Area Forecast Discussion Issued by NWS Wakefield, VA
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000
FXUS61 KAKQ 180211
AFDAKQ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1011 PM EDT FRI MAY 17 2013
.SYNOPSIS...
A WEAK FRONT REMAINS NEARLY STATIONARY OVER SOUTHWEST VIRGINIA AND NORTH
CAROLINA THROUGH SATURDAY NIGHT. THE FRONT WILL SLOWLY LIFT BACK TO THE
NORTH LATER SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
-- Changed Discussion --
LATEST WX ANALYSIS DEPICTS SFC FRONT FROM WV SSE TO SOUTH CENTRAL
VA AND INTO NE NC. ALOFT...WEAK RIDGE AXIS EXTENDS NNW FROM SE NC
TO SOUTHERN OH (WITH A TROUGH FROM THE LWR OHIO VALLEY INTO THE TN
VALLEY. FAIRLY SIGNIFICANT DEW PT/MOISTURE GRADIENT EXISTS ACRS
THE CWA WITH DEW PTS INTO THE 60S ALONG/S AND W OF THE FRONT WITH
40S OR LOWER 50S COMMON OVER CENTRAL/EASTERN VA AND THE EASTERN SHORE.
RADAR/SATELLITE TRENDS SHOW SCATTERED SHRA/ISOLATED TSRA NOW
AFFECTING AREAS W OF I-95. WILL RETAIN SLIGHT CHC FOR TSTMS
OVERNIGHT DESPITE LOSS OF DAYTIME HEATING AS SHOWALTER INDICES
SUGGEST POTENTIAL FOR ISOLATED CONVECTION (PRIMARILY ELEVATED)
EVEN AS SFC-BASED CAPES/INSTABILITY WILL BE MEAGER. IR SATELLITE
SHOWS COOLING CLOUD TOPS OVER THE PIEDMONT AND ANOTHER AREA OVER
NORTHERN NC FARTHER UPSTREAM. HAVE RAISED POPS A BIT OVERNIGHT
OVER MUCH OF THE REGION WEST OF CHES BAY (BUT STILL KEEPING POPS
IN THE 40-50% RANGE OTHER THAN A SMALL SLIVER OF LIKELY POPS
ALONG/W OF I-95 PER CURRENT RADAR PICS). ONLY A SLIGHT CHC OR LOWER
FOR PRECIP FOR THE EASTERN SHORE.
MIN TEMPS WILL RANGE FROM THE LWR-MID 50S OVER MD EASTERN SHORE
(WHERE SKIES STAY MOSTLY CLEAR/PARTLY CLOUDY THROUGH MUCH OF THE
NIGHT) TO THE UPPER 50S/LOWER 60S ACRS MOST OF THE REMAINDER OF
THE CWA.-- End Changed Discussion --
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
UNSETTLED PD OF WX FOR THE WKND INTO MON. PCPN COVERAGE (AND QPF)
WILL BE PROBLEMATIC...AND TEND TO FAVOR AFTN AND EVE HRS (ESP SAT
AND AGN MON). KEY TO THE WX NEXT FEW DAYS IS WKNG LO PRES MOVING
SLOLY EWD THROUGH TN VLY W/ IT CONCENTRATED PCPN. OUT AHD OF THAT
SYS...SCT (AT BEST) PCPN FM ERN TN INTO WRN VA/TN (THIS AFTN). XPCG
THAT TO BE THE CASE HERE ON SAT (AND AWAY FM THE IMMEDIATE CST)
AS MAIN AREA OF MSTR (W/ THE REMNANT LO) RMNG PRIMARILY W OF THE
FA. SFC BNDRY DRAPED OVR NC WILL RMN NRLY STNRY THROUGH SAT...THEN
BEGIN TO PULL BACK N AS A WRMFNT INTO SUN AFTN. AT THE SAME
TIME...DEEPER MSTR ARRIVES SAT NGT...CONTS INTO SUN (MDL
TSECTIONS HAVE MUCH BETTER UVM...ESP INLAND)...RESULTING IN HIGHER
POPS (THOUGH WILL STILL KP AT CHC). DISSIPATING LO PRES INVOF FA
SUN NGT INTO MON AS LO LVL FLO BECOMES SW (WRMFNT N OF THE FA) ONCE
RESULTS IN PTNTLLY DIURNALLY DRIVEN CNVTN.
ONSHR WNDS CONT SAT...HI TEMPS SAT FM THE L70S AT THE CST TO ARND
80F ACRS INTR SRN VA AND INTR NE NC. LO TEMPS SAT NGT FM THE U50S
TO M60S. HI TEMPS SUN AGN FM THE L70S AT THE CST TO THE U70S/ARND
80F INLAND. HI TEMPS MON MNLY IN THE L/M80S (70S AT THE BEACHES).
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
LONG TERM PERIOD WILL FEATURE PERIODS OF UNSETTLED WX AND ABOVE
NORMAL HI/LO TEMPS ON AVG. FOR TUE...MID-LVL S/W TROF PUSHES
OFFSHORE ERLY IN THE DAY WITH A CHC FOR SHWRS MAINLY OVER SE AREAS.
DECREASING CLDS DURING THE AFTN WITH TEMPS CLIMBING INTO THE MID
80S. S/SW FLOW CONTINUES WED AND THU LEADING TO CONTINUED WARM TEMPS
(HIGHS IN THE MID TO UPR 80S) AND A CHC FOR MAINLY DIURNAL SHWRS/TSTMS
WITH WEAK SFC TROFS OVER THE AREA. BEST CHC FOR RAIN WILL BE FRI AS
A COLD FRNT ADVANCES TOWARDS THE AREA. WILL CAP POPS AT 40% FOR
NOW WITH HOW FAR OUT IN TIME THIS IS ALBEIT FAIRLY GOOD
CONSISTENCY AMONGST MODEL GUIDANCE WITH THE FRNTAL TIMING. HI
TEMPS ONLY IN THE UPR 70S TO NEAR 80 FRI DUE TO PRECIP AND
WIDESPREAD CLOUDINESS.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
A WEAK COLD FRONT CONTS TO BE DRAPED ACROSS THE REGION. WINDS ARE
GENERALLY FROM THE E-SE AND LESS THAN 10 KT. A FEW SCT
SHOWERS/TSTMS ARE APPROACHING FROM THE WEST AND COULD AFFECT
CENTRL VA AND RIC AROUND MIDNIGHT. SCT SHOWERS/RAIN WILL GRADUALLY
INCREASE ACROSS THE AREA DURING THE OVERNIGHT AS WEAK LOW PRES AND
AN UPPER LVL SYS APPROACHES FROM THE SW. CAN NOT RULE OUT CHC FOR
AN ISOLD TSTM OVERNIGHT ESP FOR RIC. CIGS WILL GRADUALLY LOWER TO
MVFR BY SAT DAYBREAK ACROSS CENTRL VA AND BY EARLY AFTN FOR MOST
OF THE AREA. THE FRONT WILL LINGER ACROSS THE SOUTHERN PORTIONS OF
THE CWA THRU SAT AND SUN...WITH PERIODS OF MVFR CONDS AND CHC OF
SHOWERS/TSTMS THRU THE WEEKEND.
THE FRONT WILL SLOWLY LIFT BACK N AS A WARM FRONT BY LATE
SUN/EARLY MON.
&&
.MARINE...
A WEAK FRNT WILL REMAIN JUST SOUTH OF THE AREA TNGT. NORTH OF THIS
FRNT OVER THE WATERS EXPECT EASTERLY FLOW ~10 KT WITH 1-2 FT WAVES
OVER THE BAY AND 2-3 FT SEAS OVER COASTAL WATERS. THE FRNT
STRUGGLES TO MOVE NORTHWARD SAT...SO EASTERLY FLOW WILL
CONTINUE...AND WITH A SLGTLY ENHANCED PRES GRADIENT...CUD SEE WINDS
APPROACH SCA THRESHOLDS. WILL NOT ISSUE ANY HEADLINES FOR THIS WITH
WINDS EXPECTED TO AVG 15 KT OVER THE BAY/SOUND AND 20 KT OVER
COASTAL WATERS THRU THE DAY. WINDS SLOWLY SHIFT TO THE SE SAT NGT
INTO SUN AS THE FRNT LIFTS NORTH OF THE AREA. STILL EXPECTING
SUB-SCA WINDS...ALTHO SEAS MAY APPROACH 5 FT OVER NORTHERN COASTAL
WATERS AND 4 FT OVER THE MOUTH OF THE BAY. WILL HOLD OFF ON ANY
HEADLINES FOR THIS FORECAST PACKAGE WITH IT BEING 3RD/4TH PERIOD
AND STILL SOME UNCERTAINTY. SOUTHERLY FLOW AND 4-5 FT SEAS
CONTINUES INTO ERLY TO MID NEXT WEEK.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LKB
NEAR TERM...LKB/ALB
SHORT TERM...ALB
LONG TERM...MAS
AVIATION...DAP/JEF
MARINE...MAS