Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 271406 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1006 AM EDT WED APR 27 2016 .SYNOPSIS... A COLD FRONT WILL STALL OUT NEAR THE POTOMAC HIGHLANDS INTO NORTHEASTERN NORTH CAROLINA TODAY AND IT WILL REMAIN NEARLY STATIONARY THROUGH FRIDAY. WAVES OF LOW PRESSURE WILL RIDE ALONG THE BOUNDARY DURING THIS TIME. THE BOUNDARY MAY DROP A BIT FARTHER SOUTH SATURDAY...BUT ANOTHER WAVE OF LOW PRESSURE WILL TRACK ALONG THE FRONT FOR SUNDAY INTO MONDAY. && .NEAR TERM /THROUGH TONIGHT/...
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CDFNT ACRS SOUTHSIDE VA THIS MRNG. THERE STILL ARE SOME SHRA ACRS THE CWFA...BUT QPF IS LGT. PREVIOUS FCST IN GOOD SHAPE. AS FRONT PUSHES SOUTH TODAY...HIGH PRESSURE WILL WEDGE SOUTHWARD EAST OF THE APPALACHIANS. WE SHOULD SEE DECREASING COVERAGE OF SHOWERS THROUGH THE MORNING HOURS. HOWEVER CLOUDY SKIES WILL PREVAIL. HIGHEST CHANCES OF SHOWERS THROUGH THE AFTERNOON WILL BE OVER SOUTHERN PARTS OF THE AREA AS DEEP MOISTURE SHUNTS A LITTLE TO THE SOUTH...WHILE OVERRUNNING CONTINUES. THUNDER CHANCES WILL BE CONFINED TO FAR SOUTHERN PORTIONS OF THE CWA. SOME GUIDANCE ALLOWS HIGH TO RISE TO THE MID 70S IN THIS AREA...BUT AM SKEPTICAL GIVEN THE BUILDING HIGH. THE SOUTHERN ALLEGHENY HIGHLANDS MAY HAVE THE BEST CHANCE OF SEEING SOME INSTBY BUILD. EXPECT HIGHS BELOW NORMAL ACROSS THE REST OF THE AREA...AND VERY LITTLE MOVEMENT TO TEMPERATURES ALL DAY ACROSS THE NORTH. THERE MAY BE SOME BRIEF DRYING TONIGHT AS SHORTWAVE RIDGING MOVES OVERHEAD...BUT WILL CONTINUE WITH CHANCE POPS GIVEN THE CONTINUED OVERRUNNING ENVIRONMENT. WILL LIKELY SEE LOWERING CLOUDS AND PERHAPS SOME LIGHT FOG. LOWS WILL RANGE FROM MID 40S NORTH TO MID 50S SOUTH.
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&& .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AREA OF BROAD LOW PRESSURE WILL BE REACHING THE OHIO VALLEY THURSDAY MORNING. THIS WILL INCREASE LIFT...WITH SHOWERS SPREADING FROM WEST TO EAST ACROSS THE AREA DURING THE DAY. HAVE KEPT POPS IN LIKELY CATEGORY...BUT THESE COULD INCREASE AS TIMING AND AREAL COVERAGE COMES INTO MORE AGREEMENT. SPC PLACES MUCH OF THE SOUTHWESTERN CWA IN A MARGINAL RISK FOR SEVERE STORMS...AND DEEP LAYER SHEAR WILL INCREASE. HOWEVER...MAJORITY OF GUIDANCE SHOWS A STRONG CAD WEDGE IN PLACE...SO HAVE LOW CONFIDENCE ON RISK IN OUR CWA. AGAIN...ALLEGHENY HIGHLANDS (OUTSIDE OF WEDGE INFLUENCE) MAY HAVE THE BEST CHANCE AT SEEING THUNDER. HIGHS WILL STRUGGLE TO REACH 60 IN THE NORTH BUT PERHAPS REACH THE UPPER 60S IN THE FAR SW. AS SHORTWAVE ENERGY PASSES THURSDAY EVENING...DRYING WILL TAKE PLACE IN THE COLUMN AND SHOULD SEE A DOWNTURN IN SHOWER COVERAGE. HOWEVER WITH THE FRONT AND WEAK SFC LOW REMAINING NEARBY...WILL MAINTAIN CHANCE POPS...ALTHOUGH PRECIP MAY BECOME LIGHTER/DRIZZLY. A STRONGER SHORTWAVE TROUGH WILL CROSS THE REGION ON FRIDAY. HOWEVER IN WITH DECREASED PWATS...SHOWERS SHOULD BE LIGHT AND HAVE THUS HELD POPS IN THE CHANCE CATEGORY. AFTER THIS SYSTEM PASSES...FRIDAY NIGHT WILL HAVE DECREASING CHANCES OF MEASURABLE PRECIP...ALTHOUGH SOME DRIZZLE WILL REMAIN POSSIBLE. DAYTIME TEMPERATURES WILL CONTINUE TO RUN BELOW NORMAL WITH MUTED DIURNAL CURVES. && .LONG TERM /SATURDAY THROUGH TUESDAY/... SURFACE HIGH PRESSURE WILL STRENGTHEN OVER NEW ENGLAND BEHIND A DEPARTING UPPER-LEVEL DISTURBANCE SATURDAY. THIS WILL CAUSE A SURFACE RIDGE AXIS TO STRENGTHEN OVER THE MID-ATLANTIC...PUSHING A COLD FRONT FARTHER OFF TO OUR SOUTH. WITH HIGH PRESSURE STRENGTHENING...THIS WILL LIKELY ALLOW FOR DRY CONDITIONS SATURDAY. LOW CLOUDS AND POSSIBLE DRIZZLE ARE LIKELY UNDERNEATH THE SUBSIDENCE INVERSION SATURDAY MORNING...BUT ANY DRIZZLE WILL DIMINISH SATURDAY AFTERNOON AND THERE SHOULD EVEN BE BREAKS OF SUNSHINE. LOW PRESSURE WILL DEVELOP OVER THE MIDWEST AND IT WILL BEGIN TRACKING TO THE EAST SATURDAY NIGHT. THIS WILL ALLOW FOR WARM AND MOIST AIR TO OVERRUN THE COOLER AIR IN PLACE...RESULTING IN MORE CLOUDS AND INCREASING CHANCES FOR RAIN. THE LOW WILL TRACK THROUGH THE OHIO VALLEY SUNDAY...AND THEN ALONG THE BOUNDARY JUST TO OUR SOUTH FOR MONDAY. PLENTY OF CLOUDS ALONG WITH RAIN IS LIKELY DURING THIS TIME. EXACT TIMING IS STILL A BIT UNCERTAIN THIS FAR OUT. THE LOW WILL MOVE OFF TO THE EAST DURING THE MIDDLE PORTION OF NEXT WEEK AND HIGH PRESSURE WILL LIKELY BUILD OVERHEAD...BRINGING A RETURN OF DRY AND SEASONABLE CONDITIONS. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
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IFR CIGS RISING INTO MVFR THIS MRNG. WL HOLD ONTO FLGT RESTRICTIONS THRU THE DAY...LOW CONFIDENCE IN ACHIEVING VFR. CIGS WILL LOWER AGAIN TONIGHT. WILL LIKELY PLAY THIS CONSERVATIVELY FOR NOW...BUT MORE IFR IS POSSIBLE. VSBYS MAY ALSO REDUCE IN LIGHT FOG...DZ AND -SHRA. FAIRLY NUMEROUS SHOWERS CROSS THE AREA THURSDAY WITH SUB-VFR CONDITIONS LIKELY TO CONTINUE. WITH CAD WEDGE REMAINING IN PLACE...CAN/T REALLY GIVE AN OPTIMISTIC OUTLOOK AT ANY POINT THROUGH FRIDAY NIGHT WITH LOW CLOUDS AND OCCASIONAL SHOWERS CONTINUING THROUGH THE PERIOD. HIGH PRESSURE WILL STRENGTHEN OVER THE AREA SATURDAY. THIS WILL ALLOW FOR CIGS TO IMPROVE TO MVFR AND POSSIBLE VFR LEVELS. HOWEVER...THE HIGH WILL WEAKEN SATURDAY NIGHT AND LOW PRESSURE WILL TRACK THROUGH THE MIDWEST. OVERRUNNING WILL DEVELOP NORTH OF AN APPROACHING WARM FRONT...RESULTING IN LOW CLOUDS ALONG WITH INCREASING CHANCES FOR RAIN. RAIN AND LOW CLOUDS ARE LIKELY EARLY NEXT WEEK AS THE LOW SLOWLY PASSES BY TO THE SOUTH.
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&& .MARINE...
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NELY FLOW ACRS THE WATERS. SPEEDS HV SUBSIDED UNDER SCA CONDS...AND WL DROP HEADLINES FOR THE REST OF TODAY. LOOKING AT AN EXTENDED PERIOD OF MAINLY E OR NE FLOW THROUGH THE END OF THE WEEK. THE MAJORITY OF THE TIME WILL BE SUB-SCA...BUT AN AREA OF LOW PRESSURE MAY ENHANCE WINDS A BIT BY LATE FRIDAY AND COULD LEAD TO SOME 20 KT GUSTS. HIGH PRESSURE WILL BUILD TOWARD THE WATERS SATURDAY. NO MARINE HEADLINES ARE EXPECTED. A WARM FRONT WILL APPROACH FROM THE SOUTH SATURDAY NIGHT THROUGH SUNDAY. LOW PRESSURE WILL RIDE ALONG THE BOUNDARY...PASSING BY JUST TO THE SOUTH SUNDAY NIGHT INTO MONDAY. UNSETTLED CONDITIONS ARE EXPECTED DURING THIS TIME. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF THE WATERS LATER SUNDAY INTO MONDAY.
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&& .TIDES/COASTAL FLOODING... TIDAL ANOMALIES HAVE DROPPED CLOSER TO NORMAL THIS MORNING DUE TO A WESTERLY COMPONENT THE LOW-LEVEL FLOW OVERNIGHT. THE WINDS HAVE TURNED TO THE NORTHEAST...AND NORTHEASTERLY WINDS WILL CONTINUE THROUGH FRIDAY. WATER LEVELS WILL REMAIN BELOW MINOR FLOODING THRESHOLDS TODAY...BUT GUIDANCE DIVERGES SIGNIFICANTLY FOR THE TIDE CYCLE TONIGHT THROUGH THURSDAY. THE ETSS KEEPS WATER LEVELS WELL BELOW FLOODING THRESHOLDS...WHILE THE CBOFS SHOWS SOLID MINOR FLOODING FOR MOST AREAS. AS OF NOW...THE CURRENT FORECAST LEANS TOWARD THE ETSS GIVEN THE FACT THAT THE FLOW WILL BE LIGHT AND NORTH OF EAST. WILL CONTINUE TO MONITOR TIDAL ANOMALIES TODAY TO SEE WHICH GUIDANCE IS PERFORMING BETTER. && .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE.
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&& $$ SYNOPSIS...BJL NEAR TERM...HTS/ADS SHORT TERM...ADS LONG TERM...BJL AVIATION...HTS/ADS/BJL MARINE...HTS/ADS/BJL TIDES/COASTAL FLOODING...BJL

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