A low pressure system moving across the Mid Atlantic brought a mixture of rain and freezing rain to portions of northern and western Maryland. Sub-freezing temperatures at the surface combined with a layer of warmer air aloft caused rain to change over to freezing rain.
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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.
A low pressure system moving across the Mid Atlantic brought a mixture of rain and freezing rain to portions of northern and western Maryland. Sub-freezing temperatures at the surface combined with a layer of warmer air aloft caused rain to change over to freezing rain. Ice accumulations between one quarter and one half inch were reported in western Allegany County, with lesser amounts further east.
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 Dec 12, 9:32 PM EST, 5 hours 28 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
932 PM EST WED DEC 12 2007
.SYNOPSIS...
LOW PRESSURE WILL MOVE FROM THE LOWER MISSISSIPPI VALLEY TO THE MID
OHIO VALLEY OVERNIGHT...AND TO THE EAST THURSDAY. HIGH PRESSURE
WILL BUILD OVER THE REGION FRIDAY. A SIGNIFICANT WINTER STORM MAY
DEVELOP DURING THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
...MORNING RUSH HOUR WILL BE IMPACTED BY ICY WINTER WEATHER NORTH OF
WINCHESTER/DC/BALTIMORE...
WATER VAPOR LOOP SHOWS A RIDGE OVER THE SOUTHEAST CONUS...WITH A
PLAINS TROUGH BEING PICKED UP BY THE NORTHERN STREAM SHEAR AXIS
WHICH EXTENDS NORTHEAST THROUGH THE LOWER GREAT LAKES AND NEW
ENGLAND. ACARS 400-250MB WIND OBSERVATIONS SHOW A 130-165KT WESTERLY
JET FROM THE GREAT LAKES THROUGH NEW ENGLAND. 20Z SURFACE ANALYSIS
PLACED A COLD FRONT WEST ACROSS CENTRAL VIRGINIA...WHICH BECAME
STATIONARY AS IT EXTENDED SOUTHWEST THROUGH THE TENNESSEE VALLEY
AND WESTERN GULF STATES. A 1029MB ANTICYCLONE WAS LOCATED NORTH OF
CHICAGO.
EXPERIENCE HAS TAUGHT THAT IT IS TOUGH TO GET A FREEZING RAIN EVENT
THE NIGHT AFTER DAYTIME HIGHS IN THE 50S. THIS TIME HOWEVER THERE IS
SOME COLD ADVECTION BEHIND THE COLD FRONT...AND DEWPOINT DEPRESSIONS
ARE GROWING. CLEAR SKIES RESIDE ALONG THE PENNSYLVANIA BORDER. HAVE
HOWEVER CROPPED THE SOUTHERN TIER OF THE WINTER WEATHER ADVISORY
GIVEN CURRENT TEMPERATURES AND DEWPOINTS. IN THE ADVISORY
AREA...MOST CONCERNED NEAR THE CBE/HGR AREA WHICH COULD NEAR A
QUARTER INCH OF ICE BASED ON FORECAST SOUNDINGS.
AS FOR MODEL GUIDANCE...AM FOLLOWING GFS AND LWX WRF-NMM (WITH GFS
BOUNDARY CONDITIONS) TRENDS. ALTHOUGH PRECIPITATION TIMING COULD BE
LATER AS FAR EAST AS BALTIMORE...DID NOT WANT TO GET TOO CUTE WITH
THE BEGINNING TIME OF THE ADVISORY. FORECAST SOUNDINGS ARE QUITE
WARM ALOFT...WHICH SUPPORTS FREEZING RAIN AS THE PREDOMINATE
PRECIPITATION TYPE. SLEET IS POSSIBLE AT THE ONSET WITH
EVAPORATIONAL COOLING. ARTICULATED THESE THOUGHTS IN THE TEXT OF THE
ADVISORY.
HAVE BEEN COLLABORATING WITH PBZ/CTP/HPC ABOUT PRECIPITATION ACROSS
FAR WESTERN MINERAL AND ALLEGANY COUNTIES. GIVEN QPF AND SOUNDING
PROFILES FROM GFS/LWX WRF-NMM...HAVE UPGRADED TO A ICE STORM
WARNING. TEMPERATURES ARE CURRENTLY FREEZING IN THE HIGHER TERRAIN.
WHILE TEMPERATURES WILL RISE AT SOME POINT DURING THE EVENT...TOO
MUCH OBSERVATIONAL AND MODEL DATA TO IGNORE THE ICING POTENTIAL AT
THIS TIME. BASED ON FORECAST PROFILES...COLD AIR IS SHALLOW AND
SUPPORT FREEZING RAIN INSTEAD OF SLEET.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
WINTER WEATHER EVENT WILL BE ONGOING AND LAST INTO THE AFTERNOON
NEAR THE PENNSYLVNIA BORDER. KEPT COOLER THAN GUIDANCE
TEMPERATURES WITH EXTENT OF CLOUD COVER AND SHALLOW COLD AIR
COMING INTO PLACE.
BASED ON LWX WRF-NMM/GFS TRENDS...CUT POPS BACK IN SOUTHEAST
FORECAST AERA. THINK THERE WILL BE A BREAK BETWEEN EARLY MORNING
WARM ADVECTION AND MID AFTERNOON SHORT WAVE PASSAGE IN THESE PARTS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THE LOW PRESSURE SYSTEM WILL MAKE A QUICK EXIT OVERNIGHT THURS. THE
FEW LINGERING AREAS OF FRONTAL PRECIP WILL BE EXITING OFF THE COAST
EARLY FRI...W/ SOME AREAS OF WEAK UPSLOPE/LAKE EFFECT SNOW SHOWERS
STREAMING INTO THE ALLEGANY FRONT AND POTOMAC HIGHLANDS THRU THE
MORNG HRS ON FRI. A WEAK SFC LOW WILL MOVE ACROSS SRN QUEBEC W/
LITTLE MORE THAN GUSTY WINDS AND ANOTHER SHOT OF COLD AIR FILTERING
DOWN THE ERN GREAT LAKES REGION LATE FRI.
WILL WATCH THE CAD SET FROM THIS POINT...WITH AN ARCTIC +1030MB HIGH
BUILDING OVER SRN QUEBEC/ONTARIO SLIDING EAST DURING THE DAY ON SAT.
A FEW HRS OF DECENT EASTERLIES MAY SET UP ACROSS THE MID ATLANTIC
SEABOARD THAT WOULD REINFORCE THE INSITU COLD AIR W/ HIGHS IN THE
U30S ON SAT. A GRADUAL COOL DOWN WILL BEGIN AS THE PRECIP ENTERS THE
CWA. GFS HAS SFC LOW AT 18Z SAT ENTERING THE SRN APPALACHIANS...W/ A
LARGE BAND OF OVERRUNNING PRECIP UP THE SPINE OF THE MTNS INTO
CENTRAL PA. BECAUSE THE UPPER TROF ISN/T PROGGED TO DIG AS FAR INTO
THE SOUTHEAST AS PREV RUNS...A SPLIT SYSTEM IS SHOWN IN THE BOTH
GFS/ECMWF RUNS. ANOTHER DEEP SFC LOW DEVELOPS ALONG THE COASTAL
PLAIN OF NC AND HEADS TOWARD THE MOUTH OF THE CHESAPEAKE BAY. AS THE
SYSTEMS PROGRESS NWRD LATE SAT...THE LOW ACROSS THE ERN OHIO RIVER
VALLEY EFFECTIVELY DISSIPATES WITH AN ENERGY TRANSFER TO THE
DEEPENING LOW OVER THE CAROLINAS. THE SCENARIO ALSO IS FAVORABLE
FOR AN OCCLUSION OF THE WARM AIR INTO THE OHIO LOW...W/ THE NC LOW
CUTTING OFF THE LOW LEVEL WAA. THE UPPER TROF THEN WRAPS THE
STRONGEST AREA OF CAA INTO THE COASTAL LOW AS IT APPROACHES THE BAY.
BY 06Z...12Z GFS RUN HAS THE LOW AT THE MOUTH OF THE BAY...WITH A
FREEZING LINE STILL SET UP ACROSS THE I-95 CORRIDOR. NATURALLY THIS
FAR INTO THE FUTURE...MODELS ARE FAIRLY SPREAD OUT ON THE TRACK AND
POSITION OF THESE SFC LOWS OVER THE WEEKEND PERIOD. ANOTHER
INHIBITING FACTOR FOR A CAD EVENT IS THE RESIDENCE TIME ACROSS
SE/RN CANADA FOR A CLASSIC AND STRONG CAD SET...THOU AS
MENTIONED...A MINOR INSITU EVENT WILL BE POSSIBLE W/ THE CURRENT
SET UP FORECAST.
A WIDE AREAL RANGE OF MIXED WINTRY PRECIP EXPECTED ACROSS THE I-95
CORRIDOR W/ THIS WEEKEND EVENT. A COLD RAIN ON SAT AFTN POSSIBLY
TURNING INTO FZRA/SLEET MIX INTO THE EVENING AND OVERNIGHT HRS. SNOW
MOST LIKELY ACROSS THE I-81 CORRIDOR...MIXING INTO THE PRECIP BACK
TO THE EAST OVERNIGHT SAT/SUN MORNING. QPF LOOKS TO BE DECENT FOR
THE INCOMING SYSTEM...W/ BOTH AN ATLANTIC AND GULF OF MEXICO
MOISTURE ENHANCEMENT...THOU AMOUNTS OF WINTRY PRECIP STILL
UNCERTAIN W/ MANY INTERWORKING VARIABLES AND LOW TRACK/TROF
INTENSITY DIFFERENCES IN THE MID RANGE MODELS. THE END OF MEAN
RUNS BEGINNING TO CONVERGE ON SOLN/S CLOSE TO AFOREMENTIONED
POSSIBILITIES.
HIGH PRESSURE BUILDING INTO THE LOWER OHIO RIVER VALLEY...AND THE
SOUTHEAST FOR EARLY NEXT WEEK. WEAK UPPER WAVES W/ LIMITED STRENGTH
OR MOISTURE WILL SKIRT NRN PORTIONS OF THE REGION THRU THE MIDDLE OF
NEXT WEEK.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
IFR CONDITIONS (POSSIBLE LIFR CIGS) DEVELOPING BY 12Z
THU WITH RAIN AT ALL TAF SITES XCPT FZRA AT KMRB BETWEEN 12Z-18Z.
CONDITIONS IMPROVING TO VFR THU EVENING. NEXT SIG STORM SAT
NIGHT-SUN WILL LIKELY BRING LIFR CONDITIONS BEGINNING LATE SAT
AFTERNOON THROUGH SUN ALONG WITH POTENTIAL FOR SIG WINTER
PRECIPITATION. POTENTIAL FOR HIGH WINDS (GUSTS >40 KTS) ON SUN
AFTERNOON.
&&
.MARINE...
SMALL CRAFT CONDITIONS HAVE WANED WITH THE PASSAGE OF A COLD FRONT.
WINDS BECOME NE TONIGHT THEN SE THURSDAY WITH WARM ADVECTION.
WINDS LATE THURS EXPECTED TO REMAIN BELOW SCA AS NORTHERLY WINDS
INCREASE FROM THE EXITING SYSTEM AND A BUILDING HIGH ACROSS SRN
CANADA. NO PROBS EXPECTED FRI...THOU A STRONG STORM SYSTEM WILL
ENTER THE REGION ON SAT. A MIX OF WINTRY PRECIP POSSIBLE NEAR THE
BAY AND LOWER SRN MD OVERNIGHT SAT INTO SUN MRNG. STRONG WINDS
ASSOCIATED W/ THE SYSTEM...ESPEC ON SUNDAY AS THE LOW EXITS THE
REGION. SCA COND/S CERTAIN W/ A BRIEF PERIOD OF GALES POSSIBLE
SUNDAY AFTN...THOU A CHANGE IN THE SYSTEM TRACK MAY CHANGE THIS
POSSIBILITY AS WELL. NO PROBS EXPECTED FOR EARLY NEXT WEEK.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...ICE STORM WARNING FROM 3 AM TO 4 PM EST THURSDAY FOR MDZ501.
WINTER WEATHER ADVISORY FROM 3 AM TO 4 PM EST THURSDAY FOR
MDZ003>007-502.
VA...WINTER WEATHER ADVISORY FROM 3 AM TO 11 AM EST THURSDAY FOR
VAZ028.
WV...ICE STORM WARNING FROM 3 AM TO 4 PM EST THURSDAY FOR WVZ503.
WINTER WEATHER ADVISORY FROM 3 AM TO 11 AM EST THURSDAY FOR
WVZ050-501-504.
WINTER WEATHER ADVISORY FROM 3 AM TO 4 PM EST THURSDAY FOR
WVZ051>053.
MARINE...NONE.
&&
SYNOPSIS...HTS
NEAR TERM...ROGOWSKI
SHORT TERM...ROGOWSKI
LONG TERM...GMS
AVIATION...ROSA
MARINE...ROGOWSKI/GMSHAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 854 PM EST WED DEC 12 2007 ANZ530>537-DCZ001-MDZ003>007-009>011-013-014-016>018-501-502- VAZ021-025>031-036>042-050>057-WVZ050>055-501>504-131000- 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- DISTRICT OF COLUMBIA-WASHINGTON-FREDERICK MD-CARROLL- NORTHERN BALTIMORE-HARFORD-MONTGOMERY-HOWARD-SOUTHERN BALTIMORE- PRINCE GEORGES-ANNE ARUNDEL-CHARLES-ST. MARYS-CALVERT- EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-HIGHLAND- AUGUSTA-ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE- NELSON-ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-FAUQUIER-LOUDOUN- ORANGE-CULPEPER-PRINCE WILLIAM/MANASSAS/MANASSAS PARK-FAIRFAX- ARLINGTON/FALLS CHURCH/ALEXANDRIA-STAFFORD-SPOTSYLVANIA- KING GEORGE-HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON-PENDLETON-HARDY- WESTERN GRANT-EASTERN GRANT-WESTERN MINERAL-EASTERN MINERAL- 854 PM EST WED DEC 12 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR MARYLAND WEST OF THE EASTERN SHORE INCLUDING THE CHESAPEAKE BAY AND EAST OF GARRETT COUNTY...EASTERN WEST VIRGINIA...NORTHERN AND CENTRAL VIRGINIA... WASHINGTON DC AND THE TIDAL POTOMAC RIVER. .DAY ONE...OVERNIGHT A WINTER WEATHER ADVISORY WILL START AT 3 AM THURSDAY MORNING FOR AREAS ALONG AND NORTH OF A LINE FROM NORTHWEST GRANT COUNTY EAST TO WINCHESTER...FREDERICK MARYLAND AND HARFORD COUNTY. A MIXTURE OF FREEZING RAIN AND SLEET WILL OVERSPREAD THIS AREA FROM WEST TO EAST EARLY THURSDAY MORNING. ICE ACCUMULATIONS FROM TRACE AMOUNTS UP TO TWO TENTHS OF AN INCH IN WESTERN MARYLAND AND THE PANHANDLE OF WEST VIRGINIA ARE POSSIBLE. IN WESTERN ALLEGANY AND MINERAL COUNTIES AN ICE STORM WARNING IS IN EFFECT BEGINNING AT 3 AM FOR A QUARTER TO AS MUCH AS A HALF INCH OF ICE. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY THE WINTER WEATHER ADVISORY FOR FREEZING RAIN AND SLEET CONTINUES UNTIL 11 AM THURSDAY FOR THE REGION OUTLINED ABOVE AS THE WINTRY MIX CHANGES TO ALL RAIN...BUT CONTINUES UNTIL 4 PM FOR AREAS FURTHER NORTH CLOSE TO THE MARYLAND-PENNSYLVANIA BORDER. THE ICE STORM WARNING ALSO CONTINUES UNTIL 4 PM. A SIGNIFICANT WINTER STORM WILL IMPACT THE REGION BEGINNING SATURDAY AND CONTINUING THROUGH SUNDAY. TIMING AND EXACT STORM TRACK DETAILS ARE NOT CERTAIN AT THIS TIME...HOWEVER IT IS LIKELY THAT AT LEAST A PORTION OF THE REGION WILL EXPERIENCE SIGNIFICANT WINTRY PRECIPITATION. CLIMATOLOGICALLY FAVORED LOCATIONS FOR WINTRY PRECIPITATION ARE AREAS WEST OF INTERSTATE 81...WITH A VERY TIGHT GRADIENT OF A WINTRY MIX OF PRECIPITATION ALONG THE I-95 CORRIDOR ASSOCIATED WITH THE COASTAL FRONT...AND RAIN CLOSER TO SOUTHERN MARYLAND AND KING GEORGE COUNTY VIRGINIA. CONFIDENCE ON WHERE THE COASTAL FRONT SETS UP WILL LIKELY NOT BE HIGHER UNTIL FRIDAY...BUT ALL INTERESTS IN THE REGION SHOULD BE ON ALERT FOR FUTURE UPDATES ON THIS WEEKEND WINTER STORM. GUSTY NORTHWEST WINDS BEHIND THIS WINTER STORM MAY REQUIRE GALE WARNINGS ON SUNDAY AND SUNDAY NIGHT AND GUSTS TO 40 MPH OVER THE LAND AREAS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED TONIGHT. ANY REPORTS OF SLEET AND ICE WILL BE GREATLY APPRECIATED THURSDAY MORNING. ROGOWSKI
The national radar mosaic for the moment the first event began.
3 winter weather, 1 ice storm. Local standard time, as filed.
A trained spotter measured 0.55 of ice accretion 1 mile east of Frostburg, MD.
A trained spotter reported a tenth of an inch of ice in Cumberland, MD.
A cooperative observer reported a tenth of an inch of ice in Westminster, MD.
Broadcast Media relayed a report of two tenths of an inch of ice near Smithsburg, MD.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maryland in 2007Every state in 2007This day in weather historyWarnings in Maryland, December 2007
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: 68264, 68265, 68266, 68267.