Figure 1. Best Track analysis of Hurricane Gaston .1
Light Red=Category 1-2 Hurricane
Dark Red=Category 3-5 Hurricane
Gaston affected a large chunk of the Southeast and Mid Atlantic with significant inland flooding, severe weather, and gusty winds. The hurricane was responsible for 8 deaths, five of which occurred because motorists attempted to drive through flooded roadways2. Total damage is rather light, estimated at around $130 million (2004 USD).
Gaston, originally designated a tropical storm at landfall, was upgraded to a weak Category 1 Hurricane in post-storm analysis when it was discovered that Doppler Radar velocity data revealed Gaston had 65 kt (75 mph) surface winds.
Between 00 UTC and 12 UTC on 22 August 2004, a cold front pushed off the East Coast of the United States, which produced an area of showers and thunderstorms
just off the Southeast Coast. The front then stalled over the Atlantic Ocean on 24 August. Surface observations from coastal observing stations from North Carolina to Florida, and several buoys controlled by the National Data Buoy Center (NDBC) revealed that a very large area of low pressure had developed along the southern end of the front just off the Southeast coast between 25 and 26 August. The area of low pressure, though poorly defined and pretty much void of deep convection, became well enough organized to be classified as the seventh Tropical Depression of the 2004 Atlantic Hurricane Season at 5 PM EDT on 27 August.
Weak upper level steering currents left Tropical Depression Seven to meander around the coastline for over two days, which bought the Depression enough time to strengthen into a Tropical Storm at 11 AM on 28 August 3. Gaston continued on a lazy westward drift towards the Southeast coast before he began to turn to the northwest as a modest upper level ridge began building to his north. This, combined with an approaching trough and its attendant surface cold front, allowed Gaston to start speeding up as he approached the Southeast coastline.
Forecast Discussions out of the National Hurricane Center revealed how close Gaston was to hurricane strength just before landfall, but that radar velocity data did not support a 65 kt hurricane at landfall 4. Upon closer inspection in the post-storm analysis, however, forecasters found that Gaston had in fact reached hurricane intensity for a short period of time right before landfall 2. Shortly after making landfall near Awendaw, South Carolina, Gaston weakened to a Tropical Depression before turning northward, and then northeastward, headed towards the Mid Atlantic states, where he dumped anywhere from 3 to 10 inches of rainfall. Richmond, Virginia reported the highest rainfall total of 12.6 inches.
Gaston approached the mouth of the Chesapeake Bay during the afternoon of 30 August, and the Chesapeake Light C-MAN station just east of Cape Charles Light, Virginia reported sustained winds nearing 45 kts (50 mph) late on 30 August, which constituted upgrading Tropical Depression Gaston to a Storm 5. Gaston maintained minimal Tropical Storm status for roughly 36 hours before merging with a frontal system about 200 miles southeast of Nova Scotia.
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MODIS Terra RGB using the MOD02HKM product. This image is of the swath data from Aug 29 at 1640 hrs. More images like this and parameters animation created from other datasets can be seen in our Archive Image Gallery for hurricane Gaston
1. Image courtesy of the NOAA coastal Services Center Http://hurricane.csc.noaa.gov/hurricanes
2. Brown, Daniel; McAdie, Colin; Franklin, James. “Tropical Cyclone Report: Hurricane Gaston.” 19 November 2004. http://www.nhc.noaa.gov/2004gaston.shtml (26 July 2006).
3. Beven, Jack. “Tropical Storm Gaston Discussion Number 4.” 28 August 2004. http://www.nhc.noaa.gov/archive/2004/dis/al072004.discus.004.shtml? (25 July 2006).
4. Pasch, Richard. “Tropical Storm Gaston Discussion Number 8.” 29 August 2004. http://www.nhc.noaa.gov/archive/2004/dis/al072004.discus.008.shtml? (26 July 2006).
5. Stewart, Stacy. “Tropical Storm Gaston Discussion Number 14.” 30 August 2004. http://www.nhc.noaa.gov/archive/2004/dis/al072004.discus.014.shtml? (26 July 2006).