Heavy Rain in Delaware, October 7 to 8, 2005

The combination of a very slow moving cold front and copious moisture from the remnants of Tropical Storm Tammy produced periods of heavy rain across Delaware from the afternoon of the 7th into the evening of the 8th. Sorm total averaged between three and six inches with the highest amounts in Sussex County. This caused widespread poor drainage and field flooding, but did not cause any significant flooding along the creeks and rivers. The heavy rain caused pumpkins to rot, peppers and tomatoes to burst and delayed the harvesting of soybeans and corn. Storm totals included 5.30 inches in Lincoln (Sussex County), 5.05 inches in Delmar (Sussex County), 4.73 inches in Lewes (Sussex County), 4.50 inches in Georgetown (Sussex County), 4.32 inches in Newark (New Castle County), 3.93 inches at the Porter Reservoir (New Castle County), 3.65 inches in Dover (Kent County), 3.54 inches in Greenwood (Sussex County), 3.49 inches in Bear (New Castle County) and 3.43 inches at the New Castle County Airport. This precipitation event helped the state of Delaware have its wettest October on record dating back to 1895. The statewide average precipitation total was 8.45 inches, 3.38 inches wetter than normal. At the New Castle County Airport, the monthly precipitation total of 7.79 inches (4.71 inches wetter than normal) was the second wettest October on record. In Georgetown, the October monthly precipitation total was 8.40 inches, 5.04 inches wetter than normal. The cold front moved from near Pittsburgh, Pennsylvania at 8 p.m. EDT on the 7th, to the Susquehanna Valley in Pennsylvania at 2 a.m. EDT on the 8th, to the Poconos and Berks County in Pennsylvania and just west of Chesapeake Bay in Maryland at 8 a.m. EDT on the 8th. The cold front stalled as waves of low pressure road northeast along it. At 2 p.m. EDT on the 8th, the cold front just edged into northwestern New Jersey and the Philadelphia northwest suburbs and was still west of Chesapeake Bay in Maryland. At 8 p.m. EDT that evening the cold front barely moved into the Philadelphia New Jersey suburbs and the Delmarva Peninsula. The cold front and waves of low pressure cleared the Delaware and New Jersey coasts between Midnight EDT and 2 a.m. EDT on the 9th. The slow movement and stalling coupled with an unstable air mass and tropical moisture associated with Tammy helped enhance the torrential downpours. The flooding would have been even worse if not for the unseasonably dry weather that preceded this event from the middle of August.