-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KAKQ 170127
AFDAKQ

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

.SYNOPSIS...
A WEAK COLD FRONT APPROACHES FROM THE NORTHWEST MONDAY...THEN SLOWLY
MOVES ACROSS THE REGION TUESDAY INTO EARLY WEDNESDAY. HIGH PRESSURE
BUILDS IN FROM THE NORTH DURING THE MIDDLE OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
NOT MUCH CONVECTION NOTED ATTM. SOME CELLS TRYING TO DVLP JUST N
AND W OF FA SO WILL KEEP LOW CHC POPS GOING FOR THE REST OF THE
EVENING. SHORT RANGE MODELS STILL WANT TO DVLP SCT SHWRS ACROSS
THE AREA LATER ON AS WEAK S/W TRACKS E (HIGHEST POPS NRN HALF).

PVS DSCN:
A COLD FRONT MOVING FROM THE OHIO VALLEY STALLS ALONG THE MASON-
DIXON LINE LATE TONIGHT AND WITH WARM/UNSTABLE AIR MASS REMAINING
IN PLACE SOUTH OF THE BOUNDARY...CONTINUED SHOWER AND TSTM CHANCES
ACROSS THE LOCAL AREA OVERNIGHT. AGAIN...BEST CHANCES FOR PRECIP
WILL BE ACROSS NORTHERN AREAS...ESPECIALLY BEFORE MIDNIGHT. LOWS
TONIGHT IN THE UPR 60S TO LOW 70S.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
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 ~1.75" TUESDAY WITH AN INCREASED THREAT FOR
SLOW-MOVING 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/TUESDAY NIGHT WILL BE IN THE UPR 60S TO LOW 70S.
TUESDAY`S HIGHS IN THE LOW/MID 80S.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
DRY CONDITIONS AND BELOW NORMAL TEMPS WILL HIGHLIGHT THE BEGINNING
OF THE EXTENDED PERIOD...FOLLOWED BY A RETURN TO NEAR SEASONABLE
TEMPS BY THE WEEKEND.

PERSISTENT BLOCKY PATTERN...WRN TROUGH/PLAINS RIDGE/ERN TROUGH WILL
CONTINUE THROUGH THE BEGINNING OF THE EXTENDED. THE RIDGE WILL BEGIN
TO RELAX AS A STRONG POLAR LOW LOCATES OVER THE HUDSON BAY
THURS-FRI. THE NW UPPER LOW WILL LIFT NEWD INTO SRN CANADA
FRI...RESULTING IN A SLOW EWD PROGRESSION OF THE FLATTER/WEAKER
UPPER RIDGE AND THE DEVELOPMENT OF STRONG HIGH PRESSURE (+1 STD DEV
H5 HEIGHTS) OVER THE SRN PLAINS. OVER THE LOCAL AREA...BAGGY
TROUGH/WEAKNESS UNDER THE RIDGE WILL REMAIN ORIENTED ALONG THE
SE/MID ATLANTIC COAST THROUGH THE EXTENDED PERIOD...RESULTING IN
NWLY FLOW ALOFT. AT THE SFC...HIGH PRESSURE WILL BUILD OVER THE MID
ATLANTIC THURS...BEFORE SLIDING OFFSHORE FRIDAY...AND REMAINING
ALONG THE COAST THROUGH THE WEEKEND. THIS WILL RESULT IN ONSHORE
E-SE FLOW WITH S/SW FLOW RETURNING SAT INTO SUNDAY AS THE UPPER
TROUGH WEAKENS. DRY CONDITIONS (DEWPOINTS GENERALLY IN THE LOW 60S
AND PRECIP WATER AOB 1.5 INCHES) EXPECTED THROUGH SAT. MOISTURE WILL
BEGIN TO RETURN TO THE REGION SAT AND SUN. OPTED TO INCLUDE CLIMO
POPS (SLIGHT CHANCE) SAT AND SUN AFTERNOON DUE TO INCREASING
MOISTURE AND THE POSSIBILITY OF DIURNALLY DRIVEN THUNDERSTORMS IN
NWLY FLOW.

BIGGEST CHANGE IN THE CURRENT EXTENDED RELATES TO DAYTIME TEMPS.
LOWER HEIGHTS/LOW LEVEL THICKNESSES AND E/SE ONSHORE SFC WINDS WILL
RESULT IN BELOW NORMAL TEMPS THURS AND FRI. DAYTIME TEMPS EXPECTED
TO ONLY WARM INTO THE LOW 80S THURS (~-1 STD DEV) WITH ONLY A FEW
DEGS WARMING FRI (ONLY MID/UPPER 70S ALONG THE IMMEDIATE COAST.
INLAND FLOW WILL RETURN TO THE S SAT AND SUN...WITH TEMPS RETURNING
TO NEAR SEASONABLE NORMS (MID/UPPER 80S)...BUT STILL SEVERAL DEGS
COOLER ALONG THE COAST. OVERNIGHT LOWS GENERALLY IN THE LOW/MID 60S.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
WEAK CDFNT CONTINUES TO APPROACH FM THE NW RESULTING IN INCRSG
CLOUDS. LIGHT RAIN AFFECTING NORTHERN AND WESTERN PORTIONS OF THE
CWA. MODELS SUGGEST THAT LIGHT RAIN EXTENDING FAR BACK INTO SW VA
AND WVA WILL MOVE INTO CENTRAL AND SOUTHERN VA AFTER MIDNIGHT.
THIS WILL LIKELY CONTINUE THRU THE OVERNIGHT INTO MON MORNING.
EXPECT CONDS TO REMAIN MOSTLY VFR WITH CIGS 3500+ AND VIS
GENERALLY 5 MI OR BETTER. HOWEVER AN OCNL MVFR COND PSBL IF PTCHY
MODERATE RAIN FALLS OVER TERMINAL.

OUTLOOK...CONTD SW FLO MON/TUE WITH PROB FOR 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...
HIGH PRESSURE HAS LOCATED OFF THE SOUTHEAST COAST AS LOW PRESSURE
MOVES THROUGH THE NE STATES AND SE CANADA. A SFC TROUGH EXTENDS FROM
THE SFC LOW SWWD THROUGH THE MID ATLANTIC REGION...JUST WEST OF THE
WATERS. FOR THE REST OF THE AFTERNOON...SW WINDS WILL REMAIN AROUND
15 KTS IN THE BAY AND 15 TO 20 KT IN THE COASTAL WATERS. EXPECT
MAYBE A BRIEF UPTICK IN WINDS THIS EVENING OVER THE BAY...BUT STABLE
CONDS OVER THE WATERS SHOULD INHIBIT SCA CONDS FROM BEING MET. WILL
CONTINUE TO MONITOR AND CAP WINDS AT 15 KT IN THE BAY AND 20 KT IN
THE COASTAL ZONES. A WEAKENING COLD FRONT WILL APPROACH THE REGION
FROM THE NW TONIGHT...BUT IS EXPECTED TO DISSIPATE OVER THE REGION
BEFORE REACHING THE WATERS. ISOLATED/SCATTERED SHOWERS EXPECTED TO
ACCOMPANY THE FRONT INTO THE REGION LATE TONIGHT. SEAS MAY  APPROACH
5 FT 20 NM OUT OVER THE NRN COASTAL WATERS. GRADIENT WILL ALSO RELAX
LATE TONIGHT...WITH SW WINDS DIMINISHING TO 10-15 KT OVER THE BAY
AND 15 KT OVER THE COASTAL WATER. WINDS WILL DIMINISH TO GENERALLY
AOB 10 KT THROUGH THE DAY MONDAY. ANOTHER AREA OF LOW PRESSURE AND
AN ATTENDANT COLD FRONT WILL APPROACH THE WATERS MON INTO
TUES...CROSSING THE WATERS DURING THE DAY TUES. SW WINDS EXPECTED TO
REMAIN AOB 15 KT AS STRONGEST WINDS/TIGHTEST GRADIENT WILL BE WELL
OFFSHORE. WINDS WILL BECOME NLY AOB 15 KT BEHIND THE FRONT AS HIGH
PRESSURE BEGINS TO BUILD BACK INTO THE REGION THROUGH THE END OF THE
WEEK. ONSHORE E/SE WINDS AOB 15 KT EXPECTED WED NIGHT THROUGH THE
END OF THE WEEK.

&&

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

&&

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