Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 251355
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
855 AM EST SUN JAN 25 2015

.SYNOPSIS...
NEXT SYSTEM APPROACHES TODAY AND MOVES THROUGH TONIGHT AND MONDAY.
HIGH PRESSURE BRIEFLY ARRIVES WEDNESDAY. THE COLD PARADE CONTINUES
WITH CLIPPERS THURSDAY AND AGAIN SATURDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
855 AM UPDATE...TWEAKED HOURLY SKY AND TEMPERATURE
GRIDS...OTHERWISE...NO CHANGES NECESSARY AT THIS POINT.

PREVIOUS DISCUSSION BELOW...

BUSY WX PATTERN ROLLS ON...

WILL BE TRACKING AN UPPER LEVEL DISTURBANCE WITH AN ASSOCIATED
SURFACE LOW DROPPING THROUGH AN AMPLIFYING TROF. IT STILL APPEARS
THE BULK OF THE PRECIP TODAY WILL FOCUS ALONG A DEVELOPING WARM
FRONT FROM AFOREMENTIONED SURFACE LOW. WHERE THIS WARM FRONT SETS UP
IS CRITICAL IN TERMS OF NOT ONLY QPF BUT EVENTUALLY PRECIP TYPE. THE
MODELS ARE RELATIVELY TIGHTLY CLUSTERED ON TRACK OF SURFACE LOW AND
WARM FRONT. THE WARM FRONT IS EXPECTED TO DEVELOP ACROSS S OH AND
EXTEND INTO N WV THIS AFTERNOON. AS ISENTROPIC UPGLIDE
INCREASES...LIGHT PRECIP WILL BREAK OUT ALONG THE WARM FRONT...FIRST
ACROSS OUR N SE OH ZONES AND THEN OVERSPREADING THE N FRINGES OF OUR
N WV ZONES...INCLUDING PKB/CKB/EKN FOR A TIME LATE THIS AFTERNOON.
THERMAL PROFILES INDICATE LIGHT RAIN AT ONSET...SAVE FOR THE HIGHER
ELEVATIONS OF RANDOLPH CO. THINK ANY SNOW ACCUMULATIONS UP THERE
WOULD BE MEAGER THRU 00Z. A DECENT SPIKE IN TEMPS WILL BE REALIZED
THIS AFTERNOON ACROSS SW VA/COAL FIELDS/KANAWHA VALLEY/AND UP ALONG
AND E OF THE I79 CORRIDOR TO THE W SLOPES...COURTESY OF S TO SE LOW
LEVEL DOWNSLOPING FLOW. LOOK FOR HIGHS IN UPPER 40S WITH MAYBE A 50
SHOWING UP ACROSS THE COAL FIELDS AND KANAWHA VALLEY.

BY THIS EVENING...THE SURFACE LOW WILL BE TRACKING THRU E KY WITH
THE UPPER LEVEL TROF AXIS LAGGING A LITTLE BEHIND. THE WARM FRONT
WILL HAVE ORIENTED ITSELF MORE INTO AN INVERTED SURFACE TROF ACROSS
WV. AS SUCH...THE LOW LEVEL WARM WEDGE WILL HOLD THRU 06Z EXCEPT
ACROSS THE HIGHER ELEVATIONS IN THE MOUNTAINS AND PERRY CO. A FEW
INCHES MAY ACCUMULATE ACROSS THE HIGH TERRAIN. PERRY COUNTY IS
TRICKY AS JUST A 20 MILE SHIFT IN OVERALL TRACK TO THE S WOULD MEAN
THE DIFFERENCE BETWEEN 1 TO 2 INCHES VS 2 TO 3. THE NAM AND SREF
WOULD HAVE ONLY N PERRY REACHING CRITERIA WHILE SOME OF THE OTHER
MODELS ARE A BIT MORE GENEROUS. AFTER COORDINATION WITH SURROUNDING
OFFICES...ELECTED TO HOIST AN ADVISORY FOR 1 TO 3 INCHES...WITH THE
HIGHER END ACROSS N PERRY. WILL START IT AT 21Z THIS AFTERNOON AND
RUN IT UNTIL NOON MONDAY. ELSEWHERE AS THE LOW TRACKS THRU S WV AND
INTO VA AND THE UPPER TROF CROSSES...THE RAIN/SNOW LINE WILL BEGIN
TO COLLAPSE THRU SE OH AND NE KY DURING THE PREDAWN HRS...WHERE A
COATING OF SNOW IS POSSIBLE THRU 12Z...MAINLY ACROSS REMAINDER OF SE
OH ZONES. THE RAIN/SNOW LINE BY 12Z LOOKS TO BE JUST E OF THE OH
RIVER.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
PRECIPITATION FROM THE CLIPPER WILL GRADUALLY MOVE EASTWARD OUT OF
THE AREA ON MONDAY. WITH COLD AIR ADVECTION LATE MONDAY AND MONDAY
NIGHT HOWEVER...SOME LOW LEVEL OVER TURNING AND UPSLOPE SNOW SHOWERS
BECOME A POSSIBILITY. MODELS SHOWING THAT MOISTURE WILL INITIALLY BE
FAIRLY LIMITED WITH IN THE WEST...SO BEST CHANCE OF SNOW SHOULD BE
IN THE MOUNTAINS.

A WEAK DISTURBANCE ALSO MOVES OVER LATE MONDAY NIGHT INTO
TUESDAY...INCREASINGS MOISTURE IN THE WESTERN AND SOUTHERN COUNTIES.
THIS COULD PRODUCE SOME LIGHT SNOW...BUT MODELS ARE NOT NEARLY AS
ROBUST WITH THIS FEATURE AS THEY WERE LAST NIGHT.

HIGH PRESSURE FINALLY BUILDS IN ON WEDNESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
CLOSE TO WPC THINKING WITH POSITIVE PNA THIS PERIOD.  CLIPPER
SYSTEMS REINFORCE THE COLD AIR JUST PRIOR TO THE START OF THE
PERIOD...AND THEN AGAIN THU-THU NT AND SAT NT.  THE ONE JUST PRIOR
TO THE START OF THE PERIOD IS PROGGED TO EVOLVE INTO A SIZABLE AND
RAPIDLY INTENSIFYING STORM SYSTEM OFF THE E COAST MON-TUE.

HIGH PRESSURE CUTS OFF UPSLOPE SNOW SHOWERS IN THE WAKE OF THE FIRST
CLIPPER TUE NT...AND THEN SAILS ACROSS ON WED.  WARMING ALOFT WED
MAY NOT BE REALIZED AT GROUND UNTIL THU...IN THE SRLY FLOW AHEAD OF
THE SECOND CLIPPER.  THIS SYSTEM IS LIKELY TO PROVIDE A GOOD BUT
BRIEF UPSLOPE SNOW EVENT THU NT.  WHILE STILL AT A DISTANCE WHERE
THE MODELS ARE STILL IN FLUX...THE WEEKEND SYSTEM MAY BE MORE
INTERESTING THAN JUST A CLIPPER.

LITTLE CHANGES WERE NEEDED TO TEMPERATURES WHICH WERE CLOSE TO WPC.
THE GFS40 WAS EMPLOYED THU MORNING AND SAT MORNING...THE BETTER
RADIATIVE COOLING NIGHTS.  THE FAST MOVING SYSTEMS IN THE BAROCLINIC
ZONE CREATE BUST POTENTIAL IN THIS PERIOD.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
LOOKING AT GENERALLY 4 TO 5 THOUSAND FOOT CIGS THIS MORNING FOR
ALL TERMINALS EXCEPT KEKN/KCKB...WHERE LOW END MVFR CIGS WILL
HOLD. EXPECT KEKN AND KCKB TO SNEAK INTO LOW END VFR CIGS 15 TO
17Z.

A WARM FRONT WILL DEVELOP ACROSS SE OH AND N WV TODAY...WITH
PRECIP BREAKING OUT ALONG THIS FEATURE...MAINLY IN THE FORM OF
RAIN...CLIPPING KPKB AND KCKB LATER THIS AFTERNOON WITH PERHAPS
SOME MVFR CIGS/VSBY. THE WARM FRONT WILL LIFT N THIS EVENING AND
ORIENT ITSELF MORE INTO AN INVERTED SURFACE TROF ACROSS WV....AS
A LOW PRESSURE CENTER TRAVERSES KY AND INTO S WV TOWARD END OF TAF
PERIOD. RAIN WILL OVERSPREAD THE REST OF THE TERMINALS AFTER 00Z
WITH CIGS/VSBY LOWERING INTO MVFR AND EVENTUALLY IFR. THE RAIN
WILL CHANGE TO SNOW ACROSS SE OH THIS EVENING WITH CIGS LOWERING
INTO IFR OR WORSE ALONG WITH VSBY. THIS TRANSITION SLOW WORKS SE
TO HTS/PKB BY END OF TAF PERIOD. SOME SNOW IS EXPECTED IN THE
HIGHER ELEVATIONS OF THE N MOUNTAINS WITH IFR AND LIFR CONDITIONS.

WIND WILL GENERALLY BE OUT OF THE S FOR KCRW/KHTS/KEKN AND SSE FOR
KBKW IN THE WARM SECTOR. WIND DIRECTIONS GENERALLY NE FOR KPKB/KCKB
TODAY. FLOW GENERALLY LIGHT...ON THE ORDER OF 5 TO 10 KTS.

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

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIO: CIGS MAY STAY LOW END MVFR FOR KEKN/KCKB
INSTEAD OF IFR...BEFORE LIFTING LATER THIS MORNING. TIMING PRECIP
AND THUS AVIATION CONDITIONS MAY VARY THIS EVENING.

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       14   15   16   17   18   19   20   21   22   23   00   01
EST 1HRLY       09   10   11   12   13   14   15   16   17   18   19   20
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  M    H    H    H    H    H    H    H    H    H    M    M
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 12Z MONDAY...
IFR IN SNOW SHOWERS MONDAY MORNING IN SOUTHEAST OHIO...KY...AND THE
NORTHERN WV MOUNTAINS. IFR POSSIBLE IN SNOW MONDAY NIGHT IN THE
NORTHERN AND CENTRAL WV MOUNTAINS.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO NOON EST
     MONDAY FOR OHZ066.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...SL/30
SHORT TERM...RPY
LONG TERM...TRM
AVIATION...30








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