078
FXUS61 KRLX 201123
AFDRLX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
623 AM EST FRI DEC 20 2024
SYNOPSIS
QUICK HITTING CLIPPER WITH RAIN/SNOW TODAY, UPSLOPE SNOW
CONTINUING TONIGHT INTO SATURDAY. TURNING DRY SUNDAY AND
MONDAY. NEXT RAIN CHANCES ARRIVE TUESDAY THROUGH THURSDAY.
NEAR TERM /THROUGH TONIGHT/
AS OF 620 AM FRIDAY...
NO SIGNIFICANT CHANGES NEEDED AT THIS TIME. INITIAL SHORTWAVE
CROSSING EARLY THIS MORNING HAS SQUEEZED OUT SOME FLURRIES ACROSS
THE LOWLANDS AND LIGHT SNOW IN THE MOUNTAINS. THESE WILL EXIT OVER
THE NEXT COUPLE HOURS WITH MAINLY DRY CONDITIONS THROUGH LATE THIS
MORNING. DID WET BULB DOWN TEMPERATURES A BIT OVER THE PREVIOUS
FORECAST WITH A BIT MORE RAIN/SNOW MIX THAN ALL RAIN ACROSS THE
LOWER ELEVATIONS THIS AFTERNOON.
AS OF 230 AM FRIDAY...
ASCENT ASSOCIATED WITH AN APPROACHING MID-LEVEL WAVE (CURRENTLY
SPAWNING SOME VIRGA OVER SE OH) WILL MOVE ATOP AN INVERTED SURFACE
TROUGH NEAR THE MOUNTAINS EARLY THIS MORNING. THIS IS EXPECTED TO
PRODUCE A BRIEF BURST OF SNOW (OR PERHAPS SOME VERY PATCHY
FREEZING DRIZZLE WHERE CLOUD ICE COULD BE LOST) IN THE VICINITY
OF THE NORTHEAST MOUNTAINS JUST BEFORE DAYBREAK.
OTHERWISE, MAINLY PRECIPITATION FREE THROUGH LATE MORNING WHEN A
QUICK HITTING CLIPPER SYSTEM MOVES THROUGH THE REGION FROM WEST TO
EAST. WETBULB TEMPERATURES GENERALLY ABOVE FREEZING SHOULD YIELD A
MAINLY RAIN OR RAIN SNOW MIX ACROSS MUCH THE LOWER ELEVATIONS WITH
THIS ACTIVITY THROUGH LATE THIS AFTERNOON, WITH A BIT MORE SNOW
MIXED IN ACROSS THE SOUTHERN COALFIELDS WHERE DEW POINTS ARE
MARGINALLY LOWER. WITH CRITICAL THICKNESS LEVELS ALL GENERALLY SOUTH
OF US AFTER ONSET OF SYNOPTIC PRECIPITATION, WOULD EXPECT ONLY
A RAIN OR SNOW EVENT.
ALL ELEVATIONS SHOULD TRANSITION OVER TO SNOW BY EARLY THIS EVENING
AS THE SYNOPTIC PORTION OF THIS EVENT EXITS EAST. SNOWFALL AMOUNTS
FOR THE THE CLIPPER ITSELF GENERALLY NOTHING TO TRACE ACROSS THE
NORTHERN LOWLANDS, A DUSTING TO AN INCH OR TWO ACROSS THE SOUTHERN
COALFIELDS AND ONE TO THREE INCHES IN THE MOUNTAINS. AS
NORTHWESTERLY FLOW BECOMES ESTABLISHED TONIGHT, ADDITIONAL
LAKE/UPSLOPE ENHANCED SNOW SHOWERS ARE EXPECTED TO CONTINUE WITH
PERHAPS AN ADDITIONAL DUSTING ACROSS THE NORTHERN LOWLANDS, TRACE TO
1 INCH ACROSS THE SOUTHERN COALFIELDS AND A COUPLE INCHES IN THE
MOUNTAINS.
EXISTING WINTER WEATHER HIGHLIGHTS APPEAR REASONABLE, PERHAPS A
LITTLE UNDER TRADITIONAL CRITERIA OUTSIDE OF THE MOUNTAINS; NO
CHANGES ARE PLANNED AT THIS TIME.
SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/
AS OF 115 AM FRIDAY...
A LOW PRESSURE SYSTEM ON ITS WAY OUT WILL PROVIDE ADDITIONAL
ACCUMULATIONS IN THE AMOUNT OF UP TO HALF AN INCH ALONG THE
HIGHER ELEVATIONS AND ALONG THE MOUNTAINS THROUGH SATURDAY
AFTERNOON ALONG WITH SOME GUSTY CONDITIONS OF 25-35MPH INTO THE
EVENING. HIGH PRESSURE THEN BUILDS IN TO GIVE THE AREA A BREAK
BUT THIS HIGH PRESSURE SYSTEM WILL BE TRAILING OFF TOWARD THE
EAST BY MONDAY.
UPON EXITING, THE AFOREMENTIONED LOW PRESSURE SYSTEM WILL BE
FOLLOWED BY VERY COLD AIR WITH TEMPERATURES AROUND -8C AT 850MB.
THIS WILL TRANSLATE TO MUCH LOWER THAN SEASONABLE TEMPERATURES
FOR THE OVERNIGHT LOWS INTO SUNDAY MORNING. FOR SUNDAY, MOST
LOCATIONS WILL STRUGGLE TO BREACH THE FREEZING MARK WITH
OVERNIGHT LOWS MUCH LOWER THAN SEASONABLE AS WELL.
LONG TERM /TUESDAY THROUGH THURSDAY/
AS OF 115 AM FRIDAY...
BY TUESDAY, FLEETING HIGH PRESSURE ALLOWS ANOTHER CLIPPER TYPE
SYSTEM TO RACE PAST THE AREA TOWARD THE NORTH. LOOKS LIKE THIS
FEATURE LOSES ITS ENERGY FAIRLY QUICKLY AND MAY NOT EVEN PROVIDE
PRECIPITATION ACROSS OUR NORTHERN PERIPHERY.
WE ALSO HAVE A WARM FRONT LIFTING ACROSS THE AREA FROM SOUTH TO
NORTH COURTESY OF A SYSTEM OUT WEST. THIS FEATURE MAY PROVIDE
PRECIPITATION IN THE FORM OF RAIN ALONG WITH CHANCES OF
THUNDERSTORM ACTIVITY, HOWEVER THEY ARE BOTH VERY LOW CHANCES.
THIS SOUTHERN STREAM SYSTEM IS FORECAST TO EVENTUALLY MAKE ITS
WAY INTO THE AREA BY THURSDAY ALTHOUGH CENTRAL GUIDANCE DOES NOT
SEEM TO BE CONFIDENT ON THIS FEATURE WITH ONLY PROVIDING LOW
END CHANCE POPS.
TEMPERATURES START TO MODERATE SLOWLY BY MONDAY AND THEN A
SLIGHT WARMING TREND COMMENCES THROUGH THE REST OF THIS PERIOD
WHERE BY TUESDAY MOSTLY RAIN IN THE LOWLANDS AND SNOW IN THE
MOUNTAINS AND THEN BY THURSDAY AN ALL RAIN REGIME IS LIKELY.
AVIATION /12Z FRIDAY THROUGH TUESDAY/
AS OF 620 AM FRIDAY...
LIGHT SNOW SHOWERS EXIT EAST THIS MORNING WITH MAINLY DRY CONDITIONS
THEN EXPECTED THROUGH 16Z. CLIPPER SYSTEM MOVES ACROSS FROM WEST TO
EAST THROUGH THE DAY YIELDING A MIX OF RAIN AND SNOW, BEFORE
TRANSITIONING TO ALL SNOW AND EVENTUALLY TAPERING OFF TO SNOW
SHOWERS OVERNIGHT. ACCUMULATING UPSLOPE ENHANCED SNOW SHOWERS WILL
LINGER IN THE MOUNTAINS WELL INTO SATURDAY. AS THE COLUMN MOISTENS,
WILL SEE CEILINGS PROGRESSIVELY DETERIORATE TO MVFR/IFR. VISIBILITY
IN ANY HEAVIER RAIN/SNOW OR SNOW SHOWERS WILL ALSO DIP TO IFR AT
TIMES, ESPECIALLY LATE THIS AFTERNOON INTO THIS EVENING.
WINDS LIGHT AND SOUTHERLY THIS MORNING, TRANSITIONING TO WESTERLY 5-
10KTS THIS AFTERNOON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SATURDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: PRECIPITATION TYPE THIS AFTERNOON COULD
VARY BETWEEN RAIN, RAIN/SNOW MIX AND SNOW.
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 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H M H H H H H M H
HTS CONSISTENCY H M M H H H M M H H H H
BKW CONSISTENCY M H H H H H H H L H H H
EKN CONSISTENCY H H H M M M H H H H H H
PKB CONSISTENCY H H H H H H H H M M H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z SATURDAY...
IFR POSSIBLE SNOW SHOWERS AND STRATUS SATURDAY MORNING.
RLX WATCHES/WARNINGS/ADVISORIES
WV...WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 10 AM EST
SATURDAY FOR WVZ024>026-033-034-515-517-519.
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
SATURDAY FOR WVZ516-518-520>523-525-526.
OH...NONE.
KY...NONE.
VA...WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 10 AM EST
SATURDAY FOR VAZ003-004.
SYNOPSIS...JP/JZ
NEAR TERM...JP
SHORT TERM...JZ
LONG TERM...JZ
AVIATION...JP
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