Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 230750 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 350 AM EDT SAT AUG 23 2014 .SYNOPSIS... A WEAK COLD FRONT WILL PUSH INLAND THIS MORNING. HIGH PRESSURE WILL BUILD FROM THE CANADIAN MARITIMES DOWN THE COAST...REACHING THE DELMARVA BY SUNDAY...AND REMAINING THROUGH THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... SFC HIPRES BLDG INTO NEW ENGLAND HAS PUSHED A CDFNT WWD TWD THE APLCNS. STILL HV WK IMPULSES ALONG THIS BNDRY AS IT EXTENDS WWD INTO THE MIDWEST. HWVR...SHARPENING H5 FLOW /RDG IN THE MS VLY AND TROF IN THE WRN ATLC/ WL DRIVE THE FNT FURTHER S AND W TDA. AMS WL STILL BE PLENTY SATD /PWAT 1.5 INCHES/...BUT W/ A MARINE AMS INSTBY WL BE LMTD. AM A BIT CONCERNED AT THE PROLIFIC RAFL RATES FM THE FEW SHRA/TSRA ON RDR ATTM. WL STILL HV THE UPR JET OVHD...BUT AM HOPEFUL THAT THE LACK OF SFC INSTBY/BNDRY DURG THE DAYTIME HRS WL BE ENUF TO PRECLUDE AN ORGANIZED RAFL THREAT. THEREFORE...WL NOT BE POSTING A FF WATCH ATTM. MESO AND SYNOP SCALE GDNC ALL SUGGEST THAT PCPN CRRNTLY OVER THE WRN/SRN SXNS OF CWFA WL BE EXPANDING UPON SUNRISE/DIURNAL HTG... PEAKING DURG THE MIDDAY HRS. THEN...AS LOWER DEWPT AIR/SUBSIDENCE INFILTRATES FM THE NE...THE AXIS OF PCPN WL BE PUSHED WWD AGN. WL START THE EVNG HRS W/ POPS AREAWIDE /40-50 PCT W...20 PCT E/... BUT WL BE CARVING AWAY AT THAT FM E TO W. BELIEVE THE OVNGT HRS WL BE DRY ALONG I-95. FEW CHGS TO TEMPS REQD. KEPT GOING MAXT FCST MID 70S N TO ARND 80F. IF PCPN HAS ENUF STAYING POWER...IT/LL BE TUFF TO SEE MUCH OF A TEMP RISE. FORTUNATELY...DONT BELIEVE THAT WL HPPN. KEPT MIN-T TNGT LWR-MID 60S...AS DEWPTS WL BE A LTL BIT SLOW TO DROP. && .SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/... H5 HGTS WL BE RISING SUN AS SFC HIPRES BLDS DOWN THE COAST. AS A RSLT...CLDS SHUD BE BREAKING APART...1ST IN THE NE...BUT EVENTUALLY AREAWIDE. MTNS WL BE LAST. HV KEPT FCST DRY...BUT RECOGNIZE THERE MAY BE A LINGERING MRNG SPRINKLE OR TWO IN THE APLCNS S OF W99. MOS IN GOOD AGREEMENT ON MAXT /NEAR 80/...AND SEE NO REASON TO ARGUE. DEWPTS WL BE DROPPING...AND SHUD BE IN THE UPR 50S SUN NGT. HENCE... MON MRNG MIN-T COOLER...MID 50S TO LWR 60S. && .LONG TERM /MONDAY THROUGH FRIDAY/... POSITIVELY TILTED UPPER RIDGE AND SURFACE HIGH PRESSURE WILL THEN DOMINATE THROUGH MID NEXT WEEK WITH SLOWLY MODERATING TEMPERATURES AND HUMIDITY. POSITION OF UPPER FLOW LOOKS TO KEEP ANY TROPICAL SYSTEM ACTIVITY OFFSHORE THE MID-ATLANTIC NEXT WEEK AS WELL. RETURN FLOW SETS IN WITH TEMPS BACK TO NORMAL FOR THURSDAY AHEAD OF A PROGRESSIVE UPPER TROUGH MOVING ACROSS THE NORTHERN CONUS. THIS DEEPENING TROUGH DRAGS A SEASONABLY STRONG COLD FRONT THROUGH THE REGION FOR THE END OF THE WORK WEEK...WITH FRIDAY LOOKING TO BE BACK IN THE UPPER 70S/LOW 80S ATTM. DEEP-LAYER WIND SHEAR AND INSTABILITY MAY BE FAVORABLE FOR SOME ORGANIZED CONVECTION WITH THIS COLD FROPA. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... CHALLENGING TAF FCST THIS CYCLE. CONDS MAINLY MVFR TO OCNL IFR... PRETTY MUCH DUE TO CIGS. BRIEF LWR VSBY RESTRICTIONS INVOF SHRA. ELY FLOW CONTS TDA...WHICH WL BRING A MARITIME AMS INLAND. THUS...CIGS AND PERHAPS VSBYS WL KEEP DROPPING. XPCT IFR TO BE PREVALENT FOR THE MRNG PUSH...BEFORE CIGS LIFT AND ANY FOG DSPTS BY AFTN. WL BE OPTIMISTIC...FCSTG VFR BY ELY-MID AFTN. WHILE SCT-NMRS SHRA WL BE ARND...DONT BELIEVE THEY WL DICTATE OVERALL FLGT CONDS. THEY MAY PROVIDE BRIEFLY LWR VSBYS THO. MAY HV FLGT RESTRICTIONS AGN LT TNGT NEAR MRB/CHO. OTRW...DRIER AIR WL BE COMING DOWN FM THE NE...WHICH SHUD MAINTAIN VFR OVNGT FOR THE METROS. SKIES CLEAR FROM INCREASING HIGH PRESSURE SUNDAY. HIGH PRESSURE/VFR WILL PREVAIL THROUGH MIDWEEK. && .MARINE... ELY FLOW ARND 10 KT ATTM...WHICH SHUD CONT THRU THE AFTN. SHRA WL BECOME MORE NMRS TDA...BEFORE BEING SHUNTED INLAND TNGT. ONCE THAT HPPNS...SUSPECT THERE WL BE A PUSH OF 15 KT ELY WNDS. DONT SEE MUCH MIXING THO...SO DONT XPCT GUST TO BE TOO MUCH HIER...AND HV KEPT WNDS BLO SCA THRESHOLDS. HIPRES BLDS DOWN THE COAST TMRW. ELY FLOW WL CONT...BUT AT 5-10 KT SUSTAINED /MAYBE CLSR TO 10 KT FOR THE MID BAY/OPEN WATERS/...AND THEN DIMINISHING SUN NGT. HIGH PRESSURE WILL THEN BUILD ACROSS THE AREA SUNDAY THROUGH MID WEEK. NO FLAGS ANTICIPATED. && .TIDES/COASTAL FLOODING... WATER LVLS GENERALLY AOB 1/2 FT ABV ASTRO NORMS ATTM. HWVR...WNDS HV BECOME ELY...WHICH IS PUSHING EXTRA WATER INTO THE MOUTH OF THE BAY. DEPARTURES DOWN THERE CLOSER TO A FT...AND THAT EXCESS WL BE COMING UP THE ESTUARY. THE PM TIDE TODAY IS THE LOWER OF THE TWO ASTRONOMICALLY...BUT WITH THE FCST WATER LVL INCREASE SHOULD END UP BEING SIMILAR TO THE MRNG TIDE...IF NOT A PINCH HIGHER. THE CONCERN COMES LATE TNGT INTO ELY SUN MRNG...WHEN DEPARTURES OF A FOOT WL CAUSE WATER TO APPROACH MINOR THRESHOLDS FOR SENSITIVE LOCATIONS ON THE WESTERN SHORE AND TIDAL POTOMAC. ELY FLOW WILL CONTINUE INTO MONDAY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...HTS NEAR TERM...HTS SHORT TERM...HTS LONG TERM...AEB AVIATION...HTS/AEB MARINE...HTS/AEB TIDES/COASTAL FLOODING...HTS

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