Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 010151 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 951 PM EDT TUE JUN 30 2015 .SYNOPSIS... A FRONTAL BOUNDARY WILL REMAIN NORTH OF THE AREA THROUGH TONIGHT. LOW PRESSURE TRACKING THROUGH THE EASTERN GREAT LAKES WILL SLOWLY DRAG A COLD FRONT NEAR THE AREA WEDNESDAY...WITH THE FRONT PUSHING THROUGH AND STALLING TO THE SOUTH THROUGH THE END OF THE WEEKEND. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... SVR TSTM WATCH HAS BEEN CANCELLED FOR THE REMAINDER OF THE AREA. UPPER LVL TROF REMAINS THE MAIN PLAYER IN CONVECTION DEVELOPMENT FOR THE AREA TONIGHT INTO WED AS IT PIVOTS FROM THE GL REGION EAST INTO THE NORTHEAST. 01Z WATER VAPOR IMAGERY INDICATING EMBEDDED SHORTWAVE OVER WV TRIGGERING ON GOING CONVECTION...EXTENDING EAST INTO WESTERN VA/EASTERN WV WHERE THE BETTER INSTABILITY AND SHEAR STILL RESIDE. ISO STRONG TSTMS STILL PSBL WITH THE ENVIRONMENT STILL TO BE WORKED OVER...MAINLY THRU 03Z...WITH SCT SHOWERS THEN EXPECTED TO PUSH ACROSS THE CWA THE REMAINDER OF THE NIGHT AS THE TROF SWINGS THRU. THE TROF WL EMERGE OVER THE ERN SHORE BY WED MRNG. A CDFNT WL BE APPROACHING...ATTENDANT FM LOPRES THAT WL BE TRACKING ACRS QUEBEC BY THAT TIME. HWVR...THE CDFNT LOOKS QUITE WEAK...AND AM STRUGGLING TO FIND FORCING MECHANISMS. AMS WL STILL BE QUITE MOIST BUT NOT THAT UNSTBL. MID LVL LAPSE RATES WL BE DECENT. WL HOLD ONTO LOW END CHC POPS...HIER THAN MAV/MET...AND CONT TIL SUNSET. WL STILL BE IN THE WARM SECTOR TMRW...SO TEMPS WL BE SLGTLY MUGGY WITH HIGHS MID-UPR 80S. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... LOW PRESSURE WILL MOVE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY THURSDAY MORNING WHILE A COLD FRONT REMAINS STALLED ACROSS MUCH OF THE EASTERN SEABOARD. SHOWERS ARE EXPECTED TO MOVE INTO THE HIGHLANDS THURSDAY AFTERNOON AS LOW PRESSURE MOVES ALONG THE STALLED FRONTAL BOUNDARY. FCST MODELS HAVE SLOWED DOWN THE PROGRESSION OF SHOWERS MOVING INTO THE REGION. SHOWERS WILL SPREAD ACROSS THE MID- ATLANTIC THURSDAY NIGHT. HEAVY SHOWERS ARE EXPECTED AS ENHANCED LIFT OCCURS IN THE ENTRANCE REGION OF A UPPER LEVEL JET. DUE TO THE TIME OF DAY AND LACK OF INSTABILITY ALOFT...THUNDERSTORMS ARE NOT EXPECTED AT THIS TIME. && .LONG TERM /FRIDAY THROUGH TUESDAY/... MAIN STORY THROUGH THE EXTENDED IS CONT CHCS FOR UNSETTLED WX...AS STUBBORN FRONTAL BOUNDARY REMAINS NEAR/OVER OUR AREA. THERE REMAINS CONSIDERABLE UNCERTAINTY AND MODEL DISAGREEMENT WITH REGARDS TO FRONTAL LOCATION THROUGH THE EXTENDED. AS SUCH...IT IS DIFFICULT DETERMINE THE SPATIOTEMPORAL EXTENT OF ANY ACTIVITY AND DETERMINE CONVECTIVE VS SHOWER CHCS. MILLION DOLLAR QUESTION IS WHAT WILL THE WX BE LIKE ON SAT...FOR NOW HAVE KEPT CHC POPS AND THUNDER...THOUGH THERE IS CERTAINLY BUST POTENTIAL WITH THIS...AS FRONT COULD BE FAR ENOUGH TO OUR SOUTH...WHICH WOULD LIMIT INSTABILITY (ELEVATED). AS MENTIONED YESTERDAY...TEMPS PROGGED TO REMAIN AOB CLIMO NORMS THROUGH THE EXTENDED...WITH A GRADUAL WARMING TREND THROUGH THE PERIOD. DEWPOINTS ALSO EXPECTED TO REMAIN AOB 70F...SO NOT EXPECTING CONDITIONS TO BE VERY OPPRESSIVE. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... GENERALLY VFR CONDITIONS FOR THE TAF PERIOD. ISO TSTMS PSBL TONIGHT...WITH COULD BRIEFLY REDUCE CIGS AND VIS TO SUB-VFR AND PRODUCE GUSTY WINDS TO 30 KTS. OTHERWISE...WINDS SLY LESS THAN 10 KTS...BCMG LIGHT/VRB AFTR 06Z. TSRA CVRG LOOKING MUCH LWR ON WED...AS TROF WL BE EAST OF TERMINALS. A WEAK CDFNT WL BE DROPPING SWD IN THE AFTN-EVNG. ITS ENTIRELY PSBL THAT THERE WL BE NO TSRA AT ALL. TAFS VFR W/ CIGS BKN-OVC050-060. SUB-VFR CONDITIONS POSSIBLE THURSDAY NIGHT AS RAIN MOVES INTO THE REGION MAIN CONCERN THROUGH EXTENDED IS POTENTIAL FOR SCATTERED THUNDERSTORMS EACH DAY...WITH SUB-VFR CONDS POSSIBLE NEAR TSTMS. VFR CONDS EXPECTED OUTSIDE OF TSTMS. && .MARINE... SCA REMAINS IN EFFECT FOR THE CHESAPEAKE BAY AND LOWER TIDAL POTOMAC THRU THE NIGHT WITH SLY WINDS GUSTING TO 18 KTS. SUB-SCA CONDITIONS THEN EXPECTED AFTR DAYBREAK ON WED...CONTINUING THRU WED NIGHT. CHC OF TSTMS ON WED AFTN COULD BRING BRIEF GUSTY WINDS AND REDUCED VSBYS. SHOWERS WILL OVERSPREAD THE REGION THURSDAY NIGHT AND MAY CAUSE REDUCED VSBYS. WINDS EXPECTED TO REMAIN BELOW SCA CRITERIA THROUGH THE EXTENDED...THOUGH WILL NEED TO MONITOR AS FRONT WILL BE NEAR AREA EACH DAY. SHOWERS AND TSTMS ARE ALSO POSSIBLE EACH DAY...WHICH COULD IMPACT MARINE CONCERNS && .TIDES/COASTAL FLOODING... WATER LVLS RUNNING ABT A FOOT ABV ASTRO NORMS. THE LOWER OF THE TWO HIGH TIDES ROLLING IN NOW...WHICH WL KEEP LEVELS BELOW ADVY CRITERIA. HWVR...ISSUES WUD RESULT FROM THE NEXT TIDE...MIDNGT TO NOON. TOO SOON TO ISSUE ADVY ATTM...BUT ONE MAY BE REQD BEFORE EVNG OVER. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT WEDNESDAY FOR ANZ531>533- 537-539>542. SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ534-543. && $$ SYNOPSIS...HTS NEAR TERM...SEARS/HTS SHORT TERM...HAS LONG TERM...MSE AVIATION...HAS/MSE/SEARS MARINE...HAS/MSE/SEARS TIDES/COASTAL FLOODING...

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