Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 061230 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 830 AM EDT WED MAY 6 2015 .SYNOPSIS...
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A WEAK COLD FRONT ACROSS PENNSYLVANIA WILL DRIFT SOUTHWARD ACROSS THE AREA TODAY BEFORE DISSIPATING TONIGHT. HIGH PRESSURE BUILDS OVER THE NORTHERN MID-ATLANTIC THURSDAY. LOW PRESSURE OFF THE CAROLINA COAST FRIDAY WILL GRADUALLY ERODE THIS WEEKEND...SENDING ITS MOISTURE NORTHEASTWARD. A COLD FRONT WILL ARRIVE EARLY NEXT WEEK.
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&& .NEAR TERM /TODAY/...
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WEAK-TO-NON-EXISTANT COLD FRONT CURRENTLY POSITIONED JUST NORTH OF THE MASON-DIXON WILL NUDGE SOUTH TODAY...EVENTUALLY STALLING OVER NORTHERN PORTIONS OF THE CWA. THIS BOUNDARY WILL YET AGAIN PROVIDE THE BASIS FOR SHOWER AND TSTM DEVELOPMENT TODAY WITH LACK OF FORCING ALOFT AS RIDGING BUILDS IN. DECENT WARMING THIS MORNING AHEAD OF THE FRONT SHOULD AID IN DESTABILIZING THE ATMOSPHERE ENOUGH TO TRIGGER SCT SHOWERS. ISO TSTM PSBL IN THE MIX...THOUGH INSTABILITY IS QUITE MINIMAL AND LAPSE RATES/SHEAR ON THE WEAKER SIDE. BEHIND THE FRONT EXPECTING A MORE STABLE ATMO AS ELY FLOW SETS UP. THIS SHOULD LIMIT ANY THUNDER DEVELOPMENT...AND POTENTIALLY ANY PCPN AT ALL. SHEN VLLY SHOULD WARM INTO THE 80S...WITH AREAS TO THE NORTH CLOSER TO THE MASON-DIXON HOVERING IN THE MID-UPPER 70S.
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&& .SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
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COLD FRONT CONTINUES TO SAG S TONIGHT...DISSIPATING BY THURS MORNING. LINGERING PCPN THIS EVENING WILL TAPER OFF AFTR SUNSET WITH LOSS OF HTG. DRY WX SETTING UP BY THE SECOND HALF OF THE NIGHT AS SFC HIGH PRESSURE OVER NEW ENGLAND BUILDS SOUTH UNDER THE BUILDING RIDGE. SFC HIGH KEEPS MOST OF THE AREA DRY THURS THRU THURS NIGHT AS THE RIDGE AXIS SHIFTS EAST...STRADDLING THE CWA. DID MAINTAIN SLIGHT CHC POPS WEST OF THE BLUE RIDGE WITH MINIMAL INSTABILITY NOTED COMBINING WITH TERRAIN INFLUENCES OFF THE ELY FLOW. ANY PCPN TAPERS OFF YET AGAIN FOR THURS NIGHT. ELY FLOW WILL AID IN KEEPING TEMPS COOLER DURING THE DAY THURS...WITH MOST AREAS IN THE 70S AND ONLY POCKETS REACHING 80.
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&& .LONG TERM /FRIDAY THROUGH TUESDAY/... THERES DECENT SYNOP SCALE AGREEMENT THAT LOPRES WL BE SOMEWHERE ALONG THE CAROLINA COAST FRI WHILE RDGG WL RESIDE ACRS THE CWFA AND A CDFNT WL BE ACRS THE WRN GRTLKS. CHALLENGE INVOLVES DETERMINING WHAT HAPPENS NEXT TO THE LOW. DONT BELIEVE IT WL REACH US DIRECTLY. EVEN IF IT DECAYS TO OUR S UNDER THE MID-LVL RDG...ITS MSTR WL BE ADVECTED NWD. WHILE THAT WONT AFFECT FRI FCST...IT DOES BECOME A PLAYER FOR THE WKND. HV INCRSG DEWPTS...NEAR 60F FRI/LWR-MID 60S SAT- SUN...AND HV INTRO CHC POPS FOR SAT/EXPANDED CVRG SUN. FURTHER... THERE SHUD BE SUFFICIENT RH FOR ADDED CLDS...AND HV SOMETHING THAT/LL BE BORDERLINE PTSUN IN THE DATABASE. MAXT SHUDNT BE FAR FM PERSISTENCE...LWR 80S. BUT THE ANOMOLOUSLY HIGH DEWPTS SUGGST MIN-T WL BE ON THE MUGGY SIDE. USED THESE DEWPTS FOR A STARTING POINT FOR MIN-T-- MID 60S FOR SUN/MON ELY MRNGS. CARRIED THE TROPICAL MSTR FEED INTO MON. SAME CONSIDERATIONS BUT POPS/TEMPS/DEWPTS A PINCH HIER AS AMS FM THE SERN CONUS ADVECTS ACRS MID ATLC. AM KEEPING THUNDER IN FCST. INSTBY IMPROVES A LTL VS WKND FCST. AT THIS POINT NOT SOLD ON ANY STRONG/SVR STORMS THO. CDFNT PARKED TO OUR W/NW AT THE BGBG OF THE XTNDD FCST WL FINALLY HV ROOM TO SWEEP EAST BY TUE. IF THERE WERE ANY STRONG STORMS...THIS WUD LKLY BE THE DAY. HWVR JURY STILL OUT AS TO MAGNITUDE TO THREAT. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
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INCRSG MID-HIGH LVL CLOUDS TODAY. GENERALLY EXPECTING VFR THRU 00Z...WITH PSBL STRATUS FORMING TONIGHT WITH THE FRONT STALLING OVER THE REGION. SCT SHOWERS AND ISO TSTMS PSBL AFTR 18Z. CONFIDENCE OF TIMING/LOCATION TOO LOW TO INCLUDE AS -SHRA/TSRA ATTM...SO WILL MAINTAIN VCSH. ANOTHER DAY OF LIGHT WINDS...MAINLY LESS THAN 8 KTS. NE FLOW THIS MORNING WILL BECOME ELY FOR THE AFTN THRU TONIGHT. ANY SHOWER/TSTM COULD BRING A BRIEF PERIOD OF GUSTY WINDS THIS AFTN. OUTLOOK... VFR FRI. ISOL-SCT SHRA/TSRA PSBL DAILY SAT-SUN...MAINLY AFTN/EVE. MAY BE BRIEF FLGT RESTRICTIONS IF A TERMINAL IS IMPACTED. THATS A LOW CONFIDENCE FCST AT THIS VANTAGE POINT. FURTHER...CUD HV PREDAWN FOG ASSUMING WET GROUND BEFORE NIGHTFALL FLWD BY PRTL CLRG. THAT FCST HIGHLY CONDITIONAL.
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&& .MARINE... GENERALLY SUB-SCA CONDITIONS EXPECTED ON ALL WATERS THRU THURS NIGHT WITH WEAK PRESSURE GRADIENT IN PLACE. SCT SHOWERS AND TSTMS THIS AFTN COULD RESULT IN BRIEF PERIODS OF GUSTY CONDITIONS... MAINLY LATE AFTN AND EVENING TIME FRAME. WEAK PRESSURE PTTN THRU THE WKND. NO HAZARDS XPCTD ATTM. LOPRES S OF WATERS MAY EJECT NEWD...PROVIDING BRIEF/LCL SHRA/TSRA BCMG MORE NMRS BY END OF PD. && .CLIMATE...
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THE WARMEST AIRMASS OF THE 2015 SO FAR HAS MOVED OVER THE REGION DURING THE EARLY PART OF THIS WEEK. DCA REACHED A HIGH OF 86 DEGREES ON TUESDAY MAY 5TH...THE WARMEST DAY SINCE SEPTEMBER 21ST 2014 WHEN THE TEMPERATURE REACHED 86 DEGREES. BWI REACHED A HIGH OF 85 DEGREES ON TUESDAY MAY 5TH...THE WARMEST DAY SINCE SEPTEMBER 11TH 2014 WHEN THE TEMPERATURE REACHED 89 DEGREES. IAD REACHED A HIGH OF 85 DEGREES ON TUESDAY MAY 5TH...THE WARMEST DAY SINCE SEPTEMBER 11TH 2014 WHEN THE TEMPERATURE REACHED 86 DEGREES. CHO REACHED A HIGH OF 85 DEGREES ON TUESDAY MAY 5TH...THE WARMEST DAY SINCE SEPTEMBER 21ST 2014 WHEN THE TEMPERATURE REACHED 87 DEGREES. DMH REACHED A HIGH OF 86 DEGREES ON MONDAY MAY 4TH...THE WARMEST DAY SINCE SEPTEMBER 11TH 2014 WHEN THE TEMPERATURE REACHED 90 DEGREES. HGR REACHED A HIGH OF 85 DEGREES ON MONDAY MAY 4TH...THE WARMEST DAY SINCE SEPTEMBER 6TH 2014 WHEN THE TEMPERATURE REACHED 90 DEGREES. MRB REACHED A HIGH OF 85 DEGREES ON MONDAY MAY 4TH...THE WARMEST DAY SINCE SEPTEMBER 21ST 2014 WHEN THE TEMPERATURE REACHED 86 DEGREES.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE.
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&& $$ UPDATE...WOODY! PRVS...APS/HTS/DFH

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