-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 171029
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
629 AM EDT MON JUN 17 2013

.SYNOPSIS...
DRIER IN THE MID AND UPPER LEVELS TODAY. ANOTHER DISTURBANCE
PASSES TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
UPDATE...
ELEVATED CONVECTION TRIED TO GET GOING ACROSS THE NORTHERN ZONES
WHERE CHANCE POPS EXISTED...BUT THIS WAS WAY TOO SHORT LIVED TO
KEEP IN THE GRIDS. MADE SOME MINOR ADJUSTMENTS IN LOWERING THESE
VALUES THROUGH MID MORNING.

PREVIOUS DISCUSSION...
MODELS ARE A BONA FIDE MESS DEALING WITH THE MYRIAD OF UPPER LEVEL
DISTURBANCES THROUGH THE NEAR TERM FORECAST...AND THE TIMING OF
SUCH FEATURES WITH SOME DIFFERENCES WITHIN THESE OPERATIONAL
MODELS. ALSO DEALING WITH A SURFACE BOUNDARY/WEAK COOL FRONT THAT
WILL SLOWLY DROP IN FROM THE NORTH DURING THIS TIME...ALTHOUGH
WILL BE HARD TO DISTINGUISH AT ANY GIVEN POINT DURING THE DAY. THE
BEST APPROACH IN THIS CASE IS TO TRY TO FIND EITHER STABILITY OR
LACK OF SUFFICIENT MOISTURE DEPTH IN CONSTRUCTING THE POPS RATHER
THAN TO TRY TO LATCH ON TO SPECIFIC FEATURES.

NAM IS SHOWING SIGNIFICANT DRYING TODAY THROUGH THE MID AND UPPER
LEVELS OF THE ATMOSPHERE...LEADING TO MORE OF A CUMULUS FIELD WITH
SOME VERTICAL EXTENT...BUT POPS ON THE LOW SIDE WITHOUT MUCH ABOVE
AROUND 825MB THROUGH THE MAIN HEATING OF THE DAY. VERTICAL
PROFILES WILL TIGHTEN UP IN TERMS OF THE T/TD SPREAD TOWARDS
DAWN...ESPECIALLY ACROSS THE SOUTH WHERE MODELS ARE AT LEAST
CONSISTENT IN THE PLACEMENT OF A STRONGER MID/UPPER LEVEL WAVE
EVEN THOUGH THE TIMING IS OFF. WILL RIDE WITH SLOWER NAM PER
COLLABORATION WITH RNK TONIGHT...BUT STILL CARRYING CHANCE BY 12Z
TUESDAY.

LACK OF HIGH POPS TODAY WILL GIVE AREA WATERSHEDS SOME TIME TO
RECOVER. HAVE HAD STOUT RAIN OVER THE SOUTHERN COAL FIELDS IN THE
PAST 24 HOURS...AND THE CENTRAL CWA/ROANE STILL DEALING WITH
ISSUES FROM THIS PAST WEEK. 3 HOUR FFG DOWN TO AN INCH AND A HALF
FOR THE EASTERN HALF OF THE CWA FOR THE MOST PART.
-- End Changed Discussion --

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
CURRENT THINKING IS THAT A COLD FRONT WILL BE LOCATED NORTH OF THE
REGION AT THE BEGINNING OF THE PERIOD.  THIS FEATURE IS EXPECTED TO
PUSH SOUTHEAST TUESDAY NIGHT AND EARLY WEDNESDAY.  A MID-LEVEL
SHORTWAVE IS ALSO EXPECTED TO PUSH SOUTHEAST ACROSS THE AREA LATE
TUESDAY NIGHT INTO WEDNESDAY.

HAVE SLOWED DOWN ONSET OF LIKELY POPS ON TUESDAY.  HOWEVER...STILL
LOOKS LIKE MEASURABLE PRECIP IS A GOOD BET ACROSS THE MOUNTAINS AS
WELL AS PORTIONS OF THE SOUTHERN COALFIELDS FOR LATER IN THE DAY.

MODELS ALSO DEVELOP MEASURABLE PRECIP TUESDAY AFTERNOON/EVENING
ACROSS OUR NORTHERN COUNTIES INVOF THE COLD FRONT AS IT PUSHES
SOUTH INTO THE AREA. IN RESPONSE...HAVE ADDED HIGH CHANCE POPS FOR
NOW. MAY NEED TO INCREASE THESE POPS TO LIKELY. HOWEVER...WILL LET
NEXT SHIFT MAKE THAT DECISION.

WEAK HIGH PRESSURE BUILDS IN TUESDAY NIGHT...WHICH SHOULD BRING
PRECIP CHANCES TO AN END.

COMBINATION OF SUFFICIENT LOW-LEVEL MOISTURE AND DAYTIME HEATING MAY
BE ENOUGH TO PRODUCE A FEW AFTERNOON AND EVENING STORMS ACROSS THE
MOUNTAIN COUNTIES WEDNESDAY AND THEN AGAIN ON THURSDAY.
SUFFICIENT.

TEMPERATURE GUIDANCE IS WARMER FOR HIGHS ON TUESDAY AND
WEDNESDAYS...SO HAVE TWEAKED NUMBERS TO REFLECT CURRENT TRENDS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
UPPER RIDGE OVER THE SOUTHERN PLAINS WILL INFLUENCE MOST OF THE LONG
TERM PERIOD...WITH GRADUALLY WARMING AND MOISTENING OF THE BOUNDARY
LAYER. UNFORTUNATELY...THE RIDGE LOOKS RATHER DIRTY WITH SEVERAL
VORT MAXES DROPPING DOWN THE EASTERN SIDE IN THE NW FLOW OVER THE
MID AND UPPER OHIO VALLEY/CENTRAL APPALACHIANS. THIS SPELLS AT LEAST
SOME CHANCES OF THUNDERSHOWERS FOR THE SECOND HALF OF THE WORK WEEK.
UNTIL TIMING ON INDIVIDUAL VORTS CLEARS UP...KEPT PRECIP TIED TO THE
DIURNAL CYCLE...WITH THE HIGHEST POPS IN THE AFTERNOON OVER THE
HIGHER TERRAIN. BY NEXT WEEKEND...BOTH GFS AND ECMWF ADVERTISE A
STRONGER VORT MAX FOR SATURDAY...AND WITH MORE MOISTURE IN PLACE
INCLUDED CHANCE POPS CWA-WIDE.

&&

.AVIATION /10Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
STRATUS DECK NOW IN PLACE OVER THE AREA...ALTHOUGH PKB LINGERS IN
IFR CONDITIONS WITH CEILINGS BELOW 1KFT. EXPECT THE CEILINGS TO
RISE WITH MIXING TODAY...AND VFR CONDITIONS SHOULD PREVAIL.
CHANCES FOR RAIN MONDAY WILL BE LESSER AREA WIDE...WITH AN
INCREASE IN THE CHANCES LATE TONIGHT...ESPECIALLY SOUTH. MAY HAVE
A SLIGHTLY BETTER SHOT AT VISIBILITY ISSUES TONIGHT...BUT
OVERALL...STILL EXPECTING CLOUD COVER WHICH SHOULD LIMIT THE FOG
FORMATION. MAY SEE VCTS/VCSH OVER THE SOUTHERN MOUNTAINS LATE
TONIGHT. WILL TREND BKW CONSERVATIVE GOING THE SHOWER ROUTE WITH
VCSH.

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

FORECAST CONFIDENCE...MEDIUM.

ALTERNATE SCENARIOS: TIMING OF CEILING RISES MAY VARY. MAY NOT GET
THE MIST/FOG TONIGHT DUE TO CLOUD COVER. MAY NEED PREVAILING
PRECIPITATION LATE TONIGHT AT BKW.

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

AFTER 12Z TUESDAY...
IFR AT TIMES IN SHOWERS AND THUNDERSTORMS TUESDAY.
-- End Changed Discussion --

&&

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

&&

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