Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 020100 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 900 PM EDT SUN MAY 1 2016 .SYNOPSIS...
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A FRONT WILL REMAIN STATIONARY ACROSS THE AREA THROUGH TONIGHT THEN LIFT NORTH AS A WARM FRONT MONDAY. A COLD FRONT WILL SLOWLY MOVE THROUGH MONDAY EVENING WITH MULTIPLE SURFACE WAVES MOVING ACROSS THE AREA. ANOTHER COLD FRONT IS EXPECTED TUESDAY NIGHT AND HIGH PRESSURE WILL BRIEFLY RETURN FOR WEDNESDAY. LOW PRESSURE MAY IMPACT THE AREA THURSDAY AND FRIDAY BEFORE HIGH PRESSURE RETURNS DURING THE WEEKEND.
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&& .NEAR TERM /THROUGH MONDAY/...
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A STATIONARY FRONT REMAINS DRAPED FROM WESTERN MARYLAND THROUGH THE SHENANDOAH VALLEY INTO NORTH CAROLINA. A COOL EASTERLY FLOW WILL CONTINUE FOR AREAS NORTH AND EAST OF THE BOUNDARY...RESULTING IN LOW CLOUDS ALONG WITH OCCASIONAL DRIZZLE AND AREAS OF FOG. FOG MAY BE DENSE... ESPECIALLY ACROSS HILLTOPS AND HIGHER ELEVATIONS. A DENSE FOG ADVISORY MAY BE NEEDED FOR PORTIONS OF THE AREA OVERNIGHT. CONFIDENCE IS TOO LOW FOR AN ADVISORY AT THIS TIME WITH CONCERN BEING THAT THE STRATUS DECK MAY PREVENT WIDESPREAD VSBYS AT OR BELOW ONE-QUARTER MILE. A FEW SHOWERS AND THUNDERSTORMS HAVE POPPED UP NEAR AND TO THE SOUTH AND WEST OF THE BOUNDARY OVER THE SHENANDOAH VALLEY AND POTOMAC HIGHLANDS. THIS ACTIVITY WILL SPREAD EAST THROUGH THE REST OF THE CWA LATE THIS EVENING INTO THE OVERNIGHT HOURS. HOWEVER...IT SHOULD WEAKEN AS IT MOVES INTO THE COOLER AIR. MORNING LOW CLOUDS AND FOG WILL GRADUALLY ERODE MON MORNING WITH TEMPS RISING INTO THE 70S AS WARM FRONT LIFTS INTO PA. SOME DESTABILIZATION IS LIKELY TO TAKE PLACE IN THE AFTERNOON WITH SCT SHOWERS AND T-STORMS EXPECTED. BEST INSTABILITY IS EXPECTED OVER THE SRN HALF AND EAST OF THE BLUE RIDGE WHERE CDFNT WILL NOT CLEAR THOSE AREAS UNTIL EVENING. A FEW SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS THESE AREAS...WITH DAMAGING WINDS AND LARGE HAIL BEING THE PRIMARY THREATS.
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&& .SHORT TERM /MONDAY NIGHT/...
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MOISTURE ADVECTION CONTINUES MON NIGHT IN SOUTHWEST FLOW AHEAD OF 700-500 MB WAVE. MULTIPLE SFC WAVES ARE EXPECTED TO CROSS THE AREA MON NIGHT ALONG SLOW MOVING BDRY TO BRING ANOTHER ROUND OF MDT PRECIP.
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&& .LONG TERM /TUESDAY THROUGH SUNDAY/...
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ANOTHER IN A SERIES OF LOW PRESSURE WAVES WILL CROSS THE AREA TUESDAY...THEN DEPART TO THE NORTHEAST TUESDAY NIGHT INTO WEDNESDAY AS A STUBBORN FRONT REMAINS DRAPED OVER THE AREA. A LARGE/COLD UPPER LOW WILL DIVE OUT OF CANADA STRAIGHT SOUTH TO OVER THE MID-ATLANTIC THURSDAY...THEN SLOWLY PIVOT OFF TO THE EAST THROUGH FRIDAY LEADING TO A CONTINUATION OF UNSETTLED WEATHER. MODELS ARE MODEST WITH INSTABILITY IN SOUNDINGS AT THIS TIME BUT COULD SEE AN INCREASING TREND GIVEN THE COLD AIR ALOFT IF FLOW TAKES ON A MORE SOUTHERLY/WARM COMPONENT IN THE LOW-LEVELS WEDNESDAY. AFTER THIS UPPER LOW LIFTS OUT...A LARGE AREA OF HIGH PRESSURE WILL BEGIN BUILDING JUST OFF THE SOUTHEAST COAST LEADING TO A STRONG WARMING TREND BEGINNING OVER THE WEEKEND.
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&& .AVIATION /01Z MONDAY THROUGH FRIDAY/...
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AN EASTERLY FLOW WILL RESULT IN MORE LOW CLOUDS ALONG WITH DRIZZLE AND AREAS OF FOG. IFR/SUBIFR CONDITIONS ARE EXPECTED OVERNIGHT INTO MONDAY MORNING. FOG MAY BE DENSE OVERNIGHT WITH VSBYS AROUND ONE-QUARTER MILE POSSIBLE. A FEW SHOWERS AND PERHAPS AND ISOLATED THUNDERSTORM WILL PASS THROUGH THE TERMINALS LATE THIS EVENING. CONFIDENCE FOR THUNDER IS TOO LOW TO MENTION IN THE TAFS AT THIS POINT...BUT WILL HAVE TO BE MONITORED. LOW CLOUDS AND FOG WILL LIFT MONDAY MORNING. SCT T-STORMS EXPECTED MONDAY AFTERNOON AND EVENING WITH ANOTHER ROUND OF MDT RAIN MON NIGHT. SUB-VFR PSBL TUE-WED IN ANY LWR CIGS/SHWRS W/ FRONT STALLED NEARBY. WINDS GENERALLY ELY 10 KTS.
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&& .MARINE... WINDS GENERALLY BELOW SCA BUT GUSTY NEAR T-STORMS ESPECIALLY MON AFTERNOON MIDDLE AND LOWER PORTIONS OF POTOMAC AND CHES BAY. A WEAK PRESSURE GRADIENT WILL PREVAIL OVER THE WATERS WITH A FRONT STALLED NEARBY...LEADING TO GUSTS THAT SHOULD STAY LARGELY BELOW SMALL CRAFT ADVISORY LEVELS DURING THE MIDDLE OF THE WEEK. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...LFR NEAR TERM...BJL/LFR SHORT TERM...LFR LONG TERM...DFH AVIATION...BJL/LFR/DFH MARINE...BJL/LFR/DFH

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