Area Forecast Discussion Issued by NWS Wakefield, VA
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000
FXUS61 KAKQ 190517
AFDAKQ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
117 AM EDT SUN MAY 19 2013
.SYNOPSIS...
A WEAK FRONT REMAINS NEARLY STATIONARY OVER NORTH CAROLINA TONIGHT. THIS
FRONT IS EXPECTED TO LIFT TO THE NORTH ON SUNDAY...AND MOVE NORTH
OF THE REGION BY MONDAY AFTERNOON. A RIDGE OF HIGH PRESSURE OFF THE
SOUTHEAST COAST WILL PREVAIL INTO THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST WX ANALYSIS CONTINUES TO DEPICT A STATIONARY FRONT/BOUNDARY
OVER NC...WITH A RATHER BROAD MID/UPPER LEVEL TROUGH SITUATED FROM
KY DOWN INTO THE CAROLINAS. LATEST RADAR SHOWS THE MORE ORGANIZED
ACTIVITY FROM EARLIER IN THE EVENING NOW OFF THE COAST...BUT WITH
ANOTHER BATCH OF MOISTURE PUSHING NORTH INTO SOUTH CENTRAL VA FROM
CENTRAL NC.
TOUGH CALL AS TO THE EVOLUTION OF THIS NEXT ROUND. MODELS GENLY
CONFINE IT TO PIEDMONT COUNTIES SOUTH OF FVX...BUT WILL BROAD-
BRUSH SOME LIKELY/60% POPS OVER S CENTRAL VA AS WELL AS INTERIOR NE
NC THROUGH 07Z...WITH 40-50% OVER MOST OF THE REMAINDER OF THE CWA
(EXCEPT WILL ALSO CARRY LIKELY POPS ACRS PORTIONS OF THE EASTERN
SHORE). DUE TO FAIRLY WEAK MID/UPPER DYNAMICS DO NOT EXPECT THE
AMOUNT OF COVERAGE OR INTENSITY OF PRECIP AS LAST NIGHT.
CONCERNING TSTMS...WILL KEEP MENTION OF ISOLATED CONVECTION OVER
FAR SOUTHERN VA/NE NC GOING AFTER MIDNIGHT WHERE ML CAPE ON THE
ORDER OF 500 TO 1000 J/KG PERSISTS (JUST SHRA FARTHER NORTH). MIN
TEMPS DROP VERY LITTLE FROM CURRENT VALUES WITH MAINLY OVC SKIES
AND MIXING...LOW TO MID 60S FOR MOST LOCATIONS. ADDED FOG TO NW
SECTIONS OF THE CWA PER LATEST OBS...ALTHOUGH NOT EXPECTING VSBYS
TO DROP TO MUCH LESS THAN 1 MILE DUE TO CLOUD COVER.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
WET WEATHER WILL CONTINUE SUNDAY THROUGH MONDAY AS THE STALLED FRONT
BEGINS TO LIFT NWD. ALSO AN UPPER LEVEL TROUGH OVER THE OH/KY AREA
WILL MOVE ACROSS THE MID ATLANTIC REGION MONDAY. PCPN IS EXPECTED TO
BE MOST WIDESPREAD OVER WESTERN PORTIONS OF THE AREA SUNDAY PER
MODEL GUIDANCE WHERE UPPER LEVEL SUPPORT WILL BE BEST. POPS INCREASE
ONCE AGAIN MONDAY MAINLY ACROSS SRN PORTIONS. AS THE TROUGH MOVES
OFF TO THE EAST...PCPN DECREASES OVER WRN PORTIONS BY MONDAY AFTN.
HIGH TEMPERATURES SUNDAY AND MONDAY WILL BE WARMER...GENERALLY IN
THE UPR 70S TO LWR 80S WITH SLIGHTLY COOLER READINGS NEAR THE COAST.
LOWS WILL RANGE THROUGH THE 60S.
DURING THE REMAINDER OF THE SHORT TERM...WHILE THE UPPER LEVEL
TROUGH MOVES OFF TO THE EAST...FURTHER UPPER LEVEL IMPULSES ARE
EXPECTED TO IMPACT THE AREA. PCPN DIMINISHES BY AROUND MIDNIGHT
MONDAY NIGHT. SOME REDEVELOPMENT OF TSTMS IS EXPECTED TUESDAY AFTN
MAINLY OVER SRN VA/NE NORTH CAROLINA. HIGH TEMPERATURES TUESDAY ARE
FORECAST TO REACH INTO THE MID TO UPR 80S AT MOST LOCATIONS.
72 HR QPF TOTALS FORECAST TO RANGE FROM 1 TO 2 INCHES WITH
LOCAL AMOUNTS TO 3 INCHES POSSIBLE ACROSS THE PIEDMONT TO AROUND
A HALF INCH TO AN INCH TOWARD THE COAST. SOME ISSUES ON AREA
RIVERS ARE PSBL EARLY THIS COMING WEEK. SEE HYDRO SECTION BELOW.
AT THIS TIME...THERE ARE NO PLANS FOR A FLOOD WATCH BUT THIS WILL
CONTINUE TO BE MONITORED.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODELS SIMILAR OVER THIS TIME PERIOD WITH THE TIMING OF ANOTHER TROF
DEEPING AT 500 MB TOWARD FRIDAY AND SATURDAY. THIS WILL USHER A
STRONGER COLD FRONT THROUGH THE REGION FRIDAY INTO SATURDAY. THE
FRONT WILL HAVE SOME SHOWERS AND THUNDERSTORMS WITH IT AS IT MOVES
THROUGH. BEFORE THAT A FRONTAL BOUNDARY REMAINS NEARLY STATIONARY
ACROSS THE GREAT LAKES AND NEW ENGLAND. SOUTH OF THIS AREA WILL HAVE
GENERAL SOUTH TO SOUTHWEST FLOW ACROSS THE AREA. COULD SEE AN
ISOLATED AFTERNOON THUNDERSTORM. ANY THUNDERSTORMS THAT FORM NORTH
ALONG THE BOUNDARY COULD PUSH INTO THE NORTHERN PART OF THE AREA
DURING THE EVENINGS. TEMPERATURES WILL BE AT OR ABOVE NORMAL UNTIL
THE FRONT PASSES. THEN TEMPERATURES WILL DROP BACK ON SATURDAY TO AT
OR BELOW NORMAL.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
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AVIATION CONDITIONS NEXT 12 HOURS OR SO APPEAR TO BE SPLIT BETWEEN
MVFR/VFR AT KPHF/KECG/KORF AND MAINLY IFR AT KRIC/KSBY. LOOKS LIKE
KRIC WILL REMAIN IFR/LIFR THROUGH AT LEAST 12Z IN PRE-WARM FRONTAL
AIRMASS WITH SCTD SHWRS/FOG/DZ. KSBY...BASED UPON OBSERVATIONS
LAST 1-2 HOURS...WILL LIKELY OSCILLATE BETWEEN IFR AND
MVFR...ALTHOUGH IFR WILL DOMINATE IN THE 09Z-14Z TIME FRAME. THE
OTHER 3 TAFS SHOULD BE MAINLY VFR/MVFR...ALTHOUGH A HEAVIER
SHOWER/TSTM COULD BRIEFLY BRING CONDITIONS DOWN TO IFR. WITH
LITTLE FORCING THROUGH 20Z...DO NOT EXPECT A LOT OF SHWR/TSTM
ACTIVITY AT KORF/KPHF/KECG.
LATEST NAM SUGGESTS THAT PRECIP FOCUS WILL SHIFT TO THE NORTH AND
WEST AS WARM FRONT LIFTS NORTHWARD AHD OF WEAKENING UPR TROF FROM
THE TN VLY. THIS SHOULD LIMIT PRECIP COVERAGE AT TERMINALS IN THE
12Z-00Z TIME FRAME...ALTHO SCTD SHWRS/ISOLD TSTM PSBL AT KSBY
THROUGH 18Z...AND AT KRIC AFTER 21Z.
REGION IN WARM SECTOR MON THROUGH WED WITH SCTD...MORE
DIURNAL...SHWR/TSTM ACTIVITY...BUT MAINLY VFR/MVFR CONDITIONS.-- End Changed Discussion --
&&
.MARINE...
DIFFICULT FORECAST INITIALLY TO SEE IF WE GET TO SMALL CRAFT
CONDITIONS ON THE BAY. ALL HIGH RES MODELS WOULD SUPPORT A PERIOD OF
SMALL CRAFT WINDS INTO THIS EVENING. SEEING WINDS STAYING CLOSE BUT
JUST UNDER SMALL CRAFT AT 19Z. EXPECT THAT BY 20Z MOST SITES WILL
HAVE SMALL CRAFT CONDITIONS. THIS WIND INCREASE SEEMS TO BE
ASSOCIATED WITH A WEAK LOW PRESSURE MOVING ALONG THE BOUNDARY SOUTH
OF THE AREA INCREASING THE SOUTHEAST WINDS. WITH CONTINUED EAST TO
SOUTHEAST WINDS TONIGHT WILL SEE SEAS INCREASE TO 5 FEET ALONG THE
NORTHERN COASTAL WATERS. SEAS WILL DROP BACK TO UNDER 5 FEET ON
SUNDAY. WINDS WILL ALSO DIMINISH AND GRADUALLY BECOME MORE SOUTHERLY
ON SUNDAY AND THEN SOUTHWEST ON MONDAY AS A WARM FRONT MOVES SLOWLY
NORTH THROUGH THE WATERS. THE WARM FRONT WILL SLOWLY LIFT NORTH FROM
NORTH CAROLINA TONIGHT AND SUNDAY AND FINALLY BE NORTH OF THE WATERS
ON MONDAY A WEAK UPPER LOW WILL MOVE SLOWLY EAST FROM THE MIDWEST
AND EVENTUALLY OFF THE COAST BY MONDAY NIGHT. THESE FEATURES WILL
CONTINUE SHOWERS AND THUNDERSTORMS AT TIMES THROUGH MONDAY.
&&
.HYDROLOGY...
RAINFALL OVER THE PIEDMONT AND RIDGES TO THE WEST ARE FORECAST TO
BRING SIGNIFICANT RISES TO AREA RIVERS BY MONDAY AND TUESDAY. SOME
LOCATIONS WILL LIKELY EXPERIENCE ACTION STAGE AND MAY POSSIBLY
HAVE MINOR FLOODING. THIS WILL DEPEND ON WHICH BASINS LOCALLY
HEAVY RAINFALL SETS UP WHICH IS TOO EARLY TO DETERMINE.
&&
.EQUIPMENT...
AKQ 88D RADAR IS BACK IN SERVICE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
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MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
ANZ650.-- End Changed Discussion --
&&
$$
SYNOPSIS...LKB
NEAR TERM...LKB/LSA
SHORT TERM...LSA
LONG TERM...JAB
AVIATION...WRS
MARINE...JAB
HYDROLOGY...
EQUIPMENT...