Area Forecast Discussion
Issued by NWS Sterling, VA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KLWX 270102 AAA AFDLWX AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 902 PM EDT TUE MAY 26 2015 .SYNOPSIS... HIGH PRESSURE WILL REMAIN OFFSHORE THIS WEEK. A SOUTHERLY FLOW WILL BRING WARM HUMID CONDITIONS TO THE MID ATLANTIC THROUGH SATURDAY. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EACH AFTERNOON AND EVENING. A COLD FRONT WILL APPROACH THE AREA EARLY NEXT WEEK. && .NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
SHOWERS HAVE DIMINISHED/WEAKENED CONSIDERABLY IN THE LAST HALF HOUR WITH NO LIGHTNING SEEN IN THE LAST 30 MINUTES. CURRENT BAND OF CLOUDS AND LIGHT SHOWERS WILL LIFT NORTH INTO PA TONIGHT ON A NNE STEERING FLOW. A BAND OF SHOWERS OVER ERN OH AND WRN WV WILL MOVE EAST INTO THE HIGHLANDS TOWARD DAYBREAK AND THE I-81 CORRIDOR BY 18Z WED AND TO THE UPPER CHES BAY BY 00Z THU. THESE SHOWERS MAY PRODUCE BRIEF DOWNPOURS DUE TO VERY HIGH MOISTURE CONTENT AND HIGH K INDICES BUT FAST STORM MOTION SHOULD KEEP RAINFALL AMOUNTS MANAGEABLE.
-- End Changed Discussion --
&& .SHORT TERM /WEDNESDAY NIGHT/... THE UPPER LEVEL RIDGE MOVES FURTHER EAST WEDNESDAY AND AN UPPER LEVEL TROUGH MOVES ACROSS THE GREAT LAKES. FALLING HEIGHTS... MOISTURE AS WELL AS MULTIPLE DISTURBANCES COUPLED WITH A UPPER LEVEL JET WILL LEAD TO SHOWERS AND THUNDERSTORMS WEDNESDAY. MOISTURE FROM THE ACTIVITY ACROSS AL/GA WILL LIKELY MOVE INTO THE MID-ATLANTIC WEDNESDAY MORNING. SHOWERS ARE EXPECTED TO MOVE WEST TO EAST WEDNESDAY. THINNER CLOUDS ARE EXPECTED EAST OF THE BLUE RIDGE BY WEDNESDAY AFTERNOON AND WILL LEAD TO HEATING AND MORE INSTABILITY. SHEAR WILL BE MARGINAL...AROUND 20-30KTS WITH THE BEST SHEAR NEAR THE POTOMAC HIGHLANDS SIMILAR TO TODAY...TUESDAY. DUE TO THE MULTIPLE DISTURBANCES THAT MAY MOVE OVER THE REGION WEDNESDAY...STRONG THUNDERSTORMS ARE EXPECTED ACROSS THE REGION. && .LONG TERM /THURSDAY THROUGH TUESDAY/... WE ARE IN THE SUMMERTIME PATTERN W/ THE HIGH OFF THE CST. THIS WL CONT TO DRAW WARMTH AND MOISTURE INTO THE MID ATLC WED NGT-THU NGT. WHILE TSTMS WL BE PSBL BOTH WED EVE AND THU AFTN THERE DOES NOT APPEAR TO BE MUCH SHEAR OR A FORCING MECHANISM SO SVR THREAT LOOKS MARGINAL AT BEST. TEMPS SHOULD RMN STEADY - HIGHS IN THE 80S...PSBLY A90 IN THE CITIES. LOWS IN THE 60S...L70S IN THE CITIES. A WEAK WARM FRONT WILL SLIDE NORTHWARD ACROSS THE MID ATLANTIC REGION FRIDAY NIGHT. A SHOWER OR THUNDERSTORM COULD LINGER IN PARTS OF THE AREA WITH LOW TEMPERATURES BOTTOMING OUT IN THE MIDDLE 60S. A COLD FRONT WILL APPROACH THE REGION SATURDAY...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE REGION INTO SATURDAY NIGHT. TEMPERATURES SATURDAY WILL REACH THE MIDDLE 80S WITH LOWS SATURDAY NIGHT GETTING INTO THE MIDDLE 60S. THE COLD FRONT SHOULD SLOWLY PUSH THROUGH THE REGION SUNDAY. THE EUROPEAN MODEL REMAINS THE SLOWER MODEL OVER THE GFS. HOWEVER...THE GFS MODEL RUNS HAVE BEEN SHOWING THE FRONT SLOWING DOWN AS WELL. A SLOW-MOVING COLD FRONT TENDS TO BE THE TREND. SHOWERS AND THUNDERSTORMS WILL FORM AHEAD OF AND ALONG THE FRONT. TEMPERATURES WILL BE ABOVE NORMAL SUNDAY. A WEDGE OF HIGH PRESSURE WILL BUILD SOUTHWARD ALONG THE EAST COAST SUNDAY NIGHT AND MONDAY...HELPING TO COOL CONDITIONS DOWN A LITTLE. HOWEVER...OVERRUNNING MOISTURE FROM THE SOUTH...PASSING MID-LEVEL DISTURBANCES TO THE NORTH...AND A DEVELOPING LOW ALONG THE FRONT COULD BRING ANOTHER THREAT FOR RAIN SHOWERS. THUNDERSTORMS SHOULD BE LIMITED WITH LOW LEVEL COOLER AIR EVENTUALLY WORKS ITS WAY INTO THE REGION. TEMPERATURES MAY BE A FEW DEGREES ABOVE NORMAL EACH PERIOD. AS THE RIDGE OF HIGH PRESSURE BREAKS DOWN TUESDAY...UPPER LEVEL DISTURBANCES ARE EXPECTED TO MOVE ACROSS THE OHIO VALLEY INTO THE LOWER GREAT LAKES. THESE DISTURBANCES COULD POSE A SHOWER THREAT TUESDAY WITH HIGH TEMPERATURES ONLY IN THE LOWER 80S. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
MID-LEVEL DRYING OVERNIGHT COUPLED WITH VERY MOIST LOW-LEVELS MAY RESULT IN MVFR CIGS ESPECIALLY AT DCA...BWI AND MTN. INCLUDED A 2-3 HR PERIOD OF MVFR CIGS AT THOSE TAF SITES EARLY WED MORNING. SHOWERS/T-STORMS APPEAR LIKELY AT KMRB WED AFTERNOON AND PERHAPS BWI AND MTN. ACTIVITY SHOULD BE MORE SCATTERED AT IAD...DCA AND CHO. VFR CONDS XPCTD OUTSIDE OF ANY PSBL RW/TRW WED NGT-THU NGT. NO PROBS XPCTD FRI. VFR OR MVFR CONDITIONS FRIDAY NIGHT WITH A SHOWER OR THUNDERSTORM IN THE AREA NEAR CHO OR MRB TERMINAL. VFR ELSEWHERE. VFR CONDITIONS SATURDAY AT MTN...BWI...DCA TERMINALS. MVFR OR IFR CONDITIONS AT IAD...CHO...AND MRB TERMINALS FOR SHOWERS AND THUNDERSTORMS IN THE AREA.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
S WINDS WILL CONTINUE ON THE WATERS. SCA CONDITIONS EXPECTED TO CONTINUE ON THE LOWER TIDAL POTOMAC AND CHESAPEAKE BAY SOUTH OF POOLES ISLAND THROUGH TONIGHT. WIND FIELD SUBSIDES NORTH OF SANDY POINT LATE TONIGHT INTO WEDNESDAY. SHOWERS AND THUNDERSTORMS EXPECTED WEDNESDAY AFTERNOON AND SOME STORMS MAY PRODUCE GUSTY WINDS AND HEAVY RAIN WHICH MAY REQUIRE SPECIAL MARINE WARNINGS. NO MARINE HAZARDS THURSDAY NIGHT. SMALL CRAFT ADVISORY CONDITIONS POSSIBLE SATURDAY WITH SOUTHERLY WINDS GUSTING 20 KNOTS.
-- End Changed Discussion --
&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ531-538- 539. SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR ANZ532>534- 537-540>543. && $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...HAS LONG TERM...ABW AVIATION...LFR MARINE...LFR

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.