-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 180535
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
135 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 TODAY/...
-- Changed Discussion --
130 AM UPDATE...NO MAJOR CHANGES NEEDED.

PREVIOUS DISCUSSION FOLLOWS...
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 --

&&

.SHORT TERM /TONIGHT 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 /06Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
BULK OF CONVECTION HAS DISSIPATED...WITH MAINLY VFR
CONDITIONS...ALTHOUGH LOCAL MVFR/IFR CONDITIONS IN FOG EXIST.
SHOWERS AND STORMS WILL RAMP BACK UP AGAIN AFTER 15Z...AS AN UPPER
LOW PUSHES EAST INTO THE REGION. EXPECT BRIEF MVFR AND IFR
CONDITIONS IN VICINITY OF STORMS. IN ADDITION...SOUTHEASTERLY FLOW
WILL DEVELOP ACROSS THE AREA TODAY...CREATING WIDESPREAD MVFR CIGS
ACROSS THE MOUNTAINOUS COUNTIES...INCLUDING AT KBKW.

FOG DEVELOPMENT OVERNIGHT SATURDAY STILL IN QUESTION...BEST
CHANCE/AREA FOR ANY FOG WILL BE IN SOUTHEAST OHIO AND NORTHERN WV
WHERE BETTER CLEARING IS POSSIBLE. MVFR/IFR CIGS WILL CONTINUE TO
LINGER OVER THE HIGHER TERRAIN COUNTIES SATURDAY NIGHT.

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

FORECAST CONFIDENCE...MEDIUM

ALTERNATE SCENARIOS: LOWER CLOUDS/CEILINGS COULD DEVELOP SOONER
FOR SOUTHERN MOUNTAINS AROUND BKW THAN FORECAST. DEVELOPMENT OF
FOG SATURDAY NIGHT WILL DEPEND ON AMOUNT OF CLEARING.

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       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    M    M    M    H    H    H    H    H
HTS CONSISTENCY  M    M    M    M    M    M    M    M    H    H    H    H
BKW CONSISTENCY  M    M    M    M    M    M    M    H    H    M    M    M
EKN CONSISTENCY  M    M    M    M    H    H    H    M    H    H    H    H
PKB CONSISTENCY  H    H    M    M    M    M    H    H    H    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 06Z 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...JS/SL
NEAR TERM...KTB/SL
SHORT TERM...JMV
LONG TERM...JMV
AVIATION...SL