Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 161419 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1019 AM EDT THU OCT 16 2014 .SYNOPSIS... THE PARENT UPPER-LEVEL LOW PRESSURE SYSTEM ENCOMPASSING MUCH OF THE NORTHEAST WILL PERSIST OVER THE AREA TODAY AND INTO EARLY FRIDAY. A BRIEF REPRIEVE TAKES SHAPE BEFORE ANOTHER UPPER TROUGH SLIDES COOLER AND DRIER AIR INTO THE REGION TO BEGIN THE UPCOMING WEEK. ANOTHER SLOW-MOVING AND UPPER LEVEL LOW PRESSURE SYSTEM IS ANTICIPATED FOR THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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LOW CLDS AND FOG STUBBORN TO ERODE...BUT GRADUALLY DOING SO. CURRENT LLVL MSTR KEEPING A LID ON TEMPS... WHICH IN TURN WL LIMIT INTENSITY OF CONVECTIVE POTL LATER TDA. UPR LOW OVER NE OH ATTM. THE TROF AXIS WL SWING THRU TAFTN... W/ H8-5 LAPSE RATES NEAR 6 C/KM AND FCST SBCAPE NEAR 500 J/KG. THIS SHUD BE SUFFICIENT TO SPAWN SCT SHRA. A LTL LTNG NOTED NEAR LOWS CENTER THIS MRNG. THINK THE BEST CHC OF THAT MAY STAY N OF CWFA.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... UPPER CUTOFF LOW WILL FINALLY PULL AWAY TO THE NORTH TONIGHT AND ANY REMAINING SHOWERS SHOULD BE RELEGATED TO THE POTOMAC HIGHLANDS. OVERNIGHT LOWS WILL DIP BACK INTO THE 40S WEST TO 50S WITHIN THE I-95 CORRIDOR AND METRO AREAS. FRIDAY WILL BE THE FIRST NICE DAY IN A SHORT WHILE. SUNSHINE AND SOUTHERLY FLOW WILL MAKE A RETURN. HIGH TEMPERATURES WILL TOP OUT IN THE UPPER 60S TO LOWER 70S. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... A SHARP UPPER TROUGH AXIS WILL BE HEADING TOWARD THE AREA FROM THE GREAT LAKES REGION LATE FRI INTO EARLY SAT. THIS FEATURE WILL BRING THE MORE AUTUMN-LIKE CONDITIONS. A COMPACT AND SMALLER CLIPPER SYSTEM WILL MAKE A QUICK TREK FROM THE CANADIAN ROCKIES TO THE WRN SIDE OF THE SLOWER-MOVING UPPER LOW OVER THE GREAT LAKES. AS THIS FAST-MOVING FEATURES BUMPS INTO THE LARGER ONE...THE INTERACTION WILL CAUSE IT TO POWER THIS SHARP TROUGH DOWN ACROSS OUR REGION THIS WEEKEND. BESIDES FALLING TEMPS AND DEWPOINTS...BREEZY NW WINDS WILL RETURN WHICH IS NOT IDEAL FOR KEEPING LEAVES ON TREES. A BLEND OF SOME MED RANGE WIND GRIDS FROM THE GFS/NAM/MOS HAS IT PARTICULARLY BREEZY ACROSS THE HIGHER TERRAIN OF OUR CWA DURING THE DAYTIME HRS ON SAT. A SECONDARY PIECE OF ENERGY STRADDLING BEHIND THE MAIN TROUGH AXIS WILL MAKE ITS PASSAGE SEVERAL HRS LATER...BRINGING SOME LIGHT PRECIP TO THE HIGHER TERRAIN OF THE APLCNS BUT LIKELY DRYING OUT AS THE FEATURE MOVES OUT ACROSS THE PIEDMONT/COASTAL AREAS. WITH THE RELATIVE SLOWNESS OF THE LARGER LOW PRESSURE SYSTEM...THE BACK END COMMA HEAD MOVING ACROSS THE MID-ATLC/NEW ENGLAND THIS WEEKEND...WE WILL ONLY RECEIVE ABOUT A ONE-DAY HIGH PRESSURE REPRIEVE BEFORE THE NEXT WAVE ARRIVES. 00Z RUNS OF THE GFS AND EURO ARE IN GOOD AGREEMENT ON THE EARLY STAGES OF THIS NEXT FEATURE...AND ALSO W/ SOME OF THE TELECONNECTIONS OF THE RIDGE/TROUGH DEPICTIONS ACROSS THE REMAINDER OF THE CONUS. A HIGHLY AMPLIFIED RIDGE OVER THE LENGTH OF THE PLAINS STATES SPELLS A MUCH FURTHER SOUTH SOLUTION FOR THE PASSAGE THIS NEXT SYSTEM - WHICH APPEARS WILL BE A RESIDENT UPPER LOW FOR THE MIDDLE PART OF NEXT WEEK. INITIALLY A FAST-MOVING COMPACT CLIPPER FROM CNTRL CANADA...THIS WAVE WILL ROUND THE BOTTOM OF THE LONGWAVE TROUGH AND MAY BECOME A CUT-OFF SYSTEM DIRECTLY OVER OR NEAR THE MID-ATLC - STICKING AROUND FOR MULTIPLE DAYS. MOISTURE FETCH IS NOT OVERLY IMPRESSIVE BUT WOULD BE ENOUGH TO KEEP STEADY DAILY CLOUDS AND SOME SCATTERED PRECIP AROUND...AS WELL AS A MODERATED AIRMASS. && .AVIATION /14Z THURSDAY THROUGH MONDAY/...
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LOW CIGS AND VSBYS STUBBORN TO BURN OFF UNDER SLGT INVERSION. STILL HV SOME SGFNT /AOB IFR/ FLGT RESTRICTIONS...WHICH MAY NOT ERODE TIL AFTER 16Z. SUSPECT FLGT RESTICTION OF SOME KIND /AT LEAST MVFR/ INTO THE AFTN. ADDTL SHRA WL BE DVLP TAFTN IN RESPONSE TO TROF AXIS/UPR LOW. CONFIDENCE IN ANY SHOWER DIRECTLY IMPACTING A TERMINAL IS LOW AND MENTIONED WILL BE LEFT OUT OF THE TAFS ATTM. MOSTLY VFR CONDITIONS ARE EXPECTED OVERNIGHT AND INTO FRIDAY. SOME PATCHY FOG COULD DEVELOP ALTHOUGH COVERAGE WILL NOT BE AS GREAT AS THE PAST COUPLE NIGHTS. BREEZY W-NWLY WINDS WILL AFFECT THE REGION BOTH SAT INTO SUN. MAINLY DRY INTO EARLY NEXT WEEK...THOUGH ANOTHER SLOW-MOVING LOW PRESSURE SYSTEM MAY AFFECT THE REGION DURING THE MIDDLE PART OF NEXT WEEK. NOT NEARLY AS MUCH PRECIP TO CONTEND W/ AS THE EXITING FEATURE BUT MAY SEE PERIODICALLY LOWER CIGS AND SOME SCATTERED SHOWERS.
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&& .MARINE... WINDS ARE EXPECTED TO REMAIN BELOW SCA TODAY INTO TONIGHT. SOUTHERLY FLOW AND CHANNELING WILL RETURN ON FRIDAY. THERE IS SOME POTENTIAL FOR SCA CRITERIA ESPECIALLY OVER THE LOWER BAY FRIDAY. A SECONDARY WAVE OF DRY BUT BREEZY LOW PRESSURE WILL LIKELY INDUCE SCA WINDS OVER THE WATERS BOTH SAT AND SUN AFTNS. HIGH PRESSURE EXPECTED TO BUILD IN BEHIND THIS WAVE TO START THE WORK WEEK. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...GMS NEAR TERM...HTS SHORT TERM...KRW LONG TERM...GMS AVIATION...HTS/KRW/GMS MARINE...KRW/GMS

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