A large area of showers and thunderstorms containing heavy downpours moved through the region between the afternoon of the 15th and the morning of the 16th.  The system dropped between 2 and 4 inches of rain across western and central Maryland which caused several low lying areas to flood.  Isolated  5 inch rainfall totals were reported in northern Frederick County. In some areas it took over 10 hours for the water to recede after the rain came to an end.  In Allegany County, twenty sewage pumping stations overflowed after being inundated by water. Residents in 3 communities had to boil their water for a few days following the flood.  In Washington County, twenty five roads were closed by flooding and many small streams overflowed their banks. Schools were forced to close early and some parents had to pick up their children at school because the buses had trouble navigating the flooded roads. Two motorists became stranded in flood waters including one woman who had to be rescued from Antietam Creek near Leitersburg.  Conococheague Creek at Fairview rose above its bankful stage of 8 feet at noon on the 16th.  It crested at 9.4 feet at 8 PM and fell below bankful stage at 2:30 PM on the 17th.  Water overflowed onto Wishard Road and other low lying areas along the creek. In Frederick County, over 30 roads were closed by flooding.  Water from streams and creeks overflowed onto several low-lying bridges.  County officials said that so many roads were becoming flooded that the Wolfsville area started to become an island. Students in the northern portion of the county were sent home early as a precaution. Some residents in Thurmont were forced out of their homes after their basements flooded.  Rescue personnel  conducted 4 water rescues after drivers stalled while crossing flooded roads. One woman was caught in swift rushing water at the intersection of Dog Street and Nicodemus Mill Road  near Keedysville. The Middletown fire company pumped out 17 basements, including one where the pressure of the water was causing holes in a concrete wall.  An observer at Catoctin Mountain recorded an incredible 5.27 inches of rainfall during the event.  On the Monocacy River at Frederick, the river rose above its flood stage of 15 feet at 2:15 AM on the 17th.  It crested at 15.9 feet at 8 AM and dropped below flood stage at 1:30 PM.  Water reached the sewage treatment plant and backwater flooding occurred along Carroll Creek, inundating Gashouse Pike.  In Baltimore County, Jones Falls overflowed its banks near Owings Mills.  In Prince George's County, high water forced sewage to pour out of a manhole onto Indian Head Highway.

Flood in ALLEGANY, MARYLAND
From 16-MAY-03 06:00:00 to 16-MAY-03 18:00:00 (EST)
Reported by: NEWSPAPER

Flood in FREDERICK, MARYLAND
From 16-MAY-03 06:10:00 to 16-MAY-03 23:00:00 (EST)
Reported by: FIRE DEPT/RESCUE SQUAD

Flood in WASHINGTON, MARYLAND
From 16-MAY-03 06:00:00 to 16-MAY-03 18:00:00 (EST)
Reported by: NEWSPAPER

Flood in SOUTHERN BALTIMORE / BALTIMORE (C), MARYLAND
From 16-MAY-03 09:00:00 to 16-MAY-03 12:00:00 (EST)
Reported by: TRAINED SPOTTER

Heavy Rain in MONTGOMERY, MARYLAND
From 15-MAY-03 15:00:00 to 16-MAY-03 08:00:00 (EST)
Location: COUNTYWIDE
Reported by: TRAINED SPOTTER

Heavy Rain in HOWARD, MARYLAND
From 15-MAY-03 15:00:00 to 16-MAY-03 08:00:00 (EST)
Location: COUNTYWIDE
Reported by: TRAINED SPOTTER

Heavy Rain in BALTIMORE CITY (C), MARYLAND
From 15-MAY-03 15:00:00 to 16-MAY-03 08:00:00 (EST)
Location: COUNTYWIDE
Reported by: TRAINED SPOTTER

Heavy Rain in PRINCE GEORGE'S, MARYLAND
From 15-MAY-03 15:00:00 to 16-MAY-03 08:00:00 (EST)
Location: COUNTYWIDE
Reported by: TRAINED SPOTTER

Heavy Rain in CHARLES, MARYLAND
From 15-MAY-03 15:00:00 to 16-MAY-03 08:00:00 (EST)
Location: COUNTYWIDE
Reported by: TRAINED SPOTTER

Flood in WASHINGTON, MARYLAND
From 16-MAY-03 11:00:00 to 17-MAY-03 13:30:00 (EST)
Reported by: AWOS,ASOS,MESONET,ETC

Flood in FREDERICK, MARYLAND
From 17-MAY-03 01:15:00 to 17-MAY-03 12:30:00 (EST)
Reported by: AWOS,ASOS,MESONET,ETC