The combination of cold air over the relatively moist Great Lakes triggered snow showers for locations along and west of the Allegheny front during the evening hours of the 6th through the morning hours of the 7th.
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.
The combination of cold air over the relatively moist Great Lakes triggered snow showers for locations along and west of the Allegheny front during the evening hours of the 6th through the morning hours of the 7th.
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 6, 8:00 PM EST, 0 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
800 PM EST THU JAN 6 2011
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE MID-ATLANTIC REGION LATE
TONIGHT AND EARLY FRIDAY. A SECOND COLD FRONT WILL MOVE EAST
ACROSS THE REGION ON SATURDAY BEFORE HIGH PRESSURE RETURNS
SATURDAY NIGHT. HIGH PRESSURE WILL PERSIST THROUGH MONDAY NIGHT.
LOW PRESSURE IS EXPECTED TO APPROACH THE MID-ATLANTIC STATES
TUESDAY.
&&
.NEAR TERM /TONIGHT/...
SHRTWV TROF NOTED IN SATELLITE IMAGERY OVER OH ATTM...MAKING SLOW
EWD PROGRESS. THIS FEATURE IS RESPONSIBLE FOR ONGOING LGT SNOW
ACRS WV AND WRN PA.
LOW LVLS ACRS FCST AREA ARE CHARACTERIZED ATTM BY DRY AMS AND
TEMPS GENLY NR FRZG. INCRG CLD CVR AOA 5.0 KFT SPREADING EWD THIS
EVE WILL SLOW RADIATIONAL COOLING. THUS...TEMPS ARE LKLY TO HOVER
IN LWR 30S AND UPR 20S THRU MUCH OF TNGT. XCPTN WILL BE ERN ZONES
WHERE CLD CVR HAS BEEN SLOWER TO ARRIVE.
CURRENT FCST SPREADS AREA OF SNOW EWD WITH SHRTWV TROF THIS EVE AS
CDFNT MOVES E INTO WRN PA. POPS WERE INCRD ACRS FAR NWRN ZONES
THIS EVE. MODELS ARE CONSISTENT...HOWEVER...IN SUGGESTING THAT
PCPN WILL ERODE AS IT SPREADS E OF MTNS.
MODELS ALSO ARE DEPICTING STG COLD AIR ADVCTN IN MID LVLS...
GENERATING ELEVATED INSTBY SUFFICIENT TO SUSTAIN CLD CVR AND
GENERATE SNOW SHWRS LATE TNGT. THUS...DESPITE LACK OF QPF IN
MODELS...OCSNL SNOW SHWRS LKLY WILL DVLP ALONG AND E OF BLUE RDG
OVNGT...IMPACTING SPCLY NERN ONE-THIRD OF FCST AREA.
PCPN WINDOW WILL BE BRIEF...GENLY 4-5 HR PDS BTWN 07/06Z AND
07/13Z BFR BROADER SYNOPTIC UPWD MOTION DECRS. PCPN AT ONSET WILL
BE SPENT SATURATING THE LOW LVLS AND MAY NOT REACH THE GROUND.
THUS...ANY SNOW ACCUMULATION /IF ANY/ WILL BE LMTD TO A PD OF A
FEW HRS LATE TNGT. ADZY THRESHOLDS NOT XPCD TO BE MET ATTM...
ALTHOUGH BEST CHC FOR A RUSH HOUR ADZY WILL BE ACRS NERN MD.
ACCUMULATING SNOW WILL OCCUR ALONG WRN SLOPES OF ALLEGHENY FRONT
AS INSTBY IS GENERATED AND LOCALIZED CNVCTV SNOW ELEMENTS ENSUE.
ADZY RMNS INTACT...ALTHOUGH SNOW TOTALS MORE LKLY WILL WIND UP ON
THE LOW END OF RNG. SNOW CVRG WILL BCM LESS WITH TIME AS MODE
EVOLVES TO SHWRS.
&&
.SHORT TERM /FRIDAY/...
ANY SNOW SHWRS E OF MTNS ONGOING AT START OF PD WILL BE EXITING
QUICKLY NEWD. LOW POPS WERE RETAINED ACRS NERN ZONES THRU LATE
MRNG. DOWNSLP FLOW E OF MTNS WILL LMT ANY ADDITIONAL PCPN DVLPMT
DURG FRI.
WINDS XPCD TO BCM NWLY IN WAKE OF CDFNT PASSAGE FRI MRNG. COLD AIR
ADVCTN WILL SUSTAIN STRATOCU ACRS ENTIRE FCST AREA. ASSOCIATED
INSTBY WILL SUPPORT UPSLP SNOW SHWRS ALONG WRN SLOPES THRU MID-DAY
FRI. ADZY END TIME LOOKS FINE ATTM.
FCST MAXIMA ARE A FEW DEG F BLW GUIDANCE OWING TO XPCD CLD CVR.
MAXIMA XPCD GENLY IN UPR 20S W TO MID 30S E.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
IN LOOKING THROUGH THE UPPER MDL DEPICTION OF THE WK AHD THE WORD
THAT COMES TO MIND IS "CHAOTIC." AND WHEN THERE IS MUCH CHAOS IN THE
WINTER ATMOSPHERE THE THREAT OF A LARGE SNOW EVENT E OF THE MTNS IS
GRTLY DIMINISHED.
ON THE STLT...W.V. IMGRY SHOWS AN AREA OF ENHANCED MOISTURE OVR SRN
ALBERTA DROPPING INTO ERN MT/WRN ND. GIVEN THE LARGE UPR VORTEX
SWIRLING ARND THE UPR GRT LAKES AND A 140 KT JET (!) THIS STREAK WL
BE TRACKING RAPIDLY SE INTO THE CAROLINAS. WE HV LOW CHC POPS
ESSENTIALLY N OF THE PTMC FOR SAT MRNG. I'M UNSURE IF THAT'S THE
PROPER AREA TO HV SNOW CHCS...PERHAPS ACROSS THE CENTRAL SHEN VLLY
WOULD BE BETTER? PERHAPS PUSH IT UP TO FRI NGT...OR EVEN REMOVE THE
CHCS ALTOGETHER? WE'VE DONE STUDIES ON OUR/MDL PERFORMANCE FOR POP
FCSTG IN THE WINTER MONTHS...AND THE RULE IS TO SUBTRACT 10% FM WHAT
MDLS ARE FCSTG 24-48 HRS OUT. BEST MDL POPS ARE 40 ON SAT IN THE
I-81 CORRIDOR. I'VE ADDED SLT CHC TO THAT AREA FOR SAT MRNG IN
ADDITION TO THOSE N OF THE PTMC..BUT CONFIDENCE ISN'T TERRIBLY HIGH.
NO DOUBT CHGS FOR THE SAT FCST WL BE OCCURING.
UPSLOPE SNSH PSBL ALONG THE WRN SLOPES OF THE HIGHLANDS FRI NGT INTO
SUNDAY AND THEN AGAIN WED AND THU.
ENTERING 2ND WK OF JAN - TEMP WISE WE ARE ENTERING THE
CLIMATOLOGICALLY COLDEST PD OF THE YR W/ HIGHS IN THE L40S AND LOWS
IN LM20S. WE'VE BEEN BLO NRML FOR THE PAST SVRL WKS...AND NO REAL
WARM UP IS FORESEEN IN THE WK AHD. HIGHS IN THE 30S...LOWS IN THE
20S.
HIGH PRES OVR THE AREA SAT NGT THRU MON NGT.
WE'RE ALREADY RCVG CALLS ABT THE PTNL FOR THE TUE STORM. LOW PRES
LOOKS TO DVLP ALONG THE TX CST SUN...TRACKING ALONG THE GULF CST MON
AND THEN REAPPEARING OFF THE SC CST MON NGT. AT THIS TIME THERE IS
NOTHING TO INDICATE THAT THIS WOULD TRACK UP THE CST. THE UPR LVL
FLOW IS SUCH THAT IT WOULD BE CARRIED OUT TO SEA. I'M NOT A BIG FAN
OF ANALOGUES - EVERY SITUATION IS DIFFERENT...BUT THIS PATTERN DOES
BEAR SOME SIMILARITIES TO THE MINOR STORM OF DEC 16...WHERE THE BULK
OF THE SNOW STAYED TO THE S OF THE CWA. HIGHEST TOTALS IN THE CWA
THAT DAY WERE 3-4" IN NELSON...DC RCVD 1.5"...MD 1-2". SO DEPENDING
ON HOW THINGS DVLP AN ADVSRY MAY BE NEEDED NEXT MON. STAY TUNED.
HIGH PRES PROGGED TO RETURN FOR THE 2ND HALF OF NEXT WK.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
MID-LVL CLDS WILL INCR AT ALL TERMINALS THIS EVE AS SHRTWV TROF
APRCHS FROM W. LGT WINDS XPCD THIS EVE AS SFC TROF SHARPENS...BCMG
SLY LATE TNGT.
COLD AIR ADVCTN IN THE MID LVLS WILL YIELD ELEVATED INSTBY CAPABLE
OF SUSTAINING BKN DECK 3.5-4.0 KFT AND SNOW SHWRS. MOST LKLY WINDOW
FOR SNOW SHWRS WILL BE 3-5 HR PD BTWN 07/06Z - 07/13Z AT ALL
TERMINALS BUT KCHO. BEST CHC FOR LGT ACCUMULATION WILL BE
KBWI/KMTN LATE TNGT AND EARLY FRI MRNG.
SHRTWV TROF LIFTS ACRS PA FRI MRNG AND WILL BRING AN END TO ANY
PCPN. CONTD COLD AIR ADVCTN WILL MAINTAIN STRATOCU 3.5-4.5 KFT
THRU FRI AFTN IN WAKE OF CDFNT. GUSTY NWLY WINDS XPCD FRI AFTN.
VFR CONDS XPCTD DURG THE MAJORITY OF THE XTND PD. MOST LKLY PD WHERE
SUB VFR CIGS/VSBY WOULD BE PSBL WOULD BE FRI NGT/ERLY SAT WHEN LGT
SNOW WL BE PSBL.
&&
.MARINE...
NO CHGS XPCD IN MRN FCST. SMALL CRAFT ADZY RMNS IN EFFECT TNGT AS
SLY WINDS INCR SLGTLY AHEAD OF SHARPENING SFC TROF. WINDS WILL
DECR EARLY FRI MRNG AS TROF AXIS MOVES ACRS WATERS.
CDFNT WILL CROSS WATERS FRI MRNG. NWLY WINDS WILL GUST TO 20 KT
FOR MUCH OF FRI AS COLD AIR ADVCTN ENSUES IN WAKE OF BNDRY. SMALL
CRAFT ADZY CONTS THRU FRI.
WINDS XPCTD TO BE BLO SML CRFT ADVSRY LVLS FRI NGT...THEN INCRSG ON
SAT AS HIGH PRES BUILDS BACK INTO THE WATERS. SCA LKLY ON SAT INTO MON.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WINTER WEATHER ADVISORY UNTIL 1 PM EST FRIDAY FOR MDZ501.
VA...WINTER WEATHER ADVISORY UNTIL 1 PM EST FRIDAY FOR VAZ503.
WV...WINTER WEATHER ADVISORY UNTIL 1 PM EST FRIDAY FOR WVZ501-503-
505.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 7 PM EST
FRIDAY FOR ANZ531>534-537-539>541-543.
SMALL CRAFT ADVISORY FROM 10 AM TO 7 PM EST FRIDAY FOR ANZ530-
535-536-538-542.
&&
UPDATE...KRAMAR
PREV DISCUSSION...WOODY!HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 623 PM EST THU JAN 6 2011 ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057- 070930- 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- 623 PM EST THU JAN 6 2011 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 SNOW WILL BE POSSIBLE LATE TONIGHT...WHICH MAY IMPACT THE MORNING COMMUTE IN THE WASHINGTON DC AND BALTIMORE METROPOLITAN AREAS. A SMALL CRAFT ADVISORY IS IN EFFECT LATE TONIGHT FOR THE MARYLAND CHESAPEAKE BAY SOUTH OF POOLES ISLAND AND FOR THE TIDAL POTOMAC RIVER FROM COBB ISLAND TO SMITH POINT. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY LIGHT SNOW WILL BE POSSIBLE EARLY FRIDAY MORNING...WHICH MAY IMPACT THE MORNING COMMUTE IN THE WASHINGTON DC AND BALTIMORE METROPOLITAN AREAS. LOW PRESSURE WILL PERSIST ACROSS THE NORTHEASTERN UNITED STATES THROUGH THE WEEKEND AND WILL SUPPORT CHANCES FOR LIGHT SNOW FRIDAY NIGHT AND SATURDAY. CHANCES FOR LIGHT ACCUMULATIONS OF SNOW INCREASE AGAIN TUESDAY AND TUESDAY NIGHT. A SMALL CRAFT ADVISORY IS IN EFFECT FRIDAY FOR THE TIDAL POTOMAC RIVER AND THE MARYLAND CHESAPEAKE BAY. A SMALL CRAFT ADVISORY LIKELY WILL BE NEEDED SATURDAY THROUGH MONDAY FOR PORTIONS OF THE WATERS. A GALE WARNING MAY BE NEEDED SUNDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED THROUGH TONIGHT. PLEASE RELAY ANY REPORTS OF SNOW TO THE NATIONAL WEATHER SERVICE. MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504- WVZ050>053-055-501>506-070930- 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- 623 PM EST THU JAN 6 2011 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 A WINTER WEATHER ADVISORY FOR SNOW IS IN EFFECT TONIGHT FOR WEST- FACING SLOPES ALONG THE ALLEGHENY FRONT. PLEASE REFER TO THE LATEST HAZARD MESSAGE /WSWLWX/ FOR DETAILS. LIGHT SNOW WILL BE POSSIBLE LATE TONIGHT...WHICH MAY IMPACT THE MORNING COMMUTE IN THE WASHINGTON DC AND BALTIMORE METROPOLITAN AREAS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY LIGHT SNOW WILL BE POSSIBLE EARLY FRIDAY MORNING...WHICH MAY IMPACT THE MORNING COMMUTE IN THE WASHINGTON DC AND BALTIMORE METROPOLITAN AREAS. A WINTER WEATHER ADVISORY FOR SNOW REMAINS IN EFFECT UNTIL FRIDAY AFTERNOON FOR WEST-FACING SLOPES ALONG THE ALLEGHENY FRONT. UPSLOPE SNOW SHOWERS WILL INTENSIFY FRIDAY NIGHT AND SATURDAY AND MAY RESULT IN ADDITIONAL ACCUMULATION ON WEST-FACING SLOPES ALONG THE ALLEGHENY FRONT. LOW PRESSURE WILL PERSIST ACROSS THE NORTHEASTERN UNITED STATES THROUGH THE WEEKEND AND WILL SUPPORT CHANCES FOR LIGHT SNOW FRIDAY NIGHT AND SATURDAY. CHANCES FOR LIGHT ACCUMULATIONS OF SNOW INCREASE AGAIN TUESDAY AND TUESDAY NIGHT. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED THROUGH TONIGHT. PLEASE RELAY ANY REPORTS OF SNOW TO THE NATIONAL WEATHER SERVICE. KRAMAR
The national radar mosaic for the moment the first event began.
1 winter weather. Local standard time, as filed.
Snowfall was estimated to be over two inches across western Highland County.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Virginia in 2011Every state in 2011This day in weather historyWarnings in Virginia, January 2011
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: 278046.