-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 061009
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
508 AM EST FRI DEC 6 2013

.SYNOPSIS...
SLOW MOVING COLD FRONT TONIGHT AND FRIDAY WITH ABUNDANT
PRECIPITATION.  BRIEF HIGH PRESSURE SATURDAY. ANOTHER WET SYSTEM
SUNDAY AND MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AREAS OF MODERATE TO HEAVY RAIN CONTINUE ON THE RADAR SCOOP THIS
MORNING. MANY CREEKS AND SMALL STREAMS ARE RISING RAPIDLY.
HOWEVER...AREAS OF RAIN SHOW SIGNS OF BREAKING UP AND BECOMING
MORE SCATTERED IN NATURE...AND THE RAIN ACCUMULATION SHOULD BEGIN
TO SUBSIDE. IN THE OTHER HAND...ADDITIONAL PRECIPITATION IN THE
FORM OF SNOW WILL AFFECT SOUTHEAST OH AND PORTIONS OF WV TODAY AND
TONIGHT.

INCREASED SNOWFALL EXPECTED ACROSS SOUTHEAST OHIO AND THE LOWLANDS
OF WEST VIRGINIA PER WWD GUIDANCE SHOWING AND AREAS OF HEAVY
SNOWFALL ACROSS AND WEST OF PERRY COUNTY. THEREFORE...ISSUED A
WINTER STORM WARNING FOR SNOW FOR PERRY COUNTY AS EXPECT 3 TO 5
INCHES...AND WINTER WEATHER ADVISORIES FOR
VINTON...MORGAN...ATHENS AND WASHINGTON COUNTIES IN SOUTHEAST
OHIO THROUGH TONIGHT.

SREF PROBABILITIES SUGGEST UP TO 80 PERCENT FOR SNOWFALL GREATER
THAN 4 INCHES OVER PERRY COUNTY AND WEST. MODELS INDICATE COLD
ADVECTION UNDER NORTHWEST FLOW AT H85 REACHING MINUS 5C BY
06Z SATURDAY.

USED THE BIAS CONSENSUS NAM BLENDED WITH THE MOS FOR TEMPERATURE
THROUGH THE PERIOD.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
-- Changed Discussion --
ONLY MINOR DIFFERENCES WITH THE LARGE SCALE FEATURES IN RUN TO RUN
COMPARISONS OF VARIOUS SHORT TERM MODEL OUTPUT. NOT MUCH CHANGE WITH
THE OVERALL PREVIOUS FORECAST FOR SATURDAY. SFC FRONT AND AXIS OF
DEEP LAYER MOISTURE CONTINUES TO PUSH OFF TO THE SOUTHEAST DURING
THE DAY SATURDAY. PRECIP CHANCES WILL WIND DOWN FROM WEST TO EAST
DURING THE 12Z-18Z TIME FRAME MAINLY EAST OF THE OHIO RIVER. DRYING
IN THE MID-LEVELS DURING THIS TIME FRAME SUGGESTS THE POTENTIAL FOR
THE END OF PRECIP TO POTENTIALLY BE SLEET/FREEZING RAIN. THIS BEARS
WATCHING OF COURSE BUT AMOUNTS SHOULD REMAIN ON THE LIGHT SIDE.
CLOUDS MAY BE SLOW TO BREAK EAST OF THE OHIO AS USUAL WITH CONTINUED
COLD ADVECTION BUT EVEN HERE SHOULD SEE SOME LATE DAY PARTLY CLOUDY
SKIES. MEANWHILE...SE OHIO ZONES SHOULD SEE BREAKS IN THE CLOUDS BY
MID-MORNING SAT.

THINGS BEGIN TO CHANGE RAPIDLY OVERNIGHT SATURDAY NIGHT AS SFC HIGH
PRESSURE PUSHES OFF TO OUR NORTHEAST AND THE NEXT WAVE OF LOW
PRESSURE RIDES NORTHEAST ALONG THE FRONT TO OUR SOUTHEAST. TEMPS
SHOULD FALL DURING THE EVENING HOURS SAT NIGHT INTO THE LOW/MID 20S
MOST LOWLAND LOCATIONS BEFORE LEVELING OFF AS DENSE CLOUD COVER
MOVES OVERHEAD AND WIND DIRECTION QUICKLY VEERS FROM NORTH AT 00Z
SUN TO THE EAST BY 12Z SUN. MEANWHILE...DEEP LAYER MOISTURE PROGGED
TO ARRIVE AGAIN FROM SOUTH TO NORTH BTWN 12Z AND 18Z SUN...AND AS
SUCH HAVE BUMPED UP POPS TO CATEGORICAL PRETTY MUCH EVERYWHERE
EXCEPT THE NORTHWEST ZONES BY 18Z SUN. PRECIP TYPE AT THIS POINT
APPEARS TO TRANSITION FROM SNOW TO SLEET/FZRA TO FINALLY RAIN BY
AROUND THE 18Z-19Z TIME FRAME FOR THE CRW-HTS CORRIDOR SOUTH INTO
THE COALFIELDS...AND FOR THE PKB-CKB AREA BY AROUND 21Z. CODED UP A
QUICK HALF INCH TO AN INCH OF SNOW FOR MUCH OF THE LOWLANDS EARLY
SUNDAY MORNING PRIOR TO THE CHANGEOVER. THE NORTHWEST ZONES MAY
REMAIN IN AN ALL SNOW OR WINTRY MIX ALL DAY...WHERE THESE LOCATIONS
MAY SEE A BIT MORE TOTAL SNOW BY LATE SUNDAY...PERHAPS AROUND
1.0-1.5 INCHES. ALSO...THERE CONTINUES TO BE A GREATER CONCERN FOR A
FAIRLY PROLONGED FREEZING RAIN EVENT FOR THE EASTERN MOUNTAINS PER
LATEST GUIDANCE FROM SUN MID AFTERNOON INTO SUN EVENING AND INTO
EARLY OVERNIGHT MONDAY. AS SUNDAY AFTERNOON IS STILL FIVE PERIODS
OUT...OPTED TO NOT ISSUE ANY ICE HIGHLIGHTS DUE TO ONGOING
HIGHLIGHTS...AS WELL AS TO ALLOW THE DAY SHIFT TO TAKE ANOTHER LOOK
AT THE EVENT.

TEMPS ON SUNDAY NIGHT WILL CONTINUE TO SLOWLY RISE DURING THE
OVERNIGHT HOURS AS MOISTURE CONTINUES TO FLOW INTO THE AREA...HAVE
CONTINUED THE NON-DIURNAL TEMP CURVE WHICH THE PREVIOUS SHIFT HAD A
GOOD HANDLE ON. A GOOD CHANCE OF PRECIP WILL CONTINUE DURING THE
OVERNIGHT HOURS...BUT PRECIP BY EARLY MONDAY MORNING SHOULD BE ALL
RAIN EXCEPT PERHAPS THE FAR NORTHERN REACHES OF PERRY COUNTY OH AND
A FEW SHELTERED DEEP VALLEYS OF THE EASTERN MOUNTAINS. WILL ALSO
NEED TO CONTINUE TO MONITOR WATER AS WELL. WITH PRECIP RECEIVED FROM
THIS CURRENT ROUND...IT MAY NOT TAKE TOO TERRIBLY MUCH FOR FLOODING
WITH SUNDAY AND SUNDAY NIGHT/S ROUND.
-- End Changed Discussion --

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
REASONABLE MODEL AGREEMENT WITH THE LAST IN A SERIES OF LOW PRESSURE
SYSTEMS TO AFFECT OUR AREA THIS PERIOD. LOW CENTER LIFTS NORTH JUST
TO THE WEST OF OUR AREA MONDAY...BEFORE SWEEPING A COLD FRONT THRU
MONDAY NIGHT AND ENDING PRECIPITATION. AHEAD OF THE LOW...STUBBORN
COLD AIR DAMMING IS NOTED ON THE MODELS ON EAST FACING SLOPES OF THE
WEST VIRGINIAN MOUNTAINS...WITH A GOOD WARM SURGE WEST OF THE
MOUNTAINS SUNDAY NIGHT AND MONDAY. THUS...EXPECT A PERIOD OF
FREEZING RAIN ON EAST FACING SLOPES BEFORE CHANGING TO ALL RAIN
MONDAY MORNING. ELSEWHERE...RAIN. AMOUNT OF QPF LOOKS TO BE POSSIBLY
HEAVY...AND WILL HAVE TO WATCH WATER PROBLEMS CLOSELY IN ADDITION TO
CURRENT RAINFALL EVENTS. WITH STRONG ANTICYCLONIC CURVATURE IN THE
SURFACE HIGH BUILDING IN BEHIND THE SYSTEM MONDAY NIGHT...POST
FRONTAL SNOW SHOWERS DO NOT LOOK AS POTENT AND LONG LIVED AS ONE
WOULD THINK IN THE COLD ADVECTION UPSLOPE FLOW. THUS...MINOR SNOW
ACCUMULATIONS EXPECTED. HIGH PRESSURE BUILDS IN TUESDAY THRU
THURSDAY WITH DRY AND COLD WEATHER.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
A COLD FRONT SLOWS DOWNS JUST SOUTH OF THE AREA OVERNIGHT AND
FRIDAY. CEILINGS AND VISIBILITY WILL BOUNCE BETWEEN MVFR TO IFR
OVERNIGHT UNDER AREAS OF RAIN ACROSS MOST OF SITES. IFR/LIFR
CONDITIONS POSSIBLE AT EKN..AND BKW OVERNIGHT THROUGH AT LEAST
14Z. CEILINGS WILL REMAIN LOW AS SUGGESTED BY HIGH PROBABILITIES
FOR CEILINGS LOWER THAN 1000 FEET.

IT IS STILL UNCERTAIN HOW LONG THE LOW CLOUD DECK WILL PERSIST
FRIDAY MORNING. SUSPECT LOW CEILINGS WILL LINGER THROUGH AT LEAST
15Z OR LONGER OVER AREAS THAT RECEIVED RAIN.

CONDITIONS COULD IMPROVE ACROSS THE WESTERN SLOPES AND EASTERN
MOUNTAINS ON FRIDAY...BUT LOW CEILINGS AND VISIBILITIES WILL
DETERIORATE ONCE AGAIN FROM NORTHWEST TO SOUTHEAST AS A SECOND
UPPER LEVEL WAVE APPROACHES FRIDAY NIGHT.

THIS WILL PULL THE FRONT BACK NWD...CROSSING BKW AGAIN AS A WARM
FRONT EARLY FRI AFTERNOON. WHILE THERE MAY BE BREAKS IN THE RAIN
BETWEEN WAVES...THESE BREAKS WILL NEITHER BE LONG NOR SIGNIFICANT.

SFC FLOW WILL BE PREDOMINANTLY NW OVERNIGHT ONCE THE FRONT CROSSES
THE MOUNTAINS...AND THEN N ON FRI...VEERING IN THE MOUNTAINS MIDDAY
FRI AND THEN SHIFTING TO SW AND BECOMING GUSTY SOUTHERN WV MOUNTAINS
EARLY FRI AFTERNOON AS THE FRONT PUSHES BACK N AS A WARM FRONT AHEAD
OF THE WAVE OF LOW PRESSURE.  MODERATE SW FLOW ALOFT WILL BECOME
LIGHT W TO NW AS FAR E AS THE OHIO RIVER OVERNIGHT AND REMAIN SO
THROUGH FRI.

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

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: TIMING OF IFR CONDITIONS MAY VARY...AND BE MORE
PREVALENT THEN FCST.

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 12/06/13
UTC 1HRLY       08   09   10   11   12   13   14   15   16   17   18   19
EST 1HRLY       03   04   05   06   07   08   09   10   11   12   13   14
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    M    M
EKN CONSISTENCY  M    M    H    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    M    H    H    H    H    H    H    H    M    M    M
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 06Z SATURDAY...
IFR POSSIBLE RAIN OR SNOW/SLEET FRIDAY NIGHT. IFR POSSIBLE AGAIN
SUNDAY AND MONDAY.

&&

.HYDROLOGY...
SIGNIFICANT RISES ARE EXPECTED ON RIVERS IN RESPONSE TO
ONGOING...PROLONGED RAIN WHICH IS EXPECTED TO LAST THROUGH FRIDAY.
RIVERS THAT ARE ESPECIALLY VULNERABLE INCLUDE...BUT ARE NOT LIMITED
TO -- THE LITTLE SANDY INCLUDING GRAYSON...THE WEST FORK INCLUDING
CLARKSBURG...THE LITTLE KANAWHA...MUD...POCATALICO... TYGART
VALLEY...AND SYMMES CREEK. RISES ARE ALSO EXPECTED ON SMALL CREEKS
AND STREAMS THAT DRAIN INTO THESE LARGER...MAIN STEM WATERWAYS.

ANOTHER WET SYSTEM WILL EFFECT THE REGION ON SUNDAY AND MONDAY. WITH
THE RIVERS ALREADY RUNNING HIGH FROM THE CURRENT EVENT...THE
THREAT OF RIVER FLOODING REMAINS...AND EVEN INCREASES.|

&&

.EQUIPMENT...
AUTOMATIC OBSERVATIONS REMAIN UNAVAILABLE FOR PARKERSBURG DUE TO AN
EQUIPMENT FAILURE. PARTS ARE IN SHIPMENT.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH THROUGH SATURDAY MORNING FOR WVZ005>011-013>020-
     024>032-039-040.
OH...FLOOD WATCH THROUGH SATURDAY MORNING FOR OHZ066-067-075-076-
     083>087.
     WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 1 AM EST
     SATURDAY FOR OHZ067-075-076-084.
     WINTER STORM WARNING FROM 7 AM THIS MORNING TO 1 AM EST
     SATURDAY FOR OHZ066.
KY...FLOOD WATCH THROUGH SATURDAY MORNING FOR KYZ101>103-105.
VA...NONE.

&&

$$
SYNOPSIS...JMV/MZ/JM
NEAR TERM...ARJ
SHORT TERM...50
LONG TERM...JMV
AVIATION...ARJ