-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 261519
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
1019 AM EST MON JAN 26 2015

.SYNOPSIS...
LOW PRESSURE SYSTEM MOVES OFF TO THE EAST TODAY. COLDER AIR MOVES IN
LATE TODAY INTO TUESDAY.  HIGH PRESSURE WEDNESDAY.  LOW PRESSURE
THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
SNOW BAND HAS CROSSED THE OHIO RIVER INTO WEST VIRGINIA. REWORKING
THE TEMPERATURES BASED ON CURRENT TRENDS...AND LARGELY USING THE
RAP FOR THE NEXT FEW HOURS THROUGH 00Z. WILL BE WORKING ON SOME
FORECAST SNOW TOTALS AS WELL AS THIS TRANSITIONS TO AN UPSLOPE
EVENT LATER TODAY.

PREVIOUS DISCUSSION...
MODELS SHOWING COLD AIR GRADUALLY MOVING INTO THE REGION TODAY
CHANGING THE PRECIPITATION FROM RAIN TO SNOW. MODELS ARE ALSO
SHOWING SOME GOOD LIFT IN AN EASTWARD PROPAGATING BAND BEHIND THE
CHANGE OVER TO SNOW...ALLOWING FOR SOME LIGHT SNOW ACCUMULATIONS
TODAY...ESPECIALLY OVER CENTRAL AND NORTHERN PORTIONS OF THE
FORECAST AREA. WILL CONTINUE THE WINTER WEATHER ADVISORY FOR PERRY
COUNTY AS THAT AREA HAS ALREADY CHANGED TO SNOW AND SHOULD RECEIVE
THE MOST ACCUMULATIONS THIS MORNING.

LOW LEVEL COLD AIR MOVES IN LATE TODAY AND TONIGHT...CAUSING OVER
TURNING IN THE LOWER ATMOSPHERE. THIS COMBINED WITH UPSLOPE SHOULD
CREATE SOME LIGHT SNOW FOR MUCH OF THE AREA. WILL INCREASE POPS
SOME. THE COLDEST OF THIS AIR IS IN A LAYER THAT THE GFS SEEMS TO
NOT BE ABLE TO CAPTURE. WILL RELY ON THE MES NAM FOR LOW
TEMPERATURES TONIGHT.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
SNOW SHOWERS WILL CONTINUE ACROSS THE N LOWLANDS AND N MOUNTAINS
TUESDAY WITH A FETCH OFF LAKE ERIE AND CONTINUED CAA. THERE APPEARS
TO BE A SUBTLE SPOKE OF ENERGY DIVING ON THE BACK SIDE OF THE TROF
WHICH MAY ENHANCE THE SNOW SHOWERS AND EXPAND COVERAGE INTO THE C
LOWLANDS AND REMAINDER OF THE MOUNTAINS. HAVE A FEW INCHES CODED UP
IN THE HIGH TERRAIN WITH PERHAPS A DUSTING INTO S MOUNTAINS AND
PARTS OF THE LOWLANDS TUESDAY EVENING.

SURFACE HIGH BUILDS IN WEDNESDAY TO SHUT OFF THE SNOW SHOWERS. TRIED
TO HOLD ONTO SOME STRATUS ACROSS WV FOR AT LEAST FIRST HALF OF THE
DAY WITH SUBSIDENCE INVERSION DEVELOPING ATOP LINGERING LOW LEVEL
MOISTURE. WAA SHOULD SCATTER THIS OUT LATER IN THE AFTERNOON.

A QUICK MOVING CLIPPER TYPE SYSTEM WILL CROSS THURSDAY...WITH GOOD
AMOUNT OF WAA AHEAD OF IT FOR WEDNESDAY NIGHT. THIS WILL LIKELY
RESULT IN A NON DIURNAL TRACE...ESPECIALLY ACROSS THE RIDGES WHERE A
GOOD RIDGE/VALLEY SPLIT WILL EXIST. RIGHT NOW IT APPEARS THIS SYSTEM
WILL TRACK JUST N OF THE AREA RESULTING IN RAIN OUTSIDE OF THE
MOUNTAINS. THERE COULD BE A BRIEF WINTRY MIX AT THE ONSET ACROSS SE
OH AND N WV. PRECIP WILL CHANGE TO SNOW SHOWERS EVERYWHERE THURSDAY
EVENING.

FOR TEMPS...STAYED CLOSE TO THE NAM/MET GUIDANCE EARLY ON TO ACCOUNT
FOR THE BETTER RESOLUTION IN THE LOW LEVEL COLD AIR. THIS RESULTS IN
TUESDAY BEING RATHER COLD WITH MANY PLACES STRUGGLING TO MAKE IT TO
30 IN THE LOWLANDS. COLD TUESDAY NIGHT WITH TEENS LOWLANDS/SINGLE
DIGITS HIGH ELEVATIONS. TEMPS REBOUND ON WEDNESDAY INTO THE LOW TO
MID 30S. WITH AFOREMENTIONED WAA WEDNESDAY NIGHT...HAVE TEMPS RISING
OVERNIGHT AFTER A QUICK FALL WEDNESDAY EVENING. THURSDAY SHOULD MAKE
IT INTO THE 40S WITH SOME MID 40S S ZONES AND UP INTO FAVORED
DOWNSLOPING AREAS. THE MOUNTAINS SHOULD STAY IN THE 30S.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
PERIOD STARTS WITH HIGH PRESSURE OVERHEAD...THAT ALMOST IMMEDIATELY
GIVES WAY TO A LOW PRESSURE SYSTEM APPROACHING FROM THE W.  MODELS
ARE GENERALLY A BIT FASTER WITH THIS SYSTEM...SO PRECIPITATION COULD
REACH WRN PORTIONS OF THE FCST AREA AROUND DAWN THU.  THIS THEN
SPREADS E ACROSS THE AREA THU...FOLLOWED BY UPSLOPE PRECIPITATION IN
THE WAKE OF THE SYSTEM THU NT INTO FRI.

WITH THE LOW CENTER TRACKING OF THE AREA...ENOUGH WARM AIR SHOULD
ARRIVE FOR A MAINLY WET...NOT WHITE OR ICY...THU.  HOWEVER...MIXED
PRECIPITATION INCLUDING FREEZING RAIN COULD OCCUR AT THE BEGINNING
IF PRECIPITATION IS ABLE TO RUSH IN BEFORE SFC TEMPERATURES CLIMB
ABOVE FREEZING THU MORNING.  HOWEVER...GIVEN MOST OF THE AREA WILL
BE IN THE WARM SECTOR AHEAD OF A COLD FRONT THAT DOES NOT ARRIVE
UNTIL EVENING...MOST OF THE PRECIPITATION SHOULD OCCUR IN THE
AFTERNOON AND THEREFORE BE OF THE WET VARIETY.

COLDER AIR COMING IN BEHIND THE SYSTEM CHANGES THE RAIN TO SNOW
SHOWERS BUT THEN QUICKLY CUTS OFF THE PRECIPITATION FROM THE W AS
THE DRIER AIR MOVES IN.  UPSLOPE SNOW SHOWERS DIMINISH ON FRI...AS
HIGH PRESSURE BUILDS IN FROM THE W...CUTTING OFF THE MOISTURE AND
UPSLOPE FLOW.  THIS SHOULD LEAD TO GOOD RADIATIVE COOLING FRI NT.

ANOTHER SYSTEM AFFECTS THE AREA NEXT WEEKEND.  THE MODELS REMAIN
DIVERSE ON THE NATURE AND EVOLUTION OF THIS SYSTEM...BUT NONE
ADVERTISE ANYTHING MAJOR...AND ALL SHOW THAT THE OVERALL COLD THEME
IN A POSITIVE PNA CONTINUES.  THUS HAVE THE CHANCE FOR LIGHT SNOW
SHOWERS.

AT OR VERY CLOSE TO WPC VALUES FOR TEMPERATURES...THEY LOOKED LIKE A
VERY REASONABLE COMPROMISE BETWEEN THE INORDINATELY COLD AND DRY
ECMWFHIRES...AND THE GFS BASED GUIDANCE...WHICH SEEMED TOO HIGH
GIVEN ITS MASS FIELD SOLNS.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
A LOW PRESSURE SYSTEM WILL BE MOVING EASTWARD OUT OF THE REGION
TODAY. LOW CEILINGS AND FOG CAN BE EXPECTED NORTH AND WEST OF THE
LOW CENTER. AS COLDER AIR MOVES IN BEHIND THE LOW TODAY...RAIN WILL
TRANSITION OVER TO SNOW. A BAND OF IFR/LIFR SNOW MAY POSSIBLY MOVE
WEST TO EAST ACROSS THE REGION.

THE COLDER AIR WILL ALSO START OVER TURNING THE LOWER ATMOSPHERE
LATE TODAY. THIS WILL LEAD TO A STRATUS DECK AND SNOW...WITH THE
LOWEST RESTRICTIONS IN THE MOUNTAINS. THE SNOW WILL CONTINUE MONDAY
NIGHT...WITH SOME IMPROVEMENT LATE IN THE NIGHT IN SOUTHERN
WV...VA...KY...AND OH.

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

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIO: TIMING OF DETERIORATING CONDITIONS MAY 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    M    H    H    H    H    H    H    M    H    H
HTS CONSISTENCY  M    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  M    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  M    M    H    H    H    H    M    M    H    H    H    H
PKB CONSISTENCY  M    M    H    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 12Z TUESDAY...
IFR POSSIBLE IN SNOW TUESDAY IN THE NORTHERN AND CENTRAL WV
MOUNTAINS.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR OHZ066.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...RPY/26
SHORT TERM...30
LONG TERM...TRM
AVIATION...RPY