Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 160739 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 339 AM EDT WED JUL 16 2014 .SYNOPSIS... CANADIAN HIGH PRESSURE WILL BUILD OVERHEAD FOR TODAY THROUGH THURSDAY NIGHT. HIGH PRESSURE WILL MOVE OFF THE COAST FRIDAY THROUGH THE WEEKEND AND A SOUTHERLY RETURN FLOW WILL USHER IN MORE HUMID CONDITIONS ALONG WITH THE CHANCE FOR SHOWERS AND THUNDERSTORMS. && .NEAR TERM /THROUGH TONIGHT/... LTST SFC ANLY PLACES CDFNT NEAR THE WRN SHORE OF THE CHSPK BAY... CUTTING ACRS SRN MD...TWD RIC. HWVR...THE BACK EDGE OF CLDS REMAINS NEAR THE I-81 CRRDR...AND HAS MVD LTL SINCE MIDNGT. A DP UPR LOW EVIDENT ON WATER VAPOR LOOP ROTATING ACRS THE GRTLKS/MIDWEST...BUT A STREAM OF TROPICAL MSTR CAN ALSO BE SEEN GLIDING UP THE EAST COAST. THE AMPLITUDE OF THE FLOW PTTN ACRS NOAM LKLY WL BE INTERFERING W/ A RAPID TRANSITION TDA. BY DAYBREAK...CDFNT SHUD BE ACRS THE DELMARVA/TIDEWATER RGN. H5 TROF AXIS CROSSING THE GRTLKS WL BE THE KEY FEATURE TO MOVE IT ALONG. GFS A LTL SLOER THAN OTHER GDNC...WHICH MAKES SENSE SINCE COOLER AIR MAKING A RETREAT NWD INSTEAD OF BEING CARRIED EAST. WITH THAT IN MIND...HV HELD ONTO CHC SHRA ELY IN THE DAY FOR A LINGERING SHRA ACRS LWR SRN MD...AND AM HOLDING ONTO SOME CLDS ALONG/EAST OF I-95 THRU MIDDAY. OTRW...DRIER AIR FILTERING INTO CWFA WL PROVIDE A VERY NICE JULY DAY. XPCT NO MORE THAN SCT CU. MOS MAXT TEMPS IN FAIRLY GOOD AGREEMENT...AND TOOK THE WARMER SIDE DUE TO GFS PREFERENCE. WL HV A RELATIVELY GOOD RADL COOLING NGT TNGT UNDER BLDG HIPRES AS SKIES MOCLR AND WNDS DCPLG. MIN-T ON THE COOLER END OF GDNC TO ACCT FOR THIS BIAS AND DEWPTS IN THE 50S...AND MAYBE EVEN UPR 40S IN THE MTNS! && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... THU WL BE A QUIET DAY WXWISE AS HIPRES CONTS TO BLD OVER THE MID ATLC. IT/LL BE OVHD /OR MORE PRECISELY OVER PA/ BY THU NGT. ONLY WRINKLE WUD BE S/WV ENERGY DROPPING INTO THE RETREATING H5 TROF AXIS. THAT MAY ACCOUNT FOR A FEW MORE CU DURING THE DAYTIME...BUT THINK AMS STILL MUCH TOO DRY TO SUPPORT DIURNAL SHRA. MAXT QUITE SIMLR TO WED. MIN-T WL BE A BIT WARMER AS DEWPTS RECOVER IN WK WAA BY THU NGT. && .LONG TERM /FRIDAY THROUGH TUESDAY/... THAT WEAK WARM ADVECTION CONTINUES THROUGH THE WEEKEND AS OUR PLEASANT AREA OF HIGH PRESSURE SHIFTS OFF THE COAST AND A SOUTHERLY FLOW RETURNS WITH MORE NORMAL HUMIDITY. THE HUMIDITY COMBINED WITH WEAK UPPER TROFFING AT 500MB AND A DEVELOPING COASTAL FRONT TO OUR SE WILL SLOWLY RETURN CHANCES FOR THUNDERSTORMS TO THE FORECAST. NOTHING TOO OUT OF THE ORDINARY THRU THE WEEKEND AND FIRST HALF OF NEXT WEEK. HIGH TEMPS LARGELY IN THE LOW TO MID 80S. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... VFR FLGT CONDS ACRS THE TERMINALS FOR THE MRNG PUSH...AS CFP HAS TAKEN PLACE AND DRIER AIR FILTERING ACRS THE RGN. THIS WL CONT THRU THE UPCOMING DAYTIME...SUPPORTING NW WNDS ARND 10 KT...AND MAYBE A FEW SLGTLY HIER GUSTS. DIURNAL CU WL DVLP W/ BASES 050-060. BOTH WNDS AND CLDS WL DSPT W/ THE SETTING SUN TNGT. HIPRES OVR THE RGN THU-THU NGT. VFR. ONCE AGN XPCTG SCT DIURNAL CU CLDS. NW WNDS NEAR 5 KT DURING THE DAY...DIMINISHING AT NGT. LARGELY VFR CONDITIONS EXPECTED FRI THRU TUE EXCEPT POSSIBLE BRIEF IFR IN ANY TSTM THAT MAY DEVELOP. && .MARINE... CDFNT WL BE POSITIONED JUST E OF THE WATERS BY DAYBREAK. THE SURGE OF DRIER AIR WL BE UNDERWAY...UNABLE TO EFFECTIVELY MIX. SUNRISE SHUD CHG THAT...AS THE CORE OF THE BEST WNDS DEPART. WRF GDNC MORE EMPHATIC THAN SYNOP SCALE GDNC IN SUGGESTING INCRSD NWLY MRNG WND ON THE WATERS...MAINLY IN THE BAY. GOING FCST DEPICTS THAT...AND WL MAINTAIN IT AND THE SCA IN PLACE FOR MOST WATERS. NWLY FLOW CONTS THRU THU...BUT AT LESSER SPDS. HIPRES CRESTS NEAR THE WATERS THU NGT...FOR LGT/VRBL WNDS. OTHER THAN POSSIBLE TSTMS EARLY NEXT WEEK...NO MARINE CONCERNS FRI THRU TUE. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 2 PM EDT THIS AFTERNOON FOR ANZ531>534-537-539>541-543. && $$ SYNOPSIS...CAS NEAR TERM...HTS SHORT TERM...HTS LONG TERM...CAS AVIATION...CAS/HTS MARINE...CAS/HTS

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