Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 010049
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
849 PM EDT SUN AUG 31 2014

.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL PERSIST THROUGH TUESDAY WITH AN ACTIVE
PATTERN FOR THE EASTERN SEABOARD. A WEAK COLD FRONT WILL CROSS THE
AREA TUESDAY NIGHT...FOLLOWED BY HIGH PRESSURE.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
RGNL RADAR COMPOSITE DEPICTS NMRS SHRA/TSRA FM OMH/OKV THRU DCA TO
NAK. ACTIVITY ATTM SUPPORTED BY A TAIL OF A PVA LOBE WHICH WL BE
CROSSING THE AREA THRU 06Z. RAFL RATES STILL AOA 1 INCH/HR...AND
00Z LWX RAOB CONTAINS 2.2 IN PWAT. HWVR...W/ THE LOSS OF DAYTIME
HEATING AS WELL AS ENERGY SPENT FM PRVS STORMS...CAPE VALUES
HOVERING ARND 1000 J/KG PER MESO ANALY. /OUR RAOB ONLY CONTAINS
ABT 600 J/KG...W/ 125 J/KG CINH/. THEREFORE...XPCT A CONTD DECLINE
IN TERMS OF STRONG/PSBL SVR TSTMS. INSTEAD...WE SHUD BE LOOKING AT
JUST HVY RAINERS FOR THE REST OF THE ENVG.

IN TERMS OF HOW THAT MAY PLAY OUT...HRRR HAS BEEN PROVIDING A
FAIRLY REASONABLE DEPICTION FOR AT LEAST THE FIRST 6 HRS. WITH
THAT IN MIND...WUD THINK THAT THE CRRDR RECEIVING SHRA/STORMS WL
CONT TO DO SO THRU AT LEAST MIDNGT. AFT THAT...CNVCTN WL BE MORE
SCT IN NATURE...BUT STILL IN THE SAME ZONE.

TEMPS DROPPED QUICKLY FM W OF IAD TO NEAR NAK/BWI THX TO ERLR
TSRA. BUT...THOSE LOCATIONS NEAR DEWPTS ATTM...SO ADDTL COOLING
NOT XPCTD. USED LAMP GDNC TO RETOOL TEMPS...BUT IMPACT ON MIN-T
FCST MINIMAL.

CONSIDERING SATURATION AND WET GRND WUD BE CONCERNED ABT FOG...BUT
STILL HV A FAIRLY SOLID CLD DECK ACRS MOST OF THE AREA...WHICH WL
IMPEDE IN ITS FORMATION. FOR THE TIME BEING...AM JUST DEPICTING
PATCHY FOG IN CLIMO FAVORED VLYS. IF THERES ANY CLRG OR
LIFTING...THEN THE STRIPE FM HEF/IAD TO BWI/NAK WL NEED TO BE
REASSESSED.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
WL STILL HV LEE TROF AND AN UNSTBL AMS MON. HWVR...FORCING FOR
PCPN WL BE LACKING. STILL XPCT SCT STORM DVLPMNT DURING THE
MIDDAY...WHICH WL BE DROPPING INTO THE LEE TROF DURING THE AFTN.

THE RELATIVE LACK OF ACTIVITY AND CLEARING SKIES FROM WEST-TO-
EAST WILL ALLOW TEMPS TO CLIMB BACK INTO THE U80S AND SOME L90S
FOR THE AREA ON MON AFTN...W/ DEWPOINTS STANDING PAT IN THE
U60S/L70S - ANOTHER MUGGY DAY FOR THE AREA.

WEAK RIDGING CROSSES THE CENTRAL MID-ATLANTIC MONDAY NIGHT INTO
TUESDAY...MAKING FOR A REPRIEVE IN THUNDERSTORMS FOR 12-18 HRS. WITH
THE BERMUDA HIGH IN PLACE...EXPECT TUESDAY TO HAVE THE HIGHEST
TEMPERATURE DAY SINCE JULY. MAX TEMPS LOW TO MID 90S ACROSS LOWER
ELEVATIONS.

THE NEXT COLD FRONT APPROACHES LATE TUESDAY AND CROSSES THAT NIGHT.
WITH PLENTY OF ENERGY FROM THE HOT DAY...EXPECT AT LEAST ISOLATED
SEVERE WEATHER...PARTICULAR FOR WRN ZONES THAT ARE PROGGED TO GET
THE EVENING ACTIVITY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE OVER THE CWA WILL MOVE OFFSHORE ALLOWING A COLD FRONT
FROM THE WEST TO ENTER THE CWA FRIDAY. ALTHOUGH PVA IS WEAK...
STALLED BOUNDARY AND MOISTURE WILL SUPPLY ACTIVE WEATHER INTO THE
WEEKEND.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
VFR CONDS ACRS THE TERMINALS ATTM. TSRA HAS MOSTLY PUSHED S/E OF
THE TERMINALS. STILL MAY SEE A FEW MORE SHRA...BUT DO NOT
ANTICIPATE ADDTL SUBSTANTIVE RESTRICTIONS IN THE NEAR TERM.

CONSIDERING SATURATION AND WET GRND WUD BE CONCERNED ABT FOG...BUT
STILL HV A FAIRLY SOLID CLD DECK ACRS MOST OF THE AREA...WHICH WL
IMPEDE IN ITS FORMATION. FOR THE TIME BEING...WL HOLD METROS AT
VFR AND KEEP PREDAWN MVFR AT ONLY CHO/MRB. IF THERES ANY CLRG OR
LIFTING...THEN WL NEED TO REASSESS.

SLY WINDS WILL PERSIST INTO MON...ALONG W/ A FEW HIT/MISS SHOWERS
AS WELL THRU MON EVE. WL BE KEEPING VFR CONDS IN THE TAFS.
HWVR...FLGT RESTRICTIONS PSBL W/IN SHRA/TSRA.

BRIEF HIGH PRESSURE/VFR TUESDAY ON A HOT DAY (MAX TEMPS IN THE MID
90S). SCATTERED STRONG THUNDERSTORMS TUESDAY NIGHT AS A WEAK COLD
FRONT CROSSES THE REGION. HIGH PRESSURE/VFR OUTSIDE OF POTENTIAL
MORNING FOG MID TO LATE WEEK.

&&

.MARINE...
SLY FLOW ACRS THE MARINE AREA HAS BEEN INTERRUPTED BY CNVCTN.
CASE IN POINT...TPLM2 WNDS HV SWITCHED ARND TO NLY. HWVR...STRONGER
STORMS MAY HV HIER WND GUSTS...AND WL BE COVERED BY SMW/S. CRRNT
THINKING IS TO RIDE OUT GOING SCA FOR THE MAIN CHANNEL OF THE BAY
THRU ITS 11PM EXPIRATION.

SLY FLOW PTTN CONTS INTO MON. GDNC CONTS TO SUGGEST THAT WNDS SHUD
BE LIGHTER THAN TDA.

SUB SCA SWLY FLOW MONDAY NIGHT THROUGH TUESDAY. WEAK COLD FRONT
BRINGS WLY FLOW LATE TUESDAY NIGHT THROUGH WEDNESDAY. HIGH PRESSURE
OVERHEAD WEDNESDAY NIGHT AND THURSDAY.

&&

.TIDES/COASTAL FLOODING...
DEPARTURES ON MOST OF THE BAY STILL HOVERING AROUND 1 FT.
LWTV2/SLIM2 STILL ONLY 3/4 FT ABOVE NORMAL. LOOKS LIKE
THUNDERSTORMS THAT CROSSED NEAR WASH DC HAS PUSHED SOME OF THE
WATER OUT OF THE UPR TIDAL POTOMAC...BUT THAT SHOULD CHANGE AS THE
TIDE ROLLS BACK IN AGAIN. ANNAPOLIS ON THE CUSP OF EXCEEDING
MINOR CRITERIA ATTM...AND SVRL OTHER SITES WL REACH CAUTION STAGE.

AS SLY FLOW LIGHTENS MON...GUIDANCE SUGGESTING THAT DEPARTURES
WILL EASE SLIGHTLY. WITH THAT IN MIND...THE NEXT TIDE CYCLE /MON
AM/...WHICH IS THE LOWER ASTRONOMICALLY ANYWAY...SHOULDNT RESULT
IN ADDTL INUNDATION. OF COURSE...WE/LL CONT TO MONITOR.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR MDZ014.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
     ANZ532>534-543.

&&

$$

SYNOPSIS...BAJ
NEAR TERM...HTS
SHORT TERM...HTS/GMS
LONG TERM...CEM
AVIATION...HTS/BAJ
MARINE...HTS/BAJ
TIDES/COASTAL FLOODING...HTS




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