-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 160857
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
457 AM EDT THU MAY 16 2013

.SYNOPSIS...
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COLD FRONT STALLS OVER THE AREA TODAY INTO THE WEEKEND. UPPER
LEVEL SHORTWAVE PASSES SOUTH. NEW FRONT APPROACHES NEXT WEDNESDAY.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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WV IMAGERY AT 04Z SHOWING AREA ESSENTIALLY IN A ZONAL FLOW
REGIME...WITH UPPER LOW PROGRESSING EASTWARD ACROSS SW QUEBEC AND
ANOTHER UPPER LOW SPINNING OVER THE SOUTH CENTRAL PLAINS. AT THE SFC
A LINE OF SHOWERS AND THUNDERSTORMS HAD DEVELOPED FROM ROUGHLY
INDIANAPOLIS TO JUST NORTH OF COLUMBUS...AHEAD OF THE COLD FRONT.
PRIMARY FORECAST CONCERN FOR THIS PERIOD REVOLVES AROUND FRONTAL
POSITION AND SUBSEQUENT RAIN/THUNDER CHANCES.

FIRST...REGARDING CURRENT LINE OF SHOWERS AND THUNDERSTORMS NEAR
NORTHERN CWA BOUNDARY. THIS ACTIVITY IS ALREADY A BIT AHEAD OF THE
ACTUAL COLD FRONT. LINE CONTINUES TO MAKE VERY SLOW PROGRESS
SOUTHWARD WITH ELEMENTS BASICALLY MOVING JUST ABOUT DUE EAST.
SUSPECT THIS TO CONTINUE INTO THE EARLY MORNING HOURS...SKIRTING THE
NORTHERN ZONES WHILE DISSIPATING. DOES HAVE SOME ELEVATED
INSTABILITY TO WORK WITH SO THE LINE MAY CONTINUE UNTIL AROUND THE
12Z-14Z TIME FRAME AS THE FRONT LAGS JUST A BIT BEHIND.

REMAINDER OF TODAY...FRONT STALLS RIGHT ALONG OR JUST NORTH OF THE
AREA. WHILE EARLY MORNING LLVL MOISTURE PUSHES OFF TO THE
EAST...MORE MOISTURE REPOOLS ACROSS NW ZONES. RELAXED CONVERGENT
ZONE HERE FOR A TIME HOWEVER AS FRONTAL ZONE BECOMES A BIT MORE
DIFFUSE OUT THIS WAY. EXPECT PERIODS OF PARTLY CLOUDY SKIES FURTHER
SOUTH WHERE MOISTURE WILL BE SOMEWHAT LACKING. NUDGED UP MAX TEMPS
TODAY INTO THE LOWER 80S LOWLANDS...BUT REMAINED BELOW THE 84-85 MOS
OUTPUT. BY THE AFTERNOON A VORT MAX PUSHES ACROSS SOUTHERN PARTS OF
THE AREA. THIS COMBINED WITH LLVL MOISTURE AND WARM TEMPS SHOULD
RESULT IN REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS PRIMARILY
ACROSS THE NORTHERN ZONES ONCE AGAIN INITIALLY...BEFORE SPREADING
EASTWARD WITH PERHAPS A BIT MORE COVERAGE. NAM DEWPOINTS AND THUS
CAPE APPEAR OVERDONE AGAIN BUT INSTABILITY ON THE ORDER OF AROUND
1000-1500J/KG POSSIBLE. WEAK SHEAR SHOULD PRECLUDE MUCH IN THE WAY
OF SEVERE POTENTIAL BUT SOME STRONG STORMS ARE POSSIBLE...WITH EL/S
IN THE UPPER 30S-KFT. AS MENTIONED EARLIER...THIS ACTIVITY EXPECTED
TO PUSH EASTWARD AND SUBSIDE DURING THE OVERNIGHT HOURS. INHERITED
MINS IN THE LOWER 60S LOWLANDS STILL ON TRACK.
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&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
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THE QUASI STATIONARY FRONTAL BOUNDARY IS EXPECTED TO LIFT NORTH
FRIDAY AFTERNOON CONTINUING WITH REPETITIVE SHOWERS AND
THUNDERSTORMS THROUGH THE EVENING HOURS MAINLY NORTHERN SECTIONS.

THE UPPER RIDGE SLOWLY BUILDS OVERHEAD THIS WEEKEND. WITH LOTS OF
LOW LEVEL MOISTURE UNDER THE DIRTY BUILDING UPPER RIDGE...MODELS
ARE ALL OVER THE PLACE WITH SOME FORM OF EMBEDDED WEAK UPPER
DISTURBANCES TRAVERSING THRU THE UPPER RIDGE....SOME
INSTABILITY...AND MODEST QPF. UNCERTAINTY EXIST AS MODEL SOLUTIONS
SPREAD THIS WEEKEND...SOME KEEPING FRONTAL BOUNDARY ACROSS THE
NORTH...OTHERS SINKING IT SOUTH INTERACTING WITH UPPER LEVEL
SHORTWAVES.

INCREASED POPS TO 52 PERCENT TO ACCOUNT FOR QPF ON FRIDAY AND
SATURDAY WITH PCPN FOCUSING ALONG AND NEAR THE QUASI STATIONARY
BOUNDARY. IN GENERAL...WARMER AND MORE HUMID THIS WEEKEND AS LOW LEVEL
MOISTURE INCREASES.

KEPT PREVIOUS TEMPERATURES AS THEY REPRESENTATIVE...GENERALLY
IN LOWER 80S FOR HIGHS AND MID 60S FOR LOWS THROUGH THE PERIOD.
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&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
WE WILL BE FIRMLY IN THE WARM SECTOR MONDAY AND TUESDAY...WITH JUST
A CHANCE OF A SHOWER OR STORM...MAINLY IN THE AFTERNOON AND EVENING
WITH THE AID OF HEATING. MODELS HAVE A COLD FRONT APPROACHING FROM
THE WEST WEDNESDAY...BUT WITH THE MODEL TRENDS OF THIS UPPER SYSTEM
CLOSING OFF OVER THE OHIO VALLEY AND BECOMING THE EASTERN ANCHOR OF
AN OMEGA BLOCK...WILL GO WITH THE SLOWER SOLUTIONS AND HAVE THE BEST
POPS IN THE WEST WEDNESDAY.

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
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COLD FRONT STILL LOCATED NORTHWEST OF THE AREA WITH A LINE OF
SHOWERS AND THUNDERSTORMS NEAR COLUMBUS OHIO. THIS LINE IS
EXPECTED TO CONTINUE TO SLOWLY SAG SOUTHEASTWARD INTO THE NORTHERN
PARTS OF THE AREA WHILE ALSO SLOWLY WEAKENING. TOUGH CALL ON
EXACTLY HOW FAR SOUTH IT WILL MAKE IT BUT WILL PROBABLY AFFECT THE
NORTHERN TERMINALS ROUGHLY BETWEEN 09Z AT PKB AND 10Z-11Z FURTHER
EAST AT CKB-EKN. AT THIS POINT IT APPEARS THIS LINE WILL NOT MAKE
IT SOUTH TO HTS OR CRW. LOW VFR CIGS ARE EXPECTED WITH THIS
ACTIVITY...BUT MVFR AND INTERMITTENT IFR VIS WOULD BE A
POSSIBILITY SHOULD A STRONGER SHOWER/STORM DIRECTLY IMPACT A
TERMINAL.

OTHERWISE...EXPECT GENERALLY VFR CONDITIONS OVER THE VALID PERIOD
WITH PERHAPS INTERMITTENT MVFR CIGS MAINLY AFTER 00Z FRIDAY. WINDS
WILL CONTINUE BREEZY OUT OF THE SOUTHWEST...ALTHOUGH NOT QUITE A
BREEZY AS YESTERDAY...AS IT APPEARS THAT THE COLD FRONT WILL
REMAIN NORTH OF THE NORTHERN TERMINALS.

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

FORECAST CONFIDENCE...MEDIUM

ALTERNATE SCENARIOS: CEILINGS ALONG THE FRONT IN SHOWERS/TSTORMS
COULD BE LOWER THAN FORECASTED.

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                    THU 05/16/13
UTC 1HRLY       08   09   10   11   12   13   14   15   16   17   18   19
EDT 1HRLY       04   05   06   07   08   09   10   11   12   13   14   15
CRW CONSISTENCY  H    H    H    H    H    H    H    H    M    M    M    M
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    M    H    M
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  M    M    M    H    H    H    M    M    M    M    H    H
PKB CONSISTENCY  M    M    M    M    M    M    H    H    M    M    M    M
CKB CONSISTENCY  M    M    M    M    M    H    H    H    H    H    M    M

AFTER 06Z FRIDAY...
BRIEF/INTERMITTENT IFR POSSIBLE IN HEAVIER SHOWERS/THUNDERSTORMS
REMAINDER OF THURSDAY NIGHT THROUGH THE WEEKEND...MAINLY EASTERN
OHIO AND NORTHERN WEST VIRGINIA.
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&&

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

&&

$$
SYNOPSIS...ARJ/50
NEAR TERM...50
SHORT TERM...ARJ
LONG TERM...JMV
AVIATION...50