 in St Kitts and Nevis, 2 in Antigua, 1 in Bahamas and 1 in Alabama.

The 602* direct deaths attributed to Georges make it the 19th deadliest tropical cyclone in the Atlantic basin this century. Most of the deaths associated with Georges occurred in the Dominican Republic and Haiti, due mainly to flash flooding and subsequent mud slides in high terrain regions. The lone direct death in the United States, which was freshwater flood-related, occurred in Mobile, Alabama.


Insured property damage estimates supplied by the Property Claims Services Division of the American Insurance Services Group estimates that Georges caused a total of $2.955 Billion in damage in the United States including Puerto Rico and the U.S. Virgin Islands. This figure comes from $50 Million to US Virgin Islands, $1.75 Billion to Puerto Rico, $34 Million in Florida, $665 Million in Mississippi, $125 Million in Alabama and $25 Million in Lousiana. These estimates exclude 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 Georges is $5.9 Billion.

In Puerto Rico, there was considerable damage to homes throughout the island. A total of 72,605 homes were damaged, of which 28,005 are estimated to have been completely destroyed. During the hurricane, over 26,000 people were in shelters. In the Dominican Republic upwards of 185,000 were left homeless by Georges and 100,000 remained in shelters through mid-October as electricity and water service remain out in most of the country. Across Haiti, government officials stated that 167,332 had been left homeless by the hurricane.

The agricultural industry in Puerto Rico was hit hard by Georges with estimates of 95% of the plantain and banana crop destroyed along with 75% of the coffee crop.

Despite Georges' weakened state when it moved across Cuba, it had a substantial impact. A total of 60, 475 homes were damaged of which 3,481 were completely destroyed. As was the case in Puerto Rico, the agricultural sector was hard hit with major losses at banana plantations in eastern Cuba.

The damage to dwellings in the United States was not as extensive as that experienced across the Caribbean. In the Florida Keys 1536 homes were damaged of which 173 were completely destroyed, many of which were mobile homes. Some roof and structural damage was also reported along the coast of Mississippi.

In the first 60 days or so after Georges made its final landfall in Mississippi, the American Red Cross spent $104 Million on relief services in the United States Virgin Islands, Puerto Rico, Alabama, Louisiana, Mississippi, the Florida Keys and the Florida Panhandle. This makes it the most expensive disaster aid effort in the organization's 117-year history.


Maximum Intensity For Hurricane Georges
15 September - 01 October, 1998

Date/Time
(UTC)
Position Pressure
(mb)
Wind Speed
(mph)
Stage
Lat. (°N) Lon. (°W)
20/0600 16.0 56.3 937 155 Category 4 Hurricane


Landfall for Hurricane Georges
15 September - 01 October, 1998
Date/Time
(UTC)
Pressure
(mb)
Wind Speed
(mph)
Stage Landfall
21/0430 966 115 Category 3 Hurricane Falmouth,
Antigua
21/0800 966 115 Category 3 Hurricane Basseterre,
St.Kitts
21/2200 968 115 Category 3 Hurricane Fajardo,
Puerto Rico
22/1230 962 120 Category 3 Hurricane Santo Domingo,
Dominican Republic
23/2130 993  75 Category 1 Hurricane Guantanamo Bay,
Cuba
25/1530 981 105 Category 2 Hurricane Key West,
Florida
28/1130 964 105 Category 2 Hurricane Biloxi,
Mississippi