Flash Flood in Maryland, January 19, 1996

***Flood/Flash Flood***An unprecedented combination, in recent history, of unseasonably warm, humid air overriding a dense snow pack estimated between 12 and 18 inches (but up to 2 feet or more at higher elevations) caused nearly all of the pack to vanish in a 12-hour period. The unseasonably warm air was drawn northward around the circulation of a deepening storm west of the Appalachians late on the 18th and early on the 19th. The melting snow and heavy rains caused widespread, and in some cases, catastrophic flooding and flash flooding on the 19th.Strong low-level southeast flow developed by late afternoon on the 18th. Initially, colder temperatures in sheltered valleys slowed the rate of snow melt while the warm moist air mass attacked the snow pack at higher elevations. By mid-evening, however, even lower elevations were warming rapidly. Flash flooding began at around the same time as the onset of heavy pre-frontal rains. These heavier showers fell repeatedly over the region between 0400 and 0800EST, causing acute and widespread flooding and flash flooding. Some areas received between 2 and 4 inches of rain during this period.Some of the most pronounced damage occurred in Allegany Co, where an estimated $7 million in damage was reported from the initial floods alone. Two permanent homes were destroyed, 20 had major damage, and 205 had minor damage. Two mobile homes were destroyed, and 8 others had major damage; several apartments were flooded, and 32 businesses were damaged. Washington Co estimated over $1 million dollars in damage from flood waters. Five single-family homes had major damage; 2 had minor damage. Eleven mobile homes in Funkstown sustained major damage, 13 had minor damage; 2 apartments had major damage and 3 minor damage. An oil spill also occurred in Williamsport.