Area Forecast Discussion
Issued by NWS Charleston, WV

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
188
FXUS61 KRLX 120953
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
453 AM EST FRI FEB 12 2016

.SYNOPSIS...
ARCTIC FRONT CROSSES THIS EVENING...ACCOMPANIED BY SNOW SHOWERS
INTO SATURDAY...AND BITTERLY COLD WEATHER FOR THE WEEKEND. A
COMPLEX SYSTEM COULD BRING MIXED PRECIPITATION EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
A FAST MOVING UPPER LEVEL IMPULSE WILL ROUND THE BASE OF THE MEAN
TROF OVER THE E CONUS TODAY. THIS WILL BRING A SWATH OF MAINLY LIGHT
SNOW TO S KY/SW VA/AND PORTIONS OF SE WV. QPF AMOUNTS LOOK
LIGHT...RANGING A FEW HUNDREDTHS TO AROUND A TENTH. AFTER
INCORPORATING THE LATEST RAP/HRRR RUNS FOR QPF AND CONVERTING TO
SNOW USING NAM SNOW RATIOS RESULTED IN MAINLY ONE INCH AMOUNTS OVER
THOSE LOCATIONS WITH UP TO 2 INCHES ON THE E RIDGE OF DICKENSON
COUNTY. SINCE HEADLINES ARE ALREADY OUT SURROUNDING SW VA AND THE
FORECAST AMOUNTS OF 1 TO 2 INCHES...ELECTED TO HOIST A WINTER WX ADV
UNTIL THIS AFTERNOON FOR THOSE COUNTIES. ELSEWHERE...THINKING IT
WILL BE HARD FOR MEASURABLE PRECIP TO MAKE IT N ASIDE FROM THE
MOUNTAINS. THUS ANTICIPATE A PARTLY TO MOSTLY CLOUDY DAY ELSEWHERE
WITH TEMPS RECOVERING INTO THE UPPER 20S TO LOWER 30S.

ATTENTION THEN TURNS TO AN ARCTIC FRONT WHICH WILL USHER IN THE
COLDEST TEMPERATURES OF THE SEASON FOR THE WEEKEND. SOME SNOW
SHOWERS MAY BREAK OUT AHEAD OF THE FRONT LATE THIS AFTERNOON BUT
OVERALL WILL WAIT FOR FROPA WHICH WILL BRING WITH IT A HEALTHY DOSE
OF SQUALLS WITH PLUMMETING TEMPERATURES AND GUSTY WINDS. THESE
LOOKS TO PUT DOWN A SKIFF WITH SOME LOLLIPOP AMOUNTS TO AN INCH IN
THE LOWLANDS. HAVE THE FRONT CROSSING IN THE 00Z TO 06Z TIME
FRAME FROM NW TO SE ACROSS THE REGION. WITH PLUMMETING H85 TEMPS
AND CROSS FLOW...THINK EFFICIENT MOMENTUM TRANSFER WILL BE
REALIZED TO CREATE VERY GUSTY WINDS. HAVE CODED UP SOME 20 TO 30
KT GUSTS OVERNIGHT...WITH GUSTS TO 40 KTS OVER THE HIGHER
ELEVATIONS OF THE WV MOUNTAINS. SURFACE TEMPERATURES WILL BOTTOM
OUT IN THE SINGLE DIGITS TO LOWER TEENS OUTSIDE OF THE MOUNTAINS
BY 12Z SATURDAY...WITH BLO ZERO READINGS IN THE HIGHER ELEVATIONS.
WIND CHILL CONUNDRUMS WILL BE REALIZED OVER THE HIGH TERRAIN AND
ADJACENT COUNTIES. AFTER COORDINATION WITH SURROUNDING OFFICES WE
ELECTED TO RAISE A WIND CHILL WATCH FOR RANDOLPH/POCAHONTAS AND A
WIND CHILL ADVISORY FROM RALEIGH TO TAYLOR COUNTIES IN WV.
MENTIONED THE HIGH WINDS IN THE HEADLINE. SNOW SHOWERS WILL
CONTINUE BEHIND THE FRONT...MOST NUMEROUS IN THE MOUNTAINS WHERE A
GENERAL 2 TO 4 INCHES ARE FORECASTED WHICH FALLS SHORT OF ADVISORY
LEVEL AMOUNTS. SNOW SHOWERS WILL DIMINISH OUTSIDE OF THE MOUNTAINS
LATE TONIGHT...BECOMING CONFINED TO MOISTURE STREAMS FROM LAKE
MICHIGAN CONTRIBUTIONS.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SAT MORNING FINDS THE FCST AREA IN THE DEEP FREEZE AND DEEP LAYER
NW UPSLOPE FLOW. HIGH PRESSURE REPRESENTING THE CENTER OF THE
ARCTIC AIR MASS BUILDS OVER THE AREA LATE DAT NT...BEFORE MOVING
ON TO THE E ON SUNDAY. THE APPROACHING HIGH WILL CUT OFF THE NW
FLOW...KILLING ANY LAKE PLUMES SAT MORNING...AND THEN THE UPSLOPE
SNOW SHOWERS SAT NT. FLUFFY BUT MINOR ADDITIONAL ACCUMULATIONS ARE
POSSIBLE UNTIL THEN WITH TEMPERATURES ALOFT FAVORING DENDRITIC
GROWTH IF NOT ALMOST TOO LOW...-22C AT H85.

AS THE DEEP L/W TROUGH STARTS TO LIFT OUT...AND A S/W TROUGH
APPROACHES FROM THE NW...THE AREA GETS INTO A WARM ADVECTION
PATTERN THAT WILL BRING ON INCREASING CLOUDINESS SUNDAY...FOLLOWED
BY SNOW LATE IN THE DAY AND AT NT. THE WARM ADVECTION COULD TAKE
TEMPERATURES HIGH ENOUGH FOR A CHANGE OVER TO RAIN OVER THE
LOWLANDS MON AFTERNOON.

INTRODUCED AN HWO MENTION FOR POSSIBLE MIXED WINTRY PRECIPITATION
MON AND TUE ALTHOUGH TEMPERATURES ON THE COLD SIDE OF THE SYSTEM
ARE PROGGED TO BE MARGINAL FOR SNOW VS RAIN.

BLENDED IN MOSTLY RAW MODEL DATA FOR TEMPERATURES SAT IN THE
ARCTIC AIR AND THE BIAS CORRECTED MAV FOR LOWS SAT NT...THE
HIGHER RIDGES LEVELING OFF AND EVEN RISING A TAD TOWARD DAWN
SUNDAY. HIGHS SUNDAY WERE MAINLY BETWEEN MOS AND RAW MODEL OUTPUT
AND WERE ACCEPTED. AFTER FALLING INITIALLY SUNDAY
NT...TEMPERATURES RISE OVERNIGHT...AND GUIDANCE SUGGESTED HIGHER
TEMPERATURES FOR MON.

IN THE ARCTIC AIR...TEMPERATURES DO NOT RISE MUCH ON SAT...SO THE
WIND CHILL ADVISORIES AND WATCHES CONTINUE THROUGH THE DAY SAT AND
SAT NT INTO SUNDAY MORNING IN AND NEAR THE MOUNTAINS. THE WINDS
DO DIE DOWN THERE SAT NT BUT NOT UNTIL VERY LATE...AND LASTLY ON
THE RIDGES WHERE WIND CHILL VALUES WILL BE CLOSEST TO WARNING
CRITERIA.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
STILL LOTS OF UNCERTAINTY IN THE EXTENDED PERIOD...ALTHOUGH
MODELS ARE GRADUALLY TRYING TO COME TOGETHER. SERIES OF POTENT WAVES
TO AFFECT THE AREA EARLY NEXT WEEK. FIRST SUNDAY NIGHT INTO
MONDAY...AS WAVE MOVES INTO GREAT LAKES REGION...SPREADING MAINLY
LIGHT SNOWFALL INTO THE REGION. THE SECOND MORE POWERFUL WAVE AND
ASSOCIATED LOW WILL MOVE NORTHEAST OUT OF THE SOUTHERN U.S. TOWARDS
THE REGION BY MONDAY NIGHT INTO TUESDAY. DEPENDING ON THE TRACK OF
THE LOW...WILL DETERMINE WHETHER AREA IS LOOKING AT AN ALL SNOW
EVENT...OR A WINTRY MIX AT TIMES. AT THIS POINT...LOOKS LIKE A
WINTRY MIX CAN BE EXPECTED AT TIMES...PARTICULARLY ACROSS THE
LOWLANDS...WHICH OF COURSE WILL LIMIT SNOWFALL POTENTIAL. WITH THE
OVERALL UNCERTAINTY IN THE MODELS AT THIS TIME...WILL KEEP A MENTION
OUT OF THE HWO FOR ONE MORE DAY...AND ALLOW FOCUS TO REMAIN ON
SYSTEMS AND IMPACTS EXPECTED THIS WEEKEND.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
GENERALLY VFR CONDITIONS THRU THIS MORNING. SOME BRIEF MVFR/IFR FG
OVER KPKB WILL DISSIPATE AS BL INCREASE.

AFTER 16Z FRIDAY...RAPIDLY BECOMING MVFR WITH LIGHT SNOW AS UPPER
DISTURBANCE RACES EASTWARD WITH IFR CONDITIONS IN SE WV AND SW VA
TO INCLUDE KBKW.

AN ARCTIC FRONT PASSES FRI EVENING WITH IFR SQUALLS POSSIBLE ALONG
WITH GUSTY WINDS 20 TO 30 KTS.

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

FORECAST CONFIDENCE...MEDIUM.

ALTERNATE SCENARIOS: THERE MAY BE SOME BREAKS BETWEEN THE SNOW
FROM THE DISTURBANCE AND THE ARRIVING ARCTIC FRONT LATER IN THE
EVENING WHICH WOULD ALLOW TERMINALS TO RETURN TO VFR CONDITIONS AT
LEAST WITH VSBY.

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 02/12/16
UTC 1HRLY       09   10   11   12   13   14   15   16   17   18   19   20
EST 1HRLY       04   05   06   07   08   09   10   11   12   13   14   15
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    M    M    L    L
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    H    M    L
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    M    M    L

AFTER 06Z SATURDAY...
IFR CONDITIONS IN SNOW SHOWERS WILL BE POSSIBLE AGAIN FRIDAY
NIGHT THROUGH SATURDAY NIGHT...ESPECIALLY IN THE MOUNTAINS.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST SUNDAY
     FOR WVZ032-035>040.
     WIND CHILL WATCH FROM LATE TONIGHT THROUGH SUNDAY MORNING FOR
     WVZ046-047.
OH...NONE.
KY...NONE.
VA...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
     VAZ003-004.

&&

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



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.