Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 150715 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 315 AM EDT MON SEP 15 2014 .SYNOPSIS...
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HIGH PRESSURE OVER THE AREA WILL DRIFT EAST TODAY. A COLD FRONT PASSES THROUGH THE AREA LATE TONIGHT. HIGH PRESSURE RETURNS TUESDAY...THEN PERSISTS THROUGH THE END OF THE WEEK.
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&& .NEAR TERM /THROUGH TONIGHT/...
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HIPRES HAS SETTLED OVERHEAD...PROVIDING CALM AND COOL CONDS. ITS NOT CLEAR THO...A RESULT OF TRAPPED MSTR UNDER LRG SUBSIDENCE INVSN PER 00Z LWX RAOB. THINK WE/LL HV THESE PATCHES OF CLDS THRU SUNRISE... WHEN PERHAPS THEY CAN MIX OUT. SFC HIPRES WL GRDLY MV OFFSHORE TDA. MEAN LYR RH WL BE HIGH ENUF TO SUPPORT AT LEAST SCT CLDS...AND MID-UPR LVL MSTR WL BE INCRSG THRU THE AFTN DUE TO WAA. WHILE CONCEPTUALLY...MAV MAXT NUMBERS MAY SEEM TO BE BETTER...FCSTS HV BEEN EXHIBITING A WARM BIAS PAST CPL DAYS. HV UTILIZED BIAS CORRECTED GRIDS TO COMPENSATE...WHICH WL LWR MAXT FCST BY A CPL DEGF FOR MOST OF THE AREA. THTE RDG WL APPROACH FM THE S TNGT AHD OF A CDFNT ARRIVING FM THE W. BY FAR...MOST OF THE NRN STREAM PVA ENERGY WL REMAIN ACRS NY/PA. THUS THE TWO AREAS NEVER REALLY JOIN FORCES...RESULTING IN A DISORGANIZED UPA PTTN. QPF...IF ANY...SHUD BE LGT. GDNC POPS LWR OVERALL. THINK THATS A GOOD IDEA. WHATEVER SCT SHRA WE WL HV MOST LKLY WL OCCUR OVNGT. DEWPTS WL BE RISING TAFTN-TNGT INTO THE 50S TO PERHAPS 60F. USED THAT AS A GUIDE FOR MIN-T FCST. MET MOS CAME CLOSEST...BLENDED W/ GOING FCST.
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&& .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
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CDFNT WL CLEAR AREA BY DAYBRK TUE. ITS LOOKING REAL DOUBTFUL TO HV ANY LINGERING SHRA INTO ELY TUE...AS BINOVC SHUD BE DVLPG BY SUNRISE. CAA MOST NOTEABLE WX FEATURE...PROVIDING A WELL MIXED ATMOS. BUFKIT SUGGESTS 20 KT AT TOP OF LYR. HV GUSTY WINDS IN GRIDS DOWN PTMC AND ACRS MD. AM XPCTG CLDS TO BREAK APART DURING THE MRNG. MOSUN MOST OF THE DAY. COMPRESSIONAL WARMING MAY OFFSET SOME OF THE CAA. INCORPORATED THE TWO CONCEPTS FOR MAXT. FCST CHGS /SLGTLY COOLER/ W OF BLURDG AND ACRS NRN MD. AS HIPRES BLDS TUE NGT...SHUD HV CLR/CALM NGT...WHICH WL EQUATE TO ANTHR COOL NGT. UTILIZED THE COOLER MOS OFFERINGS.
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&& .LONG TERM /WEDNESDAY THROUGH SUNDAY/...
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HIGH PRESSURE WILL CONTINUE TO RESIDE ACROSS THE MID ATLANTIC WEDNESDAY. WINDS WILL BE VARIABLE IF NOT CALM DURING THE DAY WITH FCST MAX TEMPS IN THE UPPER 60S IN THE MTNS TO LOW TO MID 70S ELSEWHERE. A WEAK DISTURBANCE WILL DRIFT SOUTHWARD FROM THE GREAT LAKES WHILE A STRONGER AREA OF HIGH PRESSURE MOVES ACROSS ONTARIO THURSDAY. ECMWF IS MORE PRONOUNCED THAN THE GFS WITH THE FEATURE BUT BOTH HAVE LITTLE MOISTURE WITHIN THE COLUMN. DRY CONDITIONS ARE EXPECTED AND LIGHT NRLY FLOW WILL CONTINUE ACROSS THE MID-ATLANTIC. FCST MAX TEMPS WILL CONTINUE TO BE SLIGHTLY BELOW NORMAL...IN THE UPPER 60S IN THE MTNS AND LOT O MID 70S ELSEWHERE THURSDAY. HIGH PRESSURE WILL MOVE EASTWARD BY THE END OF THE WEEK. A WEDGE SHOULD SETUP BY FRIDAY AFTERNOON AND WINDS WILL BECOME N-NE. THIS SETUP WILL CONTINUE INTO SATURDAY AS HIGH PRESSURE MOVES OFF THE NEW ENGLAND COAST. A SHORTWAVE TROUGH WILL APPROACH THE POTOMAC HIGHLANDS THIS WEEKEND. SHOWERS ARE POSSIBLE SUNDAY.
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&& .AVIATION /07Z MONDAY THROUGH FRIDAY/...
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VFR CONDS ACRS THE TERMINALS ATTM. HWVR...FOG HAS DVLPD INVOF CJR/HWY AND W99. GDNC EXIBITING ITS TYPICAL BIAS OF OVERDOING CVRG. DO THINK THAT THERE IS POTL...SPCLY FOR CHO AND PERHAPS MRB. HV LIMITED RESRICTIONS TO BRIEF IFR AT CHO AND MRVF AT MRB NEAR SUNRISE. VFR CONDS WL PREVAIL FOR THE REST OF THE DAY INTO THE EVNG. A WK CDFNT WL CROSS THE TERMINALS OVNGT. ATTM...AM THINKING THAT SHRA CVRG SHUD BE SCT AND LGT IN NATURE. NOT WORTH INTRO RESTRICTIONS INTO FCST ATTM. HIGH PRESSURE WILL RESIDE ACROSS THE REGION. NO FLIGHT RESTRICTIONS EXPECTED FOR THE END OF THE WEEK AT THIS TIME.
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&& .MARINE...
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WNDS AOB 5 KT UNDER HIPRES. IT WL REMAIN THAT WAY THRU THE DAY ON MON. WL HV A SLY FLOW DVLP AHD OF AN UPR LVL DISTURBANCE AND CDFNT MON NGT. HV CAPPED WNDS AT 10 KT FOR THE EVNG AND 15 KT FOR THE OVNGT HRS. CFP COMING NEAR SUNRISE TUE. A NWLY SURGE BHD THE FNT SHUD SUPPORT DECENT MIXING. HV ISSUED SCA ALL WATERS FOR 20 KT GUSTS DURING THE DAY. HIGH PRESSURE WILL RESIDE ACROSS THE WATERS MID TO LATE WEEK.
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&& .TIDES/COASTAL FLOODING...
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WATER LVLS AVERAGING BETWEEN 1/2 TO 3/4 FT ABV ASTRO NORMS... CLOSER TO 3/4 FT ON THE BAY. THESE POSITIVE DEPARTURES WILL REMAIN THROUGH AT LEAST THE MONDAY NIGHT/TUESDAY MORNING TIDE CYCLE. CBOFS INDICATES ANNAPOLIS WILL TOUCH MINOR FLOOD AGAIN THIS MORNING...AND SOLOMONS/PINEY POINT WILL THREATEN AS WELL. ESTOFS...ON THE OTHER HAND...IS SUGGESTING THAT THE MRNG TIDE WILL BE OK. ETSS IN BETWEEN...SIDING CLOSER TO CBOFS. WHILE CBOFS HAS A HIGH BIAS AT ONSET...IT TENDS TO BE PRETTY GOOD AFTER THAT. HAVE MORE CREEDENCE IN A CBOFS/ETSS BLEND. AM STILL UNSURE HOW THIS WILL TRANSLATE TO OBSVD WATER LEVELS. SUSPECT WE WILL REACH CAUTION STAGE AND APPROACH MINOR STAGE WITH INCOMING TIDE. THE MARGIN BETWEEN THE TWO WILL BE A MATTER OF A COUPLE OF INCHES. REGARDLESS OF WHAT HAPPENS THIS MRNG...THE PM TIDE CYCLE IS LOOKING HIGHER. ALL GUIDANCE IS IN DECENT AGREEMENT ON THAT. THEREFORE...ADVYS APPEAR PROBABLE FOR THIS AFTN-TNGT.
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&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 9 AM TO 5 PM EDT TUESDAY FOR ANZ530>543. && $$ SYNOPSIS...HTS NEAR TERM...HTS SHORT TERM...HTS LONG TERM...HAS AVIATION...HTS/HAS MARINE...HTS/HAS TIDES/COASTAL FLOODING...HTS

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