Area Forecast Discussion
Issued by NWS Charleston, WV

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000
FXUS61 KRLX 290542
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
1215 AM EST THU JAN 29 2015

.SYNOPSIS...
HIGH PRESSURE EXITS EAST OVERNIGHT. LOW PRESSURE DRAGS A COLD FRONT
THROUGH LATE THURSDAY INTO THURSDAY EVENING.  UPSLOPE SNOW THURSDAY
NIGHT INTO FRIDAY NORTHEAST MOUNTAINS.  HIGH PRESSURE SATURDAY.

&&

.NEAR TERM /THROUGH TODAY/...
915 PM UPDATE...
A THINNER OVERCAST THAN PREVIOUSLY EXPECTED IS/WILL ALLOW
TEMPERATURES TO GET LOWER OVERNIGHT...USED MOSTLY THE LAV AND
CURRENT TRENDS TO MAKE ADJUSTMENTS.

THESE SMALL DOWNWARD ADJUSTMENTS IN THE MIDDLE OHIO VALLEY INTO THU
MORNING...AND MAINTAINING THE ARRIVAL OF PRECIPITATION BY MID
MORNING...IS JUST ENOUGH TO WARRANT A FREEZING RAIN ADVISORY FOR
PERRY AND MORGAN COUNTIES IN SE OHIO.  THE 21Z SREF ALSO NOW SHOWS
THIS POTENTIAL STARTING TO EDGE INTO THESE COUNTIES.

THANKS TO PBZ AND ILN FOR COORD ON THIS.

700 PM UPDATE...
FCST ON TRACK BUT WITH ONSET OF PRECIPITATION MEASURABLE OR NOT VERY
CLOSE TO WHEN TEMPERATURES CLIMB ABOVE FREEZING IN SE OHIO AFTER
DAYBREAK THU MORNING.  THE 15Z SREF SUGGESTS THE FREEZING RAIN
SCOOTS JUST TO THE NW OF PERRY CO.

PREV DISCN...
STRATUS DECK FINALLY BREAKING UP ACROSS THE WESTERN SLOPES...BUT
STILL A CHILLY DAY. HIGH CLOUDS BEGIN INCREASING LATE TODAY AND
TONIGHT IN ADVANCE OF LOW PRESSURE MOVING THROUGH THE PLAINS. HAVE
WARM FRONT MOVING THROUGH THURSDAY. INITIALLY...LOW LEVELS ARE
VERY DRY SO ANTICIPATE LOTS OF VIRGA TO START. WITH THE DRY LOW
LEVELS...WILL ALSO SEE SOME WET BULBING AND IN NW PART OF CWA
COULD SEE BRIEF SLEET AT THE ONSET OF PRECIP. HAVE A SMALL AMOUNT
OF FREEZING RAIN IN PERRY AND MORGAN COUNTIES...BUT WITH THE WET
BULBING THIS COULD JUST AS EASILY BE SLEET. ACROSS THE
LOWLANDS...ANY PRECIP WILL CHANGE TO RAIN BY MID MORNING.
SNOW/SLEET WILL LINGER AT THE HIGHEST ELEVATIONS OF THE WV MOUNTAINS
THROUGH MUCH OF THE DAY...WITH SOME LIGHT ACCUMULATIONS. SLOWED DOWN
ONSET OF PRECIPITATION WHEN COMPARED TO PREVIOUS FORECAST AS NEW GFS
AND NAM ARE BOTH SLOWER. DID NOT GO QUITE AS SLOW AS THE MODELS AS
WARM AIR ADVECTION PRECIP OFTEN SEEMS TO ARRIVE SOONER THAN EXPECTED.

AS WARM AIR ADVECTION BEGINS ALOFT TONIGHT...HAVE NON DIURNAL
TREND FOR HIGHER ELEVATIONS. EVEN BEGIN WARMING SOME PRE-DAWN IN
SE OHIO AS 925MB TEMPS CLIMB TO AROUND 5C IN KHTS AREA BY 09Z. IT
MAY TAKE A LITTLE WHILE FOR THE INVERSION TO BREAK...SO TIMING OF
THE WARM-UP IS UNCERTAIN...BUT IT SHOULD BE QUICK ONCE IT HAPPENS.
SPENDING MUCH OF THE DAY IN THE WARM SECTOR WILL PROVIDE A NICE
WARM-UP WITH TEMPS INTO THE 40S ACROSS THE LOWLANDS...AND EVEN
ABOVE FREEZING FOR MANY MOUNTAIN LOCATIONS.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...
WILL SEE A GRADUAL CHANGE OVER TO SNOW THURSDAY NIGHT AS COLDER
AIR RUSHES INTO THE REGION AS CLIPPER TYPE SYSTEM MOVES THROUGH
THE AREA. ALONG WITH THE COLDER AIR...WILL SEE A GRADUAL LOSS OF
MOISTURE...SO ONLY EXPECTING LIGHT ACCUMULATIONS ACROSS THE
LOWLANDS...WITH BETTER SNOWFALL ACCUMULATIONS IN FAVORED UPSLOPE
AREAS...ESPECIALLY AS SNOW RATIOS INCREASE IN THE COLDER AIR.
STILL FIGURING ON SEVERAL INCHES OF ACCUMULATIONS ACROSS THE
NORTHERN MOUNTAIN ZONES...BUT AT THIS POINT...AM NOT GETTING
ADVISORY CRITERIA. HOWEVER...WILL MAINTAIN THE MENTION IN THE HWO
IN CASE THE FORECAST CHANGES.

TEMPERATURES WILL FALL THROUGHOUT THE DAY ON FRIDAY. IN
ADDITION...GUSTY WINDS WILL DEVELOP...CREATING WIND CHILLS IN THE
SINGLE DIGITS TO TEENS. RANDOLPH AND POCAHONTAS COUNTIES WILL SEE
WIND CHILL ADVISORY CRITERIA ALONG RIDGE TOPS...BUT AT THIS
POINT...DO NOT SEE COUNTY AVERAGE.

&&

.LONG TERM /SATURDAY 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 /06Z THURSDAY THROUGH MONDAY/...
CLOUDS WILL BE LOWERING THIS MORNING BUT SHOULD SHOULD REMAIN VFR. A
BAND OF SHOWERS WILL MOVE ACROSS THE AREA FROM LATE MORNING TO MID
AFTERNOON. RESTRICTIONS WITH THIS BAND ARE EXPECTED TO BE VFR OR
BRIEFLY MVFR.

A COLD FRONT WILL THEN MOVE THROUGH THIS AFTERNOON AND EVENING. MVFR
RESTRICTIONS IN CLOUDS CAN BE EXPECTED ALONG AND BEHIND THE COLD
FRONT. AS COLDER AIR MOVES IN THURSDAY NIGHT...SNOW WILL DEVELOP
CAUSING SIGNIFICANT RESTRICTIONS IN VISIBILITIES AND CEILINGS.

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

FORECAST CONFIDENCE: HIGH.

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.

DATE                                   THU 01/29/15
UTC 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
EST 1HRLY       01   02   03   04   05   06   07   08   09   10   11   12
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  H    H    H    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 06Z FRIDAY...
IFR CONDITIONS POSSIBLE LATE THURSDAY NIGHT ACROSS THE ENTIRE REGION
AND THEN IN THE MOUNTAIN COUNTIES ON FRIDAY MORNING IN SNOW.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...FREEZING RAIN ADVISORY FROM 8 AM THIS MORNING TO NOON EST
     TODAY FOR OHZ066-067.
KY...NONE.
VA...NONE.

&&

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









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