Canadian high pressure affected the weather pattern on the 7th. A northerly flow around the high ushered in cold air to the region.
Every event with a place to put it; 11 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.
Canadian high pressure affected the weather pattern on the 7th. A northerly flow around the high ushered in cold air to the region.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Baltimore/Washington wrote its last area forecast discussion before the first event at Apr 6, 8:29 PM EST, 5 hours 31 minutes earlier.
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</html>HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1108 PM EDT FRI APR 6 2012 ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057- 071000- CHESAPEAKE BAY NORTH OF POOLES ISLAND MD- CHESAPEAKE BAY FROM POOLES ISLAND TO SANDY POINT MD- CHESAPEAKE BAY FROM SANDY POINT TO NORTH BEACH MD- CHESAPEAKE BAY FROM NORTH BEACH TO DRUM POINT MD- CHESAPEAKE BAY FROM DRUM POINT MD TO SMITH POINT VA- TIDAL POTOMAC FROM KEY BRIDGE TO INDIAN HEAD MD- TIDAL POTOMAC FROM INDIAN HEAD TO COBB ISLAND MD- TIDAL POTOMAC FROM COBB ISLAND MD TO SMITH POINT VA- PATAPSCO RIVER INCLUDING BALTIMORE HARBOR- CHESTER RIVER TO QUEENSTOWN MD-EASTERN BAY- CHOPTANK RIVER TO CAMBRIDGE MD AND THE LITTLE CHOPTANK RIVER- PATUXENT RIVER TO BROOMES ISLAND MD- TANGIER SOUND AND THE INLAND WATERS SURROUNDING BLOODSWORTH ISLAND-DISTRICT OF COLUMBIA-NORTHERN BALTIMORE-HARFORD- SOUTHERN BALTIMORE-PRINCE GEORGES-ANNE ARUNDEL-CHARLES-ST. MARYS- CALVERT-PRINCE WILLIAM/MANASSAS/MANASSAS PARK-FAIRFAX- ARLINGTON/FALLS CHURCH/ALEXANDRIA-STAFFORD-SPOTSYLVANIA- KING GEORGE- 1108 PM EDT FRI APR 6 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE MARYLAND PORTION OF THE CHESAPEAKE BAY...TIDAL POTOMAC RIVER...AND ADJACENT COUNTIES IN CENTRAL MARYLAND AND NORTHERN VIRGINIA AS WELL AS THE DISTRICT OF COLUMBIA. .DAY ONE...TONIGHT NEAR FREEZING TEMPERATURES ARE EXPECTED AGAIN TONIGHT FOR PORTIONS OF NORTHERN MARYLAND. A FREEZE WARNING HAS BEEN ISSUED OVERNIGHT FOR HARFORD AND NORTHERN BALTIMORE COUNTIES BEGINNING AT 200 AM. SEE WBCNPWLWX FOR DETAILS. AREAS OF FROST ARE POSSIBLE OUTSIDE OF THE FREEZE WARNING. A SMALL CRAFT ADVISORY IS IN EFFECT TONIGHT FOR THE MARYLAND CHESAPEAKE BAY. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THE FREEZE WARNING FOR HARFORD AND NORTHERN BALTIMORE COUNTIES CONTINUES UNTIL 900 AM SATURDAY MORNING. A FIRE WEATHER WATCH HAS BEEN ISSUED FOR THE ENTIRE OUTLOOK AREA FOR SATURDAY AFTERNOON. SEE WBCRFWLWX FOR DETAILS. A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THE TIDAL POTOMAC AND MARYLAND CHESAPEAKE BAY FOR SATURDAY. SMALL CRAFT ADVISORY CONDITIONS WILL LIKELY CONTINUE INTO SUNDAY FOR PORTIONS OF THE WATERS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504- WVZ050>053-055-501>506-071000- WASHINGTON-FREDERICK MD-CARROLL-MONTGOMERY-HOWARD- EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-AUGUSTA- ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE-NELSON- ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-LOUDOUN-ORANGE-CULPEPER- NORTHERN FAUQUIER-SOUTHERN FAUQUIER-WESTERN HIGHLAND- EASTERN HIGHLAND-HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON-HARDY- WESTERN GRANT-EASTERN GRANT-WESTERN MINERAL-EASTERN MINERAL- WESTERN PENDLETON-EASTERN PENDLETON- 1108 PM EDT FRI APR 6 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN WEST VIRGINIA... NORTHERN AND CENTRAL VIRGINIA...AND CENTRAL AND WESTERN MARYLAND WITH THE EXCEPTION OF GARRETT COUNTY. .DAY ONE...TONIGHT NEAR FREEZING TEMPERATURES ARE EXPECTED AGAIN TONIGHT. A FREEZE WARNING HAS BEEN ISSUED OVERNIGHT FOR MUCH OF MARYLAND...THE EXTREME EASTERN PANHANDLE OF WEST VIRGINIA...THE SHENANDOAH VALLEY...THE CENTRAL FOOTHILLS...PORTIONS OF THE PIEDMONT...AND THE NORTHERN AND WESTERN SUBURBS OF WASHINGTON DC AND BALTIMORE. SEE WBCNPWLWX FOR DETAILS. AREAS OF FROST ARE POSSIBLE OUTSIDE OF THE FREEZE WARNING. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THE FREEZE WARNING CONTINUES UNTIL 900 AM SATURDAY MORNING. A FIRE WEATHER WATCH HAS BEEN ISSUED FOR MUCH OF MARYLAND FROM THE WESTERN SHORE OF THE CHESAPEAKE TO WASHINGTON COUNTY...EXTREME EASTERN WEST VIRGINIA...AND THE VIRGINIA SUBURBS OF WASHINGTON DC FOR SATURDAY AFTERNOON. SEE WBCRFWLWX FOR DETAILS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
The national radar mosaic for the moment the first event began.
13 frost/freeze. Local standard time, as filed.
A temperature of 17 degrees was measured at Mill Gap.
Temperatures were estimated to be between 17 and 30 degrees.
Temperatures were reported to be around 30 degrees.
Temperatures were reported to be around 30 degrees.
Temperatures were reported to be between 28 and 29 degrees.
Temperatures were reported to be around 29 degrees.
Temperatures were reported to be around 29 degrees.
Temperatures were estimated to be around 30 degrees.
Temperatures were estimated to be around 30 degrees.
Temperatures were estimated to be in the upper 20s.
A temperature of 30 degrees was reported at Manassas.
A temperature of 31 degrees was reported at Dulles.
A temperature of 31 degrees was reported at Fort Belvoir.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Virginia in 2012Every state in 2012This day in weather historyWarnings in Virginia, April 2012
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: 379097, 379098, 379091, 379092, 379094, 379095, 379096, 379099, 379100, 379101, 379104, 379105, 379562.