-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KAKQ 160119
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
919 PM EDT SAT JUN 15 2013

.SYNOPSIS...
HIGH PRESSURE MOVES OFF THE CAROLINA COAST TONIGHT AND SUNDAY. A
WEAK COLD FRONT APPROACHES FROM THE NORTHWEST LATE SUNDAY INTO
SUNDAY NIGHT.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
CRNT FCST ON TRACK WITH ONLY MINOR CHANGES MADE TO GRIDS. SFC HIGH
PRS SLIDES OVRHD RESULTING IN ANTH CONFY NITE. SOME HIGH LVL CLDS
FROM TIME TO TIME...OTW M CLR. LOWS 60-65.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
STRENGTHENING SW WINDS ON SUNDAY WILL BRING WARMER TEMPS AND
INCREASED MOISTURE INTO THE AREA WITH INCREASING CLOUD COVER. NAM
SOUNDING SHOWING AROUND 1.75 INCHES OF PWAT DURING THE LATE
AFTERNOON WITH CAPE VALUES ~1000 J/KG. MOISTURE AND INSTABILITY
COUPLED WITH A WEAK SURFACE TROUGH CROSSING THE AREA ON SUNDAY WILL
BRING A CHANCE OF SHOWERS AND TSTMS TO MAINLY THE NORTHERN PORTION
OF THE LOCAL AREA LATE SUNDAY AFTN. MODEL DIFFERENCES EXIST WITH THE
INFLUENCE THE SURFACE TROUGH WILL HAVE ON STORM INITIATION. THE
ECMWF KEEPS THE AREA CLEAR OF ANY PRECIP...HOWEVER HI-RES
MODEL-DERIVED REFLECTIVITY DOES INDICATE THE POSSIBILITY FOR
CONVECTIVE DEVELOPMENT SUNDAY NIGHT. SOME STRONG THUNDERSTORMS MAY
DEVELOP BUT NOT EXPECTING ANY SEVERE DEVELOPMENT AT THIS TIME.

CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE MONDAY THROUGH
TUESDAY AS WARM/MOIST AIRMASS REMAINS IN PLACE WITH WEAK
SHORTWAVE ENERGY CROSSING THE AREA. AGAIN...STRONG STORMS MAY
DEVELOP BUT SEVERE POTENTIAL REMAINS LOW WITH BEST DYNAMICS STAYING
TO THE NORTH OF THE FA. HIGH TEMPS A BIT ABOVE AVERAGE SUN AND MON
TOPPING UP IN THE UPR 80S TO NEAR 90. EXPECT LOWS MONDAY/TUESDAY
MORNING IN THE UPPER 60S TO LOW 70S.

&&

.LONG TERM /MONDAY 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 /01Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. SFC HIGH
PRESSURE BUILDS OVER THE RGN THROUGH TNGT. EXPECTING LGT W-NW WINDS
INLAND, WITH LIGHT WINDS RESULTING IN TYPICAL MID-AFTERNOON SEABREEZE
EFFECTS AT ORF. OTHERWISE, LOOK FOR FLOW TO REMAIN LIGHT AND
BECOME MORE S-SW OVERNIGHT AND ERY SUN AS SFC HIGH MOVES OVERHEAD
AND SLIDES OFFSHORE BY LATE TONIGHT. AS GRADIENT INCREASES, EXPECT
DIURNAL MIXING TO ALLOW FOR GUSTS TO 20-25KT OVER AREA TAF SITES
ON SUNDAY AFTN.

OUTLOOK: WEAKENING CDFNT APPROACHING FM THE NW LT SUN AND SETTLES
SOUTH OVER THE FA SUN NGT W/ PSBL ISOLD/WIDELY SCT TSTMS AND
PERHAPS A FEW SHORT LIVED CIG/VSBY RESTRICTIONS, MAINLY ACROSS
NORTHERN TERMINALS (RIC/SBY). CONTINUED SW FLOW MON/TUE WITH LOW
PROB FOR (MAINLY) DIURNALLY DRIVEN SHRAS/TSRAS ON MON...WITH
INCREASING CHCS ON TUE AS WEAK AREA OF LOW PRESSURE PIVOTS ACROSS
THE REGION.

&&

.MARINE...
HIGH PRESSURE HAS SETTLED OVER THE WATER TODAY WITH WINDS AOB 10 KT
AND SEAS AOB 3 FT. HIGH PRESSURE WILL SLIDE OFF THE COAST TONIGHT
AND LOCATE OFF THE SE COAST THROUGH MONDAY. LOW PRESSURE WILL CROSS
THE NE SUN AFTERNOON THROUGH MONDAY MORNING...TIGHTENING THE
PRESSURE GRADIENT OVER THE WATER. THE RESULT WILL BE INCREASING LOW
LEVEL WINDS AND SWLY SFC WINDS SUN AFTERNOON THROUGH EARLY MONDAY
MORNING. ATTM...WAA...STRONG LOW LEVEL INVERSION AND WARMING WATER
TEMPS EXPECTED TO RESULT IN STABLE CONDS OVER THE WATER. THUS...WILL
CAP WINDS AT 15 KT IN THE BAY AND 20 KT OVER THE COASTAL WATERS.
STRONGEST WINDS WILL BE OVER NRN COASTAL WATERS...AS WATER TEMPS ARE
STILL IN THE 60S. GRADIENT WILL RELAX MON. A WEAKENING COLD FRONT
WILL CROSS THE WATER TUES NIGHT. SEAS MAY REACH 5 FT OVER THE NRN
COASTAL WATERS TUES NIGHT. WINDS WILL BACK AROUND TO THE N/NE BEHIND
THE FRONT...BUT EXPECTED TO REMAIN AOB 15 KT. HIGH PRESSURE WILL
THEN RETURN WEDS THROUGH THE END OF THE WEEK...WITH SWLY WINDS AOB
15 KT.

&&

.HYDROLOGY...
FLOOD WARNING CANCELLED FOR THE BLACKWATER AT FRANKLIN. LEVEL FELL
BELOW FLOOD STAGE LATE THIS AFTRN.

&&

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

&&

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