NWS Sterling Area Forecast Discussion

000
FXUS61 KLWX 050822
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
322 AM EST SUN FEB 5 2012

.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST ALONG A STALLED FRONTAL BOUNDARY
DRAPED ACROSS THE CAROLINAS TODAY. HIGH PRESSURE WILL BUILD
TONIGHT INTO MONDAY. AN UPPER LEVEL DISTURBANCE WILL CROSS THE MID
ATLANTIC WEDNESDAY...BRINGING THE POSSIBILITY OF A WINTRY MIX TO
THE REGION.

&&

.NEAR TERM /THROUGH TODAY/...
THE PARENT UPPER LOW STILL MEANDERING OVER THE KANSAS CITY METRO
AREA...BUT A LARGE PORTION OF THE ACTUAL SYSTEM HAS ALREADY MOVED
OFF THE ATLC COAST. POCKETS OF LIGHT-MOD PRECIP STREWN OUT ACROSS
THE CAROLINAS W/ LESSER ACTIVITY STRETCHING BACK ACROSS THE MID
ATLC AND OHIO VLY. TEMPS ACROSS THE CWA HAVE RISEN TO OR JUST
ABOVE FREEZING AT THE SFC. PORTIONS OF THE NRN SHENANDOAH VLY
/I-81 CORRIDOR/ HANGING ONTO FREEZING TEMPS AND A COOLER LOW LEVEL
PROFILE - SO A MIX OF SNOW/SLEET/RAIN STILL OCCURRING ACROSS THESE
AREAS.

BATCHES OF LIGHT AND COLD RAIN WILL CONTINUE TO SLIDE EWD ACROSS
THE MID ATLC OVERNIGHT...MAINLY STRETCHED ALONG WEST-EAST ORIENTED
BANDS. LOCAL WRF MODEL GUIDANCE SHOWS SEVERAL MORE HRS LEFT TILL
ALL THIS PRECIP MAKES IT INTO AND OUT OF THE REGION. THE WRN-MOST
BATCHES OF PRECIP STILL ACROSS ERN IN/WRN OH WILL LIKELY BE MOVING
OVER AND EAST OF THE CNTRL APLCNS BY MID-LATE MRNG. EAST OF THE
MTNS...ONLY A FEW MORE HRS OF THIS ACTIVITY...AS TEMPS CONTINUE TO
HOVER ABOVE FREEZING AND SLIGHTLY DRIER AIR BEGINS TO SINK SWD
INTO NERN MD.

LATER THIS MRNG...THE ENTRAINMENT OF THIS DRIER AIR FROM THE NORTH
WILL BE USHERED IN AHEAD OF AN INCOMING UPPER VORT MAX DRIFTING
SEWD FROM THE GREAT LAKES REGION. THIS FEATURE WILL ALSO HELP TO
PUSH THE REMAINDER OF THIS ACTIVITY OFF THE COAST TODAY...WHILE
ACTING TO WEAKEN THE PARENT UPPER LOW OVER THE MIDWEST AND
DISSIPATE IT TO AN OPEN WAVE. AS CLOUDS/PRECIP RECEDE TOWARD THE
SOUTH AND EAST DURING THE DAYTIME HRS...TEMPS WILL SLOWLY CLIMB
OUT OF THE 30S AND JUST INTO THE 40S BY MIDDAY.

&&

.SHORT TERM /TONIGHT/...
CLEARING SKIES AND ANY RESIDUAL NWLY BREEZE WILL ALSO DISSIPATE
OVERNIGHT...ALLOWING FOR SOME RADIATIONAL COOLING AND SUB-FREEZING
TEMPS TO AGAIN OVERCOME THE REGION BY THE PREDAWN HRS.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
ONLY CHANGES TO THE LONG TERM WERE FOR MAX/MIN AND WIND GRIDS
MONDAY THROUGH TUESDAY NIGHT. NO CHANGES PAST TUESDAY NIGHT.

HIGH PRESSURE IN PLACE ACROSS THE MID ATLANTIC EARLY MONDAY BUT
WILL MOVE OFFSHORE BY THE AFTERNOON. A WEAK LOW PRESSURE SYSTEM
WILL MOVE UP THE COAST OF THE CAROLINAS MONDAY NIGHT INTO TUESDAY.
MODELS KEEP CWFA DRY FOR NOW.

AN UPPER LEVEL DISTURBANCE MOVES THROUGH WEDNESDAY...BRINGING
ANOTHER CHANCE FOR WINTRY PRECIP. HIGH PRESSURE BRIEFLY RETURNS
FOR THURSDAY INTO EARLY FRIDAY. A COLD FRONT IS EXPECTED FOR THE
WEEKEND.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
THICK LOW LEVEL DECKS WILL COVER THE MID ATLC INTO THE MID MRNG
HRS. LIGHT PRECIP /MAINLY RAIN AND DRIZZLE/ SLIDING OVER THE
AREA...BUT VERY SCATTERED IN NATURE. AREAS OF FOG AND LOCALIZED
IFR CIGS ARE THE MAIN CONCERN HEADING INTO THE PREDAWN HRS. AN HR-
OR-2 AFTER DAWN...THESE CONDITIONS WILL GRADUALLY IMPROVE AND THE
LOWER DECKS WILL BEGIN TO LIFT AND SCATTER OUT. BY MIDDAY...MOST
OF THE LOW-MID LEVEL DECKS WILL BE SLIDING SEWD AND OFF THE COAST.
CLR SKIES OVERNIGHT...LIGHTS WINDS AND LITTLE ELSE OF CONCERN TO
START OFF THE WEEK.

SUB VFR CONDITIONS POSSIBLE ON WEDNESDAY AS AN UPPER LEVEL
DISTURBANCE BRINGS A WINTRY MIX TO THE REGION.

&&

.MARINE...
RELATIVELY LIGHT NLY WINDS STREAMING DOWN THE BAY OVERNIGHT...
THOUGH MORE STEADY 10-15KT WINDS AFFECTING THE LOWER MD BAY ZONES.
THIS WILL CONTINUE AS AN AREA OF LOW PRESSURE DRIFTS OFF THE
CAROLINA COAST OVERNIGHT AND INTO THE DAYTIME HRS TODAY. WINDS
WILL REMAIN N-NWLY THROUGHOUT THE DAY...THEN SWITCHING TO WLY
OVERNIGHT TONIGHT AS HIGH PRESSURE BUILDS IN FROM THE WEST.

HIGH PRESSURE IN PLACE AT THE SURFACE THROUGH MOST OF NEXT WEEK.
NO HEADLINES ANTICIPATED.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...LISTEMAA
NEAR TERM...GMS
SHORT TERM...GMS
LONG TERM...LISTEMAA
AVIATION...GMS/LISTEMAA
MARINE...GMS/LISTEMAA

NWS LWX Office Area Forecast Discussion