Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 250140
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
940 PM EDT FRI JUL 24 2015

.SYNOPSIS...
HIGH PRESSURE REMAINS OVER THE REGION THROUGH SUNDAY. A WEAK COLD
FRONT WILL SLIDE INTO THE AREA FROM THE NORTHWEST SUNDAY NIGHT AND
MONDAY BEFORE DISSIPATING TUESDAY. ANOTHER COLD FRONT WILL
APPROACH FROM THE NORTHWEST ON THURSDAY.

&&

.NEAR TERM /THROUGH SATURDAY NIGHT/...
SFC HIGH SLOWLY BUILDING EAST...WITH CENTER CURRENTLY MVG INTO
WESTERN AREAS OF THE CWA. RIDGE AXIS STILL WELL WEST...OVER THE
CENTRAL US...WHICH WILL CONTINUE TO BUILD AND BROADEN HEADING INTO
THE WEEKEND. A SHORTWAVE...AS EVIDENT ON 01Z WATER VAPOR
IMAGERY TRAVERSING THE GREAT LAKES WILL BRING INCREASED CLOUD COVER
TONIGHT AS IT DIVES SE THRU THE MID ATLANTIC. PATCHY FOG WILL BE
PSBL IN THE VALLEYS WITH WINDS OVERALL LIGHT AND VRB. OVERNIGHT
SLIGHTLY WARMER THAN LAST NIGHT WITH THE CLOUD COVER.

THE RDG WL BE ATOP US TMRW MRNG...BUT WL DRIFT E BY AFTN. THIS WL
ENABLE A PINCH OF RETURN FLOW-- SUFFICIENT FOR DEWPTS TO BEGIN ITS
CREEP UPWD. STILL NOT BAD FOR THIS TIME OF YR...LWR 60S. NAM
ATTEMPTING TO DVLP DIURNALLY DRIVEN/OROGRAPHICALLY ENHANCED CNVCTN
IN THE SW CORNER OF THE CWFA. AM NOT BUYING THAT SOLN ATTM...AS
THERE IS NOTHING OTHER THAN THE TRRN TO PROVIDE FORCING...AND MID
LVL TEMPS SHUD BE QUITE WARM. DO THINK THAT THERE WL BE MORE CLDS
DVLPG...BUT STILL NOT ENUF TO PRECLUDE A MOSUN FCST. HV BROGUTH MAXT
UP CLOSER TO 90F...BUT ASIDE FM DCA/DMH/EZF HV NOT TAKEN TEMPS ABV
THAT LVL.

SAT NGT WL BE QUIET AS WELL...W/ LGT SLY FLOW. HV GONE ON THE WARMER
SIDE OF MOS IN RESPONSE...W/ MIN-T IN THE MID-UPR 60S FOR A GREATER
PROPORTION OF THE AREA.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
HEIGHTS WILL GRADUALLY RISE SUNDAY AS A DEEP-LAYER RIDGE BUILDS OVER
THE CENTRAL CONUS. EMBEDDED SHORTWAVES IN NORTHWEST FLOW ALOFT
COUPLED WITH A SHARPENING SURFACE TROUGH/WEAK COLD FRONT APPROACHING
FROM THE NORTHWEST SHOULD TRIGGER A FEW SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON. SOUTHERLY FLOW AHEAD OF THE
TROUGH AND WARM NOSE AT 850 MB WILL RESULT IN INCREASING
HEAT/HUMIDITY DURING THE AFTERNOON. MODEL FORECAST SOUNDINGS SUGGEST
MLCAPE OF 500-1000 J/KG BY LATE IN THE DAY BUT EFFECTIVE SHEAR
REMAINS IN THE 20-25 KT RANGE. STILL...INVERTED-V PROFILES AND DCAPE
APPROACHING 1000 J/KG ALONG WITH MODEST FORCING FROM UPPER-JET /65
KTS AROUND 250 MB/ COULD LEND TO BRIEF MULTI-CELLULAR ORGANIZATION
WITH A FEW STRONG WIND GUSTS POSSIBLE.

THE WEAK COLD FRONT STALLS OVER THE EASTERN THIRD OF THE CWA LATE
SUNDAY NIGHT INTO MONDAY. 850 TEMPS MONDAY A COUPLE DEGREES COOLER
WITH MORE CLOUDS AROUND AND THAT SHOULD RESULT IN SURFACE TEMPS A
FEW DEGREES LOWER THAN ON SUNDAY. NO REAL CHANGE IN DEW POINTS
THOUGH AS FLOW REMAINS LIGHT AND VARIABLE OR EVEN EASTERLY FOR A
BRIEF TIME MONDAY AS A WEAK WAVE OF LOW PRESSURE DEVELOPS TO THE
SOUTH OVER THE CAROLINAS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
WEAKENING FRONT/SFC TROUGH REMAINS IN THE AREA MON NIGHT INTO
TUE. SOME SHOWERS AND TSTMS ARE PSBL AS THIS BOUNDARY WEAKENS
DURING THIS PERIOD. HIGH PRES BRIEFLY BUILDS OVER OVER OUR REGION
WED INTO THU BRINGING DRIER CONDITIONS. COLD FRONT APPROACHES FROM
THE NW LATE ON THU AND MOVE ACROSS OUR CWA ON FRI... BRINGING
SHOWERS AND TSTMS TO THE REGION. HIGH TEMPS WILL BE NEAR NORMAL
TUE AND WARMING UP INTO THE 90S ON THU... AND BACK TO NEAR NORMAL
FRI.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS FOR THE TAF PERIOD. LIGHT FLOW...WITH WINDS
GENERALLY 5 KTS OR LESS THRU 21Z SAT. SLIGHT INCREASE AFTR
21Z...WITH SLY FLOW 8-10 KTS PSBL HEADING INTO SAT NIGHT.

MAINLY VFR EXPECTED SUN-MON. SLY WINDS GENERALLY 10 KT OR LESS.

VFR CONDITIONS EXPECTED MOST OF THE TIME MON NIGHT INTO TUE. SUB-
VFR CONDITIONS PSBL DUE TO SCATTERED SHOWERS AND TSTMS.

&&

.MARINE...
SUB-SCA CONDITIONS TONIGHT THRU SAT AFTN. PSBL SLY CHANNELING
LATER SAT COULD RESULT IN OCNL GUSTS TO SCA LVLS. HOWEVER...VERY
MARGINAL THREAT ATTM...AND CONFIDENCE NOT ENOUGH TO ISSUE SCA.

SOUTHERLY CHANNELING AHEAD OF A SHARPENING SURFACE TROUGH/WEAK
COLD FRONT WILL LIKELY RESULT IN SCA GUSTS FOR PORTIONS OF THE
WATERS SUNDAY AFTERNOON INTO SUNDAY EVENING. AS THE FRONT STALLS
OVER THE AREA INTO MONDAY...GUSTS SHOULD SUBSIDE.

SUB-SCA CONDITIONS EXPECTED FOR MON NIGHT INTO TUE. PSBL SHOWERS
AND TSTMS OVER THE WATERS DURING THIS PERIOD.

&&

.TIDES/COASTAL FLOODING...
SOUTHERLY FLOW INCREASES SUNDAY INTO MONDAY. THIS WILL PUSH TIDAL
ANAMOLIES UP ENOUGH TO APPROACH MINOR FLOOD NEAR TIMES OF HIGH
TIDE AT MOST VULNERABLE LOCATIONS STARTING WITH SUNDAY EVENING`S
HIGH TIDE CYCLE...LASTING INTO MONDAY.

&&

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

&&

$$
SYNOPSIS...HTS/SEARS
NEAR TERM...SEARS/HTS
SHORT TERM...DFH
LONG TERM...IMR
AVIATION...SEARS/IMR/DFH
MARINE...SEARS/IMR/DFH
TIDES/COASTAL FLOODING...



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