Prior to a cold frontal passage, the Mid Atlantic region, east of the Blue Ridge Mountains, experienced calm winds and clear skies which led to radiation fog to form. There were some areas that did not experience the fog due to a light wind at the surface.
Every event with a place to put it; 4 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.
Prior to a cold frontal passage, the Mid Atlantic region, east of the Blue Ridge Mountains, experienced calm winds and clear skies which led to radiation fog to form. There were some areas that did not experience the fog due to a light wind at the surface.
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 Mar 31, 8:04 PM EST, 4 hours 51 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
904 PM EDT SUN MAR 31 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL PUSH THROUGH THE AREA OVERNIGHT. A
REINFORCING COLD FRONT WILL MOVE THROUGH MONDAY AFTERNOON.
CANADIAN HIGH PRESSURE WILL THEN BUILD THROUGH WEDNESDAY
NIGHT...BEFORE A COASTAL LOW PRESSURE SYSTEM BRINGS THE POTENTIAL
FOR RAIN AND GUSTY WINDS OVER THE MIDDLE ATLANTIC LATE THURSDAY
INTO FRIDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
WATER VAPOR LOOP SHOWING DRIER AIR PUNCHING IN FROM THE MID LEVELS
WITH WEAK COLD FRONT PUSHING EAST ACROSS THE FORECAST AREA. A FEW
SPRINKLES WILL BE POSSIBLE ALONG THE BOUNDARY IN THE NEXT HOUR. LOW
CLOUDS AND PATCHY FOG WILL CONTINUE OVER THE NEXT FEW HOURS BEFORE
DRIER AIR SCOURS IT OUT EAST OF THE BLUE RIDGE AFTER MIDNIGHT.
DONT THINK FOG WILL REDEVELOP ATTM BUT WILL MONITOR CLOSELY.
POTOMAC HIGHLANDS WILL STAY IN THE CLOUDS LONGER WITH SOME UPSLOPE
LIGHT SHOWERS STILL POSSIBLE OVERNIGHT. LOWS IN THE MID 40S
EAST...UPPER 30S TO LOWER 40S WEST.
MONDAY...A MORE SIGNIFICANT TEMPERATURE FRONT WILL MOVE THROUGH
IN THE EARLY AFTERNOON. THAT WILL LIKELY KICK OFF A FEW WIDELY
SCATTERED SHOWERS. ON THE WINDWARD SIDE OF THE MOUNTAINS OUT IN
OUR WEST...SNOW SHOWERS WITH SOME MINOR ACCUMS POSSIBLE WITH 850MB
TEMPS FALLING BELOW ZERO AROUND NOON. ACCUMULATIONS...IF ANY WILL
BE HELD TO THE HIGHEST ELEVATIONS. ALL PRECIPITATION CHANCES WILL
END BETWEEN 00Z-06Z TUESDAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY/...
MONDAY NIGHT...NWLY FLOW MIXES DOWN THROUGH THE NIGHT IN CAA BEHIND
THE COLD FRONT...GUST POTENTIAL 25 TO 30 MPH. CLEARING SKIES IN
SUBSIDENCE. SUBFREEZING MIN TEMPS INLAND LOCALES ONLY...WITH TEENS
IN THE POTOMAC HIGHLANDS...OTW UPR 20S TO LOW 30S...URBAN/NEARSHORE
MID TO UPR 30S. IF THERE IS ANY UPSLOPE SNOW IT WILL BE LIGHT AND
ENDING AROUND MIDNIGHT.
TUESDAY...WEAK UPR TROUGH AXIS FROM UPR LOW OVER THE ST LAWRENCE
VALLEY SHOULD BRING SOME MID-LEVEL CLOUDS...PARTICULARLY NW OF
BALT-WASH. OTW...NWLY FLOW GUSTS 30 TO 35 MPH. 850MB TEMPS -6 TO -8C
SHOULD RESULT IN MAX TEMPS IN THE MID TO UPR 40S NORTH AND LOW TO
MID 50S SOUTH /THE FARTHER SOUTH FROM THE MASON-DIXON THE MORE
DOWNSLOPING COMPRESSION HEATING OCCURS/. THIS IS 15 DEGREES OR SO
BELOW NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
CANADIAN HIGH PRESSURE CONTINUES TO BUILD THROUGH WEDNESDAY NIGHT
BEFORE MOVING OFFSHORE THURSDAY. AIRMASS MODIFIES IN THE EARLY
APRIL SUN WITH A SLOW WARMING TREND TO MAX TEMPS WED/THUR.
NEXT WEATHER MAKER IS A CUT OFF UPPER LOW REACHING THE DEEP SOUTH
THURSDAY NIGHT...WITH A COASTAL SFC LOW PUSHING UP THE CAROLINA
COAST FRIDAY. RAIN SHOULD OVERSPREAD AT LEAST THE SRN/ERN HALF OF THE
LWX CWA LATE THURSDAY NIGHT THROUGH FRIDAY. BUMPED UP POPS TO LIKELY
SOUTH OF A LINE FROM KEZF TO KCHO WITH STRONG WLY COMPONENT TO THE
WIND AND DECENT GULF STREAM MOISTURE. P-TYPE LOOKS TO BE ALL RAIN
OUTSIDE OF A CHANCE FOR SOME SLEET MIXING IN FOR THE HIGHEST
ELEVATIONS OF THE POTOMAC HIGHLANDS.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
IFR CONDITIONS WILL BE THE BATTLE THRU TONIGHT WITH LOW CIGS
AND FOG. LOW CLOUDS AND FOG WILL MIX OUT LATER TONIGHT...BUT THEN
THERE WILL BE THE POTENTIAL FOR WIDELY SCATTERED SHOWERS MON
AFTERNOON AND A WIND SHIFT TO THE NORTHWEST.
VFR AND NWLY FLOW MONDAY INTO THURSDAY AS HIGH PRESSURE BUILDS
ACROSS THE REGION. GUST POTENTIAL 25 KT MON NIGHT THEN 30 KT FOR
TUESDAY. NEXT RAIN EVENT ON FRIDAY WITH A COASTAL LOW CROSSING THE
REGION.
&&
.MARINE...
WINDS BENEATH THE INVERSION WILL REMAIN BELOW SCA LEVELS TONIGHT
INTO EARLY MONDAY.
MAINLY DRY COLD FROPA MONDAY EVENING. NWLY FLOW POST-FROPA MONDAY
NIGHT INTO THURSDAY. SCA IN EFFECT FOR MONDAY NIGHT...LIKELY NEEDED
TO BE EXTENDED THROUGH WEDNESDAY...WITH SOME TRIBUTARIES DROPPING
OFF FOR TUESDAY NIGHT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM MONDAY TO 6 AM EDT TUESDAY FOR
ANZ530>543.
&&
SYNOPSIS...BAJ
NEAR TERM...KRW
SHORT TERM...BAJ/CAS
LONG TERM...BAJ
AVIATION...BAJ/KRW
MARINE...BAJ/KRW<!doctype html>
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</html>The national radar mosaic for the moment the first event began.
4 dense fog. Local standard time, as filed.
Visibilities of a quarter mile were measured at Stafford Airport and by satellite.
Visibilities of a quarter mile were measured at Fredericksburg Airport and by satellite.
Visibilities of a quarter mile were estimated at Fort Belvior.
Visibilities of a quarter mile were estimated at Fredericksburg Airport and by satellite.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Virginia in 2013Every state in 2013This day in weather historyWarnings in Virginia, April 2013
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 2026-09-30. Each event’s entry at NCEI: 447368, 447369, 447372, 447370.