Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 061230
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
830 AM EDT WED MAY 6 2015

.SYNOPSIS...
A WEAK COLD FRONT ACROSS PENNSYLVANIA WILL DRIFT SOUTHWARD ACROSS
THE AREA TODAY BEFORE DISSIPATING TONIGHT. HIGH PRESSURE BUILDS
OVER THE NORTHERN MID-ATLANTIC THURSDAY. LOW PRESSURE OFF THE
CAROLINA COAST FRIDAY WILL GRADUALLY ERODE THIS WEEKEND...SENDING
ITS MOISTURE NORTHEASTWARD. A COLD FRONT WILL ARRIVE EARLY NEXT
WEEK.

&&

.NEAR TERM /TODAY/...

WEAK-TO-NON-EXISTANT COLD FRONT CURRENTLY POSITIONED JUST NORTH
OF THE MASON-DIXON WILL NUDGE SOUTH TODAY...EVENTUALLY STALLING
OVER NORTHERN PORTIONS OF THE CWA. THIS BOUNDARY WILL YET AGAIN
PROVIDE THE BASIS FOR SHOWER AND TSTM DEVELOPMENT TODAY WITH LACK
OF FORCING ALOFT AS RIDGING BUILDS IN.

DECENT WARMING THIS MORNING AHEAD OF THE FRONT SHOULD AID IN
DESTABILIZING THE ATMOSPHERE ENOUGH TO TRIGGER SCT SHOWERS. ISO
TSTM PSBL IN THE MIX...THOUGH INSTABILITY IS QUITE MINIMAL AND
LAPSE RATES/SHEAR ON THE WEAKER SIDE. BEHIND THE FRONT EXPECTING A
MORE STABLE ATMO AS ELY FLOW SETS UP. THIS SHOULD LIMIT ANY
THUNDER DEVELOPMENT...AND POTENTIALLY ANY PCPN AT ALL.

SHEN VLLY SHOULD WARM INTO THE 80S...WITH AREAS TO THE NORTH
CLOSER TO THE MASON-DIXON HOVERING IN THE MID-UPPER 70S.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...

COLD FRONT CONTINUES TO SAG S TONIGHT...DISSIPATING BY THURS
MORNING. LINGERING PCPN THIS EVENING WILL TAPER OFF AFTR SUNSET
WITH LOSS OF HTG. DRY WX SETTING UP BY THE SECOND HALF OF THE
NIGHT AS SFC HIGH PRESSURE OVER NEW ENGLAND BUILDS SOUTH UNDER THE
BUILDING RIDGE.

SFC HIGH KEEPS MOST OF THE AREA DRY THURS THRU THURS NIGHT AS THE
RIDGE AXIS SHIFTS EAST...STRADDLING THE CWA. DID MAINTAIN SLIGHT
CHC POPS WEST OF THE BLUE RIDGE WITH MINIMAL INSTABILITY NOTED
COMBINING WITH TERRAIN INFLUENCES OFF THE ELY FLOW. ANY PCPN
TAPERS OFF YET AGAIN FOR THURS NIGHT. ELY FLOW WILL AID IN KEEPING
TEMPS COOLER DURING THE DAY THURS...WITH MOST AREAS IN THE 70S AND
ONLY POCKETS REACHING 80.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...

THERES DECENT SYNOP SCALE AGREEMENT THAT LOPRES WL BE SOMEWHERE
ALONG THE CAROLINA COAST FRI WHILE RDGG WL RESIDE ACRS THE CWFA AND
A CDFNT WL BE ACRS THE WRN GRTLKS. CHALLENGE INVOLVES DETERMINING
WHAT HAPPENS NEXT TO THE LOW. DONT BELIEVE IT WL REACH US DIRECTLY.
EVEN IF IT DECAYS TO OUR S UNDER THE MID-LVL RDG...ITS MSTR WL BE
ADVECTED NWD. WHILE THAT WONT AFFECT FRI FCST...IT DOES BECOME A
PLAYER FOR THE WKND. HV INCRSG DEWPTS...NEAR 60F FRI/LWR-MID 60S
SAT- SUN...AND HV INTRO CHC POPS FOR SAT/EXPANDED CVRG SUN.
FURTHER... THERE SHUD BE SUFFICIENT RH FOR ADDED CLDS...AND HV
SOMETHING THAT/LL BE BORDERLINE PTSUN IN THE DATABASE. MAXT SHUDNT
BE FAR FM PERSISTENCE...LWR 80S. BUT THE ANOMOLOUSLY HIGH DEWPTS
SUGGST MIN-T WL BE ON THE MUGGY SIDE. USED THESE DEWPTS FOR A
STARTING POINT FOR MIN-T-- MID 60S FOR SUN/MON ELY MRNGS.

CARRIED THE TROPICAL MSTR FEED INTO MON. SAME CONSIDERATIONS BUT
POPS/TEMPS/DEWPTS A PINCH HIER AS AMS FM THE SERN CONUS ADVECTS ACRS
MID ATLC. AM KEEPING THUNDER IN FCST. INSTBY IMPROVES A LTL VS WKND
FCST. AT THIS POINT NOT SOLD ON ANY STRONG/SVR STORMS THO.

CDFNT PARKED TO OUR W/NW AT THE BGBG OF THE XTNDD FCST WL FINALLY HV
ROOM TO SWEEP EAST BY TUE.  IF THERE WERE ANY STRONG STORMS...THIS
WUD LKLY BE THE DAY. HWVR JURY STILL OUT AS TO MAGNITUDE TO THREAT.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...

INCRSG MID-HIGH LVL CLOUDS TODAY. GENERALLY EXPECTING VFR THRU
00Z...WITH PSBL STRATUS FORMING TONIGHT WITH THE FRONT STALLING
OVER THE REGION.

SCT SHOWERS AND ISO TSTMS PSBL AFTR 18Z. CONFIDENCE OF
TIMING/LOCATION TOO LOW TO INCLUDE AS -SHRA/TSRA ATTM...SO WILL
MAINTAIN VCSH. ANOTHER DAY OF LIGHT WINDS...MAINLY LESS THAN 8
KTS. NE FLOW THIS MORNING WILL BECOME ELY FOR THE AFTN THRU
TONIGHT. ANY SHOWER/TSTM COULD BRING A BRIEF PERIOD OF GUSTY WINDS
THIS AFTN.

OUTLOOK...
VFR FRI. ISOL-SCT SHRA/TSRA PSBL DAILY SAT-SUN...MAINLY AFTN/EVE.
MAY BE BRIEF FLGT RESTRICTIONS IF A TERMINAL IS IMPACTED. THATS A
LOW CONFIDENCE FCST AT THIS VANTAGE POINT. FURTHER...CUD HV
PREDAWN FOG ASSUMING WET GROUND BEFORE NIGHTFALL FLWD BY PRTL
CLRG. THAT FCST HIGHLY CONDITIONAL.

&&

.MARINE...
GENERALLY SUB-SCA CONDITIONS EXPECTED ON ALL WATERS THRU THURS
NIGHT WITH WEAK PRESSURE GRADIENT IN PLACE. SCT SHOWERS AND TSTMS
THIS AFTN COULD RESULT IN BRIEF PERIODS OF GUSTY CONDITIONS...
MAINLY LATE AFTN AND EVENING TIME FRAME.

WEAK PRESSURE PTTN THRU THE WKND. NO HAZARDS XPCTD ATTM. LOPRES S OF
WATERS MAY EJECT NEWD...PROVIDING BRIEF/LCL SHRA/TSRA BCMG MORE NMRS
BY END OF PD.

&&

.CLIMATE...
THE WARMEST AIRMASS OF THE 2015 SO FAR HAS MOVED OVER THE REGION
DURING THE EARLY PART OF THIS WEEK.

DCA REACHED A HIGH OF 86 DEGREES ON TUESDAY MAY 5TH...THE WARMEST
DAY SINCE SEPTEMBER 21ST 2014 WHEN THE TEMPERATURE REACHED 86
DEGREES.

BWI REACHED A HIGH OF 85 DEGREES ON TUESDAY MAY 5TH...THE WARMEST
DAY SINCE SEPTEMBER 11TH 2014 WHEN THE TEMPERATURE REACHED 89
DEGREES.

IAD REACHED A HIGH OF 85 DEGREES ON TUESDAY MAY 5TH...THE WARMEST
DAY SINCE SEPTEMBER 11TH 2014 WHEN THE TEMPERATURE REACHED 86
DEGREES.

CHO REACHED A HIGH OF 85 DEGREES ON TUESDAY MAY 5TH...THE WARMEST
DAY SINCE SEPTEMBER 21ST 2014 WHEN THE TEMPERATURE REACHED 87
DEGREES.

DMH REACHED A HIGH OF 86 DEGREES ON MONDAY MAY 4TH...THE WARMEST DAY
SINCE SEPTEMBER 11TH 2014 WHEN THE TEMPERATURE REACHED 90 DEGREES.

HGR REACHED A HIGH OF 85 DEGREES ON MONDAY MAY 4TH...THE WARMEST DAY
SINCE SEPTEMBER 6TH 2014 WHEN THE TEMPERATURE REACHED 90 DEGREES.

MRB REACHED A HIGH OF 85 DEGREES ON MONDAY MAY 4TH...THE WARMEST DAY
SINCE SEPTEMBER 21ST 2014 WHEN THE TEMPERATURE REACHED 86 DEGREES.


&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
UPDATE...WOODY!
PRVS...APS/HTS/DFH



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