Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 311411
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1011 AM EDT MON AUG 31 2015

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN ANCHORED OFFSHORE TODAY. A TROUGH AXIS
WILL PIVOT ACROSS THE REGION THIS AFTERNOON. HIGH PRESSURE WILL
REFOCUS OVER THE CENTRAL APPALACHIANS AND UPPER OHIO VALLEY
TUESDAY...AND PERSISTS THROUGH THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
DISORGANIZED HIGH PRESSURE EXTENDS FROM THE TN VALLEY TO THE MID-
ATLANTIC OFFSHORE WATERS. A WEAKNESS IN THE PRESSURE FIELDS
EXTENDS ALONG THE NEW ENGLAND COAST...WITH A REFLECTION IN THE
925-850 MB LAYER INTO OUR NORTHERN CWA. THIS COULD ACT AS A
FOCUS/FORCING MECHANISM FOR PRECIP AS THE DAY WEARS ON. THE OTHER
IS A VORT MAX LOCATED IN SW VA WHICH WILL BE LIFTING ACROSS THE
AREA THROUGH THIS AFTERNOON. SOME ISOLATED MODERATE SHOWERS HAVE
ALREADY DEVELOPED...BUT OVERALL COVERAGE HAS BEEN DISORGANIZED.
SOME BREAKS IN THE CLOUDS N/W OF DC MAY ALLOW SOME INSTBY TO BE
REALIZED AND HAVE LIMITED THUNDER MENTION TO THESE AREAS TODAY.
HAVE RELIED ON HRRR/RAP/NAM AND AFOREMENTIONED FEATURES FOR
LOCATIONS OF HIGHEST POPS (STILL IN SCATTERED CATEGORY)...ALTHOUGH
TOUGH TO RULE OUT PRECIP JUST ABOUT ANYWHERE. IN THE AREAS WITH
HIGHER INSTBY...THERE COULD BE A FEW SLOW MOVING HEAVIER SHOWERS.
TEMPERATURES WILL DEPEND ON CLOUD COVER...AND LOCATIONS OF
BREAKS BECOME MORE UNCERTAIN AS THE DAY PROGRESSES. SO MINIMAL
CHANGES TO THE FORECAST MID-80S AT THIS TIME.

THE UPR TROF WL CROSS MID-LT AFTN...ABANDONING A POCKET OF LWR HGTS
IN THE OHVLY. THE RESULTANT FLOW PTTN SHUD PROMOTE THINNING OF THE
CLD DECK. WL BRING CLRG SKIES INTO CWFA FM N TO S...AND CARRY A
MOCLR NGT. LOWS WILL FALL CLOSE TO THE DEW POINTS IN THE MID
60S...WITH URBAN AND COASTAL AREAS REMAINING IN THE 70S.

&&

.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
ALTHO THERE WL BE A CUTOFF LOW WANDERING ARND THE OHVLY /AND SOME
GDNC SUGGESTING A CSTL SFC LOW MAY DVLP OFF THE CAROLINAS/...THE RE-
EMERGENCE OF RDGG WL BE THE MAIN WX PLAYER LOCALLY. THEREFORE THE
SUN AND WARMTH WL DOMINATE. SHUD BE ABLE TO GET CLOSER TO FULL SUN
TEMPS...MARKING A 90 DEG DAY FOR MOST AREAS. SUBSEQUENTLY...HV A
BETTER CHC AT REACHING CNVCTV TEMPS. WL NEED THE BOOST FROM TRRN
CIRCULATIONS...AND HV RESTRICTED 20-30 POPS TO THE SWRN CWFA. TUE
NGT MIN-T WL OFFER A HVY DOSE OF PERSISTENCE FM MON NGT.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
A SHORTWAVE TROUGH WILL LIKELY RIDE AN UPPER LEVEL RIDGE WEDNESDAY.
MODELS DIFFER WITH INTENSITY AND TIMING OF THE TROUGH BUT THERE IS
CONSENSUS THAT THE TROUGH WILL MOVE THROUGH THE REGION OR
CLOSE BY. SHOWERS AND THUNDERSTORMS ARE POSSIBLE MAINLY WEST OF THE
BLUE RIDGE WEDNESDAY AFTERNOON. THE RIDGE BUILDS BACK INTO THE
REGION AS THE SHORTWAVE TROUGH EXITS BY THURSDAY. WARM AND HUMID
CONDITIONS WILL LEAD TO THE POSSIBILITY OF SHOWERS AND
THUNDERSTORMS MAINLY IN THE AFTERNOON AND MAINLY ALONG THE RIDGE
LINES THROUGH FRIDAY. COVERAGE WILL LIKELY BE ISOLATED TO SCATTERED.
TEMPS WILL BE AROUND 5 DEG ABOVE CLIMO THROUGH THE END OF THE WORK
WEEK.

HIGH PRESSURE NOSES INTO THE MID-ATLANTIC FROM THE NORTHEAST THIS
WEEKEND AND A BACKDOOR COLD FRONT MAY MOVE INTO THE REGION. THIS MAY
RESULT IN DRIER AND COOLER CONDITIONS MAINLY IN THE NE HALF OF THE
REGION.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
SHOWER ACTIVITY IS EXPECTED TO REMAIN SCATTERED AND DISORGANIZED
TODAY WITH ISOLATED THUNDER THIS AFTERNOON...SO WILL BE
TOUGH TO NAIL DOWN ANY IMPACTS. THERE COULD BE A BRIEF PERIOD OF
SUB-VFR CONDITIONS SHOULD ONE OF THESE DEVELOP OVER A
TERMINAL. SSWLY FLOW AOB 10 KT WL BRING PLENTY OF CLDCVR THO.
CIGS MAINLY MID DECK BUT COULD LOWER AT TIMES. PCPN WIDELY SCTD
AND LGT. IMPACT TOO LOW TO MENTION.

SKIES WL CLR TNGT AS WIND DROP TO BLO 5 KT AND VEER WLY. SINCE RADL
COOLING BETTER FOG BECOMES MORE OF A CONCERN. ATTM BEST CHC CHO/MRB.

OUTLOOK...
TUE-FRI...VFR.

&&

.MARINE...
SOUTHERLY TO SOUTHWESTERLY FLOW WILL CONTINUE OVER THE WATERS
TODAY. CLDS AND WK PRES PTTN WL KEEP MOST SUSTAINED SPDS NEAR 10
KT. CAN/T RULE OUT AN ISOLATED STORM NEAR DC/BALTIMORE...BUT FOR
THE MOST PART ONLY A FEW LIGHT SHOWERS EXPECTED ON THE WATERS. MUCH
LESS OF A CHC AT CHANNELING LT TNGT THRU TUE THAN PREVIOUS
EVENINGS.

HIGH PRESSURE WILL BE IN CONTROL ACROSS THE WATERS WED-FRI. A SFC
TROUGH MAY FORM CAUSING WINDS TO SHIFT BUT THEY SHOULD STAY BELOW
SCA CONDITIONS.

&&

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

&&

$$
SYNOPSIS...HTS
NEAR TERM...ADS/HTS
SHORT TERM...HTS
LONG TERM...HAS
AVIATION...ADS/HAS/HTS
MARINE...ADS/HAS/HTS



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