Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 250133 AAA AFDLWX AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 933 PM EDT TUE MAR 24 2015 .SYNOPSIS... HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT THROUGH WEDNESDAY. A COLD FRONT WILL PASS THROUGH THE AREA LATE THURSDAY INTO THURSDAY NIGHT BEFORE REMAIN OVERHEAD THIS AFTERNOON. THE HIGH WILL MOVE OFF THE COAST WEDNESDAY AND A COLD FRONT IS EXPECTED TO PASS THROUGH LATE THURSDAY INTO THURSDAY NIGHT. CANADIAN HIGH PRESSURE WILL RETURN FOR FRIDAY INTO THE WEEKEND. && .NEAR TERM /THROUGH WEDNESDAY/... AFTER THE AFTN STRATUS DECK BROKE UP AND MOVED EAST...CLEARING MET THE MID-ATLC REGION W/ BRIEF SUNLIGHT TO HELP OUR TEMPS CLIMB BACK TOWARD THE 50S OVER THE SRN HALF OF THE CWA AND AT LEAST ABOVE THE 40F DEG MARK N OF I-66. A DRY NE BREEZE HAS BEGUN TO SHIFT TOWARD SE AS HIGH PRESSURE ROLLS OFF THE COAST. A SLIGHTLY MORE MOIST LOW LEVEL FLOW IN THE COMING HRS WILL INCREASE DEWPOINTS SLIGHTLY...INTO THE M-U20S. THIS WILL HELP MODERATE TEMPS OVERNIGHT A BIT BUT STILL ALLOW MIN TEMPS TO NEAR THE FREEZING MARK BY DAWN WED. MEANWHILE...THE LONG OUTSTRETCHED ARM OF THE WARM SECTOR FROM A POTENT LOW OVER THE NRN PLAINS REACHES ALL THE WAY TO THE CAROLINAS. WE ARE ON THE NRN FRINGE OF THIS ACTIVITY...W/ SOME LIGHT SHOWERS AND UPSLOPE ACTIVITY OVER THE SRN APLCNS. THE EXTREME SWRN PORTION OF THE CWA UNDER A FEW HRS OF STEADY PRECIP HAS NEARLY SATURATED AN OTHERWISE DRY COLUMN BUT STILL MAINLY RETURNS NOT REACHING THE SFC. A BRIEF PERIOD OF FREEZING TEMPS ALONG THE HIGHEST TERRAIN OF THIS AREA DURING THE PREDAWN HRS MAY ALLOW FOR SOME BRIEF FZRA/DZ BUT MORE LIKELY TO STAY AS A COLD RAIN. RAIN CHANCES MAY EXTEND FARTHER NORTH INTO THE SHENANDOAH VALLEY WEDNESDAY. HOWEVER...WITH LITTLE FORCING CONFIDENCE IN PRECIP IS LOW. EVEN IF THERE IS RAIN...IT WILL BE LIGHT AND MOST OF THE TIME WILL TURN OUT DRY. MAX TEMPS WILL REMAIN BELOW CLIMO FOR MOST AREAS DUE TO THE CLOUD COVER. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... HIGH PRESSURE WL BE MOVG OFFSHORE WED NGT. IN RETURN FLOW TEMPS WL BE FAIRLY MILD W/ LOWS IN THE 40S. THU LOOKS TO BE WARM...CLDY..AND WET. A CD FNT WL BE APRCHG THE MID ATLC...ALLOWING TEMPS TO CLIMB INTO THE LM70S ACROSS MUCH OF THE AREA. COLDEST TEMPS SHOULD BE IMMEDIATELY ALONG THE BAY. ALTHO THE E CST HAD A COLD WINTER LATE MAR IS NOT TOO ERLY TO BE THINKING ABT PSBL CNVTN. AHD OF THE FNT LO TOPPED CELLS COULD DVLP. THE THEAT FOR RA/ISOLD TSTMS WL CONT THU EVE B4 WANING. FRI WL BE COOLER BUT NOT AS COLD AS THE WKND WL BE - HIGHS STILL XPCTD TO REACH 55-60 W/ BRZY NW WINDS. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... AN UPPER-LEVEL TROUGH WILL SWING THROUGH THE AREA FRIDAY NIGHT INTO SATURDAY BEFORE COLD HIGH PRESSURE BUILDS OVERHEAD SATURDAY NIGHT INTO SUNDAY. A NORTHWEST FLOW AHEAD OF THE HIGH WILL USHER IN UNUSUALLY COLD CONDITIONS FOR THIS TIME OF YEAR. THE HIGH WILL MOVE OFF THE COAST LATER SUNDAY AND MILDER CONDITIONS ARE EXPECTED IN THE AFTERNOON DUE TO A RETURN FLOW...BUT TEMPS WILL LIKELY REMAIN BELOW CLIMO. A COLD FRONT WILL PASS THROUGH THE AREA MONDAY...BRINGING A CHANCE FOR SHOWERS. MILDER CONDITIONS ARE EXPECTED WITH A SOUTHWEST FLOW AHEAD OF THE FRONT. HIGH PRESSURE WILL RETURN FOR THE MIDDLE PORTION OF NEXT WEEK. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... VFR CONDS WILL LINGER INTO THE DAYTIME HRS WED. WINDS CHANGING TO MORE SE OVERNIGHT AND AN INCREASE OF MID DECKS ABOUT THE ONLY NOTE THRU THEN. KCHO MAY BE THE EXCEPTION...BEING CLOSER TO SOME LIGHT RAIN AND LOWER CIGS. MVFR CONDS WILL BECOME MORE WIDESPREAD BY LATE AFTN. ALTHOUGH RAIN CANNOT BE RULED OUT...ESPECIALLY ACROSS KCHO...MOST OF THE TIME WILL TURN OUT DRY ACROSS THE TERMINALS. M CLDY CONDS XPCTD WED NGT...PSBLY IN THE LIFR CAT. SOME IMRVMNT XPCTD THU MRNG...THEN DEGRADING LATE IN THE DAY AND OVRNGT AHD OF A CD FNT. RA XPCTD THU AFTN/OVRNGT W/ ISOLD TSTMS PSBL. CONDS SHOULD BEGIN IMPRVG AS WINDS TURN TO THE NW FRI. VFR CONDITIONS ARE EXPECTED THROUGH THE WEEKEND. && .MARINE... HIGH PRESSURE WILL REMAIN OVER THE WATERS TONIGHT BEFORE MOVING OFF TO THE EAST WEDNESDAY. A SOUTHERLY FLOW WILL DEVELOP WEDNESDAY AND WINDS MAY GUST CLOSE TO SCA CRITERIA DURING THE AFTERNOON. HAVE CAPPED GUSTS AROUND 15 KNOTS FOR NOW DUE TO THE RELATIVELY COOLER WATERS. SCA CONDS XPCTD THU AHD OF A CD FNT...W/ ISOLD TSTMS PSBL...THEN TURNING TO THE NW AFTR MDNGT THU W/ WINDS CONTINUING ABV SCA VALUES INTO FRI MRNG. HIGH PRESSURE WILL BUILD OVER THE WATERS FOR THE WEEKEND. && .TIDES/COASTAL FLOODING... SOUTHERLY WINDS WILL DEVELOP WEDNESDAY AND THE SOUTHERLY FLOW WILL INCREASE AHEAD OF A COLD FRONT THURSDAY. THE INCREASED SOUTHERLY FLOW WILL CAUSE WATER LEVELS TO ELEVATE...AND TIDAL ANOMALIES MAY BE HIGH ENOUGH FOR MINOR FLOODING NEAR TIMES OF HIGH TIDE THURSDAY INTO THURSDAY NIGHT. THE COLD FRONT WILL PASS THROUGH LATER THURSDAY EVENING AND A NORTHWEST FLOW WILL CAUSE WATER LEVELS TO DECREASE LATE THURSDAY NIGHT INTO FRIDAY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ UPDATE...GMS PREV DISCUSSION...BJL/WOODY!/IR

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