Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 070801 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 401 AM EDT TUE JUL 7 2015 .SYNOPSIS... HIGH PRESSURE WILL DOMINATE TODAY INTO THE FIRST PART OF TONIGHT. A COLD FRONT WILL MOVE IN FROM THE GREAT LAKES ON WEDNESDAY. THE FRONT WILL SLIDE SLOWLY SOUTH ACROSS THE AREA THURSDAY AND FRIDAY BEFORE SLOWLY MOVING BACK NORTH OVER THE WEEKEND. && .NEAR TERM /THROUGH WEDNESDAY/... A WARM AND HUMID DAY IS ON TAP FOR THE MIDDLE ATLANTIC REGION WITH HIGH TEMPERATURES CLIMBING INTO THE LOW 90S EAST OF THE BLUE RIDGE...MID TO UPPER 80S OUT WEST. A COLD FRONT WILL APPROACH FROM THE WEST LATER TONIGHT AND MOVE THROUGH THE REGION ON WEDNESDAY. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE BY THIS EVENING OVER THE POTOMAC HIGHLANDS WITH COVERAGE INCREASING FROM WEST TO EAST ON WEDNESDAY. HAVE INCREASED POPS TO CATEGORICAL DURING THE DAY. NOT EXPECTING SEVERE WEATHER AT THIS TIME AND WILL LEAVE MENTION OUT OF THE HAZARDOUS WEATHER OUTLOOK. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... MAIN PRECIP ASSOCIATED WITH WEAK COLD FRONT SHOULD BE ENDING BY THU MORNING...WITH ONLY LINGERING SHOWERY ACTIVITY REMAINING...IF ANY. LOW CHCS FOR PRECIP DURING THE DAY THU...AS COLD FRONT WILL BE TO OUR SOUTH AND WE ARE LIKELY UNDER SUBSIDENCE FROM DEPARTING MID/UPPER LEVEL WAVE. DIFFICULT TO FIND ANY INSTABILITY THU AFTERNOON...BUT CANNOT RULE OUT A DIURNALLY DRIVEN ISOLATED SHWR/TSTM ALONG/NEAR ANY NEBULOUS FORCING MECHANISMS. TEMPS NEAR CLIMO NORMS WITH M/U 80S IN CWA. WEAK COLD FRONT WILL ONLY TEMPORARILY REDUCE DEWPOINTS...AS BY AFTERNOON THEY WILL RETURN TO THE U60S...WHICH WILL KEEP HEAT INDICES IN THE M90S. SECONDARY COLD FRONT...ASSOCIATED WITH LP MOVING ACROSS OHIO VALLEY...APPEARS TO SLIDE THROUGH THE AREA LATE THU. AT THIS POINT...POOR TIMING ALONG WITH LIMITED MOISTURE AND INSTABILITY AHEAD OF THE FRONT...WOULD KEEP PRECIP CHCS FAIRLY LOW. BETTER MOISTURE/TEMP GRADIENT ALONG FRONT...SO EXPECT TEMPS AND DEWPOINTS TO DROP FURTHER BEHIND THIS SECONDARY SURGE. FRI HIGHS SHOULD BE IN L/M 80S...OR A FEW DEGREES BELOW NORMAL. && .LONG TERM /SATURDAY THROUGH TUESDAY/... QUASI-ZONAL MID/UPPER FLOW PATTERN OF MID-WEEK TRANSITIONS TO NW FLOW PATTERN THROUGH THE EXTENDED...AS RIDGING BECOMES ESTABLISHED OVER THE SE STATES. OUR AREA REMAINS ALONG THE PERIPHERY OF THE RIDGE/ NEAR RING OF FIRE/ WHICH WILL KEEP CHCS FOR UNSETTLED WEATHER THROUGH THE PERIOD...DESPITE ANY CLEAR FORCING MECHANISMS. WARM FRONT LOOKS TO LIFT BACK NORTH THROUGH THE REGION OVER THE WEEKEND...WHICH WILL HELP TO INCREASE TEMPERATURES BY SUN BACK INTO THE U80S...DESPITE THE NW FLOW. BEST CHCS FOR PRECIP APPEAR MON AS RIDGING SLIDES FURTHER EAST OVER SOUTHERN PLAINS AND SW TROUGH DROPS INTO THE AREA. && .AVIATION /08Z TUESDAY THROUGH SATURDAY/... PATCHY FOG AND LOW CLOUDS WILL PERSIST THROUGH MID MORNING BEFORE DISSIPATING. VFR EXPECTED TODAY INTO THE FIRST PART OF TONIGHT. SHOWER AND THUNDERSTORMS WILL BECOME LIKELY LATE TONIGHT AND ESPECIALLY ON WEDNESDAY. VFR CONDS EXPECTED FOR THE REMAINDER OF THE PERIOD OUTSIDE OF ANY SHWR/TSTM ACTIVITY. LOCALIZED SUB-VFR CONDS ARE PSBL DUE TO SHWRS/TSTMS...THOUGH CHCS FOR TSTMS ARE LOW EACH DAY WITH NEBULOUS FORCING. && .MARINE... PERIODIC SCA CONDITIONS ESPECIALLY OVER THE SOUTHERN WATERS THIS AM AND AGAIN AHEAD OF A COLD FRONT THIS EVENING. WINDS BELOW SCA EXPECTED ON WEDNESDAY. SHOWERS AND THUNDERSTORMS MAY CONTAIN GUSTY WINDS AND HEAVY RAINFALL ON WEDNESDAY. WINDS EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH THE EXTENDED. LOW CHCS FOR TSTMS OVER THE WATERS ARE FORECAST EACH DAY THROUGH THE EXTENDED. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR ANZ533- 534-537-543. && $$ SYNOPSIS...KRW NEAR TERM...KRW SHORT TERM...MSE LONG TERM...MSE AVIATION...MSE/KRW MARINE...MSE/KRW TIDES/COASTAL FLOODING...

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