103
FXUS61 KRLX 150644
AFDRLX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
144 AM EST SUN DEC 15 2024
SYNOPSIS
STOUT HIGH PRESSURE TO THE NORTHEAST AND LOW PRESSURE
TO THE WEST SET UP A WINTRY PRECIPITATION EVENT IN THE WV
MOUNTAINS, RAIN LOWLANDS, SUNDAY. MORE RAIN MONDAY AFTERNOON.
NEAR TERM /THROUGH TONIGHT/
AS OF 639 PM SATURDAY...
PREVIOUS FORECAST REMAINS ON TRACK. ONLY FEW ADJUSTMENTS TO
HOURLY TEMPERATURES WERE NEEDED.
AS OF 240 PM SATURDAY...
UPGRADED THE WINTER STORM WATCH IN SOUTHEAST RANDOLPH AND
NORTHWEST POCAHONTAS COUNTIES TO A WINTER STORM WARNING DUE TO
LOCALLY UP TO THREE TENTHS OF AN INCH OF ICE ACCRETION, ALONG
WITH UP TO TWO INCHES OF SLEET AND SNOW. WITH UPWARDS OF A HALF
AN INCH OF LIQUID EQUIVALENT PRECIPITATION WITH TEMPERATURES
BELOW FREEZING SUNDAY, TRAVEL IS LIKELY TO BE HAZARDOUS, AND THE
COMBINATION OF ICE ACCRETION AND WIND COULD CAUSE TREE DAMAGE
LEADING TO POWER OUTAGES. ROLLED WITH A WINTER WEATHER ADVISORY
FOR THE REMAINDER OF WHAT WAS THE WINTER STORM WATCH, SOUTHEAST
POCAHONTAS COUNTY, WHERE LESS SNOW AND ICE IS EXPECTED, AND
POWER OUTAGES ARE LES LIKELY. EXTENDED THE HAZARD PRODUCT FOR
ALL THREE OF THESE ZONES UNTIL 1 AM EARLY MONDAY MORNING WITH
SLOWER WARMING EXPECTED.
THE ADVISORY FOR THE HIGHER RIDGES AND SOUTHEAST FACING SLOPES
OF THE CENTRAL MOUNTAINS OF WV REMAIN THE SAME IN TIMING AND
AREAL EXTENT.
AS OF 125 PM SATURDAY...
HIGH MID-LEVEL HEIGHTS AND STRONG, ARCTIC HIGH PRESSURE RIDGING DOWN
THE EAST SIDE OF THE APPALACHIANS SPELL A CLASSIC COULD AIR DAMMING
/ FREEZING RAIN PATTERN ALONG THE HIGHER RIDGES AND SOUTHEAST FACING
SLOPES ON SUNDAY.
FROM ITS POSITION OVER THE NORTHEASTERN U.S. THIS MORNING, THE
HIGH PROMOTES A CONTINUATION OF DRY WEATHER ACROSS THE FORECAST
AREA INTO TONIGHT. AFTER AN ONLY MODEST RECOVERY IN AND
SOUTHEAST OF THE MOUNTAINS TODAY, TEMPERATURES RADIATE EARLY
TONIGHT UNDER A STILL THIN VEIL OF HIGH CLOUDS, WHICH THEN LOWER
AND THICKEN OVERNIGHT.
A MID-LEVEL LOW SCOOTS FROM THE CENTRAL PLAINS EARLY THIS AFTERNOON
ALL THE WAY TO THE GREAT LAKES BY LATE SUNDAY. H5 HEIGHTS IN THE
570S ARE RATHER HIGH FOR A SNOWSTORM EVEN IN THE MOUNTAINS, FALLING
ONLY FROM 577 TO 570 DAM OR SO, AS THE MID-LEVEL SHORT WAVE TROUGH
EXTENDING SOUTH-SOUTHEAST FROM THE LOW, A MODEST NEGATIVE TILT,
SCOOTS IN. NONETHELESS, THE NAM CONTINUES TO TREND COLDER EVEN WITH
THE WARM NOSE ALOFT, WHICH NOW COLLAPSES TO FREEZING AS THE COLUMN
SATURATES THERE SUNDAY MORNING, BEFORE SLOWLY CLIMBING ABOVE
FREEZING THE BALANCE OF THE DAY.
SURFACE TEMPERATURES WILL BE VERY SLOW TO CLIMB ALONG THE HIGHER
RIDGES AND SOUTHEAST FACING SLOPES OF THE NORTHERN AND CENTRAL
MOUNTAINS ON SUNDAY, NOT GETTING ABOVE FREEZING AT ALL ALONG THE
HIGHER RIDGES AND HIGHER WINDWARD TERRAIN. THE SOUTHEAST FLOW AHEAD
OF A SURFACE SYSTEM THAT WILL NOT EVEN EVER PUSH A COLD FRONT
THROUGH THE AREA WILL AMPLIFY THE COLD AIR DAMMING WEDGE, WITH
DOWNSLOPE WARMING NORTHWEST OF THE MOUNTAINS KEEPING TEMPERATURES
MOSTLY ABOVE FREEZING TONIGHT AFTER A GOOD RECOVERY TODAY, AND THEN
UP INTO THE 40S IN THE RAIN ON SUNDAY.
PRECIPITATION CROSSING THE MID MISSISSIPPI VALLEY EARLY THIS
AFTERNOON REACHES THE MIDDLE OHIO VALLEY LATE TONIGHT, AND THEN THE
MOUNTAINS OVERNIGHT AND EARLY SUNDAY MORNING. PRECIPITATION MAY
TAPER OFF IN THE MIDDLE OHIO VALLEY SUNDAY AFTERNOON, AS MID-LEVEL
DRYING ALONG THE TROUGH AXIS MOVES IN.
WHILE THE SURFACE LOW, ITS CENTRAL PRESSURE NOT EVEN AS LOW AS THE
STANDARD ATMOSPHERIC PRESSURE EARLY THIS AFTERNOON, FILLS SUNDAY
MORNING, HENCE NEVER A COLD FRONTAL PASSAGE WITH THE SYSTEM, THE
MOISTURE INFLUX AHEAD OF IT FROM THE GULF AND ATLANTIC IS POWERED BY
THE NUMEROUS ISOBARS OWING TO THE MAGNITUDE OF THE HIGH OVER THE
NORTHEASTERN U.S., A STOUT 1050 MB. AS SUCH, PRECIPITATION AMOUNTS
THROUGH SUNDAY ARE FORECAST TO BE IN THE THREE-QUARTERS OF AN INCH
TO AN INCH RANGE OVER MUCH OF THE MIDDLE OHIO VALLEY, AND ONE HALF
TO THREE QUARTERS OF AN INCH ALONG THE HIGHER RIDGES AND HIGHER
WINDWARD TERRAIN. CONVERSELY, DOWNSLOPE SOUTHEAST FLOW CREATES A
RAIN SHADOW, WITH AMOUNTS OF LESS THAN ONE HALF INCH ALONG THE
NORTHWEST FACING SLOPES OF THE MOUNTAINS AND MUCH OF THE LOWLANDS OF
WV.
WHILE THIS IS ANOTHER WELCOME RAIN EVENT IN A SERIES COMING OUT OF
THE SUMMER AND EARLY FALL DROUGHT, THESE AMOUNTS ARE CRUCIAL IN THE
MOUNTAINS, WHERE IT WILL COME ALMOST ENTIRELY IN THE FORM OF SNOW,
SLEET AND FREEZING RAIN. WITH THE MODELS TRENDING COLDER, AMOUNTS
SHIFT MORE TOWARD SNOW EARLY ON. WHILE NEITHER THE SNOW OR ICE
TOTALS MEET WINTER STORM WARNING CRITERIA, THE COMBINATION OF
THESE WINTRY PRECIPITATION TYPE SIS LIKELY TO BE IMPACTFUL, THE
DAY OF THE WEEK BEING A MITIGATING FACTOR.
SHORT TERM /MONDAY THROUGH MONDAY NIGHT/
AS OF 130 PM SATURDAY...
AS SURFACE HIGH PRESSURE WEAKENS AS SHIFTS NORTHEAST SUNDAY NIGHT
COLD AIR DAMMING WEAKENS ALLOWING TEMPERATURES TO RISE ABOVE
FREEZING BRINGING THE THREAT FOR ANY LINGERING WINTRY PRECIPITATION
TO A CLOSE A LITTLE AFTER MIDNIGHT. SHOULD SEE A BREAK IN
PRECIPITATION EARLY MONDAY INTO THE FIRST HALF OF THE DAY AS THE
FIRST SYSTEM DEPARTS WITH TRANSIENT RIDGING AHEAD OF THE NEXT SYSTEM
BRIEFLY MAKING AN APPEARANCE. ASSOCIATED WARM ADVECTION WILL MAKE
FOR SOMEWHAT MILD DECEMBER LOW TEMPERATURES FOR MONDAY MORNING,
GENERALLY IN THE LOWER TO MID 40S ACROSS THE LOWER ELEVATIONS AND
LOWER TO MID 30S IN THE MOUNTAINS.
LOW LEVEL RESPONSE TO A 100KT JET MOVING INTO THE UPPER GREAT LAKES
DURING THE DAY MONDAY DRAWS GULF ENHANCED MOISTURE CHARACTERIZED BY
PRECIPITABLE WATER VALUES NEAR 1.25 INCHES INTO THE OHIO VALLEY
BENEATH STRONG SYNOPTIC FORCING ASSOCIATED WITH AN APPROACHING MID-
LEVEL WAVE. WITH MILD MID-DECEMBER CONDITIONS, THIS WILL BE AN ALL
RAIN EVENT PRODUCING PERHAPS UP TO AN INCH ACROSS THE MIDDLE OHIO
VALLEY WITH LESSER AMOUNTS FARTHER SOUTHEAST AWAY FROM THE BEST LOW
LEVEL MOISTURE. SOME DECENT RESPONSES ARE LIKELY ON SMALLER CREEKS,
AND STREAMS ACROSS THE MIDDLE OHIO VALLEY GIVEN LACK OF ACTIVE
VEGETATION. CURRENT LOW FLOWS SHOULD LIMIT CHANCES OF THESE REACHING
BANKFULL LEVELS.
THE LOW LEVEL MOISTURE PLUME QUICKLY EXITS EAST MONDAY NIGHT WHICH
SHOULD SERVE TO TAPER ANY REMAINING PRECIPITATION DOWN TO LIGHT
SHOWERS.
A WEAK COLD FRONT WASHES OUT JUST NORTHEAST OF OUR FORECAST AREA ON
TUESDAY WITH MILD CONDITIONS CONTINUING - HIGHS IN THE LOWER TO MID
50S ACROSS THE LOWLANDS WITH 40S IN THE MOUNTAINS.
LONG TERM /TUESDAY THROUGH SATURDAY/
AS OF 130 PM SATURDAY...
THE NEXT SYSTEM DEVELOPS ACROSS THE LOWER MISSISSIPPI VALLEY TUESDAY
EVENING AND MOVES INTO OUR REGION EARLY WEDNESDAY MORNING BRINGING
MOSTLY RAIN WITH PERHAPS A FEW FLAKES MIXED IN ACROSS OUR FAR
NORTHWESTER ZONES, TRANSITIONING TO ALL RAIN DURING THE DAY. AS
COLDER AIR FILTERS IN WEDNESDAY NIGHT, SHOULD SEE A TRANSITION TO
SNOW, INITIALLY IN THE MOUNTAINS AND THEN IN THE NORTHERN LOWLANDS
HEADING INTO THURSDAY MORNING, WHERE OF RAIN AND SNOW SHOWERS MAY
LINGER UNTIL LOW LEVEL FLOW BECOMES MORE WESTERLY CUTTING OFF ANY
UPSTREAM MOISTURE CONNECTION FROM THE UPPER GREAT LAKES.
UNCERTAINTY INCREASES HEADING INTO THE WEEKEND, BUT A GENERAL MODEL
CONSENSUS YIELDS EVENTUAL NORTHERN STREAM SYSTEM PASSAGE FOLLOWED BY
A PERIOD OF NORTHWESTERLY FLOW.
AVIATION /06Z SUNDAY THROUGH THURSDAY/
AS OF 143 AM SUNDAY...
MOSTLY VFR CONDITIONS WILL REMAIN ACROSS THE AREA UNTIL ABOUT
~10Z-12Z. A DISTURBANCE APPROACHES FROM THE WEST WITH PRECIPITATION
CHANCES INCREASING THIS MORNING AHEAD OF IT. MOST LOCATIONS WILL
ONLY SEE RAIN, BUT LOCATIONS IN THE MOUNTAINS, MOSTLY ABOVE
2,500 FEET ELEVATION, WILL LIKELY SEE FZRA AND SN. BKW AND EKN
WILL LIKELY BE TOO WARM, BUT A BRIEF PERIOD OF FZRA, PL OR SN
COULD OCCUR BETWEEN ~10Z AND ~12Z WHEN TEMPERATURES WOULD BE
AROUND FREEZING. MVFR AND IFR VIS RESTRICTIONS ARE LIKELY WITH
PRECIPITATION, ESPECIALLY HEAVIER PRECIPITATION.
MVFR CIGS FILTER INTO THE OHIO VALLEY AND ACROSS THE MOUNTAINS
BY ABOUT ~09Z. ELSEWHERE, MVFR CIGS WILL MOVE IN BY ABOUT ~16Z
WITH THE HEAVIEST PRECIPITATION. THE MOUNTAINS WILL LIKELY SEE
IFR CIGS OR LOWER FORM ABOUT THE SAME TIME. THE CENTRAL
LOWLANDS, INCLUDING CRW, WILL LIKELY KEEP VFR CIGS CONDITIONS
THROUGH THE PERIOD.
WINDS WILL MOSTLY BE LIGHT AND VARIABLE EARLY THIS MORNING,
EXCEPT ACROSS THE MOUNTAINS WHERE SOUTHEASTERLY FLOW COULD BE
BREEZY OR GUSTY AT TIMES. SOUTHEASTERLY WINDS WILL INCREASE
ACROSS THE AREA THROUGH THE DAY TODAY WITH GUSTS BETWEEN 20KTS
AND 30KTS POSSIBLE ACROSS THE MOUNTAINS AND FOOTHILLS.
LLWS IS EXPECTED AT MOST SITES FROM ~06Z THROUGH ~20Z.
EXPECTING A SSE LLWS COMPONENT ALOFT DURING THE PERIOD WITH
SPEEDS BETWEEN 40KTS AND 50KTS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING, LOCATION AND INTENSITY OF RAIN AND
WINTRY PRECIPITATION MAY VARY FROM FORECAST. TIMING AND
INTENSITY OF DETERIORATING CIGS AND VIS MAY ALSO VARY. WIND
SPEEDS AND LLWS 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 SUN 12/15/24
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 M L M M H H H
HTS CONSISTENCY H M M M M H L M H L L H
BKW CONSISTENCY H H H M M M H H H M H H
EKN CONSISTENCY H H H H H H H H H L L L
PKB CONSISTENCY H H H H H M M L L H H L
CKB CONSISTENCY H H H H H H H H M M L L
AFTER 06Z MONDAY...
IFR CONDITIONS POSSIBLE IN RAIN AND LOW CEILINGS LATE SUNDAY
NIGHT THROUGH MONDAY.
RLX WATCHES/WARNINGS/ADVISORIES
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ516-
518-520-522.
WINTER STORM WARNING FROM 5 AM EARLY THIS MORNING TO 1 AM EST
MONDAY FOR WVZ523-526.
WINTER WEATHER ADVISORY FROM 5 AM EARLY THIS MORNING TO 1 AM
EST MONDAY FOR WVZ524.
OH...NONE.
KY...NONE.
VA...NONE.
SYNOPSIS...TRM/JP
NEAR TERM...TRM/ARJ
SHORT TERM...JP
LONG TERM...JP
AVIATION...LTC
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page