Low pressure tracked through the central portion of the country while surface high pressure remained off the New England Coast. Warm and moist air overran surface cold air while a light snowpack remained on the ground.
Every event with a place to put it; 1 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.
Low pressure tracked through the central portion of the country while surface high pressure remained off the New England Coast. Warm and moist air overran surface cold air while a light snowpack remained on the ground. The warm and moist air interacted with the surface cold air and snowpack, causing areas of dense fog to develop.
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 Jan 22, 9:04 PM EST, 5 hours 48 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
904 PM EST SUN JAN 22 2012
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT AS A COLD FRONT APPROACHES
FROM THE WEST. THE COLD FRONT WILL PASS THROUGH OUR AREA MONDAY
NIGHT. HIGH PRESSURE BUILD OVERHEAD TUESDAY AND WEDNESDAY BEFORE A
STORM SYSTEM IMPACTS THE REGION LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
WAVES OF DRIZZLE CONTINUE TO RIDE UP THE PIEDMONT IN THE LEE OF
THE BLUE RIDGE. BESIDES THE COLD AIR DAMMING IN PLACE...WHAT IS
DRIVING THE INCOMING LOW LEVEL MOISTURE IS A RAPIDLY DEVELOPING
LOW PRESSURE SYSTEM OVER THE CNTRL PLAINS. THIS FEATURE IS STRONG
ENOUGH TO DEVELOP A LARGE FETCH OF LOW LEVEL MOISTURE FROM THE
GULF...SPREADING IT UP THE SOUTHERN STATES AND ERN SEABOARD.
THE DAMMING EFFECT OF THE COLDER AIR FOR THE PAST SEVERAL HOURS
HAS CREATED A ENVIRONMENT FOR WIDESPREAD LIGHT RAIN AND DRIZZLE
FREEZE AT THE SFC. KIAD 00Z SOUNDING DEPICTS THESE LAYERS
WELL...W/ A SATURATED LOWEST 6KFT AND A WARM NOSE /SLIGHTLY ABOVE
FREEZING/ SANDWICHED IN BETWEEN SUB-FREEZING LAYERS. HOWEVER...THE
MID ATLC IS WELL AWAY FROM ANY STRONG LIFTING MECHANISM OR AN AREA
OF SUFFICIENT ISENTROPIC LIFT. ABOUT THE MOST THE ATMOS CAN
SQUEEZE OUT OF THIS SATURATED COLUMN IS WIDESPREAD DRIZZLE. W/
TEMPS AT THE SFC EXPECTED TO REMAIN AOB FREEZING /OUTSIDE OF AREAS
ALONG THE COAST/ FOR MUCH OF THE OVERNIGHT HRS...A FREEZING RAIN
ADZY REMAINS IN EFFECT THRU MID MRNG ON MONDAY.
GRADUALLY FROM SOUTH-TO-NORTH MID MRNG...TEMPS WILL RISE ABOVE
FREEZING - ALL JUST AHEAD OF A RAPIDLY MOVING COLD FRONT /FROM THE
CNTRL PLAINS STORM SYSTEM/. SLY WINDS WILL INCREASE LATER IN THE
MRNG...TEMPS WILL BEGIN TO CLIMB INTO THE 40S /L50S CLOSER TO THE
BAY/. THE FRONT WILL MOVE THRU THE OHIO VLY DURING THE MRNG
HRS...ARRIVING AT THE CNTRL APLCNS BY MIDDAY. INSTEAD OF CROSSING
THE AREA W/ A TYPICAL COLD AIR SURGE BEHIND IT...THE FRONT WILL
PULL UP AND LARGELY MISS THE CWA TO THE NORTH. THE TAIL END OF THE
BOUNDARY WILL MOVE ACROSS THE AREA...BUT THE STRONG PRE-FRONTAL
LIFT WILL DISSIPATE OVER THE TAIL END - STAYING CLOSER TO THE LOW
THAT WILL BE MOVING NE OVER THE GREAT LAKES REGION.
AREAS OF MODERATE TO LOCALLY HEAVY RAIN HOWEVER WILL MAKE THEIR
WAY OVER THE NRN HALF OF THE AREA...WHILE THE SRN HALF WILL SEE
LESSER AMNTS AS THE BOUNDARY MOVES OVER THE REGION. TEMPS WILL
PEAK JUST AHEAD OF THE BOUNDARY...BUT ONLY DROP A FEW DEGREES FOR
OVERNIGHT LOWS WELL AFTER THE FRONT HAS PASSED.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/...
THE COLD FRONT WILL PASS THROUGH THE REGION MONDAY EVENING. ANY
SHOWERS AHEAD OF THE BOUNDARY MONDAY EVENING WILL DISSIPATE AS THE
FRONT MOVES OFF TO THE EAST. HIGH PRESSURE WILL APPROACH THE AREA
FROM THE TENNESSEE VALLEY OVERNIGHT MONDAY. LIGHT WINDS ALONG WITH
CLEARING SKIES OVERNIGHT MONDAY WILL ALLOW FOR RADIATIONAL COOLING.
HOWEVER...LOW-LEVEL MOISTURE WILL REMAIN HIGH CAUSING SOME FOG TO
DEVELOP.
ANY FOG TUESDAY MORNING WILL BURN OFF BY MID-MORNING AND HIGH
PRESSURE WILL BUILD OVERHEAD CAUSING PLENTY OF SUNSHINE ALONG WITH
MILD CONDITIONS. MAX TEMPS TUESDAY WILL BE IN THE 50S ACROSS MOST
LOCATIONS WITH LOWER 60S POSSIBLE ACROSS CENTRAL VIRGINIA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL REMAIN OVERHEAD THROUGH WEDNESDAY BEFORE MOVING
OFF THE COAST. ANOTHER STORM SYSTEM WILL LIKELY IMPACT THE REGION
LATE IN THE WEEK. THERE APPEARS TO BE ENOUGH WARM AIR WITH THIS
SYSTEM FOR PRECIPITATION TO BE IN THE FORM OF RAIN ACROSS MOST
LOCATIONS. HIGH PRESSURE MAY RETURN FOR NEXT WEEKEND.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
CIGS WEST OF I-95 HAVE SETTLED IN ON CIGS LOWER THAN 1KFT...THOUGH
I-95 AND EAST ARE STILL JUST ABOVE THAT...WILL ALSO DROP GRADUALLY
IN THE NEXT FEW HRS - FREEZING DRIZZLE ALL THE WHILE FOR THE
ENTIRE AREA. ONLY ISOLATED POCKETS ARE MODERATE DRIZZLE...W/ MOST
AREAS RECEIVING LIGHT FZDZ - WILL LINGER OVERNIGHT AND EARLY MONDAY
MORNING. SOME IMPROVEMENT IN CIGS TO MVFR EXPECTED BY TOMORROW
AFTERNOON AS A FRONT MOVES THROUGH THE REGION.
N/NE WINDS AOB 10 KT THIS EVENING WILL SWITCH TO THE NW OVERNIGHT.
SE WINDS EXPECTED ON MONDAY.
A COLD FRONT WILL PASS THROUGH THE TERMINALS MONDAY NIGHT. IFR
CIGS/VSBYS MAY IMPROVE BRIEFLY BEHIND THE FRONT...BUT FOG MAY IMPACT
THE TERMINALS OVERNIGHT MONDAY INTO TUESDAY MORNING.
HIGH PRESSURE WILL BUILD OVER THE TERMINALS LATER TUESDAY INTO
WEDNESDAY WITH VFR CONDITIONS EXPECTED. A STORM SYSTEM WILL LIKELY
IMPACT THE TERMINALS THURSDAY.
&&
.MARINE...
HIGH PRESSURE RIDGE WILL MOVE OFFSHORE LATE TONIGHT AS A COLD FRONT
MOVES INTO THE MID ATLANTIC. LIGHT FREEZING RAIN AND RAIN WILL BREAK
OUT THIS EVENING AND CONTINUE THROUGH MONDAY MORNING. A CHANGE OVER
TO ALL RAIN IS EXPECTED BY EARLY MONDAY MORNING ACROSS THE WATERS.
N/NE FLOW WILL CONTINUE ACROSS THE WATERS THIS AFTERNOON AND
EVENING...BUT SWITCH AROUND TO THE NW AFTER MIDNIGHT. SPEEDS WILL
REMAIN AOB 15 KT. DURING THE AFTERNOON ON MONDAY..FLOW SWITCHES TO
THE SOUTH AHEAD OF A COLD FRONT. SPEEDS REMAIN AOB 15 KT.
A COLD FRONT WILL PASS THROUGH THE WATERS MONDAY NIGHT. SOUTHERLY
WINDS WILL GUST AROUND 20 KNOTS AHEAD OF THE FRONT MONDAY EVENING
ACROSS THE MIDDLE PORTION OF THE BAY AND LOWER TIDAL POTOMAC RIVER.
A SMALL CRAFT ADVISORY IS IN EFFECT FOR THESE AREAS.
HIGH PRESSURE WILL BUILD BUILD TOWARD THE WATERS OVERNIGHT MONDAY
THROUGH TUESDAY. WIND GUSTS SHOULD REMAIN BELOW SCA CRITERIA DUE TO
THE RELATIVELY COOLER WATERS. A STORM SYSTEM WILL LIKELY IMPACT THE
WATERS LATE IN THE WEEK.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZING RAIN ADVISORY UNTIL 6 AM EST MONDAY FOR DCZ001.
MD...FREEZING RAIN ADVISORY UNTIL 9 AM EST MONDAY FOR MDZ003>006-
009-010-501-502.
FREEZING RAIN ADVISORY UNTIL 6 AM EST MONDAY FOR MDZ007-011-
013-014-016-018.
VA...FREEZING RAIN ADVISORY UNTIL 9 AM EST MONDAY FOR VAZ025>031-
040-042-501-503-504.
FREEZING RAIN ADVISORY UNTIL 6 AM EST MONDAY FOR VAZ036>039-
050>057-502.
WV...FREEZING RAIN ADVISORY UNTIL 9 AM EST MONDAY FOR WVZ050>053-
055-501>506.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM MONDAY TO MIDNIGHT EST MONDAY
NIGHT FOR ANZ533-534-537-541>543.
&&
UPDATE...GMS
PREV DISCUSSION...LISTEMAA/BJLHAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 916 PM EST SUN JAN 22 2012 ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057- 231230- 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- 916 PM EST SUN JAN 22 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 LIGHT FREEZING RAIN AND FREEZING DRIZZLE WILL DEVELOP ACROSS MUCH OF THE OUTLOOK AREA LATE TONIGHT AND OVERNIGHT. A WINTER WEATHER ADVISORY IS IN EFFECT FOR MOST LOCALES. SEE WBCWSWLWX FOR FURTHER DETAILS. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY A WINTER WEATHER ADVISORY CONTINUES FOR RUSH HOUR MONDAY MORNING. A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THE LOWER MARYLAND CHESAPEAKE BAY AND TIDAL POTOMAC INLET MONDAY AFTERNOON AND EVENING. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. PLEASE FORWARD ANY ICING REPORTS TO THE NATIONAL WEATHER SERVICE. MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504- WVZ050>053-055-501>506-231230- 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- 916 PM EST SUN JAN 22 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 LIGHT FREEZING RAIN AND FREEZING DRIZZLE WILL DEVELOP ACROSS THE OUTLOOK AREA LATE TONIGHT AND OVERNIGHT. A WINTER WEATHER ADVISORY HAS BEEN ISSUED. SEE WBCWSWLWX FOR FURTHER DETAILS. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY A WINTER WEATHER ADVISORY CONTINUES THROUGH RUSH HOUR MONDAY MORNING. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. PLEASE FORWARD ANY ICING REPORTS TO THE NATIONAL WEATHER SERVICE.
The national radar mosaic for the moment the first event began.
2 dense fog. Local standard time, as filed.
Visibility was estimated to be around one quarter mile across portions of the county.
Visibility was reported to be around one quarter mile at Dulles Airport.
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, January 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: 362217, 362218.