Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 282010
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
310 PM EST SAT FEB 28 2015

.SYNOPSIS...
WARM FRONT LATE TONIGHT INTO SUNDAY. COLD FRONT SUNDAY NIGHT. HIGH
PRESSURE BRINGS DRIER WEATHER MONDAY INTO MONDAY NIGHT. ANOTHER
WARM/COLD FRONT COMBO TUESDAY INTO WEDNESDAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
WARM ADVECTION S FLOW INTO AN ARCTIC AIR MASS...ON THE BACK SIDE OF
THE EXITING ARCTIC HIGH...WILL CREATE MIXED PRECIPITATION IN THE
AREA OVERNIGHT TONIGHT AND SUNDAY..BENEATH FLAT UPPER LEVEL SW
FLOW..  PRECIPITATION SHOULD SPREAD INTO THE OHIO VALLEY AFTER
MIDNIGHT TONIGHT.  MODELS WARM THE LAYERS ABOVE FREEZING MORE OR
LESS AT THE SAME TIME ALTHOUGH BUFKIT SOUNDINGS DO SUGGEST A SHALLOW
LAYER OF COLD AIR HANGING ON INTO SUNDAY AFTERNOON ESPECIALLY TO THE
NW OF THE OHIO RIVER...AND IN THE GREENBRIER VALLEY.

STILL GETTING AROUND 2 INCHES SNOW PERRY AND MORGAN COUNTIES TO KEEP
THE ADVISORY GOING THERE...WITH A TOUCH OF FREEZING RAIN POSSIBLE
THERE IN THE TRANSITION.  ALSO CONSIDERING ADVISORY FOR FREEZING
RAIN OVER THE EASTERN SLOPES OF OUR WV MOUNTAIN COUNTIES OF
POCAHONTAS...FAYETTE AND RANDOLPH COUNTIES.  WILL CONSIDER EXPANSION
OF ADVISORY TO THESE COUNTIES IN COORD WITH NEIGHBORS THIS
AFTERNOON.  ANY FREEZING RAIN ELSEWHERE IS EXPECTED TO BE BRIEF AND
RELATIVELY INCONSEQUENTIAL.

USED NAM / MET BLENDED WITH PREVIOUS RUN FOR TEMPERATURES AND DEW
POINTS.  DO HOLD ON THE COLD AIR A LITTLE LONGER IN SE OHIO AND IN
THE GREENBRIER VALLEY ON SUNDAY.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
SOME COLD AIR ADVECTION CONTINUES SUNDAY NIGHT UNDER NORTHWEST FLOW
BEHIND FIRST COLD FRONT TRANSITIONING PCPN INTO A MIX OR SNOW WITH
LINGERING MOISTURE. PCPN SHOULD BRIEFLY END SUNDAY NIGHT BEFORE NEXT
SYSTEM APPROACHES.

A BRIEF HIGH PRESSURE WILL CROSS THE AREA MONDAY NIGHT WITH DRY
WEATHER. BY LATE SUNDAY NIGHT INTO MONDAY...FLOW BECOMES SOUTHWEST
TO BRING WAA. A WARM FRONT LIFTS NORTH LATE MONDAY NIGHT NIGHT INTO
TUESDAY...TO BRING CHANCES OF PCPN TO THE AREA. BUFKIT SOUNDINGS
FROM THE GFS SUGGEST ONSET OF PCPN AS FZRA ACROSS THE SOUTHERN THIRD
OF THE AREA EARLY TUESDAY MORNING BEFORE SWITCHING TO RAIN.  MODELS
INDICATE STRONG WARM AIR ADVECTION AT H850 UNDER AROUND 50 KNOTS
FROM THE SOUTHWEST WITH TEMPERATURES INCREASING FROM 4C TO 9C BY 06
WEDNESDAY. THEREFORE...EXPECT MOST PCPN IN THE FORM OF RAIN THROUGH
TUESDAY NIGHT. A BRIEF WINTER WEATHER ADVISORY MAY BE REQUIRED FOR
THAT AREA FOR FREEZING RAIN TUESDAY MORNING.

CONCERNS CONTINUES AS EXTENDED PERIOD OF RAIN IS FORECAST TUESDAY
INTO MID WEEK. WITH WET TERRAIN...SNOW PACK AND WHATEVER RAINFALL
AMOUNTS OCCUR...FLOODING THREAT INCREASES TUESDAY INTO WEDNESDAY.
THERE IS MORE LIQUID EQUIVALENT IN THE DEEPER SNOW PACK OVER THE
EASTERN MOUNTAINS...WHERE FLOODING IS MORE LIKELY.


KEPT HIGH POPS WITH THE AFOREMENTIONED SYSTEM RANGING FROM
CATEGORICAL SOUTHEAST OH...AND WESTERN HALF OF WV INCLUDING THE
NORTHEAST MOUNTAINS AHEAD OF AN APPROACHING COLD FRONT. H850 WINDS
INCREASE TO NEAR 70 KNOTS BY THE END OF THE PERIOD WITH STRONG WAA
AHEAD OF THE FRONT.

WENT WITH BIAS CORRECTED CONSENSUS MOS BLENDED WITH ALL BLEND
GUIDANCE THROUGH THE PERIOD.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
LONG TERM STARTS OUT RATHER SOAKING WET. COLD FRONT WILL SLOWLY BE
PROGRESSING EASTWARD ACROSS THE CWA AT THE BEGINNING OF THE
PERIOD...WITH A WAVE OF LOW PRESSURE RIDING ALONG THE FRONT FROM
SOUTHWEST TO NORTHEAST...ENHANCING PRECIPITATION AS IT DOES SO.
STILL LOOKING LIKE HEAVY RAIN ON WEDNESDAY...IN THE MOIST
ATMOSPHERE...ALONG WITH SOME RATHER GUSTY WINDS EXPECTED TUESDAY
NIGHT INTO EARLY WEDNESDAY...WITH THE STRONG SOUTHWESTERLY FLOW AND
TIGHT PRESSURE GRADIENT. RAISED WIND GUSTS AND ADDED HEAVY RAIN
WORDING IN THE TUESDAY NIGHT THROUGH WEDNESDAY PERIOD.

FRONT WILL BEGIN TO PUSH EAST THURSDAY OR THURSDAY NIGHT...WITH
COLDER AIR RUSHING IN...AND A CHANGE OVER TO SNOW AREA WIDE. ITS
POSSIBLE THERE COULD BE SOME LIGHT ACCUMULATIONS...BUT WITH THE
WET...WARM GROUND...AT THIS POINT NOT SURE HOW MUCH WILL ACTUALLY BE
ABLE TO ACCUMULATE.

COLD HIGH PRESSURE WILL BUILD IN BEHIND THE EXITING FRONT FOR FRIDAY
INTO THE REMAINDER OF THE EXTENDED. WITH TEMPERATURES DIPPING BELOW
NORMAL ONCE AGAIN.

WILL CONTINUE TO HIGHLIGHT WATER ISSUES FOR NEXT WEEK IN THE HWO.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
VFR FINISH TO THE DAY AS THE LAST MAJOR ARCTIC AIR MASS OF THE
SEASON LEAVES THE AREA.   THIS WILL GIVE WAY TO WARM ADVECTION
TONIGHT AND SUNDAY...AS A WEAK LOW PRESSURE SYSTEM MOVES UP THE
OHIO RIVER VALLEY. THIS WILL PUMP MOISTURE AND MILDER AIR INTO THE
AREA.

SNOW IS LIKELY TO OVERSPREAD THE MIDDLE OHIO VALLEY OVERNIGHT
TONIGHT AND THEN MIX WITH SLEET...THEN BRIEFLY TO FREEZING
RAIN...AND THEN ALL RAIN BY 18Z SUNDAY.  ANOTHER WEAK DISTURBANCE
MOVING UP FROM THE S WILL BRING SNOW AND SLEET TO THE NRN WV
MOUNTAINS EARLY SUNDAY MORNING WITH SLEET...FREEZING RAIN AND RAIN
INTO THE SOUTHERN AND CENTRAL WV MOUNTAINS.  THE PRECIPITATION IN
THE MOUNTAINS WILL ALSO GO TO RAIN BY 18Z SUNDAY...SAVE FOR PERHAPS
THE HIGHEST TERRAIN AND ERN SLOPES...WHERE A MIX MAY PERSIST.

CIGS WILL DROP TO MVFR SUNDAY MORNING WITH LOW MVFR MOST PLACES BY
18Z SUNDAY.  EXPECT MVFR VSBY IN PRECIPITATION SUNDAY MORNING BUT
IFR SNOW WILL BE CLOSE BY PKB...TO THE W OF THE OHIO RIVER...AND IN
THE HIGHER TERRAIN.

LIGHT AND VARIABLE SFC FLOW WILL HAVE MOSTLY AN ERLY COMPONENT...A
LITTLE STRONGER SE IN THE MOUNTAINS.  LIGHT SW FLOW ALOFT WILL
BECOME MODERATE SW OVERNIGHT TONIGHT AND THEN REMAIN SO ON SUNDAY.

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

FORECAST CONFIDENCE: MEDIUM TO HIGH.

ALTERNATE SCENARIOS: TIMING OF ONSET OF PRECIPITATION AND ASSOCIATED
LOWER CIGS AND VSBYS COULD VARY.  IFR SNOW COULD GET INTO PKB SUNDAY
MORNING.  MUCH OF THE MOS GUIDANCE IS SUGGESTING IFR CIGS AND VSBYS
BY MIDDAY SUNDAY.

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       20   21   22   23   00   01   02   03   04   05   06   07
EST 1HRLY       15   16   17   18   19   20   21   22   23   00   01   02
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    L    L
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 18Z SUNDAY...
IFR POSSIBLE IN RAIN OR MIXED RAIN/SNOW LATE SUNDAY INTO EARLY
MONDAY. IFR POSSIBLE AGAIN IN RAIN SHOWERS TUESDAY INTO WEDNESDAY.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY FROM 4 AM TO 1 PM EST SUNDAY FOR
     WVZ035-036.
     WINTER WEATHER ADVISORY FROM 4 AM TO 7 PM EST SUNDAY FOR
     WVZ046.
OH...WINTER WEATHER ADVISORY FROM 1 AM TO 1 PM EST SUNDAY FOR
     OHZ066-067.
KY...NONE.
VA...NONE.

&&

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







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