Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 240750
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
350 AM EDT FRI OCT 24 2014

.SYNOPSIS...
HIGH PRESSURE AT THE SURFACE DOMINATES THROUGH TONIGHT...EVEN AS
UPPER LEVEL DISTURBANCES CROSS.  MAINLY DRY COLD FRONT CROSSES
SATURDAY EVENING.  HIGH PRESSURE SUNDAY.  WARMER EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
WEAK HIGH PRESSURE DOMINATES AT THE SFC EVEN AS WEAK UPPER LEVEL
DISTURBANCES CROSS.  UPSLOPE STRATOCU IN THE MOUNTAINS RESULTING
FROM THE LOW LEVEL NW FLOW WILL MIX OUT LATER THIS MORNING ON
HEATING AND DRYING.  MODELS SUGGEST IT MAY REFORM IN THE MOUNTAINS
LATE TONIGHT WITH LOW LEVEL FLOW STILL FROM THE W TO NW.  HAVE A
HINT OF THIS IN THE FCST.  OTHERWISE EXPECT JUST MID AND HIGH CLOUD
WITH THE UPPER LEVEL DISTURBANCES FOR MOST OF THE PERIOD.

LOWER CLOUDS WILL MOVE INTO THE MIDDLE OHIO VALLEY TOWARD DAWN SAT
IN WEAK LOW LEVEL WARM ADVECTION...PROBABLY LATE ENOUGH TO ALLOW FOR
DENSE VALLEY FOG TO FORM AGAIN OVERNIGHT TONIGHT.

INHERITED TEMPERATURES WERE CLOSE TO THE LATEST GUIDANCE BLENDS AND
LOOKED REASONABLE.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
FOR SATURDAY...A WEAKENING COLD FRONT MOVES THROUGH AND REACHES THE
EASTERN MOUNTAINS OVERNIGHT.  THE LATEST NAM12...AND TO A LESSER
EXTENT THE GFS...ARE SPITTING OUT THE SLIGHTEST AMOUNT OF QPF FOR
THE 06Z SUN TIMEFRAME. LEFT MENTION OF LIGHT SHOWERS IN FOR
MOUNTAINS FOR THE OVERNIGHT HOURS...AS THIS DYING FRONT MAKES ITS
EXODUS.

SURFACE HIGH PRESSURE OVER TENNESSEE WILL GRADUALLY SHIFT
EASTWARD THROUGH THE LATER PART OF WEEKEND AS A WEAK WARM FRONT
PUSHED NORTH ACROSS THE FORECAST AREA.  ATMOSPHERIC COLUMN WILL
GENERALLY REMAIN DRY...WITH WARM AIR ADVECTION TAKING PLACE.  THIS
WILL RESULT IN LITTLE CHANCES FOR PRECIPITATION WITH AN UPSWING IN
DAYTIME HIGHS...ESPECIALLY BY MONDAY AFTER WARMER AIRMASS NUDGES
INTO THE OHIO VALLEY.

USED INHERITED TEMPS WITH A BLEND TOWARD CONSENSUS BC GRIDS TO COVER
DAYTIME HIGHS WHICH LEAD TO MINIMAL CHANGES IN VALUES.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
WARMING ALOFT...ALONG WITH A PSEUDO DRY WARM FRONT...SHOULD BE
LIFTING NORTH AND NORTHEAST OVERNIGHT SUNDAY NIGHT INTO MONDAY
MORNING.  WILL KEEP MINIMUM TEMPERATURES JUST ABOVE FROST ADVISORY
CRITERIA WHERE THE PROGRAM STILL IS ONGOING.

WARMING ON MONDAY APPEARS FASTER THAN WE PICTURED 24 HOURS AGO. 850
MB TEMPERATURES OF 15 TO 16C BY 00Z TUESDAY ARE PROJECTED BY 12Z GFS
AND ECMWF.  A MARGINAL INCREASE IN MOISTURE AT 850 MBS ON TUESDAY
HAS GFS AND ECMWF DROPPING 850 MB TEMPERATURES TO AROUND 12C TUESDAY
AFTERNOON.  WILL INCREASE MAXIMUM TEMPERATURES MONDAY...BUT
BOUNDARY LAYER SHOULD KEEP MAXIMUM READINGS TUESDAY NEARING AS
WARM.  STRONGEST WIND GUSTS SHOULD BE TUESDAY AFTERNOON.  HAVE
SURFACE DEW POINTS INCREASING FROM WEST TO EAST IN WAKE OF THE
PSEUDO WARM FRONT ON MONDAY.  DO NOT EXPECT RED FLAG CRITERIA TO BE
MEET.  HOWEVER...WITH THE INCREASE IN WIND AND THE WARM AFTERNOON
TEMPERATURES...WILL INCLUDE AN ELEVATED/ENHANCED RISK OF THE SPREAD
OF WILD/BRUSH FIRES MONDAY AFTERNOON AND AGAIN TUESDAY.

WAS ALSO SLOWER INCREASING CLOUD COVER MONDAY INTO TUESDAY...THAN
OUR MEDIUM RANGE GUIDANCE FROM WPC.

GLAD WE DELAYED THE POPS 24 HOURS AGO...WITH THE NEXT FRONT.  THE
FRONT WILL HAVE SOME RIGHT REAR 250 MB JET SUPPORT.  SO HAVE
INCREASED POPS...MOSTLY IN THE 40 TO 60 PERCENT RANGE FOR LATE
TUESDAY NIGHT INTO WEDNESDAY.  HAVE POPS LOWERING WEDNESDAY
AFTERNOON IN OUR OHIO VALLEY COUNTIES.

THE FRONT WILL LIKELY SLOW DOWN IN OUR SOUTHEASTERN COUNTIES...WITH
ANOTHER 500 MB TROF STILL TO OUR WEST WEDNESDAY NIGHT.  SO WILL HOLD
POPS ALONG OUR VIRGINIA BORDER COUNTIES INTO THURSDAY...BUT HAVE THE
WESTERN SLOPES DRY ON THURSDAY.  WAVE LIKELY TO ENHANCE THE RAIN
THURSDAY TO OUR EAST AND SOUTHEAST.  A DEEPENING LOW PRESSURE WILL
LIKELY BE WELL TO OUR NORTH...OVER ONTARIO LATE THURSDAY...WHICH
WILL OPEN THE DOOR TO ANOTHER DOWNWARD SWING ON OUR AUTUMN
TEMPERATURE SEESAW RIDE.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
MVFR STRATOCU DISSIPATING IN THE MOUNTAINS OVERNIGHT MAY REFORM
BRIEFLY AS MORNING CU AFTER DAYBREAK FRI.  OTHERWISE VLIFR DENSE FOG
LIKELY MOST SITES...EVEN BKW MAY GET IFR FOG.

THE REMAINDER OF THE PERIOD...THE BALANCE OF THE DAY FRI AND FRI
NT...WILL BRING MAINLY VFR CONDITIONS AS AN UPPER LEVEL TROUGH
BRINGS MID AND HIGH CLOUD.  VALLEY FOG MAY START TO FORM BY 06Z
SAT.  MVFR STRATOCU MAY ALSO START TO REFORM IN THE MOUNTAINS BY 06Z
SAT.

CALM AIR WILL GIVE WAY TO LIGHT W SFC FLOW FRI AND THEN BECOME CALM
AGAIN FRI NT.  LIGHT N FLOW ALOFT WILL BECOME LIGHT NW FRI.

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

FORECAST CONFIDENCE: MEDIUM OVERNIGHT INTO FRI MORNING...THEN HIGH.

ALTERNATE SCENARIOS: FOG TIMING...DENSITY...AND LOCATIONS OVERNIGHT
COULD VARY...AS MAY MVFR CIGS AT EKN INTO FRI MORNING AND AGAIN FRI
NT.

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                              FRI 10/24/14
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    M    L    L    L    H    H    H    H    H
HTS CONSISTENCY  H    M    L    L    L    L    L    L    M    H    H    H
BKW CONSISTENCY  M    M    M    M    M    H    H    H    H    H    H    H
EKN CONSISTENCY  M    M    M    L    L    L    L    H    H    H    H    H
PKB CONSISTENCY  H    H    H    M    L    L    L    H    H    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 06Z SATURDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.

&&

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

&&

$$
SYNOPSIS...KMC/TRM
NEAR TERM...TRM
SHORT TERM...KMC
LONG TERM...KTB
AVIATION...TRM






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