Heavy Rain, Washington
- When
- September 29, 9:30 PM EST to 11:30 PM EST
- Where
- Washington County, Sharpsburg
- Reported by
- AWOS,ASOS,MESONET,ETC
- Coordinates
- 39.604, -77.814 (the zone’s center; the record gives no point)
Over 2 inches in 2 hours
An area of intense showers moved across much of Maryland from 10:00 PM EDT on the 29th through 2:00 AM EDT on the 30th, producing winds in excess of 55 MPH and very heavy downpours. Minor flooding was reported in a few locations, and high winds knocked numerous trees and power lines down.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS LWX wrote it up.
An area of intense showers moved across much of Maryland from 10:00 PM EDT on the 29th through 2:00 AM EDT on the 30th, producing winds in excess of 55 MPH and very heavy downpours. Minor flooding was reported in a few locations, and high winds knocked numerous trees and power lines down. In Washington County, high winds damaged 2 buildings on Willow Road in Hancock. Trees and power lines were downed from Clear Springs to Hagerstown. A wind gust of 51 MPH was recorded in Hagerstown at 11:53 PM EDT. Sharpsburg recorded 2.49 inches of rainfall. In Frederick County, rainfall amounts included 2.80 inches at Wolfsville, 2.5 inches at Thurmont, and 2.45 inches at Catoctin Mountain Park. Trees and power lines were downed in Libertytown, Urbana, Emmitsburg, Yellow Springs, Meyersville, Frederick, and Brunswick. 6000 county customers lost power as a direct result of the storm. Four roads were closed by fallen trees, and the MARC train was delayed by debris on the tracks in Brunswick. Trees and power lines were downed in Montgomery County, resulting in 6600 electrical outages. Trees blocked Route 108 at Brink Road in Damascus. Three trees were downed, loose items where thrown about, and leaves were plastered against one side of a home in Laytonsville. In Carroll County, winds gusted to 65 MPH in Westminster around 12:45 AM EDT. A wind gust of 53 MPH was recorded in Millers at around 1:00 AM EDT. A dozen large trees were downed in Tayneytown. Howard County reported downed trees and power outages near Route 32 and 39 in Columbia. In Prince George's County, 4200 customers lost power. Trees were downed in Mitchelsville around 1:00 AM EDT. Winds gusted to 43 MPH at Andrews Air Force Base at 1:03 AM EDT and 41 MPH at the University of Maryland in College Park. Oxon Hill reported 1.47 inches of rainfall. Anne Arundel County reported several downed trees in the northern half of the county. Winds gusted to 44 MPH at Baltimore/Washington International Airport (BWI) at 1:12 AM EDT. Annapolis reported 2.30 inches of rainfall and BWI received 1.16 inches. Over 60 trees and many power lines were downed in the city of Baltimore. 14,000 city customers lost power.
The Sterling radar (KLWX), 75 km away, was scanning. The volume nearest the first event began at 03:17 UTC.
11 thunderstorm wind, 2 heavy rain. Local standard time, as filed.
Over 2 inches in 2 hours
Over 2 inches in 2 hours
2 buildings damaged on Willow Road
Trees and power lines downed
Numerous trees and power lines downed
Tree downed
Several trees downed on Brink Road at Route 108
12 trees downed
Estimated 60 MPH wind gust
4 feet diameter oak trees downed
Power lines downed
60 trees downed
Several trees downed, concentrated in the Annapolis area
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maryland in 1999Every state in 1999This day in weather historyWarnings in Maryland, September 1999
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5718294, 5718296, 5718292, 5718293, 5718295, 5718297, 5718298, 5718299, 5718300, 5718301, 5718302, 5718303, 5716558.