An upper-level low passed through the Mid-Atlantic triggering snow on the 30th. The heaviest snow fell during the late morning and afternoon hours.
Every event with a place to put it; 8 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 upper-level low passed through the Mid-Atlantic triggering snow on the 30th. The heaviest snow fell during the late morning and afternoon hours.
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 29, 10:16 PM EST, 5 hours 44 minutes earlier.
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1016 PM EST FRI JAN 29 2010
.SYNOPSIS...
AN EXTENSIVE LOW PRESSURE SYSTEM OVER MUCH OF THE SOUTHEASTERN
STATES WILL APPROACH THE MID-ATLANTIC OVERNIGHT. THE STORM SYSTEM
WILL MOVE OFF THE CAROLINA COAST ON SATURDAY...WHICH WILL BRING
AREAS OF SNOW ACROSS THE REGION. HIGH PRESSURE WILL BUILD IN
BEHIND THIS SYSTEM ON SUNDAY AND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
OVERNIGHT...OVERCAST SKIES...DROPPING TEMPS /SINCE THE NEAR SFC IS
STILL VERY DRY - W/ DEWPOINTS STILL IN THE SINGLE DIGITS. BEFORE
AREAS OF SNOW ARRIVE FROM THE SW OVER THE MID ATLC BY THE PRE-DAWN
HRS...OVERNIGHT LOWS WILL LIKELY DROP ALL THE WAY INTO THE UPPER
TEENS AND LOW 20S. THE BOUNDARY LAYER MOISTENING UP OVER SRN VA AS
A STEADY STREAM OF THE WAA PRECIP BEGINS TO MIX-OUT THE DRIER AIR.
THIS PROCESS IS STILL A FEW HRS AWAY FROM OCCURRING A BIT FURTHER
N INTO N CNTRL VA/SRN MD.
LITTLE CHANGE TO GRIDS SINCE UPDATE EARLIER THIS EVENING...
UPGRADING WINTER WX PRODUCTS. 00Z NAM CONSISTENT W/ ITS EARLIER
RUN...WHICH KEEP THE SOUTHERN TIER COUNTIES OF THE CWA IN THE
WARNING CRITERIA /ADVISORY FOR THE TIER OF COUNTIES JUST NORTH OF
THERE/. A FEW 00Z NAM STORM-TOTAL QPF VALUES RANGE FROM 0.7 INCHES
FOR CHO - 0.3 FOR DCA - 0.19 FOR BWI - 0.7 FOR NHK - FOR EXAMPLE.
THESE NUMBERS...SLIGHTLY LESS FROM THE 18Z GFS JUST STILL THE SAME
GENERAL RANGE/PLACEMENT.
PREV DISC...
18Z GUIDANCE PULLING A BIT FURTHER NORTH /A BIT MEANING AT LEAST
A COUPLE OF COUNTIES NORTH-TO-SOUTH/ FOR ADVISORY LEVEL SNOWFALL
AND WARNING ACROSS THE SRN-MOST COUNTIES OF THE CWA. THE MAIN
SWATCH OF TOTAL ACCUMULATION LOOKS TO BE FROM THE VA/NC
BORDER...TAPERING OFF CLOSER TO THE I-66 CORRIDOR.
WITH THE TIMING PUSHED BACK INTO THE FUTURE A FEW HRS...START
TIMES FOR ACCUMULATING SNOW EXPECTED FROM NEAR SUNRISE /ACROSS
THE SRN PORTION OF THE CWA/ AND MID-MORNING INTO THE DC METRO
AREA. THE HEAVIEST BANDS WILL BEGIN TO PUSH NWD INTO CNTRL AND
NRN VA-SRN MD DURING THE EARLY AFTN HRS...LINGERING INTO THE
EARLY EVENING HRS. AT THIS TIME...A COASTAL LOW OFF THE CAROLINA
COASTLINE WILL BE STRENGTHENING AND THE SYSTEM WILL BRIEFLY PIVOT
MORE NEWD. THE WRAP-AROUND SNOW BANDS WILL ALSO PIVOT MORE
SW-TO-NE AS THEY MOVE ACROSS THE I-95 CORRIDOR AND OVER DELMARVA.
THE AFTERNOON PERIOD WILL ALSO BE THE TIME WHERE THE BEST
COMBINATION OF LIFT AND LOW LEVEL MOISTURE INFLUX WILL PUSH AS FAR
AS N CNTRL VA/SRN MD.
BY EARLY EVENING...THE LOW WILL BE DRIFTING FURTHER OFF THE
COAST...TAKING THE PRECIP W/ IT AND ENDING MUCH OF THE SNOWFALL
OVER THE MID ATLC BY LATE EVENING. FOR MORE DETAILS ON
ACCUMULATIONS/LOCATIONS...SEE WBCWSWLWX.
&&
.SHORT TERM /SATURDAY NIGHT/...
THE MID-LEVEL TROUGH AXIS THAT WILL BE ASSOCIATED WITH THIS LOW
PRESSURE SYSTEM WILL PASS THROUGH OUR CENTRAL AND SOUTHERN AREAS
SATURDAY EVENING AS THE SURFACE LOW MOVES OUT TO SEA. HIGH PRESSURE
WILL BUILD TOWARD THE AREA OVERNIGHT. SNOW WILL CONTINUE AHEAD OF
THE TROUGH AXIS ACROSS THE CENTRAL AND SOUTHERN AREAS...MAINLY
DURING THE EVENING HOURS BEFORE TAPERING OFF OVERNIGHT AS HIGH
PRESSURE BUILDS CLOSER.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
SURFACE HIGH WILL CONTINUE TO BUILD OVER THE REGION SUNDAY AND
MONDAY...BRINGING DRY AND SEASONABLY CHILLY CONDITIONS. AN
UPPER-LEVEL DISTURBANCE WILL PASS THROUGH TUESDAY NIGHT INTO
WEDNESDAY...BUT LITTLE MOISTURE WILL BE ASSOCIATED WITH IT. MOST
PRECIPITATION SHOULD BE CONFINED TO THE POTOMAC HIGHLANDS. HIGH
PRESSURE BEHIND THIS SYSTEM WILL BUILD OVERHEAD FOR THE MIDDLE OF
THE WEEK. ANOTHER AREA OF LOW PRESSURE MAY IMPACT THE REGION LATE IN
THE WEEK.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS CONDITIONS WILL CONTINUE THROUGH THE EVENING.
SNOWFALL WILL BEGIN TO REDUCE CIGS/VSBYS AT KCHO AFTER MIDNIGHT
TONIGHT. SNOWFALL IS EXPECTED TO BE LIGHTER ACROSS THE NORTHERN
TERMINAL SITES...WITH KMRB/KBWI HAVING THE LEAST CIG/VSBY
RESTRICTIONS.
WINDS WILL REMAIN NORTH OR NORTHEAST OVERNIGHT WITH SUSTAINED SPEEDS
AROUND 10 KT. WINDS MAY BECOME GUSTIER IN THE AFTERNOON AS LOW
PRESSURE BEGINS EMERGE OFF THE SE COAST.
SUBVFR CIGS/VSBYS ALONG WITH LIGHT SNOW SATURDAY EVENING ACROSS KCHO
AND POSSIBLY KIAD/KDCA WILL GIVE WAY TO VFR CONDITIONS AS HIGH
PRESSURE BUILDS IN FROM THE WEST.
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS SUNDAY THROUGH EARLY
NEXT WEEK...BRINGING VFR CONDITIONS. AN UPPER-LEVEL DISTURBANCE WILL
PASS THROUGH TUESDAY NIGHT INTO WEDNESDAY...BUT LITTLE MOISTURE WILL
BE ASSOCIATED WITH IT.
&&
.MARINE...
WINDS WILL REMAIN OUT OF THE NORTH/NORTHEAST THROUGH TONIGHT WITH
SUSTAINED SPEEDS BETWEEN 10 AND 15 KT. SMALL CRAFT ADV HAS BEEN
RAISED FOR A COUPLE OF ZONES N OF THE PREV ADV...NOW TO S OF
POOLES IS /NOT INCLUDING THE SURR RIVERS/...STARTING EARLIER...4
AM. SC CONDITIONS EXPECTED ACROSS THE CENTRAL BAY AND LOWER TIDAL
POTOMAC AS LOW PRESSURE EMERGES OFF THE SE COAST SATURDAY
AFTERNOON.
LOW PRESSURE WILL GRADUALLY MOVE OUT TO SEA SATURDAY NIGHT WHILE
HIGH PRESSURE APPROACHES FROM THE WEST. THE GRADIENT BETWEEN THESE
TWO SYSTEMS WILL BRING SCA WINDS TO THE LOWER TIDAL POTOMAC AND
MIDDLE PORTION OF THE CHESAPEAKE BAY. WILL CONTINUE WITH AN SCA
FOR SATURDAY NIGHT ACROSS THESE AREAS. WIND GUSTS MAY APPROACH SCA
CRITERIA ACROSS THE NORTHERN BAY...BUT HAVE LEFT GUSTS CAPPED AT
15 KNOTS GIVEN THE LIGHTER GRADIENT.
SCA WINDS MAY CONTINUE INTO SUNDAY MORNING ACROSS THE LOWER TIDAL
POTOMAC AND MIDDLE PORTION OF THE BAY...BUT HIGH PRESSURE WILL BUILD
OVERHEAD LATER SUNDAY THROUGH EARLY NEXT WEEK.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER WEATHER ADVISORY FROM 7 AM SATURDAY TO 4 AM EST SUNDAY
FOR DCZ001.
MD...WINTER WEATHER ADVISORY FROM 7 AM SATURDAY TO 4 AM EST SUNDAY
FOR MDZ013-014.
WINTER STORM WARNING FROM 7 AM SATURDAY TO 4 AM EST SUNDAY FOR
MDZ016>018.
VA...WINTER WEATHER ADVISORY FROM 7 AM SATURDAY TO 4 AM EST SUNDAY
FOR VAZ039-040-051>054-501-502.
WINTER WEATHER ADVISORY FROM 4 AM TO 11 PM EST SATURDAY FOR
VAZ021-026-029-038.
WINTER STORM WARNING FROM 4 AM TO 11 PM EST SATURDAY FOR
VAZ025-036-037.
WINTER STORM WARNING FROM 7 AM SATURDAY TO 4 AM EST SUNDAY FOR
VAZ050-055>057.
WV...WINTER WEATHER ADVISORY FROM 4 AM TO 11 PM EST SATURDAY FOR
WVZ054.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM SATURDAY TO 6 AM EST SUNDAY FOR
ANZ531>534-537-540>543.
&&
UPDATE...GMS
PREV DISCUSSION...LISTEMAA/BJL<!doctype html>
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</html>The national radar mosaic for the moment the first event began.
6 winter weather, 3 winter storm. Local standard time, as filed.
A snowfall report of 10.5 inches was received from Circleville and 6.0 inches was received from near Brandywine.
Snowfall amounts were estimated around four inches across the central and eastern portions of the county.
Snowfall amounts averaged between four and five inches across the county.
Snowfall totaled up to 6.0 inches near Harpers Ferry and 5.8 inches near Shenandoah Junction.
Snowfall amounts around five inches were received across the western portion of Grant County.
Snowfall totaled up to 3.0 inches in Smith Crossroads.
Snowfall amounts averaged around four inches across the county.
A snowfall report of 4.2 inches was received from Keyser.
Snowfall amounts were estimated around four inches across the western part of the county.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in West Virginia in 2010Every state in 2010This day in weather historyWarnings in West Virginia, January 2010
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 2026-10-01. Each event’s entry at NCEI: 209652, 209663, 209664, 209653, 209654, 209659, 209660, 209661, 209662.