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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KAKQ 161811
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
211 PM EDT SUN JUN 16 2013

.SYNOPSIS...
HIGH PRESSURE REMAINS OFF THE CAROLINA COAST TODAY. A WEAK COLD FRONT
APPROACHES FROM THE NORTHWEST MONDAY...THEN MOVES ACROSS THE REGION
TUESDAY INTO EARLY WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
SW WINDS WILL INCREASE OVER THE REGION TODAY THANKS TO A TIGHTENING
PRESSURE GRADIENT BETWEEN HIGH PRESSURE OFF THE CAROLINA COAST AND
A COLD FRONT MOVING INTO THE OHIO VALLEY. THIS STRENGTHENING SW
FLOW WILL BRING WARMER TEMPS AND INCREASED MOISTURE TO THE AREA ALONG
WITH INCREASING CLOUD COVER. A LEE TROUGH DEVELOPS BY THIS
AFTERNOON WITH ENOUGH MOISTURE/INSTABILITY PRESENT FOR TSTM
DEVELOPMENT (PW`S ~1.75" AND CAPE 1000-1500 J/KG). MODELS DIFFER
ON AMOUNT OF CONVECTIVE DEVELOPMENT THIS AFTERNOON DUE TO TIMING/STRENGTH
DIFFERENCES ASSOCIATED WITH A WEAK S/W EXPECTED TO REACH OUR FA LATE
TODAY IN DAMPENING W-NW FLOW ALOFT. STILL ENOUGH CONSENSUS TO
WARRANT 30-40% POPS ACROSS N-NW HALF OF THE CWA THIS AFTERNOON.
HIGHS TODAY WILL REACH THE UPR 80S TO LOW 90S MOST PLACES.

THE COLD FRONT MOVING ACROSS THE OH VALLEY TODAY STALLS ALONG THE
MASON-DIXON LINE LATE TONIGHT. WARM/UNSTABLE AIR MASS REMAINS IN
PLACE SOUTH OF THE BOUNDARY FOR CONTINUED TSTM CHANCES ACROSS THE
LOCAL AREA OVERNIGHT. BEST CHANCES WILL BE ACROSS NORTHERN AREAS
AND ESPECIALLY BEFORE MIDNIGHT. LOWS TONIGHT IN THE UPR 60S TO LOW
70S.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE MONDAY AND TUESDAY
AS WARM/MOIST AIRMASS REMAINS IN PLACE. THE STALLED FRONTAL
BOUNDARY REMAINS NORTH OF THE AREA MONDAY. SHORTWAVE ENERGY DIVING
SOUTH OUT OF THE GREAT LAKES/MIDWEST ON TUESDAY WILL PUSH THE
FRONT SOUTH THROUGH THE AREA DURING THE DAY AND WILL BE THE
FOCUSING MECHANISM FOR NUMEROUS SHOWER AND THUNDERSTORM DEVELOPMENT.
PWAT VALUES RISE TO OVER 2" TUESDAY WITH AN INCREASED THREAT FOR
SLOW-MOVING TRAINING THUNDERSTORMS AND LOCALIZED FLASH FLOODING.
COULD ALSO SEE A COUPLE OF STRONG THUNDERSTORMS BUT THAT WILL
HINGE ON JUST HOW QUICKLY THE FRONT PUSHES SOUTH (BEST CHANCE
WOULD BE ACROSS OUR SOUTHERN TIER COUNTIES). HIGHS MONDAY WILL BE
WELL INTO THE 80S. LOWS MONDAY NIGHT IN THE UPR 60S TO LOW 70S.
TUESDAY`S HIGHS IN THE LOW/MID 80S (BUT COULD BE COOLER NORTH
DEPENDING ON SPEED OF COLD FRONT.)

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
NEAR SEASONABLE DAYTIME TEMPERATURES AND GENERALLY DRY CONDITIONS
WILL HIGHLIGHT THE EXTENDED PERIOD.

UPPER PATTERN WILL FEATURE TROUGH IN THE WEST/RIDGE OVER THE
PLAINS/TROUGH OVER THE EAST DURING THE BEGINNING OF THE EXTENDED
PERIOD. TROUGH AXIS WILL PUSH OFFSHORE WEDS AS CONFLUENCE ALLOWS
HIGH PRESSURE TO BUILD BACK OVER THE MID ATLANTIC. REMNANT MOISTURE
AND THE PRESENCE OF THE MID LEVEL TROUGH WILL BE ENOUGH TO SUPPORT
SHOWERS ALONG THE COAST EARLY WEDS...BUT EXPECTED DRY ELSEWHERE.
THEREAFTER...POLAR LOW WILL DIVE SWD OVER THE HUDSON BAY/NRN CANADA
THURS...FLATTENING THE TOP OF THE UPPER RIDGE AND WEAKENING THE NW
UPPER LOW. THIS WILL RESULT IN AN EWD PROGRESSION OF A
WEAKER/FLATTER UPPER RIDGE. BAGGY TROUGH WILL REMAIN OVER THE LOCAL
AREA THROUGH FRIDAY...BEFORE STRONG MID LEVEL HIGH PRESSURE (+1 STD
DEV) BUILDS INTO THE SRN PLAINS DURING THE WEEKEND. AT THE
SFC...HIGH PRESSURE WILL REMAIN CENTERED OFF THE MID ATLANTIC COAST
FRI INTO THE WEEKEND WITH A MEAN FRONT LOCATED OVER THE DEEP SOUTH.
MODEST MOISTURE ADVECTION AND UPSLOPE FLOW WILL BRING SCATTERED
SHOWERS TO THE MOUNTAINS OF WRN VA. HOWEVER...LOCAL AREA EXPECTED TO
REMAIN DRY AS DEWPOINTS ONLY EXPECTED IN THE LOW/MID 60S AND PRECIP
WATERS AOB 1.5 INCHES.

TEMPS WILL REMAIN NEAR SEASONABLE NORMS THROUGH THE END OF THE WEEK
WITH TEMPS WARMING INTO THE UPPER 80S TO NEAR 90 BY NEXT WEEKEND.
OVERNIGHT LOWS GENERALLY IN THE MID/UPPER 60S.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
-- Changed Discussion --
VFR CONDS FOR THE BEGINNING OF THE TAF PERIOD. WL CONTINUE TO SEE
GUSTS OUT OF THE SW TO 20-25 KT THROUGH 22-23 Z OR SO UNTIL
DIURNAL MIXING WANES. WEAKENING CDFNT CONTINUES TO APPROACH FM THE
NW LT TDA RESULTING IN INCRSG CLDNS (THOUGH CIGS RMNG AOA
5KFT)...THEN SETTLES SOUTH OVER THE FA THIS EVE INTO TNGT. EXPECT
SCT SHRAS/ISO TSRAS TO DEVELOP ALONG AND WEST OF KRIC-KSBY
LINE...POTENTIALLY IMPACTING TERMINALS AFTER 21Z/5PM. LATEST RADAR
TRENDS DON`T INSPIRE TOO MUCH CONFIDENCE ATTM W/EXPECTING ANY
WIDESPREAD FLIGHT RESTRICTIONS, BUT A BRIEF PERIOD OF MVFR
CIGS/VSBY ARE POSSIBLE BETWEEN 23Z/16 AND 04Z/17 AT KRIC/KSBY.
CONSEQUENTLY, CONSIDERING LOWER THAN NORMAL FORECAST CONFIDENCE HV
GONE WITH VICINITY THUNDER WORDING FOR RIGHT NOW IN LIEU OF TEMPO.

OUTLOOK...CONTD SW FLO MON/TUE WITH LOW PROB FOR (MAINLY)
DIURNALLY DRIVEN SHRAS/TSRAS ON MON...THEN INCRSG CHCS ON TUE AS
WEAK AREA OF LOW PRES TRACKS ACRS THE RGN.
-- End Changed Discussion --

&&

.MARINE...
SW WNDS AVGG (JUST) SHORT OF SCAS THROUGH THIS AFTN. WEAKENING
CDFNT APPROACHES THE WTRS FM THE NW LT TDA...SLOLY PUSHING ACRS
THE WTRS TNGT WHILE DISSIPATING. SEAS MAY APPROACH 5 FT INVOF NRN
OCN WTRS (INTO TNGT). CONTD SW WNDS ERY IN THE UPCOMING WK AS HI
PRES OFF THE SE CONUS CST HOLDS ITS GROUND AND AHD OF NEXT AREA OF
LO PRES TRACKING TWD THE WTRS FM THE W. BY TUE...MDL DIFFERENCES
WRT HANDLING OF SFC LO PRES ENTERING THE RGN FM THE W. 00Z/16 GFS
SHOWING MUCH FASTER ARRIVAL OF/STRONGER NNE WNDS BY LT TUE/TUE NGT
AS LO PRES TRACKS NR/JUST S OF THE WTRS. MADE ONLY MINOR
ADJUSTMENTS TO WNDS/WAVES-SEAS TUE INTO WED BASED ON UNCERTAINTY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...JDM
NEAR TERM...JDM
SHORT TERM...JDM/DAP
LONG TERM...SAM
AVIATION...ALB/MAM
MARINE...ALB