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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 181026
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
626 AM EDT SAT MAY 18 2013

.SYNOPSIS...
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.

&&

.NEAR TERM /THROUGH TONIGHT/...
UNSETTLED WEATHER PATTERN CONTINUES IN THE NEAR TERM PERIOD. BULK OF
CONVECTIVE ACTIVITY HAS DIMINISHED OVERNIGHT AS EXPECTED...BUT
ACTIVITY WILL RAMP BACK UP ONCE AGAIN THIS AFTERNOON AS AN UPPER
LEVEL SHORTWAVE TROUGH PUSHES EAST INTO THE REGION TODAY AND
TONIGHT...AND AS FRONTAL BOUNDARY CONTINUES TO MEANDER ACROSS THE
CWA. LOOKS LIKE AREA OF GREATEST ACTIVITY TODAY WILL BE ACROSS THE
SOUTH AND EAST...WHERE BETTER DYNAMICS WILL EXIST...AND AS A
SOUTHEASTERLY UPSLOPE FLOW SETS UP ACROSS THE REGION. AS WITH
FRIDAY...RELATIVELY WEAK FLOW PATTERN TO REMAIN IN PLACE
TODAY...WITH FLOW GENERALLY 10-15 KTS. THIS COMBINED WITH THE
MOIST...UNSTABLE ATMOSPHERE IN PLACE...COULD CREATE SOME LOCALIZED
WATER ISSUES. AT THIS POINT...WILL ELECT TO HOLD OFF ON A FFA...AND
CONTINUE MENTION IN THE HWO. WETTEST AREAS OF THE CWA ARE GENERALLY
ALONG THE I-64/I-79 CORRIDORS...GENERALLY EASTERN KY...AND AREAS
NORTH OF A LINE FROM KHTS TO KCRW. MOUNTAINOUS COUNTIES HAVE SEEN
DECENT PRECIPITATION IN RECENT DAYS...BUT IT HAS BEEN RATHER SPOTTY
IN COVERAGE. THINKING BASED ON DYNAMICS AND UPSLOPE FLOW...BULK OF
PRECIPITATION WILL OCCUR OVER MOUNTAINOUS COUNTIES...AND SINCE MUCH
OF THE PRECIPITATION IN THESE AREAS HAS BEEN RATHER SPOTTY...AND
THERE HAS BEEN A BREAK IN THE PRECIPITATION OVERNIGHT...WILL ALLOW
THE DAY SHIFT TO MONITOR THE SITUATION...AND ISSUE A FFA IF THEY
FEEL IT IS WARRANTED.

BULK OF CONVECTIVE ACTIVITY WILL START TO WANE WITH THE LOSS OF
DAYTIME HEATING SATURDAY NIGHT...ALTHOUGH A FEW SHOWERS MAY LINGER
WELL INTO THE EVENING...NIGHTTIME HOURS. FOG DEVELOPMENT SATURDAY
NIGHT WILL PROBABLY BE SIMILAR TO FRIDAY NIGHT...IN THAT IT SHOULDNT
BE AS WIDESPREAD AS THURSDAY NIGHT...AS PLENTY OF CLOUD COVER SHOULD
CONTINUE TO LINGER WITH UPPER TROUGH CONTINUING TO PUSH THROUGH THE
REGION. KEPT TEMPERATURES TOWARDS THE WARMER SIDE OF GUIDANCE FOR
SATURDAY NIGHT/SUNDAY MORNING AS A RESULT...AND KEPT TEMPERATURES
TOWARDS THE COOLER SIDE OF GUIDANCE TODAY DUE TO EXPECTED CLOUD
COVER.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
A SUMMER PATTERN HAS RETURNED TO THE FORECAST AREA.  THE WEAK BROAD
UPPER LEVEL LOW OVER THE LOWER AND MIDDLE MISSISSIPPI VALLEY WILL
CONTINUE TO DRIFT EASTWARD.  WITH WEAK HIGH PRESSURE SETTING UP OFF
THE EASTERN US COAST THIS WILL CONTINUE TO PUMP MOISTURE ACROSS THE
FORECAST AREA THROUGH AT LEAST MONDAY.  WITH WEAK UPPER LEVEL FLOW A
CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH THE
SHORT TERM MAINLY DIURNAL IN NATURE.  THE HEAVIEST RAINFALL AMOUNTS
WILL DEPEND HEAVILY ON THE LEFT OVER BOUNDARIES FROM THE PREVIOUS
DAY.  THE STATIONARY/WARM FRONT BOUNDARY THAT HAS BEEN DRAPED ACROSS
THE AREA WILL SLOWLY LIFT NORTHWARD BY MONDAY NIGHT AS THE LOW OVER
THE EAST NORTH CENTRAL US MOVES NORTH.

TEMPERATURES WILL WARM THROUGH THE SHORT TERM.  THE WARMEST DAY WILL
BE TUESDAY WITH HIGHS RANGING FROM THE UPPER 70S IN THE MOUNTAINS TO
LOWER 90S IN THE COAL FIELDS.

&&

.LONG TERM /TUESDAY 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 /12Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
MVFR/IFR FOG WILL GRADUALLY DISSIPATE BY 13Z...FOR A BRIEF RETURN
OF VFR CONDITIONS EVERYWHERE. CONVECTION WILL INCREASE IN COVERAGE
AGAIN AFTER 16Z...WITH MVFR/IFR CONDITIONS IN AND IN VICINITY OF
SHOWERS/STORMS. GENERALLY LIGHT SOUTHEASTERLY FLOW DURING THE TAF
PERIOD. WITH THE SOUTHEASTERLY FLOW IN PLACE...EXPECTING
WIDESPREAD MVFR CIGS TO GRADUALLY DEVELOP ACROSS THE MOUNTAINOUS
COUNTIES...INCLUDING AT KBKW PARTICULARLY AFTER 00Z SUNDAY.

EXPECTING SOME FOG DEVELOPMENT AGAIN TONIGHT...MAINLY AFTER
03-06Z...WITH MVFR/IFR CONDITIONS EXPECTED.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY...

FORECAST CONFIDENCE...MEDIUM

ALTERNATE SCENARIOS: LOWER CLOUDS/CEILINGS COULD DEVELOP SOONER
FOR SOUTHERN MOUNTAINS AROUND BKW THAN FORECAST. DEVELOPMENT AND
COVERAGE OF FOG SATURDAY NIGHT COULD VARY FROM 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.

UTC 1HRLY       11   12   13   14   15   16   17   18   19   20   21   22
EDT 1HRLY       07   08   09   10   11   12   13   14   15   16   17   18
CRW CONSISTENCY  M    M    M    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    M    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  M    M    H    H    M    M    M    M    M    H    H    H
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 12Z SUNDAY...
BRIEF/INTERMITTENT IFR POSSIBLE IN HEAVIER SHOWERS/THUNDERSTORMS
THROUGH THE WEEKEND. IFR FOG POSSIBLE IN OVERNIGHT HOURS.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...FB/SL
NEAR TERM...SL
SHORT TERM...FB
LONG TERM...JMV
AVIATION...SL