Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 180801 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 401 AM EDT FRI JUL 18 2014 .SYNOPSIS...
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DRY WEATHER IS FORECAST INTO THE WEEKEND AS HIGH PRESSURE ALONG THE EAST COAST TRACKS OFFSHORE. INCREASING HEAT AND HUMIDITY IS EXPECTED TO RETURN EARLY NEXT WEEK. THIS WILL BE ACCOMPANIED BY A CHANCE OF SHOWERS AND THUNDERSTORMS DURING THE SECOND HALF OF THE WEEK.
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&& .NEAR TERM /TODAY/...
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AS OF 07Z...1023MB SFC HIGH OVER CNTRL PA WITH LIGHT NLY FLOW OVER THE AREA (UNLESS DECOUPLED). AREAS OF MID LEVEL CLOUDS FROM ELEVATED LAYER OF GULF MOISTURE STREAMING AHEAD OF THE UPR TROUGH OVER THE MID-SOUTH STATES AND OVER THE SFC HIGH. WIDESPREAD SHOWERS EXTEND FROM THE MS DELTA TO NASHVILLE AND WILL CONTINUE TO PROGRESS NORTHEAST UP THE SPINE OF THE APPALACHIANS THROUGH THE MORNING. EXPECT AT LEAST SCATTERED SHOWERS IN THE ALLEGHENY HIGHLANDS BY THIS AFTERNOON. INSTABILITY GREATLY LIMITED BY WARM NOSE IN THE SWLY FLOW ABOVE THE BOUNDARY LAYER SO WENT WITH NO THUNDER MENTION. FARTHER EAST...EXPECT AN ONSHORE FLOW AS THE SFC HIGH SHIFTS EAST TO NYC. MID-LEVEL CLOUDS COME AND GO THROUGH THE DAY. 00Z MAV AND TO AN EXTENT MET GUIDANCE HAVE BEEN A DEGREE OR TWO WARM AS OF LATE SO TOOK A BLEND AND LOWERED A DEGREE. MAX TEMPS LOW TO POSSIBLY MID 80S.
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&& .SHORT TERM /TONIGHT THROUGH SATURDAY/...
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TONIGHT...ONGOING SHOWERS BLUE RIDGE AND WEST WITH FAIRLY THICK MID-LEVEL CLOUDS ACROSS THE AREA. THE ELY FLOW MAY ALLOW UPSLOPE SHOWERS ON THE ERN FOOTHILLS. MID TO UPR 60S MIN TEMPS. UPR TROUGH AND NEAR NORMAL CONDITIONS PERSIST THIS WEEKEND INTO NEXT WEEK FOR THE MID-ATLANTIC. THUNDERSTORM ACTIVITY EACH DATE LOOKS TO BE LIMITED TO AREAS WEST OF THE BLUE RIDGE. SATURDAY...SFC HIGH PRESSURE PERSISTS TO OUR NORTH CONTINUING AN ONSHORE FLOW EAST...BUT SLY FLOW OUT WEST. THE MID-LEVEL INVERSION ERODES BY MIDDAY WITH AN ISOLATED THUNDER MENTION SHEN VLY AND WEST FOR THE AFTERNOON. POSSIBLE SHOWERS IN THE ELY FLOW FOR SRN MD. MAX TEMPS LIMITED TO AROUND 80F/LOW 80S EAST DUE TO CLOUD COVER.
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&& .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
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THIS IS A TIME OF YR WHERE SYNOPTICALLY THERE`S USUALLY NOT A LOT GOING ON...PRBLY A BERMUDA HIGH OFFSHORE CREATING A CHC OF AFTN TSTSM OVR THE MTNS. THIS HAS NOT BEEN THE CASE FOR MOST OF THIS SUMMER...AND THE TREND SHOULD CONT INTO THE BEGINNING OF THE NEW WK. TEMPS SHOULD RMN BLO CLIMO NORMS THRU MONDAY (SEE CLIMO SXN BLO) AS A WEAK UPR LVL TROF RESIDES OVR THE MID ALTC. IT APPEARS THE TROF WL BE LIFTING OUT ON TUE...AND HENCE TEMPS WL RISE BACK TO CLIMO NORMS OF NEAR 90 DURG THE DAY. HUMIDITY WL BE ON THE INCRS...AS WL TSTM CHCS AS THE WK PROGRESSES. LOOKING DEEP INTO THE CRYSTAL BALL...A CD FNT MAY MOVE INTO THE AREA NEXT FRI...AGN NOT NRMLY WHAT IS SEEN IN THE LATTER PART OF JUL IN THE MID ATLC.
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&& .AVIATION /06Z FRIDAY THROUGH TUESDAY/...
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UPPER LEVEL TROUGH APPROACHES THE AREA FROM THE WEST. ASSOCIATED SHOWERS WILL BE LIMITED TO THE ALLEGHENY MOUNTAINS TODAY AND SHOWERS AND THUNDERSTORMS LOOK TO BE WEST OF THE TERMINALS SATURDAY. NORTH FLOW THIS MORNING BECOMES ONSHORE TODAY AND PERSISTS THROUGH SATURDAY. VFR LIKELY TO CONTINUE INTO THE WEEKEND INTO EARLY NEXT WEEK AS HIGH PRESSURE WILL BE LOCATED ALONG THE NEW ENGLAND/MID-ATLANTIC COAST. THERE WILL BE MORE CLOUDS...BUT AT THIS TIME THESE LOOK TO MAINLY BE OF THE VFR VARIETY. TSRA CHANCE LOOKS MAINLY RELEGATED TO THE HIGHER TERRAIN.
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&& .MARINE...
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NLY FLOW THIS MORNING BECOMES NELY/ELY THROUGH THE DAY AS HIGH PRESSURE SHIFTS EAST FROM CNTRL PA TO NYC. FLOW GENERALLY 10 KT OR LESS. NO PROBS FORESEEN ON THE WATERS SAT NGT INTO THE 1ST PART OF THE NEW WK.
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&& .CLIMATE...
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WE ARE NOW IN THE WARMEST CLIMATOLOGICAL PD OF THE YR. PRETTY AMAZING TO WALK OUTSIDE AT 1 AM AND HV IT FEEL MORE LK SEPT THAN JUL. A RECORD LOW OF 55 DEGS WAS TIED AT IAD THU (SET IN 1976). DOING A CHECK OF THE PAST 30 YRS AVG TEMP FOR THE PD OF JUN 1-JUL 17 AT IAD...THIS SO FAR HAS BEEN THE 24TH COOLEST. DEFINITELY ON THE COOLER END OF THE SPECTRUM, THIS HAS BEEN THE RESULT OF THE SEMI- PERSISTENT WRN N. AMERICA RDG/ERN N. AMERICA TROF. HIGHEST TEMPS SO FAR THIS YR: IAD 95 (7/2)...DCA 99 (7/2)...BWI 96 (6/18).
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&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ PRODUCTS...BAJ/WOODY!

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