Area Forecast Discussion Issued by NWS Charleston, WV
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000
FXUS61 KRLX 180204
AFDRLX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
955 PM EDT FRI MAY 17 2013
.SYNOPSIS...
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MOIST AIR MASS WITH WEAK STEERING CURRENT INTO SUNDAY. REMNANTS OF
MID AND UPPER LEVEL WAVE ADDS SUPPORT FOR CONVECTION TOO THIS
WEEKEND. NEW FRONT APPROACHES WEDNESDAY.-- End Changed Discussion --
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.NEAR TERM /THROUGH SATURDAY/...
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FIGURING THE BEST SYNOPTIC LIFT OVERNIGHT ALONG THE EASTERN
SLOPES...SO HELD POPS HIGHER THERE OVERNIGHT...AND ALSO INCREASE
POPS AND CLOUDS ALONG THE EASTERN SLOPES ON SATURDAY...INCLUDING THE
UPPER GREENBRIER VALLEY AND THE SRN WV MOUNTAINS AND THE BKW VCNTY.
STILL FIGURING ON THE LINGERING SHOWERS TO DECREASE IN THE VCNTY OF
ATHENS TO PARKERSBURG LATE THIS EVENING...AND NOT CONTINUE UP THE
OHIO RIVER VALLEY.
HAVE SOME FOG FORMING FOR AVIATION...BUT WITH SOME LAYERED CLOUDS
STILL LINGERING OVERNIGHT AND EVEN SOME CHANCE POPS...DID NOT GO WITH
THE THICK FOG FOR THE PUBLIC. SO OVERALL...LESS FOG THAN 24 HOURS
AGO.
CONCERNED ABOUT THE LIGHT STEERING CURRENT ON SATURDAY INTO SATURDAY
NIGHT. DO NOT WANT A LOT OF SUN IN THE MORNING. HOPEFULLY LOTS OF
CLOUDS AND AN EARLY START TO THE SHOWERS...WILL LIMIT INTENSITY
DURING THE AFTERNOON AND EVENING. OTHERWISE...WILL MONITOR FOR
POSSIBLE FLASH FLOOD WATCH IN THE WEAK FLOW. STILL HAVE MENTION OF
THAT HAZARD IN HAZARDOUS WX POTENTIAL. YET...OVERALL...ONLY A FEW
CONCENTRATED AREAS HAVE GOTTEN HIT THE PAST 48 HOURS WITH MORE THAN
AN INCH.-- End Changed Discussion --
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.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
LOOKING MORE LIKE AN EARLY SUMMER PATTERN. WEAK BUT BROAD UPPER LOW
CURRENTLY OVER THE LOWER AND MIDDLE MISSISSIPPI VALLEY IS FORECAST
BY THE MODELS TO DRIFT BASICALLY EAST THIS WEEKEND...EXITING THE
AREA BY MONDAY. WITH A MOIST AND CONDITIONALLY UNSTABLE ATMOSPHERE
IN PLACE...THE THREAT OF SHOWERS AND THUNDERSTORMS CONTINUES THROUGH
THE WEEKEND...BUT MAINLY ON A DIURNAL BASIS AND MAINLY ACROSS THE
SOUTH HALF WHERE THE BEST OF ANY WEAK UPPER DYNAMICS WILL OCCUR.
THERE WILL BE A VERY WEAK EAST TO WEST FRONT WILL MEANDERING ACROSS
THE AREA BEFORE LIFTING NORTH BY MONDAY...BUT AREAS AND INTENSITY OF
THE ACTIVITY WILL BE DETERMINED MORE BY PREVIOUS OUTFLOW BOUNDARIES
AND WHERE SUNSHINE THROUGH LOTS OF CLOUDS THIS WEEKEND CAN REALLY
BOOST THE TEMPERATURES. THUS...GIVEN UNCERTAINTY OF THE FRONTAL
POSITION AND OUTFLOW BOUNDARIES...AND AREAS WHERE CLOUDS UNDER THE
UPPER LOW CAN BREAK FOR SUNSHINE...WE WILL KEEP HIGHEST POPS IN THE
HIGH CHANCE RANGE. STILL...WHERE THERE ARE HEAVIER STORMS...SOME
LOCALIZED MINOR FLOODING MAY OCCUR IN THOSE AREAS.
HIGH TEMPERATURES AS A WHOLE LOOK TO BE NEAR NORMAL WHILE LOWS WILL
BE ABOVE NORMAL.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
DID NOT CHANGE MUCH WITH THE NEXT SYSTEM MID WEEK...WITH MORE WET
WEATHER COMING BACK IN AND SLOW TO LEAVE.
LOOKS TO BE A RELATIVE BREAK IN THE WET PATTERN MONDAY AND
TUESDAY...BEING BETWEEN EXITING UPPER LOW AND A FRONTAL SYSTEM
FORECAST TO BEGIN AFFECTING US FROM THE WEST WEDNESDAY. STILL...LOTS
OF MOISTURE AND MORE SUNSHINE UNDER THE WEAK UPPER RIDGE WILL STILL
BRING A THREAT FOR A FEW STORMS MONDAY AND TUESDAY. TEMPERATURES
WILL RESPOND WITH SUNSHINE...LIFTING INTO THE 80S MONDAY AND TUESDAY.
PREVIOUS DISCUSSION...
EXTENDED PERIOD BEGINS WITH CWA IN NE PORTION OF AN UPPER
RIDGE...HOWEVER A SW TROUGH RESIDES ON ERN PERIPHERY OF THIS RIDGE
AND IS SLOW TO PUSH EAST. THIS SHOULD KEEP OUR AREA IN DISTURBED
WEATHER THROUGH DAY 4...WITH PRIMARILY DIURNALLY DRIVEN SHOWERS AND
THUNDERSTORMS IN THE WV MOUNTAINS. LITTLE BREAK...IF ANY...IN THE
AGITATED WEATHER PATTERN AS NEXT SYSTEM IS QUICK TO MOVE IN FROM
THE WEST TUESDAY. GFS AND ECMWF DIVERGE SOLNS WITH THE HANDLING OF
THE UPPER LEVEL LOW TRACK THROUGH THE GREAT LAKES. RELUCTANT TO GO
ANY HIGHER THAN CHC POPS WITH TIMING DIFFERENCES BETWEEN OPERATIONAL
GUIDANCE. STAYED NEAR WPC GUIDANCE WITH TEMPS THROUGH THE EXTENDED
SAVE FOR LOCAL ADJUSTMENTS.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
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LINGERING CONVECTION AT 00Z SATURDAY SHOULD DIMINISH TO LIGHT
SHOWERS 00Z TO 03Z.
SOUTHEAST LOW LEVEL FLOW THROUGH THE PERIOD. SO WILL BE MORE
PESSIMISTIC ON THE EASTERN SLOPES INCLUDING KBKW FOR THE DAY ON
SATURDAY. MORE WIDESPREAD AND LOWER CEILINGS...AND FIGURING THE
MOST WIDESPREAD SHOWER ACTIVITY 18Z SAT TO 00Z SUNDAY...BUT STILL
POSSIBLE ANYWHERE.
AREAS OF FOG STILL POSSIBLE OVERNIGHT TONIGHT IN WAKE OF SHOWERS.
HAVE SOME IFR BUT FOR BRIEFER TIME PERIOD AND LESS COVERAGE THAN 24
HOURS.
HAVE LAYERED CLOUDS MOSTLY 5 TO 10 THSD FT OVERNIGHT...THEN CEILINGS
3 TO 4 THSD FT DEVELOPING IN WESTERN COUNTIES...WITH 1 TO 2 THSD FT
CEILINGS POSSIBLE IN THE UPSLOPE AREAS INCLUDING THE GREENBRIER
VALLEY FOR THE DAY ON SATURDAY.
VSBY MOSTLY 3 TO 5 MILES IN PCPN.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY...
FORECAST CONFIDENCE...MEDIUM
ALTERNATE SCENARIOS: LOWER CLOUDS/CEILINGS COULD DEVELOP SOONER
FOR SOUTHERN MOUNTAIN AROUND BKW THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SAT 05/18/13
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EDT 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
CRW CONSISTENCY M H M L L M M M H H H M
HTS CONSISTENCY H H H M M M M M M H M M
BKW CONSISTENCY H H H M M M M M M M M H
EKN CONSISTENCY H H M M M H H H H H H M
PKB CONSISTENCY H H H H H H M M M M M H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 00Z SUNDAY...
BRIEF/INTERMITTENT IFR POSSIBLE IN HEAVIER SHOWERS/THUNDERSTORMS
THROUGH THE WEEKEND. IFR FOG POSSIBLE IN OVERNIGHT HOURS.-- End Changed Discussion --
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.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JS/SL
NEAR TERM...KMC/KTB
SHORT TERM...JMV
LONG TERM...JMV
AVIATION...KTB