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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 151803
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
203 PM EDT WED MAY 15 2013

.SYNOPSIS...
-- Changed Discussion --
COLD FRONT APPROACHES FROM THE NORTH TONIGHT...AND STALLS OVER
THE AREA THURSDAY INTO THE WEEKEND. UPPER LEVEL SHORTWAVE PASSES
SOUTH.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH THURSDAY/...
-- Changed Discussion --
COLD FRONT LOOKS RATHER UNIMPRESSIVE AT THIS HOUR OVER THE
SOUTHERN GREAT LAKES. SOUTHWARD MOVEMENT IS JUST AS
UNIMPRESSIVE...AND WILL TAKE SOME TIME TO REACH THE NORTHERN
COUNTIES OF THE CWA LATER THIS EVENING AND TONIGHT. DO NOT SEE
MUCH IN THE WAY OF INSTABILITY OUTSIDE EITHER...WITH VIRTUALLY NO
CUMULUS FORMATION. NAM BUFR SOUNDINGS IN LINE WITH THIS...AND SHOW
A VERY DRY COLUMN THAT WILL NEED TO SATURATE WITH THE FRONT.

BLENDED THE NAM AND THE LOCAL MODELS FOR TIMING LATER
TODAY...WHICH WERE NOT ALL THAT DIFFERENT FROM EACH OTHER. BRING
THE POPS TO LIKELY AROUND SUNSET...THEN TRAIL THEM OFF IN THE
OVERNIGHT WITHOUT GOING DRY. KEEP THE GENERAL DIURNAL TREND TO THE
POPS GOING INTO THURSDAY. SURFACE FORCING WILL BE AIDED BY VARIOUS
UPPER LEVEL DISTURBANCES PASSING THROUGH. EXPECT THE SURFACE FIELD
TO BECOME MUDDLED HOWEVER...WITH THE FORMATION AND DISSOLVING OF
BOUNDARIES FROM PREVIOUS CONVECTION. COLD FRONT MAY BE DIFFICULT
TO DETECT THIS TIME THURSDAY...BUT SHOULD BE CUTTING THROUGH OUR
SOUTHEAST OHIO COUNTIES.

THUNDER POTENTIAL UTILIZED THE GFS CAPE...AS NAM IS OVERDONE FROM
THE HIGHER DEWPOINTS. CAPPED THE POTENTIAL FOR THUNDER AT CHANCE.
NO OUTLOOK FOR SEVERE FROM SPC THIS AFTERNOON OR THURSDAY AT THIS
TIME.
-- End Changed Discussion --

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
MODELS IN AGREEMENT ON APPROACHING COLD FRONT TIMING AND LOCATION...STALLING
WEST TO EAST ACROSS THE AREA THURSDAY INTO AT LEAST SATURDAY. THE
NAM LOOKS MORE ASSERTIVE WITH GFS ON TOTAL DEFORMATION BANDS
ORIENTED WEST TO EAST MOVING SOUTH AS IT WEAKENS THURSDAY...AND
ANOTHER BAND MOVING SOUTH THROUGH OUR NORTH FRIDAY. PW FROM 1.33
TO 1.50 INCHES...AND THETA-E TONGUE UP TO 340K WITHIN THE BOUNDARY
LAYER MAY SUGGEST SUFFICIENT MOISTURE AVAILABLE. TOGETHER WITH
BOUNDARY LAYER CONVERGENCE...MODELS SHOW SFC BASED CAPE EXCEEDING
1200 J/KG...DEWPOINTS IN THE MID 60S...IN A LOW DEEP SHEAR
ENVIRONMENT...MAINLY ALONG QUASI STATIONARY BOUNDARY BY 00Z
FRIDAY.

FAVORED OH RFC QPF MAXIMUM LOCATIONS...BUT CLOSER TO WPC INTENSITY
NEARING 0.75 INCHES THURSDAY THRU 00Z FRIDAY...WITH AN ADDITIONAL
0.50 INCHES THRU 00Z SUNDAY. ADJUSTED POPS ACCORDINGLY...LEAVING THUNDER
ON THE WEATHER GRIDS.

UNIDIRECTIONAL WEAK DEEP LAYER SHEAR COULD PROMOTES PULSE...SLOW
MOVING STORMS THURSDAY AND FRIDAY. ON SATURDAY...MODELS SHOW A
SPREAD SOLUTION IN H5 VORT MAXES ASSOCIATED WITH A WEAKENING
SHORTWAVE PASSING SOUTH SATURDAY INTO SUNDAY. REPETITIVE RAIN
SHOWERS INTO THE WEEKEND MAY RESULT IN SOME WATER PROBLEMS.

WENT A DEGREE LOWER THAN SIMILAR MET/MAV GUIDANCE FOR HIGHS
THURSDAY AND FRIDAY. USED BIAS CORRECTED GFS/GMOS FOR HIGHS
SATURDAY AND LOWS THROUGH THE PERIOD.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HAVE FOLLOWED WPC THINKING FOR THIS PORTION OF THE FORECAST. STATIONARY
FRONT WILL LIFT NORTH AS A WARM FRONT BY EARLY SUNDAY...LEAVING THE
REGION IN THE WARM SECTOR FOR THE REMAINDER OF THE PERIOD. EXPECT A
CHANCE OF SHOWERS AND STORMS ALMOST EVERY PERIOD...WITH THE GREATEST
CONCENTRATION AND INTENSITY DURING THE AFTERNOON AND EVENING HOURS.

WPC TEMPS LOOKED GOOD...SO WERE USED WITH SOME MINOR TWEAKS.

&&

.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
TAFS HAVE HIGHLIGHTED THE CHANCES FOR SHOWERS AND THUNDERSTORMS
MAINLY DURING THE AFTERNOON/EVENING HOURS TODAY AND THURSDAY...AND
HAVE DONE SO CONSERVATIVELY. NO IFR IN THE FIRST 9 TO 12 HOURS OF
THE TAFS...ALTHOUGH DO BRING IN BRIEF MVFR THIS EVENING AND
TONIGHT DURING SHRA. WIND SHOULD KEEP THE LOWER LEVELS WELL
MIXED...EVEN AFTER ROUNDS OF PRECIPITATION TONIGHT. EXPECT MORE
COVERAGE OF CONVECTION THURSDAY...BUT CANNOT JUSTIFY PREVAILING
RESTRICTIONS AT THIS TIME WITH THE EXCEPTION OF MVFR VISIBILITIES
ONCE AGAIN.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY...

FORECAST CONFIDENCE...HIGH

ALTERNATE SCENARIOS: TIMING SHOWERS AND THUNDERSTORMS MAY VARY.

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       18   19   20   21   22   23   00   01   02   03   04   05
EDT 1HRLY       14   15   16   17   18   19   20   21   22   23   00   01
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    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 18Z THURSDAY...
BRIEF/INTERMITTENT IFR POSSIBLE IN HEAVIER SHOWERS/THUNDERSTORMS
LATER THURSDAY AND FRIDAY THROUGH THE WEEKEND.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...JSH/26
NEAR TERM...26
SHORT TERM...ARJ
LONG TERM...JSH
AVIATION...26