Winter Weather in Virginia, March 19, 2014

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
646 AM EDT WED MAR 19 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER QUEBEC WILL CONTINUE TO RIDGE DOWN THE
EASTERN SEABOARD TODAY. A COLD FRONT OVER THE MISSISSIPPI RIVER
VALLEY WILL MOVE THROUGH THE MID-ATLANTIC REGION TONIGHT. HIGH
PRESSURE BUILD INTO FRIDAY...BEFORE THE NEXT COLD FRONT MOVES
THROUGH ON SATURDAY. CANADIAN HIGH PRESSURE RETURNS SUNDAY AND
MONDAY.

&&

.NEAR TERM /THROUGH THURSDAY/...
CHALLENGING FORECAST EARLY THIS MORNING. WEDGE OF HIGH PRESSURE
PERSISTS THROUGH THE MID-ATLANTIC...WITH COLD AIR DAMMING SIGNATURE
NOTED. HOWEVER...TEMPERATURES HAVE BEEN A LITTLE SLOWER TO FALL THAN
PREVIOUSLY INDICATED AND HAVE BEEN GENERALLY STEADY IN THE MID TO
UPPER 30S.

PER PREVIOUS FORECASTS...LIGHT RETURNS ARE STARTING TO SHOW UP ON
THE RADAR ACROSS PORTIONS OF CENTRAL AND SOUTHWEST VIRGINIA. EVEN
HAVE HAD A REPORT OF DRIZZLE AT STAUNTON LAST HOUR /WITH 33
DEGREES/. AND PER GUIDANCE...AREAS OF LIGHT DRIZZLE AND LIGHT RAIN
SHOULD EXPAND/DEVELOP NORTHWARD THROUGH THE MORNING HOURS...FAVORING
EASTERN SLOPES.

QUESTION IS HOW MUCH MORE WILL TEMPERATURES BE ABLE
TO DROP DURING THIS TIME. SOUNDINGS SUGGEST WE DON/T HAVE TO WORRY
ABOUT SNOW OR SLEET...SO SURFACE TEMPERATURES WILL DICTATE DRIZZLE
VS FREEZING DRIZZLE /OR RAIN VS FREEZING RAIN IN THOSE PLACES THAT
CAN MEASURE/.

WINTER WEATHER ADVISORY IS IN EFFECT FOR AREAS ON THE LEE SIDE OF
THE BLUE RIDGE AND FOR WEST OF THE BLUE RIDGE. THIS IS FOR LIGHT
ICING DUE TO FREEZING DRIZZLE/RAIN. EVEN THOUGH TEMPERATURES HAVE
BEEN SLOWER TO DECREASE THUS FAR...THE EXPECTATION IS FOR A FEW MORE
DEGREES OF COOLING TO OCCUR THROUGH DAYBREAK. THIS WOULD LEAD TO
AREAS OF FREEZING PRECIPITATION AND SOME ICING. THUS PLAN ON KEEPING
ADVISORY IN EFFECT FOR NOW.

AREAS/POCKETS OF SUB-FREEZING SURFACE AIR SHOULD RISE ABOVE FREEZING
BY MID MORNING...AND ANY PRECIPITATION BY THEN LIQUID AND EXPANDING
EASTWARD TOWARD THE INTERSTATE 95 CORRIDOR PER SREF. WHILE
TEMPERATURE WILL BE ABOVE FREEZING FOR THE BALANCE OF THE
DAY...PREFER THE LOWER MET GUIDANCE IN A WEDGE SET UP.

EROSION OF THE WEDGE SHOULD OCCUR LATER THIS AFTERNOON OR
EVENING...AS SOME SEMBLANCE OF A WARM FRONT ATTEMPTS TO LIFT NORTH
OF THE AREA. WHETHER IT MAKES IT ALL THE WAY THROUGH OR NOT IS
UNCERTAIN...BUT EITHER WAY A COLD FRONT FROM THE WEST WILL SWEEP
THROUGH THE CWA OVERNIGHT. THIS WILL INITIATE A WIND SHIFT AND ALLOW
THE CEILING TO RISE OVERNIGHT...IN ADDITION TO ENDING POPS.

COLD ADVECTION OCCURS BEHIND THE COLD FRONT FOR THURSDAY...AND WILL
HELP TO MIX DOWN GUSTY WINDS TO THE SURFACE. BUT COLD ADVECTION WILL
ALSO BE NEGATED BY A DOWNSLOPING FLOW AND THE RETURN OF SOME
SUNSHINE /HIGHER MARCH SUN ANGLE/. THE RESULT WILL BE A MILDER
THURSDAY...THE ONLY EXCEPTION PERHAPS BEING ON THE WESTERN SLOPES
WITH SOME CLOUDS.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
SFC HIPRES BUILDS EWD INTO THE MID-ATLANTIC REGION THU NGT AND FRI
MRNG. A RELATIVELY COOL AIRMASS CHARACTERIZED BY H8 TEMPS AROUND -5C
THU NGT WILL MODERATE ON FRI VIA ADIABATIC COMPRESSION FROM W-NW
FLOW DOWNSLOPING OFF THE MTS AND EVENTUALLY WAA ASSOCIATED WITH A
WARM FRONT LIFTING THRU THE AREA LATE IN THE DAY. LEANED ON THE WARMER
SIDE OF GUIDANCE UNDER THIS SETUP...GIVING US HIGHS RANGING FROM THE
MID 50S NEAR THE MASON-DIXON LINE TO MID 60S IN THE NRN PIEDMONT.

FROPA WILL BE ACCOMPANIED BY INCREASING CLOUDS AND PERHAPS A FEW
SPRINKLES MAINLY NEAR THE ALLEGHENY FRONT DURING THE LATE FRI AFTN
AND EVE. MIN TEMPS FRI NGT WILL BE MILD AS WELL IN PRE-FRONTAL WARM
SECTOR.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
LOPRES OVER THE GREAT LAKES IS EXPECTED TO MOVE EWD OVER EITHER ERN
CANADA OR NRN NEW ENGLAND ON SAT WHILE THE ATTENDANT COLD FRONT
PROGRESS THRU THE MID-ATLANTIC REGION. MODELS HAVE BEEN IN FAIRLY
GOOD AGREEMENT WITH TIMING OF COLD FROPA FOR THE CWA ON SAT. WENT
WITH A DRY FCST EXCEPT FOR MOST OF THE AREA EXCEPT LOW CHANCES IN
THE WRN HIGHLANDS AND NRN MD AS THE BEST SYNOPTIC LIFT REMAINS NORTH
OF THE AREA. ADDITIONALLY...THERE IS LIMITED MOISTURE AVAILABLE WITH
THIS SYSTEM WITHOUT A DIRECT FEED FROM THE GULF OF MEXICO OR
ATLANTIC.

COLD AIR RETURNS TO THE REGION SAT NGT AND SUN WHEN CANADIAN HIPRES
BUILDS IN BEHIND THE COLD FRONT. MODELS CONTINUE TO THE COLDER THAN
NORMAL TEMPS PERSISTING INTO THE EARLY AND MIDDLE PORTIONS OF NEXT
WEEK WITH THE LARGE-SCALE PATTERN FEATURING A MEAN TROUGH OVER THE
ERN CONUS. WEAK CLIPPER SYSTEMS MAY MOVE THRU DURING THIS TIME...
PROVIDING LIMITED OPPORTUNITIES FOR RA/SN SHOWERS.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
COLD WEDGE IS IN PLACE...AND EXPECT LOWERING CIGS THROUGH DAYBREAK.
CIGS MOST LIKELY BELOW 2K FT BUT STILL WITHIN MVFR FOR THE MORNING
PUSH. LAMP GUIDANCE WAS FOLLOWED WITH FURTHER DETERIORATION THIS
AFTERNOON/EVENING INTO IFR COINCIDENT WITH THE HIGHEST PROBABILITY
OF RAIN OCCURRENCE AND THUS PREVAILING IN TAFS. SOME GUIDANCE
SUGGESTS A PERIOD OF LIFR CIGS THIS EVENING ALTHOUGH DUE TO LOWER
CONFIDENCE KEPT CIGS IN IFR ATTM. EITHER WAY...IMPROVEMENT IS
EXPECTED TO OCCUR OVERNIGHT DUE TO A WIND SHIFT WITH A COLD
FRONT...MOST LIKELY 06Z-09Z AT THE HUBS. MAIN IMPACT THEN SHIFTS TO
GUSTY WEST WINDS FOR THURSDAY.

VFR THRU THE WEEKEND. LGT WLY FLOW THU NGT BECOMES SLY FRI AFTN AND
NGT AHEAD OF A COLD FRONT. NW WINDS SUN AS HIPRES BUILDS INTO THE
AREA.

&&

.MARINE...
WINDS HAVE DIMINISHED OVERNIGHT...WITH TPLM2 DOWN TO 13G15KT AT 07Z.
THEREFORE WILL CANCEL THE OVERNIGHT SCA. WINDS SHOULD BE BELOW SCA
CRITERIA TODAY/TONIGHT...VEERING TO THE SE LATER TODAY THEN A WIND
SHIFT TO THE W LATE TONIGHT BEHIND A COLD FRONT. SHOULD BE ABLE TO
MIX DOWN 20 KT WINDS DURING THE DAY THURSDAY...THUS SCA WILL BE
ISSUED.

WINDS JUST BELOW SCA LEVELS THU NGT. SLY FLOW DEVELOPS LATE FRI INTO
SAT MRNG AHEAD OF A COLD FRONT. FLOW MAY APPEARS TO STRENGTHEN
ENOUGH TO WARRANT AT LEAST THE RISK OF A SCA BY SAT MRNG...
ESPECIALLY IN THE LOCATIONS PRONE TO SLY CHANNELING. COLD FRONT
MOVES THRU SAT AFTN. SCA CONDITIONS POSSIBLE IN ITS WAKE THRU THE
REMAINDER OF THE WEEKEND.

&&

.TIDES/COASTAL FLOODING...
POSITIVE TIDAL DEPARTURES HAD INCREASED EVER SO SLIGHTLY LAST NGT
ALONG THE WRN SHORE OF THE BAY AND IN THE TIDAL POTOMAC TO AROUND
ONE FOOT. ONLY CONCERN WOULD BE AT THE MOST SENSITIVE LOCATIONS FOR
COASTAL FLOODING SUCH AS ANNAPOLIS...WHICH NEEDS A 1.2 FT ANOMALY
FOR MINOR COASTAL FLOODING AT HIGH TIDE THIS MRNG. CBOFS
GUIDANCE...WHICH INDICATES ANNAPOLIS TO REMAIN BELOW STAGE...HAS
VERIFIED WELL THUS FAR.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WINTER WEATHER ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
     MDZ003-004-501-502.
VA...WINTER WEATHER ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
     VAZ025>031-036>040-042-501-503-504.
WV...WINTER WEATHER ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM TO 6 PM EDT THURSDAY FOR
     ANZ530>543.

&&

SYNOPSIS...JRK
NEAR TERM...BPP
SHORT TERM...JRK
LONG TERM...JRK
AVIATION...BPP/JRK
MARINE...BPP/JRK
TIDES/COASTAL FLOODING...JRK

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
531 AM EDT WED MAR 19 2014

ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057-
201000-
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-
531 AM EDT WED MAR 19 2014

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...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

A SMALL CRAFT ADVISORY IS IN EFFECT THURSDAY FOR THE TIDAL POTOMAC
RIVER AND MARYLAND CHESAPEAKE BAY.

SMALL CRAFT ADVISORIES MAY BE REQUIRED FOR PORTIONS OF THE WATERS
THIS WEEKEND.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504-
WVZ050>053-055-501>506-201000-
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-
531 AM EDT WED MAR 19 2014

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...TODAY AND TONIGHT

A WINTER WEATHER ADVISORY FOR FREEZING RAIN AND FREEZING DRIZZLE IS
IN EFFECT FOR AREAS ALONG AND WEST OF THE BLUE RIDGE THIS MORNING.
PLEASE SEE OUR WINTER WEATHER MESSAGE...WBCWSWLWX...FOR FURTHER
DETAILS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.