-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 291721
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
1221 PM EST THU JAN 29 2015

.SYNOPSIS...
A MOISTURE STARVED WARM FRONT MOVES THROUGH TODAY. A COLD FRONT
ARRIVES THIS AFTERNOON AND EVENING. UPSLOPE SNOW TONIGHT INTO
FRIDAY. HIGH PRESSURE SATURDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
915 AM UPDATE...WARM FRONT AND CONNECTED LIGHT RAIN NEAR THE OHIO
RIVER AS OF 9 AM. AIR TEMPS ARE SURGING INTO THE UPPER 30S AND 40S
JUST AHEAD OF THE PRECIP...HOWEVER STILL GETTING SOME REPORTS OF
ICY CONDITIONS AS ROAD SURFACE TEMPS ARE SLOWER TO RESPOND. WITH
SOME WET BULBING ALOFT...ALSO EXPECT SLEET MIXING IN ACROSS
NORTHERN HALF OF CWA THROUGH MID MORNING. WILL CONTINUE WITH
CURRENT FREEZING RAIN ADVISORY...AND GO WITH SPECIAL WEATHER
STATEMENTS OUTSIDE OF THAT AREA DETAILING POTENTIAL FOR BRIEF
PERIOD OF FREEZING RAIN.

PREVIOUS DISCUSSION...
MODELS SHOWING A BAND OF LIGHT PRECIPITATION MOVING ACROSS THE
REGION TODAY. THIS BAND WILL ARRIVE THIS MORNING IN PORTIONS OF
SOUTHEAST OHIO WHERE TEMPERATURES WILL BE VERY CLOSE TO FREEZING.
WITH ROAD SURFACE TEMPERATURES READING IN THE MID 20S...SOME
FREEZING RAIN COULD OCCUR EVEN IT READINGS ARE SLIGHTLY ABOVE
FREEZING. WILL EXPAND THE FREEZING RAIN ADVISORY TO INCLUDE VINTON
AND ATHENS COUNTIES. MES NAM SOUNDING ALSO SHOW SOME CONCERN FOR
BRIEF FREEZING RAIN/DRIZZLE IN POCAHONTAS COUNTY WHEN THIS BAND
ARRIVES EARLY THIS AFTERNOON. WILL HOLD OFF IN THIS AREA DUE TO
TIME OF DAY AND LIMITED DURATION...BUT WILL HAVE TO KEEP AND EYE
ON THE SITUATION.

A COLD FRONT MOVES THROUGH LATE THIS AFTERNOON AND EVENING...BRINGING
MUCH COLDER AIR. IT APPEARS THAT MOST PRECIPITATION WITH THE FRONT
WILL BE POST FRONTAL. RAIN SHOULD CHANGE OVER TO SNOW DURING THE
NIGHT AND START A DECENT UPSLOPE SNOW EVENT.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
BUSY MOPPING UP ONE STORM AND BRINGING IN ANOTHER ON THIS GRAVEYARD
SHIFT...

ITS ALL DOWNHILL AFTER 12Z FRIDAY...AS CAA ON GUSTY NW WINDS WILL
ALLOW FOR FALLING TEMPS THRU THE DAY. SO...HAVE HIGHS AT
12Z...GENERALLY IN THE MID 20S SE OH/N WV TO AROUND 30 SOUTH. TEMPS
WILL FALL AS THE DAY PROGRESSES...INTO THE LOW TO MID 20S OUTSIDE OF
THE MOUNTAINS...AND TEENS IN THE MOUNTAINS. WINDS WILL BE
GUSTY...ESPECIALLY OVER THE HIGH TERRAIN WHERE SOME 30 TO 35 KT
GUSTS WILL BE REALIZED. AS SUCH...WIND CHILLS WILL ALSO TAKE A HIT
BUT NOT EXPECTING CRITERIA TO BE MET OVER THE N MOUNTAINS.

AS FOR SNOW...DESPITE A SHRINKING MOISTURE COLUMN...CAA WILL ALLOW
FOR A COLDER CLOUD LAYER AS THE MORNING PROGRESSES. SOUNDINGS BEAR
THIS OUT WITH SHRINKING CLOUD LAYER COOLING TO -15 TO -20C IN THE
MORNING. THIS COMBINED WITH SOME LOW LEVEL INSTABILITY SHOULD ALLOW
FOR CONVECTIVE OVERTURNING SNOW SHOWERS ACROSS THE AREA. STREAMLINE
ANALYSIS SUGGEST SOME ENHANCEMENT FROM LAKE MICHIGAN EARLY ACROSS S
OH AND NE KY. MODELS ARE NOT EXCITED ABOUT QPF POTENTIAL
THOUGH...NONETHELESS...FELT PRUDENT IN GOING DETERMINISTICALLY HIGH
WITH POPS IN THE MORNING. WITH RATIOS QUICKLY DROPPING INTO THE -20
TO -25C RANGE...THE FLUFF FACTOR MAY PRODUCE SOME COATINGS TO ONE
INCHES OUTSIDE OF THE MOUNTAINS. ACROSS THE MOUNTAINS...HAVE
ANYWHERE FROM 2 TO 6 IN THE N MOUNTAINS /DEPENDENT ON ELEVATION/ TO
1 TO 2 FURTHER S DOWN THE MOUNTAIN CHAIN INTO SW VA. IT WILL BE
CLOSE AS TO WHETHER ANY 12HR PERIOD MEETS CRITERIA OVER THE N
MOUNTAINS. SINCE THERE WILL BE SOME BLOWING AND DRIFTING OF SNOW TO
COMPOUND THINGS...FELT BEST WAY TO GO WAS WITH AN ADVISORY WHICH
MATCHES WILL WITH SURROUNDING OFFICES.

THE MOISTURE COLUMN SHOULD BECOME SUFFICIENTLY SHALLOW ENOUGH TO
ALLOW A FAIR AMOUNT OF BREAKS IN THE CLOUDS ACROSS THE W AND S
ZONES. HARD TO SAY IF N MOUNTAINS CLEAR OUT FRIDAY NIGHT GIVEN THE
THERMAL TROF GETTING PINCHED OFF. DO THINK SOME CLEARING WILL WORK
ITS WAY THRU REMAINDER OF CWA WITH A COLD NIGHT IN STORE WITH WINDS
SLACKENING OUTSIDE OF THE MOUNTAINS AS A SURFACE HIGH BUILDS IN FROM
THE W. SATURDAY WILL FEATURE MORE STRATOCU ACROSS SE OH AND N
WV...WITH THE MOST SUN NE KY/S WV/SW VA. THERE WILL BE REBOUND IN
TEMPS WITH WAA BEGINNING TO TAKE SHAPE IN THE AFTERNOON. HAVE HIGHS
GENERALLY IN THE 30S...WITH SOME 20S IN THE N MOUNTAINS.

STORMS AND RUMORS OF STORMS CONTINUE FOR SUNDAY/MONDAY. THERE
CONTINUES TO BE VOLATILITY IN THE OPERATIONAL GLOBAL MODELS
REGARDING HOW MUCH PHASING OCCURS WITH N STREAM ENERGY AND ENERGY
EJECTING OUT OF SW CONUS. AS HPC NOTED...UNTIL THE N STREAM ENERGY
CAN GET INTO W CANADA...SUSPECT WAFFLING TO CONTINUE WITH JUST HOW
STRONG OF A WAVE/LOW PRESSURE THERE WILL BE. THE ENSEMBLES DONT
OFFER MUCH HELP WITH LARGE SPREADS OVER THE OH VALLEY ON THE GFS
ENSEMBLES. ALL OF THIS UNCERTAINTY RESULTED IN LITTLE CHANGE IN
PREVIOUS FORECAST EXCEPT TO GO A HAIR COOLER ACROSS THE AREA ON
SUNDAY. MAIN FEATURE FOR PRECIP SUNDAY WILL BE WARM FRONT DEVELOPING
OVER THE AREA WHICH WILL ULTIMATELY DETERMINE PRECIP TYPE. DO FEEL
THAT THERE IS ENOUGH CONFIDENCE TO PUT A BLANKET HWO OUT GIVEN THE
UPSLOPE SNOW POTENTIAL BEHIND THIS SYSTEM.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
THE MODELS SEEM TO BE AT A CROSS ROADS ON HOW TO HANDLE THE WEEKEND
SYSTEM. MODELS AGREE IN A PACIFIC SYSTEM CUTTING UNDER THE HIGH
AMPLITUDE WESTERN U.S. UPPER RIDGE AND CLOSING OFF OVER THE
SOUTHWESTERN STATES EARLY IN THE WEEKEND. THE BIG QUESTION IS HOW A
NORTHERN STREAM SHORT DROPPING OVER THIS WESTERN UPPER RIDGE
INTERACTS WITH THE SOUTHERN STREAM SYSTEM. THE LATEST MODEL RUNS
CONTINUE TO DIVERGE. THE 12Z GFS PUTS ALMOST ALL ITS EMPHASIS ON
LEAVING MOST OF THE SOUTHWESTERN UPPER LOW ENERGY IN PLACE AND
DRIVING THE NORTHERN STREAM SHORT WAVE AND COLD FRONT ACROSS THE
AREA SUNDAY. THE 12Z NAM THRU 84 HOURS HINTS AT THIS ALSO. THE 12Z
CMC STILL WANTS TO PHASE THE TWO STREAMS AND DRIVE A STRONG LOW UP
TOWARD THE GREAT LAKES SUNDAY. THE SREF AND 00Z UKMET/EURO ARE IN
BETWEEN THESE TWO SOLUTIONS. AT THIS POINT...IN COORDINATION WITH
WPC GRAPHICS...CHOSE TO ADJUST TO A SLIGHTLY MORE SOUTHERN
TRACK...WHICH STILL CARRIES A DECENT CHUNK OF SOUTHERN ENERGY JUST
OUT AHEAD OF THE NORTHERN STREAM SYSTEM. THIS SCENARIO HAS THE
SURFACE LOW MOVING ACROSS THE NORTHERN PART OF THE AREA ON
SUNDAY...THEN DRIVING A COLD FRONT RAPIDLY ACROSS THE AREA EARLY
SUNDAY NIGHT. SO...SENSIBLE WEATHER INCLUDES INITIALLY WINTRY
PRECIPITATION EARLY SUNDAY...THEN CHANGING TO RAIN DURING SUNDAY
CENTRAL AND SOUTH...AND KEEPING AT LEAST A MIX ACROSS SOUTHEAST OHIO
AND NORTHERN WEST VIRGINIA NEAR THE TRACK OF THE LOW...THEN RAPIDLY
CHANGING TO SNOW ALL AREAS EARLY SUNDAY NIGHT AS THE COLD AIR RUSHES
BACK IN. SNOW SHOWERS WILL CONTINUE INTO AT LEAST MONDAY MORNING
WITH A WRAPAROUND MOISTURE FIELD. SNOW SHOWERS THEN WIND DOWN FROM
WEST TO EAST DURING MONDAY AS HIGH PRESSURE BUILDS IN THRU MID WEEK.
THERE WILL LIKELY BE SOME SNOW ACCUMULATION ACROSS THE AREA SUNDAY
INTO MONDAY....ESPECIALLY IN THE MOUNTAINS. EXCEPT FOR THE BRIEF
WARMUP SUNDAY...TEMPERATURES WILL AVERAGE WELL BELOW NORMAL FOR THE
PERIOD.

&&

.AVIATION /17Z THURSDAY THROUGH MONDAY/...
BAND OF MAINLY RAIN SHOWERS MOVING INTO THE MOUNTAINS AS WARM
FRONT PASSES. HAVE SEEN MOSTLY VFR WITH THIS...ALTHOUGH COULD GET
SOME MVFR AT HIGHER ELEVATIONS OUTSIDE OF TAF SITES. WINDS
BEGINNING TO PICK UP IN THE WARM SECTOR...ALONG WITH THE CLOUDS
SCATTERING OUT FOR A BIT. COLD FRONT APPROACHES THIS EVENING
PASSING OVERNIGHT WITH RAIN CHANGING TO SNOW. HAVE MVFR TO IFR
WITH THE SNOW AND REMAINING FAIRLY WINDY. LOWER FLIGHT CONDITIONS
WILL STICK AROUND IN THE EASTERN LOWLANDS AND MOUNTAINS THROUGH
MUCH OF FRIDAY...BUT SHOULD SEE SOME IMPROVEMENTS ACROSS FAR WEST.

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

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIO: TIMING OF PRECIPITATION AND LOWER CLOUDS COULD
VARY.

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    M    H
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    H    H    H    H    H    H    M    M    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    H    H    M    M    H    H

AFTER 18Z FRIDAY...
IFR CONDITIONS MAY LINGER IN THE MOUNTAINS INTO FRIDAY NIGHT. IFR
CONDITIONS POSSIBLE SUNDAY INTO MONDAY WITH RAIN CHANGING TO SNOW.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 1 PM EST
     FRIDAY FOR WVZ038-046-047.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...RPY/JMV/30
NEAR TERM...RPY/MZ
SHORT TERM...30
LONG TERM...JMV
AVIATION...MZ