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
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KLWX 041857 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 257 PM EDT MON MAY 4 2015 .SYNOPSIS... HIGH PRESSURE HAS MOVED OFF THE SOUTHEAST COAST. A COLD FRONT OVER THE UPPER MIDWEST WILL PUSH SLOWLY SOUTH...STALLING ACROSS THE MID ATLANTIC DURING MIDWEEK. HIGH PRESSURE IS EXPECTED TO RETURN TO THE REGION LATE IN THE WEEK WHILE LOW PRESSURE DEVELOPS SOUTH OF FLORIDA AND MOVES SLOWLY UP THE SOUTHEAST COAST. && .NEAR TERM /TONIGHT/... WARMESY DAY SINCE LAST SEPT COURTESY OF WAA ARND HIGH PRES OFF THE SE CST. M80S CURRENTLY BEING XPRNCD OVR A LARGE PORTION OF THE MID ATLC. CU HV DVLPD OVR THE MTNS...BUT THESE ARE NOT XPCTD TO GROW INTO RW/TRW. TNGT WL BE THE CLOSEST TO "SULTRY" AS WE`VE SEEN SINCE...WELL... SEPT. THE THING THAT IS MSG IS HIGH DWPTS...WHICH WL ACTUALLY BE IN THE 40S AND 50S. OUTSIDE OF THE HIGHLANDS LOWS WL RANGE FM THE M50S TO THE M60S. && .SHORT TERM /TUESDAY/... A FNTL BNDRY XTNDS ACROSS QUEBEC..INTO MI AND THE MIDWEST. THIS WL BE SINKING INTO PA TNGT...WORKING SLOWLY TOWARD THE MASON-DIXON LN DURG THE DAY. POPS WL BE INCRSG DURG THE AFTN...ESPECIALLY ACROSS MD/ERN WV. BLV TEMPS WL STILL MAKE IT INTO THE LM80S OVR MUCH OF THE AREA. THE WIND FIELD ALOFT IS WEAK TUE. THIS WL PRECLUDE ANY CNVCTN THAT IS ABLE TO FORM FM DVLPG IN SVR STORMS. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... THERE IS MINOR DISAGREEMENT BETWEEN OPERATIONAL MODELS ON TIMING AND ORIENTATION OF THE WEAKENING COLD FRONT AS IT SLIPS SOUTH INTO THE AREA TUESDAY NIGHT AND WEDNESDAY. WHILE THIS COULD HAVE SOME INFLUENCE ON TEMPERATURES AND WHERE THE HIGHEST RAIN CHANCES ARE ORIENTED...SENSIBLE WX IMPACTS WILL BE RATHER MINIMAL DUE TO THE WEAK NATURE OF THE FRONT. BY TUESDAY EVENING...THE PARENT LOW IS NEARLY OUT OF THE PICTURE TO THE NE...WITH THE SFC FRONT STRETCHED BETWEEN HIGH PRESSURE CENTERS OVER THE GREAT LAKES AND NEAR BERMUDA. THERE SHOULD BE A DIURNAL DOWNTURN IN CONVECTION...ALTHOUGH THERE WILL REMAIN A CHANCE OF SHOWERS WITH THE FRONT NEAR THE NORTHERN PART OF THE CWA. CLOUDS AND ELEVATED DEW POINTS WILL KEEP LOWS IN THE MID 50S TO MID 60S. AS THE FRONT PROGRESSES SOUTHWARD WEDNESDAY...THE HIGHEST SHOWER CHANCES WILL BE OVER SOUTHERN AND WESTERN PORTIONS OF THE CWA. TERRAIN FORCING MAY PLAY A GREATER ROLE IN SHOWER DEVELOP UNDER THE WEAK FORCING REGIME. INSTBY REMAINS RATHER MEAGER...SO KEPT ONLY A SLIGHT CHANCE OF THUNDER. TEMPERATURES WILL BE A TOUCH COOLER...ESPECIALLY TOWARD NORTHERN MD. HIGHS RANGE FROM MID 70S TO LOWER 80S. SFC HIGH BUILDS TOWARD LONG ISLAND WEDNESDAY NIGHT...AS MID LEVEL RIDGE AXIS BUILDS TOWARD APPALACHIANS. NOT A PARTICULARLY DRYING INFLUENCE AS MOISTURE WILL REMAIN IN THE DECAYING FRONTAL ZONE. HOWEVER SHOWERS SHOULD DIMINISH WITH LOWS IN THE MID 50S TO NEAR 60. MAIN STORY DURING THE EXTENDED WILL BE CONTINUED ABV NORMAL TEMPS WITH LOW CHANCES OF PRECIP. THU LIKELY THE COOLEST DAY OF THE PERIOD...ALTHOUGH HIGH TEMPS WILL STILL BE U70S AS RETURN FLOW RECOMMENCES. HIGH TEMPS LIKELY L/M 80S DURING THE REMAINDER OF THE PERIOD...WHICH IS NEARLY 10 DEGREES ABV CLIMO NORMS. DEWPOINTS WILL ALSO RISE INTO THE L60S...WHILE NOT OPPRESSIVE...THE INCREASE IN LOW LEVEL MOISTURE WILL HELP KEEP NIGHTTIME LOWS IN M60S. DAILY PRECIP CHANCES FOR ANY ONE LOCATION HARD TO NAIL DOWN PRECISELY...AS FORCING IS RATHER NEBULOUS AND WILL BE PRIMARILY DIURNALLY DRIVEN. REGARDLESS...DEEP LAYER SHEAR RATHER WEAK...SO NOT EXPECTING ORGANIZED SVR WX. HOWEVER...INSTABILITY DOES INCREASE OVER THE WEEKEND SO THERE COULD BE A FEW ISOLATED STRONGER T-STORMS DURING THE AFTERNOON HOURS. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... VFR CONDS TNGT. CLDS SHOULD BE ON THE INCRS TUE...ESPECIALLY BWI/MTN/MRB...ALTHO STILL STAYING AT VFR LVLS. RW/TRW ARE PSBL IN THE AFTN. CHANCES OF SHOWERS WILL LESSEN TUESDAY NIGHT BUT BE RENEWED WEDNESDAY. ISOLATED THUNDERSTORM POSSIBLE WEDNESDAY AFTERNOON. COVERAGE OF ANY AVIATION IMPACTS WOULD BE SCATTERED AND BRIEF. IF A MARINE INFLUENCE IS ESTABLISHED BEHIND A COLD FRONT...SUBVFR CIGS/VSBYS COULD BE POSSIBLE WEDNESDAY NIGHT. VFR CONDS EXPECTED THROUGH REMAINDER OF THE PERIOD. && .MARINE... W/ GUSTY SW WINDS HV ISSUED AN SCA FOR THE MAJORITY OF THE WATERS. UPR PTMC SEEING GUSTS INTO THE L20S. SCA IN EFFECT THRU 8 PM THERE. CHANNELING ON THE BAY XPCTD TNGT. SCA ALREADY IN EFFECT THERE. COLD FRONT SLIPS THROUGH THE WATERS LATE TUESDAY NIGHT/ WEDNESDAY...SHIFTING WINDS FROM SW TO NE. COULD BE A HIGHER SURGE OF WINDS NEAR THE FRONT...BUT TIMING IS IN QUESTION AND GUSTS WILL BE MARGINAL IN TERMS OF SMALL CRAFT CONDITIONS. CHANCE OF SHOWERS AND ISOLATED STORMS LINGER INTO WEDNESDAY. LIGHT NE FLOW INTO WEDNESDAY NIGHT. NOT EXPECTING MARINE CONCERNS THROUGH REMAINDER OF THE PERIOD. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR ANZ531>533- 538>542. SMALL CRAFT ADVISORY UNTIL NOON EDT TUESDAY FOR ANZ534-543. SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ535- 536. SMALL CRAFT ADVISORY UNTIL 6 AM EDT TUESDAY FOR ANZ537. && $$ PRODUCTS...WOODY!/ADS/MSE

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