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/...
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.
&&

.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/...
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.

&&

.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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