Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 250741
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
341 AM EDT SAT OCT 25 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION TODAY. A REINFORCING COLD
FRONT WILL PASS THROUGH THE REGION LATE TONIGHT INTO SUNDAY
BEFORE HIGH PRESSURE RETURNS FOR MONDAY. THE HIGH WILL MOVE OFF
THE COAST TUESDAY AND ANOTHER COLD FRONT WILL PASS THROUGH THE
AREA WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AN UPPER LEVEL VORT MAX RIBBON HELPING MIX-DOWN THE GUSTY WINDS ATTM
AND WILL CONTINUE HOVERING OVER THE AREA INTO THE POST-DAWN HRS THIS
MRNG. OCCASIONAL GUSTS IN THE 20-25KT RANGE...W/ OVERALL SFC WINDS
AT A STEADY 10-15KT CLIP OUT OF THE NW. THE EXITING AND SLOW-MOVING
UPPER LEVEL SYSTEM FROM A COUPLE OF DAYS AGO STILL HANGING AROUND
NEW ENGLAND...E OF THE HUDSON RVR/ERN NY. THE VORT MAX MERELY
SWINGING AROUND THE BACKSIDE OF THE UPPER LOW...BEING PULLED ALONG
BY THE SYSTEM...NOT EXPECTED TO MAKE MUCH EWD PROGRESS IN THE COMING
HRS. FOR THIS REASON...WINDS WILL STAY FAIRLY BREEZY OVERNIGHT WHICH
IS NOT ALL THAT COMMON - THEN PICK BACK UP EVEN FURTHER AFTER DAWN.

TRAPPED LOW LEVEL MOISTURE ALSO MIXING-DOWN W/ SOME OF THE
GUSTS...WHICH IS KEEPING DEWPOINTS RELATIVELY HIGHER THAN W/ A NW
FLOW REGIME. EVEN THOUGH SKIES ARE GENERALLY CLEAR ATTM...DEWPOINTS
ARE REMAINING RELATIVELY HIGH AND THIS IS KEEPING TEMPS ON THE
WARMER SIDE. IF NOT FOR THE MOISTURE...TEMPS WOULD LIKELY BE
DROPPING WELL INTO THE 40S AND 30S IN SHELTERED VLYS...BUT MOST
SITES ARE BARELY AOB 55F CURRENTLY.

NOT QUITE AS GUSTY TODAY AS ON THU BUT TEMPS WILL END UP IN ABOUT
AROUND THE SAME LEVELS - M60S...U60S OVER THE SRN TIER COUNTIES.
PLENTY OF SUN TODAY...A FEW PASSING UPPER DECKS AS A PRECIP-LESS
SHORTWAVE DIGS WELL TO OUR SOUTH...OVER THE SRN APLCNS. THIS FEATURE
WILL KEEP ITS INFLUENCES AWAY FROM THE MID-ATLC BUT WILL HELP TO
USHER-IN THE MORE CALMING EFFECT OF AN UPPER MIDWEST HIGH. AFTER THE
SFC FLOW DISSIPATES POST-SUNSET TONIGHT...DEWPOINTS WILL SLOWLY
REBOUND AGAIN INTO THE 40S...FOR ANOTHER REL MILD TEMP RANGE FOR OUR
OVERNIGHT LOWS. APPLIED A BIAS-CORRECTED MET/MEX FOR TODAY`S
HIGH/LOW TEMP GRIDS. ALSO MODIFIED WINDS IN THE NEAR/SHORT TERMS W/
NEWER HI-RES WRK GUIDANCE.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
THE NOSE OF A POTENT UPPER LEVEL JET WILL MAKE A QUICK ENTRANCE ON
SAT...SLAMMING UP AGAINST THE EXITING UPPER LEVEL JET FROM THE
OFFSHORE LOW. THIS FAST UPPER NW FLOW WILL START TO BRING IN THE
CLOUD COVER TO THE MTNS ON SAT...BUT LEAVE THE REMAINDER OF THE AREA
FAIRLY DRY AND CLEAR UNTIL LATER IN THE EVE. BEING ON THE RIGHT-EXIT
DOWNWARD MOTION SIDE OF THE UPPER JET WILL KEEP THE AREA DRY HEADING
INTO THE WEEKEND. WEAK BUT STEADY DOWNSLOPING FLOW MAY HELP BRING
TEMPS UP A FEW MORE DEG...PEAKING IN THE M-U60S - POSSIBLY JUST
ABOVE 70F FOR SAT AFTN.

HIGH PRESSURE WILL BUILD OVERHEAD SUNDAY NIGHT...CAUSING WINDS TO
DIMINISH. LIGHT WINDS...MAINLY CLEAR SKIES AND DRY CONDITIONS WILL
PROVIDE A GOOD SETUP FOR RADIATIONAL COOLING. THEREFORE...MIN
TEMPS SUNDAY NIGHT WILL BE CHILLY...ESPECIALLY IN SHELTERED
VALLEYS AND RURAL AREAS. MIN TEMPS WILL RANGE FROM THE MID 30S IN
PORTIONS OF THE SHENANDOAH VALLEY...EASTERN WEST
VIRGINIA...NORTHERN MARYLAND AND THE NORTHERN AND WESTERN SUBURBS
OF WASHINGTON/BALTIMORE...TO THE MID 40S IN DOWNTOWN WASHINGTON
AND BALTIMORE. FROST IS POSSIBLE ACROSS MANY LOCATIONS LATE SUNDAY
NIGHT AND EARLY MONDAY MORNING...ESPECIALLY NORTH AND WEST OF
INTERSTATE 95.

HIGH PRESSURE OVER THE REGION MONDAY MORNING WILL SHIFT TO THE
COAST BY LATE IN THE DAY. A RETURN SOUTHERLY FLOW WILL
DEVELOP...ALLOWING FOR MILDER CONDITIONS MONDAY AFTERNOON ALONG
WITH PLENTY OF SUNSHINE. MAX TEMPS WILL RANGE FROM THE MID 60S
ACROSS NORTHEASTERN MARYLAND TO THE MIDDLE 70S IN PORTIONS OF
CENTRAL VIRGINIA.

A SOUTHERLY FLOW WILL CONTINUE AROUND THE HIGH MONDAY
NIGHT...ALLOWING FOR MILDER CONDITIONS COMPARED TO SUNDAY NIGHT.
MIN TEMPS WILL RANGE FROM THE MID AND UPPER 40S ACROSS SHELTERED
VALLEYS AND RURAL AREAS TO THE MIDDLE 50S IN DOWNTOWN WASHINGTON
AND BALTIMORE.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
A COLD FRONT WILL APPROACH FROM THE WEST TUESDAY...BUT IT WILL
REMAIN TO OUR WEST AND A SOUTHWEST FLOW AHEAD OF THIS SYSTEM WILL
USHER IN UNUSUALLY WARM CONDITIONS FOR THIS TIME OF YEAR. MAX
TEMPS WILL APPROACH 80 DEGREES ACROSS MANY LOCATIONS.

THE COLD FRONT WILL MOVE INTO WESTERN PORTIONS OF OUR CWA TUESDAY
NIGHT. CLOUDS WILL INCREASE AHEAD OF THIS SYSTEM AND THERE MAY
EVEN BE A FEW SHOWERS LATE ACROSS THE POTOMAC HIGHLANDS...BUT
PRECIPITATION AMOUNTS WILL BE LIGHT. THE COLD FRONT WILL MOVE
THROUGH THE AREA WEDNESDAY INTO WEDNESDAY NIGHT...BRINGING THE
CHANCE FOR SHOWERS. PRECIPITATION AMOUNTS WILL BE LIGHT SINCE
LITTLE MOISTURE WILL BE ASSOCIATED WITH THE FRONT. HIGH PRESSURE
WILL BUILD OVERHEAD FOR LATE IN THE WEEK...BRINGING A RETURN OF
MORE SEASONABLE CONDITIONS.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
ANOTHER BREEZY AFTN TODAY BUT A TIER LOWER IN TERMS OF PEAK
GUSTS...WHERE 15-20KT WILL BE FAIRLY COMMON FROM AFTER SUNRISE.
SEVERAL MORE HEADING INTO THE DAYTIME HRS...OF THE STEADY BREEZE
TODAY. WINDS WILL THEN QUICKLY DROP OFF TOWARD SUNSET. HIGH PRESSURE
CONTINUE STRENGTHENING OVER THE AREA INTO SAT.

VFR CONDITIONS ARE EXPECTED MOST OF THE TIME SUNDAY NIGHT THROUGH
WEDNESDAY. A SOUTHERLY FLOW WILL INCREASE AHEAD OF A COLD FRONT
MONDAY AND TUESDAY. WINDS WILL SHIFT TO THE NORTHWEST BEHIND THE
FRONT FOR WEDNESDAY.

&&

.MARINE...
A WEAK UPPER LOW WILL MEANDER JUST OFF THE COAST INTO THE LATE NIGHT
HRS TONIGHT BUT TAKE IT`S BREEZY INFLUENCE. SCA CONTINUED FOR ALL
THE WATER THIS AFTN. MAY NEED TO FURTHER EXPAND THE SCA FOR THE
LOWEST BAY ZONES BUT WILL MONITOR UPCOMING SCA POTENTIAL.

HIGH PRESSURE OVER THE WATERS SUNDAY NIGHT WILL MOVE OFF THE COAST
MONDAY THROUGH TUESDAY. A SOUTHERLY FLOW WILL DEVELOP DURING THIS
TIME. A COLD FRONT WILL PASS THROUGH THE WATERS WEDNESDAY. A SMALL
CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF THE WATERS TUESDAY
AND WEDNESDAY. HIGH PRESSURE WILL RETURN FOR LATE IN THE WEEK.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 AM TO 6 PM EDT SUNDAY FOR
     ANZ530>543.

&&

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







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