-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 220728
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
328 AM EDT WED MAY 22 2013

.SYNOPSIS...
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A COLD FRONT CROSSES LATE TONIGHT...FOLLOWED BY ANOTHER LATE
THURSDAY.  UPPER LOW CROSSES EARLY FRIDAY...FOLLOWED BY HIGH
PRESSURE...WITH COOLER AND DRIER AIR...FOR THE WEEKEND.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
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TODAY LOOKS LIKE THE MIDDLE DAY OF THE THREE DAYS OF STRONG TO
SEVERE WE SEEM TO GET PRECEDING WARM SEASON COLD FRONTS.  THE
WEATHER TODAY INTO TONIGHT LOOKS TO BE SIMILAR TO THAT OF TUE.

UPPER LEVEL FORCING APPEARS TO REMAIN IN TACT AS IT CROSSES FCST
AREA RIGHT DURING PEAK HEATING...EVEN AS SURFACE COLD FRONT SEEMS TO
LOSE DEFINITION.  AS HEIGHTS FALL...LIX VALUES DROP TO AROUND -6
WHILE CAPE INCREASES TO AT LEAST 2KJ/KG AND WBZ HEIGHTS HOVER AROUND
10KFT.  MEAN MID LAYER FLOW RANGES FROM AROUND 20 KTS SE TO AS HIGH
AS 40 KTS NW...WHICH JIBES WITH SPC/S EASTERN EDGE OF THE SLIGHT
RISK WHICH IS OVER THE MOUNTAINS.  ESSENTIALLY THE ENTIRE AREA IS IN
THE DAY 1 SLIGHT RISK NOW.

WILL KEEP STRONG WORDING IN FCST FOR AFTERNOON AND EVENING
THUNDERSTORMS AND EXPAND HWO THREAT TO ENTIRE FCST AREA.

PW VALUES EXCEED 1.5 INCHES SO HEAVY DOWNPOURS ARE ALSO LIKELY.

THE CONVECTION WILL DIE DOWN OVERNIGHT TONIGHT...BUT NOT AS QUICKLY
AS THIS PAST NT ON ACCOUNT OF THE UPPER LEVEL FORCING AND WHAT IS
LEFT OF THE SFC FRONT.

NO IMPORTANT CHANGES NEEDED TO TEMPERATURES.  HIGHS TODAY WERE
AROUND MIDDLE GROUND IN LIGHT OF LATEST GUIDANCE AND BIAS CORRECTED
GUIDANCE AND WILL BE HIGHLY DEPENDENT ON TIMING OF CLOUDS AND
CONVECTION...SO SAW LITTLE CHANCE FOR IMPROVEMENT UPON PREVIOUS
FCST.  CONVERSELY...SMALL RANGE OF POSSIBILITIES ON LOWS TONIGHT.
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&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
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UNSETTLED WEATHER CONTINUES ON THURSDAY...AND PART OF FRIDAY...AS
UPPER TROUGH AND SURFACE COLD FRONT SWEEP ACROSS THE REGION. THIS
WILL KEEP A CHANCE FOR SHOWERS AND THUNDERSTORMS IN THE FORECAST FOR
THE START OF THE SHORT TERM PERIOD. STILL COULD BE SOME STORMS ON
THURSDAY THAT MAY CONTAIN SOME STRONGER WIND GUSTS AS THERE WILL
STILL BE MODERATE WINDS ALOFT...BUT OVERALL INSTABILITY IS
WEAK...AND SO SEVERE RISK IS LOW.

DRIER...COOLER...NORTHWESTERLY FLOW PATTERN WILL TAKE HOLD FOR
FRIDAY THROUGH SATURDAY AS THE UPPER TROUGH PUSHES EAST. DID ELECT
TO LOWER TEMPS SLIGHTLY DURING THIS PERIOD...PARTICULARLY SATURDAY
MORNING...AS GOOD CLEARING...LIGHT SURFACE WINDS EXPECTED AS HIGH
PRESSURE BUILDS IN FROM THE NORTH. MAY BE SOME FOG DEVELOPMENT
ESPECIALLY SATURDAY MORNING UNDER THESE CONDITIONS.
-- End Changed Discussion --

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
HAVE GENERALLY FOLLOWED WPC THINKING FOR THIS PORTION OF THE
FORECAST.

HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER ACROSS THE AREA INTO
SUNDAY NIGHT.  HOWEVER...MODELS SUGGEST A FEW WEAK MID-LEVEL
SHORTWAVE MAY MOVE SOUTHEAST.  BELIEVE AREA SHOULD REMAIN DRY...WITH
A FEW MORE CLOUDS BEGINNING SATURDAY NIGHT

A WARM FRONT WILL THEN DEVELOP AND APPROACH THE REGION ON MONDAY. AS
A RESULT...THERE WILL BE A CHANCE OF SHOWERS AND STORMS MONDAY AND
TUESDAY...MAINLY DURING THE AFTERNOON AND EVENING HOURS.

TEMPERATURES ON SATURDAY SHOULD BE NEAR NORMAL WITH DAYTIME HIGHS IN
THE 70S ACROSS THE LOWLANDS...WITH 60S ACROSS THE HIGHER
ELEVATIONS.  AS THE HIGH PUSHES EAST ON SUNDAY...EXPECT TEMPERATURES
TO WARM TO SLIGHTLY ABOVE NORMAL VALUES MONDAY AND TUESDAY.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
CONVECTION IS OVER FOR THE OVERNIGHT...SO THE ONLY RESTRICTIONS TO
NOCTURNAL AND EARLY WED MORNING AVIATION IS DENSE VALLEY FOG WHICH
MAY AFFECT THE CRW AND EKN RUNWAYS.

A COLD FRONT APPROACHING FROM THE W DURING THE HEATING OF THE DAY
WED WILL CONTRIBUTE TO STRONG CONVECTION ONCE AGAIN.  ANY
THUNDERSTORM WED AFTERNOON AND WED NT COULD PRODUCE IFR CONDITIONS
AND VERY STRONG WIND GUSTS.  DENSE POST RAIN NOCTURNAL VALLEY FOG IS
AGAIN LIKELY IN THE WAKE OF THUNDERSTORMS WED NT.

SFC FLOW WILL CONTINUE LIGHT S TO SW AT NT...BECOMING A BIT GUSTY
OUTSIDE THUNDERSTORMS DURING THE DAY WED.  LIGHT TO MODERATE SW FLOW
ALOFT OVERNIGHT WILL BECOME S TO SW WED.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...

FORECAST CONFIDENCE...MEDIUM.

ALTERNATE SCENARIOS: TIMING AND EXTENT OF DENSE VALLEY FOG OVERNIGHT
COULD VARY...AS WELL AS TIMING AND DEGREE OF FLIGHT RESTRICTIONS DUE
TO CONVECTION WED AFTERNOON AND EVENING.

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                              WED 05/22/13
UTC 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
EDT 1HRLY       02   03   04   05   06   07   08   09   10   11   12   13
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    M    M    M    H    M    H    H    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  H    M    L    L    L    L    L    M    H    M    M    H
PKB CONSISTENCY  H    H    M    M    M    M    M    H    H    H    H    H
CKB CONSISTENCY  H    H    M    M    M    M    M    H    H    H    H    H

AFTER 06Z THURSDAY...
IFR CONDITIONS POSSIBLE WED NT INTO THU MORNING IN SHOWERS AND
THUNDERSTORMS...AND POST RAIN NOCTURNAL VALLEY FOG.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...TRM/SL
NEAR TERM...TRM
SHORT TERM...SL
LONG TERM...JSH
AVIATION...TRM