Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 291915
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
315 PM EDT FRI APR 29 2016

.SYNOPSIS...
STALLED FRONTAL BOUNDARY WILL WAVER ACROSS THE AREA THROUGH
SATURDAY...THEN LOW PRESSURE MOVES THROUGH THE MID- ATLANTIC
SUNDAY AND MONDAY. ANOTHER FRONT WILL MOVE THROUGH LATER NEXT
WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
MRNG PCPN HAS LIFTED INTO PA. WEAK S/WV IN NW PA ATTM WL TRACK EWD
TAFTN-TNGT. THERE MAY BE A FEW ASSOCD SHRA IN CWFA...BUT UPSTREAM
RDR ATTM LOOKS UNIMPRESSIVE. HV BEEN TRIMMING POPS AND WL CONT
TO DO SO. THE MOST NOTICEABLE ASPECT OF THE FCST WL BE THE XTNSV
CLDCVR...WHICH AFFECTS MOST OF THE CWFA XCPT FOR THE CENTRAL SHEN
VLY AND MUCH OF THE APLCNS. STALLED BNDRY SEEMS TO HV WIGGLED NWD.
/EKN 2PM TEMP 70F WHILE DCA REMAINS AT 53F./ THE PASSAGE OF THE
VORT SHUD NUDGE IT SWD AGN.

FOR THE OVNGT HRS...CONTD OVERRUNNING SHUD SUPPORT DZ. THAT WL BE
THE PRIMARY PCPN WORDING FOR MUCH OF THE AREA TNGT. AM HOLDING W/
PERSISTENCE WRT MIN-T...WHICH MEANS 45-50F N AND LWR 50S S.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
THE MOST RECENT MDL RUNS /06Z AND 12Z/ ARE TRENDING WETTER...AND
THUS HV INCREASED POPS A PINCH FOR LATE DAY SAT...AND FURTHER INTO
CAT TERRITORY FOR SAT NGT AND SUN.

SAT CULPRIT WL BE ISENT LIFT...WHICH IMPRV THRU THE DAY. BY LT
DAY...HV LKLY POPS. A SOLID SWATH OF MSTR EMINATES FM THE GLFMEX
/PWAT EXCEEDS AN INCH/...WHICH SUPPORTS DECISION TO INCR TO CAT
POPS BY SAT NGT...AS WELL AS INCR TO MDT RAFL IN OUR DATABASE.

SFC LOPRES AND H5 VORT TRACK ALONG THE STALLED BNDRY UP THE OHVLY
SUN INTO SUN NGT. THIS PATH TAKES THE BNDRY N OF THE CWA...AND
DISLODGES LLVL WEDGE. AM A BIT SKEPTICAL OF FULL SCOURING DUE TO
CLIMO...BUT AT THE VERY LEAST IT APPEARS AS THOUGH THERE WL BE AN
ELEVATED UNSTBL LYR. ISENT LIFT/MSTR ADVCTN WL CONT TO FUEL THIS
SYSTEM. AM ATTEMPTING TO PROVIDE A LTL DEFINITION BY CAPTURING A
DIURNAL MIN /RELATIVELY SPEAKING/ IN THE MRNG...FLLWD BY CAT POPS
WHEN DAYTIME HEATING WL HV THE BIGGER IMPACT. IN ADDITION...AM A
LTL MORE EXPANSIVE IN AREA OF CHC THUNDER...AT LEAST FM AN
ELEVATED SENSE. SHEAR LOOKS GOOD...BUT AM CHALLENGED TO SEE TOO
MUCH SFC BASED INSTBY.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
LOW PRESSURE DEPARTS TO THE NORTHEAST MONDAY...BUT THE FRONTAL
BOUNDARY IT RODE IN ON WILL REMAIN STALLED NEAR THE REGION THROUGH
MUCH OF NEXT WEEK. MULTIPLE AREAS OF LOW PRESSURE WILL CONTINUE TO
DEVELOP AND MOVE ALONG IT...AS THE LARGE SCALE TROUGH RESPONSIBLE
FOR THIS ACTIVE PATTERN PERSISTS OVER EASTERN NORTH AMERICA. THIS
WILL ALSO LEAD TO BELOW NORMAL TEMPERATURES THROUGH MUCH OF NEXT
WEEK...WITH HIGHS STRUGGLING TO REACH 70.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
FLGT CONDS ON THE CUSP BTWN MVFR AND IFR. BELIEVE WL HV IMPRVMNT
THRU THE AFTN BEFORE CONDS DROP ONCE AGN. HV KEPT ALL TAFS AT
MVFR TNGT...ALTHO IFR /OR LWR/ CERTAINLY WITHIN THE REALM OF
POSSIBILITY.

CONDS WL GRDLY IMPRV ONCE AGN SAT...ALTHO FLGT RESTRICTIONS
REMAIN. THERE IS A CHC AT BRIEF VFR PRIOR TO RAFL ARRIVING. ATTM
CONFIDENCE TOO LOW TO CARVE OUT A WINDOW OF VFR IN THE TAFS.

LT AFTN OR EVE SAT CONDS WL DROP AS RA OVERSPREADS THE AREA. RA
MAY BE MDT TO BRIEFLY HVY SAT NGT INTO SUN. FLGT RESTRICTIONS WL
BE WIDESPREAD.

POOR FLYING CONDS CARRY OVER INTO SUN...THO BREAKS IN THE OVC PSBL
AS BDRY ATTEMPTS TO WIGGLE N OF THE TERMINALS. HWVR THAT ALSO
YIELDS A THUNDER RISK.

SUB-VFR PSBL MON-TUE IN ANY LWR CIGS/-RA W/ FRONT STALLED NEARBY.
WINDS GENERALLY NELY 10 KTS.

&&

.MARINE...
PREV FCST REMAINS ON TRACK. ONSHORE FLOW WILL CONTINUE THROUGH
SATURDAY. GENERALLY EXPECTING 5- 10 KT WITH OCCASIONAL INCREASES
TO 15 KT. LIGHT FOG AND DZ WILL CONTINUE AT TIMES.

NEXT ROUND OF RAIN AND ASSOCIATED LLJ REACHES WATERS BY ELY SAT
EVNG. AM KEEPING WINDS UNDER SCA CRITERIA THRU SAT NGT EVEN THO
WINDS ALOFT INCREASE DUE TO POOR MIXING. MIXING MAY IMPROVE ON
SUN...PSBLY AFTN/EVE...BUT CONFIDENCE ON THAT RATHER LOW.

THUNDERSTORMS WILL BE POSSIBLE SUNDAY AFTERNOON AND EVENING. SCA
CONDITIONS ALSO REMAIN POSSIBLE SUN-MON WITH LOW PRESSURE PASSING
ON MONDAY.

A FRONTAL BOUNDARY STALLED NEAR OR JUST SOUTH OF THE WATERS
SHOULD RESULT IN A WEAK ENOUGH GRADIENT TO PRECLUDE SMALL CRAFT
ADVISORIES MONDAY INTO TUESDAY.

&&

.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES STILL AT OR BELOW A HALF-FOOT ABV NORMAL. WL CONT
TO MONITOR...THERE ARE NO INDICATIONS OF POTL INUNDATION THRU THE
WKND. SUN COMES THE CLOSEST.

&&

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

&&

$$
SYNOPSIS...RCM/HTS
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...DFH
AVIATION...HTS/DFH
MARINE...HTS/DFH
TIDES/COASTAL FLOODING...HTS



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