Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 270016 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 816 PM EDT SUN APR 26 2015 .SYNOPSIS... LOW PRESSURE OVER THE CAROLINAS AND OFFSHORE WATERS WILL STRENGTHEN AS IT MOVES FURTHER OUT TO SEA TONIGHT. AN UPPER LEVEL TROUGH WILL MOVE THROUGH THE AREA MONDAY. HIGH PRESSURE WILL MOVE INTO THE AREA TUESDAY. ANOTHER LOW PRESSURE SYSTEM IS EXPECTED TO TRACK ACROSS THE SOUTHEASTERN U.S. LATE IN THE WEEK. && .NEAR TERM /THROUGH MONDAY/...
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ONLY A FEW CLOUDS AROUND THE MID-ATLANTIC THIS EVENING AS HIGH PRESSURE PERSISTS OVERHEAD. THE PARENT HIGH ACROSS THE NRN PLAINS WILL CONTINUE TO BUILD INTO THE REGION TONIGHT AND A PRESSURE GRADIENT WILL FORM ACROSS THE REGION INTO MONDAY. WINDS WILL INCREASE TO 5-10KTS BY MON MORNING AND THEREFORE PLACES WILL NOT RADIATE AS WELL. FCST MIN TEMPS IN THE LOW TO MID 40S EAST OF THE BLUE RIDGE AND THE 30S ACROSS THE MTNS. PATCHY FROST POSSIBLE ALONG THE BLUE RIDGE MTNS AND HIGHER ELEVATIONS IN THE VA HIGHLANDS AS TEMPS APPROACH 35 DEG. AN UPPER LEVEL TROUGH EXTENDS FROM THE GULF OF MAINE TO THE LOWER GREAT LAKES WHILE A SHORTWAVE TROUGH MOVES ACROSS MI. THESE FEATURES WILL MOVE SOUTH TONIGHT AND CLOUDS WILL INCREASE FROM N TO S LATE TONIGHT...ANOTHER ASPECT THAT WILL HAMPER TEMPS FROM DROPPING TOO LOW. THE UPPER LEVEL TROUGH WILL MOVE INTO THE MID-ATLANTIC MONDAY WITH EMBEDDED SHORTWAVE TROUGHS. COLD AIR ALOFT WILL LEAD TO STEEPENING LAPSE RATES. SHOWERS ARE EXPECTED TO BREAK OUT ACROSS NY/PA MONDAY MORNING AS THE UPPER LEVEL TROUGH AXIS SWINGS SOUTHWARD. SHOWERS ARE EXPECTED TO MOVE INTO NRN MD AFTER 16Z MONDAY BUT COVERAGE SEEMS WEAK AND THEREFORE ONLY SCATTERED SHOWERS ARE EXPECTED. AN INVERTED V SIGNITURE ON FCST SOUNDINGS AND 20-30KTS AT THE TOP OF THE MIXING LAYER WILL LEAD TO GUSTY N-NW WINDS THROUGH THE AFTERNOON MONDAY. FCST MAX TEMPS ARE IN THE UPPER 50S LOW 60S AND 40S IN THE MTNS.
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&& .SHORT TERM /MONDAY NIGHT/...
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WINDS TAPER OFF MON EVENING AS UPPER LVL TROUGH PIVOTS OFFSHORE AND THE SHORTWAVE PUSHES SOUTH. SUBSIDENCE BUILDING IN THE WAKE SHOULD LEAD TO SKIES SCATTERING AND DRY CONDITIONS. LOWS MON NIGHT WILL BE SLIGHTLY BELOW NORMAL.
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&& .LONG TERM /TUESDAY THROUGH SUNDAY/...
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DRY WX THEN PERSISTS TUES THRU TUES NIGHT AS THE REGION REMAINS POSITIONED BETWEEN TWO CLOSED LOWS. HIGH PRESSURE CENTERED OVER THE CENTRAL PLAINS WILL NUDGE IN FROM THE NORTH DURING THE DAY TUES...BUT WILL QUICKLY RETREAT AS LOW PRESSURE OVER THE GULF STATES BEGINS TO ORGANIZE AND PUSH NORTH. OVERSPREADING PCPN WITH THIS LOW LOOKS TO REMAIN SOUTH THRU AT LEAST 12Z WED. TEMPS REMAIN JUST BELOW NORMAL FOR TUES-TUES NIGHT...THOUGH IF THE WINDS HOLD MORE TO A NW FLOW RATHER THAN SHIFTING TO THE NORTH...COULD SEE TEMPS SLIGHTLY WARMER WITH DOWNSLOPING EFFECTS. WED WILL BE A RELATIVELY NICE SPRING DAY...WITH TEMPS NEAR CLIMO. CLOUDS SHOULD START INCREASING BY LATE WED...ESPECIALLY IN THE SOUTH...AS LOW PRESSURE ALONG GULF COAST BEGINS TO IMPACT OUR REGION. CLOUDINESS SHOULD HELP TEMPS FROM FALLING TOO FAR WED NIGHT...KEEPING THEM SLIGHTLY AOA NORMAL. MODEL GUIDANCE HAS COME INTO SLIGHTLY BETTER AGREEMENT WITH OVERALL HANDLING OF LOW PRESSURE TRACKING TO OUR SOUTH ON THU. STILL APPEARS THAT THE BULK OF THE IMPACTS REMAIN TO OUR SOUTH...WITH MAINLY LIGHT SHOWERS OVERSPREADING THE CWA THROUGH THU. HOWEVER...THIS COULD CHANGE IF TRACK OF LOW SHIFTS CLOSER TO OUR AREA. COULD BE SOME WRAPAROUND PRECIP LINGERING INTO FRIDAY...ALTHOUGH IT WOULD LIKELY BE LIGHT. HIGH TEMPS SAT SLIGHTLY AOA NORMAL (L70S) ACROSS CWA...WITH LOW HUMIDITY.
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&& .AVIATION /00Z MONDAY THROUGH FRIDAY/... VFR EXPECTED THROUGH THE TAF PERIOD. NORTH WINDS 5-10KT. LIGHT N-NW FLOW CONTINUES. WINDS INCREASE MONDAY TO 10-15 KT WITH GUSTS 20 TO 25 KT. VFR CONDITIONS MON NIGHT-TUES NIGHT. VFR COND LIKELY WED...BEFORE A CHANCE OF SUB-VFR IN RAIN SHOWERS THU AS LOW PRESSURE TRACKS TO OUR SOUTH. && .MARINE...
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N-NE WINDS 10KT OR LESS THIS AFTERNOON. WINDS SHIFT NW LATE TONIGHT AND INCREASE TOWARDS MORNING AS THE GRADIENT STRENGTHENS BETWEEN LOW PRESSURE OFFSHORE AND HIGH PRESSURE WELL TO THE WEST. A SCA REMAINS IN EFFECT FOR ALL WATERS MONDAY FOR WINDS 15-20 KT WITH 25 KT GUSTS. SCA CONDITIONS WILL PERSIST FOR THE MAIN CHANNEL OF THE BAY AND LOWER TIDAL POTOMAC MONDAY NIGHT. SUB-SCA CONDITIONS ALL WATERS TUES AFTN-NIGHT. NOT EXPECTING MARINE CONCERNS WED AS FLOW REMAINS LIGHT UNDER HIGH PRESSURE. WIND FIELD INCREASES SOME ON THU...BUT OVERALL STRENGTH WILL DEPEND ON PROXIMITY OF SFC LOW...WHICH IS STILL UNCERTAIN.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 8 AM MONDAY TO 6 AM EDT TUESDAY FOR ANZ531>534-537>543. SMALL CRAFT ADVISORY FROM 8 AM TO 8 PM EDT MONDAY FOR ANZ530- 535-536.
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&& $$ SYNOPSIS...KS NEAR TERM...HAS/KS SHORT TERM...SEARS LONG TERM...MSE AVIATION...SEARS/KS/MSE MARINE...SEARS/HAS/KS/MSE

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