Area Forecast Discussion Issued by NWS Wakefield, VA
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000
FXUS61 KAKQ 200553
AFDAKQ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
152 AM EDT MON MAY 20 2013
.SYNOPSIS...
A WEAK FRONT WILL SLOWLY PUSH NORTH OF THE AREA TONIGHT AS HIGH
PRESSURE BECOMES ANCHORED WELL OFF THE COAST. SHOWERS AND THUNDERSTORMS
WILL BECOME MORE WIDELY SCATTERED AFTER MONDAY...WITH ABOVE AVERAGE
TEMPERATURES PREVAILING THROUGH MUCH OF THE UPCOMING WEEK. A COLD
FRONT WILL PASS THROUGH THE MID ATLANTIC STATES LATE THURSDAY INTO
EARLY FRIDAY...WITH COOLER TEMPERATURES EXPECTED BY NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST WX ANALYSIS DEPICTS A RATHER DIFFUSE UPPER LEVEL LOW
SITUATED FROM EASTERN KY TO SW VA AND NC. AT THE SFC...THE FRONTAL
BOUNDARY IS ALSO FAIRLY WEAK...NOW TO THE N OF THE CWA. SFC WINDS
ARE FAIRLY LIGHT AND GENERALLY FROM THE SOUTH. MADE ONLY MINIMAL
CHANGES TO THE FORECAST OVERNIGHT...WITH CHC POPS FOR MOST OF THE
CWA. IR SATELLITE GENLY SHOWS CLOUD TOPS ARE WARMING...DO NOT
EXPECT ANY THUNDER THROUGH THE MORNING HOURS BUT WITH PWATS ~1.5IN
EXPECT MODERATE RAINFALL TO OCCUR DURING ANY SHOWERS...GREATLY
REDUCING VISIBILITIES.
SOME PATCHY FOG IS EXPECTED TO DEVELOP ONCE AGAIN EARLY MONDAY
MORNING... ESPECIALLY IN AREAS NORTH OF INTERSTATE 64 AND ON THE
MARYLAND EASTERN SHORE. WIDESPREAD DENSE FOG IS NOT ANTICIPATED AS
THE FOG SHOULD MAINLY DEVELOP FROM LOWERING STRATUS.
LOW TEMPERATURES MONDAY MORNING ARE FORECAST TO RANGE THROUGH THE
60S ACROSS THE AREA.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS CAN BE EXPECTED MONDAY
UNDER THE INFLUENCE OF THE DISSIPATING UPPER LEVEL TROUGH. A BIT
MORE INSTABILITY IS EXPECTED WHICH WILL RESULT IN MORE WIDESPREAD
THUNDERSTORM ACTIVITY THAN WAS EXPERIENCED SUNDAY. HEAVY RAINFALL
WILL BE THE MAIN THREAT WITH ACTIVITY MOVING RATHER SLOWLY. HAVE
LIKELY POPS ACROSS THE SOUTHERN PIEDMONT AND SOUTH CENTRAL VIRGINIA
AND INTO THE NORTH CAROLINA COUNTIES EAST TO NEAR THE CHOWAN RIVER.
HIGH TEMPERATURES WILL BE SLIGHTLY WARMER THAN SUNDAY WITH READINGS
GENERALLY AROUND 80 INLAND AND THE LOW TO MID 70S AT THE COAST.
CONDITIONS SHOULD BEGIN TO DRY OUT MONDAY NIGHT AND TUESDAY AS THE
HIGH PRESSURE OVER THE SOUTHEASTERN STATES BEGINS TO DOMINATE.
HIGHEST POPS (SHOWERS/THUNDERSTORMS) WILL BE IN SOUTHEAST VIRGINIA
AND NORTHEAST NORTH CAROLINA AT 30 PERCENT. TEMPERATURES ARE
FORECAST TO TOP OUT IN THE MID TO UPR 80S IN MOST AREAS WITH UPR 70S
TO LWR 80S NEAR THE COAST AND OVER THE LOWER EASTERN SHORE.
PRECIPITATION SHOULD END BY LATE TUESDAY EVENING.
FOR WEDNESDAY...MODELS ARE ALL OVER THE PLACE WITH POPS. WITH NO
STRONG TRIGGERS FOR CONVECTION OR INDICATIONS OF WHERE CONVECTION
WILL FOCUS...KEPT POPS AT 30 PERCENT THROUGHOUT THE CWA. HIGH
TEMPERATURES WILL BE SIMILAR TO WHAT IS FORECAST FOR TUESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIOD STARTS OFF WED NGT WITH A CHC FOR RAIN...MAINLY
WEST OF I-95...AHEAD OF AN APPROACHING MID-LVL TROF AND ASSOCIATED
COLD FRNT. S/SW FLOW WILL KEEP TEMPS ABOVE NORMAL...WITH LOWS IN THE
MID TO UPR 60S. THIS PATTERN CONTINUES INTO THU/THU NGT WITH STILL A
30-40% CHC FOR SHWRS/TSTMS. DEEP-LAYER MOISTURE IS ABUNDANT HOWEVER
FORCING IS A LIMITING FACTOR DUE TO A LACK OF WAA AND MOST S/W
ENERGY STAYING OFF TO THE NORTH. MODELS HAVE CONTINUED TO SPEED UP
THE TIMING OF THE FRNT...WITH THE FROPA NOW EXPECTED TO BE SOMETIME
LATE THU/THU NGT. HIGHS THU IN THE LO TO MID 80S. BEHIND THE FRNT FRI
INTO THE WEEKEND...DIMINISHING CHCS FOR RAIN AND SLGTLY LWR TEMPS
(BUT STILL AROUND SEASONAL NORMS) WITH HIGHS IN THE MID 70S TO LWR
80S AND LOWS IN THE 50S.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
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CONSIDERABLY LESS STRATUS/FOG ACROSS THE AREA AND TERMINALS
TONIGHT VS. LAST NIGHT. MAIN AREA OF POTENTIAL IFR CONDITIONS
APPEARS TO BE ON THE DELMARVA. HAVE KSBY IN IFR THE NEXT 6
HOURS...BASED UPON OBSERVATION TRENDS AT KOXB/KWAL AND KGED.
ELSEWHERE...EXPECT SOME BR...AND PERHAPS SOME STRATUS
DEVELOPMENT...BUT GENERALLY VFR/MVFR CONDITIONS EXPECTED.
INCREASED LO LVL MIXING VICE LAST NIGHT ALSO EXPECTED TO INHIBIT
FOG DEVELOPMENT BEFORE SUNRISE. COULD BE A FEW SHWRS AS
WELL...BUT HAVE LEFT OUT OF MOST TERMINALS DUE TO LACK OF
DEFINITIVE TIMING.
FOR THE MOST PART...EXPECT TODAY TO BE VFR. HOWEVER...SIGNIFICANT
UNCERTAINTY EXISTS WITH REGARD TO POTENTIAL SHWR/TSTM ACTIVITY.
GIVEN INCREASED AMOUNT OF SUNSHINE EXPECTED TODAY...HAVE OPTED TO
INCLUDE PROB30 FOR TSTMS AT MOST TERMINALS IN THE 19Z TO 23Z TIME
FRAME. HEAVIER SHWRS/TSTMS WILL CAUSE BRIEF IFR CONDITIONS. EXPECT
TONIGHT TO BE SIMILAR TO CURRENT CONDITIONS...WITH MAINLY VFR/MVFR
CONDITIONS PREVAILING.
MAINLY VFR IN THE TUE TO THU TIME FRAME...WITH THE POTENTIAL FOR
ISOLD/SCTD SHWRS AND TSTMS BOTH TUE/WED. MORE WIDESPREAD SHWR/TSTM
ACTIVITY EXPECTED THU ALG/AHD OF NEXT CDFNT...WHICH MOVES ACROSS
THE AREA THU/THU NIGHT.-- End Changed Discussion --
&&
.MARINE...
SE FLOW PREVAILS TNGT AS A WARM FRNT LIFTS NORTH OF THE AREA. HIRES
MODELS SHOW A QUICK SHOT OF SCA WINDS OVER THE BAY LATER THIS
AFTN/EVENG...BUT NOT CONFIDENT ENUF OR LONG LASTING ENUF TO ISSUE A
SCA HEADLINE FOR THIS ATTM. WINDS STAY GENRLY 10-15 KT OVRNGT AND
SHIFT FROM SE TO S. SEAS WILL APPROACH 4-5 FT OUT 20 NM OVER COASTAL
WATERS...WITH BEST CHC FOR 5+ FT OVER THE NORTHERN TWO ZONES WHERE
SCA HEADLINES CONTINUE THRU THE OVRNGT HRS. 12Z WAVEWATCH SHOWS 5 FT
SEAS THERE LASTING INTO MON AND MON NGT...BUT WITH WAVEWATCH
RUNNING HIGH DURING SOUTHERLY FLOW AS OF LATE...WILL END THE SCA AT
4 AM TNGT WITH THE NEXT SHIFT EITHER EXPIRING THE HAZARD OR
EXTENDING IT OUT IN TIME. OTW...SUB-SCA SOUTHERLY WINDS CONTINUE FOR
THE NEXT FEW DAYS AHEAD OF AN APPROACHING COLD FRNT WHICH CROSSES
THE AREA LATE THU/THU NGT.
&&
.HYDROLOGY...
RIVER LEVEL FORECASTS HAVE BEEN LOWERED SUBSTANTIALLY DUE TO LACK
OF SIGNIFICANT RAINFALL IN THE HEADWATERS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT EARLY THIS MORNING FOR
ANZ650-652.
&&
$$
SYNOPSIS...LKB
NEAR TERM...LKB/DAP
SHORT TERM...LSA
LONG TERM...JEF
AVIATION...WRS
MARINE...MAS
HYDROLOGY...