-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 312057
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
339 PM EST SAT JAN 31 2015

.SYNOPSIS...
-- Changed Discussion --
WARM ADVECTION PRECIP EARLY SUNDAY. LOW PRESSURE SYSTEM PASSES NORTH
OF THE AREA LATE SUNDAY NIGHT. MUCH COLDER AIR BLOWS IN ON MONDAY.
HIGH PRESSURE BUILDS IN MONDAY NIGHT INTO TUESDAY.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH SUNDAY/...
MODELS CONTINUE TO STAY WITH THE CURRENT WARM WEDGE SOLUTION OVER
MUCH OF CWA. GENERALLY USED A BLEND OF SREF AND GFS FOR POPS. ONLY
REAL SIGNIFICANT CHANGE WAS TO INCLUDE A DRY SLOT ACROSS MUCH OF THE
CWA FOR SUNDAY.

HAVE WARM ADVECTION PRECIP MOVING IN PRE-DAWN SUNDAY MORNING.
TEMPS...AND THUS PRECIP TYPE FOR THIS TIME ARE A LITTLE TRICKY...AND
HINGE ON HOW QUICKLY THE CLOUDS THICKEN UP AND STOP A RADIATIVE
COOLING TONIGHT. ON TOP OF THAT...DRY AIR MAY WET BULB SOME. ENDED
UP WITH A FAIRLY BRIEF PERIOD OF WINTRY MIX ACROSS SOUTHWESTERN AND
WESTERN ZONES...WITH SNOW FARTHER NORTH. WILL MENTION POTENTIAL OF
VERY LIGHT ICING IN HWO. THIS IS NOT REALLY A SITUATION LIKE LAST
FREEZING RAIN EVENT EARLIER THIS WEEK WHERE TEMPS SURGED INTO THE
UPPER 30S WITH ROADS STILL BELOW FREEZING. ROAD SURFACES TODAY
SHOULD BE RELATIVELY WARM DUE TO SUNSHINE...AND SHOULD NOT GET AS
COLD OVERNIGHT AS CLOUDS MOVE IN. STILL...CAN ENVISION SOME PATCHY
SLICK SPOTS EARLY SUNDAY MORNING. FARTHER NORTH...IT SHOULD BE
MAINLY SNOW POSSIBLY MIXED WITH SOME SLEET THROUGH MID MORNING.
850MB TEMPS CONTINUE TO WARM SUNDAY...AND HAVE RAIN ACROSS ENTIRE
FORECAST AREA BY MID AFTERNOON...EXCEPT FOR JUST A COUPLE OF THE
HIGHEST SPOTS IN THE NORTHERN MOUNTAINS. WITH THE DRY SLOT...AND
SOME DOWNSLOPE COMPONENT TO THE WIND...REDUCED CLOUD COVER IN
EASTERN LOWLANDS...AND BOOSTED AFTERNOON HIGHS ROUGHLY 5 DEGREES
OVER PREVIOUS FORECAST FOR THIS SAME AREA.

IN COORDINATION WITH SHORT TERM FORECASTER...GOING WITH A WINTER
WEATHER ADVISORY FOR PERRY AND MORGAN COUNTIES IN OHIO WITH 1-3
INCHES OF SNOW SUNDAY MORNING AND THEN ALSO COVERING THE SNOW THAT
FALLS SUNDAY NIGHT INTO MONDAY. WILL ALSO CONTINUE THE BUFFER ZONE
AROUND THE ADVISORY CURRENTLY IN THE HWO...ALLOWING FOR SOME SHIFT
IN LOW TRACK AND INHERENT THERMAL PROFILE CHANGES.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
LOW PRESSURE STARTING TO MOVE THROUGH OHIO VALLEY REGION AT THE
START OF THE SHORT TERM PERIOD. BASED ON THE NORTHERN PATH OF THE
LOW...WILL SEE A WARM SURGE OF AIR ACROSS THE AREA...WITH THE BULK
OF PRECIPITATION STARTING OUT AS RAIN ACROSS THE AREA. THE LOW WILL
GRADUALLY MOVE OFF TO THE NORTH AND EAST OF THE AREA LATE SUNDAY
NIGHT/EARLY MONDAY...WITH MUCH COLDER AIR RUSHING INTO THE AREA
BEHIND THE LOW...WITH A GRADUAL CHANGE OVER FROM RAIN...TO SNOW.
SOUTHEAST OHIO WILL SEE A CHANGE OVER FIRST...WITH CHANGE OVER FROM
RAIN TO SNOW GENERALLY AFTER 2 AM. MUCH OF THE WEST VIRGINIA
LOWLANDS WONT START TO SEE A CHANGE OVER TO SNOW UNTIL AFTER DAWN ON
MONDAY. AS THE COLDER AIR IS FINALLY ABLE TO WORK ITS WAY IN ENOUGH
FOR A CHANGE OVER TO SNOW...THE BULK OF MOISTURE WILL GRADUALLY EXIT
WITH THE EXIT OF THE LOW TO THE EAST. AS A RESULT...FIGURING ONLY
LIGHT ACCUMULATIONS FOR MUCH OF THE AREA...WITH GENERALLY 2 TO 4
INCHES POSSIBLE ACROSS PERRY COUNTY....WITH 1 TO 3 IN MORGAN
COUNTY...AND AROUND AN INCH FOR THE REMAINDER OF SOUTHEAST OHIO.
EXPECT MUCH OF THE WEST VIRGINIA LOWLANDS TO RECEIVE AROUND AN INCH
OR LESS...EXCEPT NORTHERN WEST VIRGINIA LOWLAND COUNTIES SUCH AS
CLARKSBURG AREA...WHERE A GOOD INCH OR TWO IS POSSIBLE. MOUNTAINOUS
COUNTIES COULD EASILY GET 2 TO 4 INCHES...WITH ADDITIONAL
ACCUMULATIONS POSSIBLE ON NW FACING SLOPES. THE SNOW WILL TRANSITION
FROM A HEAVY WET SNOW...TO A LIGHTER FLUFFIER SNOW AS THE DAY
PROGRESSES ON MONDAY AS 850MB -16C AIR RUSHES INTO THE REGION. THIS
SHOULD ALLOW FOR ACCUMULATIONS IN THE HIGHER TERRAIN COUNTIES IN
LINGERING UPSLOPE FLOW.

WE WILL ISSUE A WINTER WEATHER ADVISORY FOR PERRY AND MORGAN
COUNTIES THROUGH MONDAY MORNING. WILL KEEP AN EYE ON THE POTENTIAL
FOR MOUNTAINOUS COUNTIES.

HIGH PRESSURE WILL BUILD IN FOR TUESDAY...WITH DRY CONDITIONS...AND
MODERATING TEMPERATURES.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
-- Changed Discussion --
BROAD EASTERN MID/UPPER LEVEL TROF WITH FAST FLOW...AND FEW
OPPORTUNITIES TO ACCESS THE GULF OF MEXICO MOISTURE.

WEAK WARM AIR ADVECTION ONGOING TUESDAY NIGHT...WILL TRY TO BRING
SOME 20/30 POPS A BIT FASTER SOUTH BY DAWN WEDNESDAY INTO OUR
NORTHERN COUNTIES.

12Z GFS A BIT MORE AGGRESSIVE WITH THE MOISTURE  MOVING UP THE OHIO
VALLEY WEDNESDAY ALONG THAT FRONTAL BOUNDARY. ECMWF CERTAINLY NOT AS
MOIST. FOR NOW...WILL KEEP POPS IN CHANCE CATEGORY WITH FRONT
WEDNESDAY INTO WEDNESDAY NIGHT.

HAVE COLDER AIR BLOWING SOUTH AGAIN OVERNIGHT WEDNESDAY NIGHT INTO
THURSDAY.  WENT COLDER THAN OUR PREVIOUS FORECAST.

DRYING AGAIN THURSDAY NIGHT THRU FRIDAY NIGHT.

IN THE FAST FLOW...NEXT SYSTEM COULD ARRIVE BY LATE DAY 7.
-- End Changed Discussion --

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
VFR CONDITIONS WITH LIGHT WIND TODAY AS HIGH PRESSURE CROSSES. LOW
PRESSURE APPROACHES LATE TONIGHT...WITH WARM FRONT BRINGING LOWER
CLOUDS BY PRE-DAWN AND IS POSSIBLE ALONG AND NORTH OF I-64. BEST
CHANCE OF IFR WITH THIS SNOW WILL BE AT NORTHERN TAF SITES DURING
THE EARLY TO MID MORNING. PRECIP CHANGES TO RAIN FROM SOUTH TO
NORTH THROUGH THE MORNING. CANNOT RULE OUT PATCHES OF FREEZING
RAIN EARLY ON...MAINLY IN SOUTHEAST OHIO.

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

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIO: TIMING OF DROPS IN FLIGHT 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       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  M    M    H    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  M    M    H    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  M    M    H    H    H    H    H    H    H    H    H    H

AFTER 18Z SUNDAY...
IFR CONDITIONS POSSIBLE IN SNOW SUNDAY NIGHT...LINGERING IN THE
MOUNTAINS MONDAY.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...WINTER WEATHER ADVISORY FROM 1 AM SUNDAY TO 10 AM EST MONDAY
     FOR OHZ066-067.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...MZ/SL
NEAR TERM...MZ
SHORT TERM...SL
LONG TERM...KTB
AVIATION...MZ