735
FXUS62 KCAE 210001
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
701 PM EST TUE JAN 20 2026
WHAT HAS CHANGED
CONFIDENCE CONTINUES TO GRADUALLY INCREASE REGARDING THE
POTENTIAL FOR AN IMPACTFUL WINTER EVENT THIS WEEKEND.
KEY MESSAGES
- 1) CHILLY TEMPERATURES EXPECTED TONIGHT WITH LOWS INTO THE
UPPER TEENS TO LOWER 20S.
- 2) GUIDANCE CONTINUES TO TREND TOWARDS A SIGNIFICANT WINTER
STORM ACROSS THE FORECAST AREA THIS WEEKEND.
DISCUSSION
KEY MESSAGE 1: CHILLY TEMPERATURES EXPECTED TONIGHT WITH LOWS
INTO THE UPPER TEENS TO LOWER 20S.
STRONG ARCTIC HIGH PRESSURE CENTERED OVER KENTUCKY THIS EVENING
WILL BRING MAINLY CLEAR SKIES AND LIGHT WINDS ALLOWING
TEMPERATURES TO ONCE AGAIN DROP QUICKLY TONIGHT. TEMPERATURES
ARE EXPECTED TO FALL INTO THE UPPER TEENS AND LOWER 20S FOR MOST
LOCATIONS, COLDER IN NORMALLY SHELTERED SPOTS. AT THESE
TEMPERATURES, WE BEGIN TO SEE COLD WEATHER IMPACTS, SO BE SURE
TO TAKE PRECAUTIONS FOR PEOPLE, PETS, PIPES, AND PLANTS.
TEMPERATURES WILL RISE ABOVE FREEZING WEDNESDAY MORNING.
KEY MESSAGE 2: GUIDANCE CONTINUES TO TREND TOWARDS A
SIGNIFICANT WINTER STORM ACROSS THE FORECAST AREA THIS WEEKEND.
THERE CONTINUES TO BE SIGNAL A SIGNIFICANT WINTER STORM THIS
WEEKEND. CONFIDENCE IS INCREASING IN WIDESPREAD, IMPACTFUL
SNOW/SLEET/FREEZING RAIN ACCUMULATIONS ACROSS THE FORECAST AREA,
WITH A LONG DURATION WINTER STORM POSSIBLE.
FROM A SYNOPTIC STANDPOINT, THE SIGNAL FOR A SIGNIFICANT WINTER
STORM THIS WEEKEND IS VERY ROBUST. A STRONG, +3 STANDARD DEVIATIONS
ABOVE NORMAL SURFACE HIGH IS FORECAST TO INVADE THE NORTHERN PLAINS
AND OH VALLEY ON FRIDAY, ANCHORED BY A STRONG UPPER-LEVEL JET STREAM
AND SUBSIDENCE ASSOCIATED WITH CONVERGENCE THEREIN. AS THIS OCCURS,
A BRANCH OF THE SOUTHERN STREAM OF THE JET STREAM IS FORECAST TO
AMPLIFY AS A BAJA LOW DEEPENS AND SLOWLY MOVES EASTWARD. AS THE
SURFACE HIGH PRESSURE CONTINUES TO SHIFT EASTWARD SATURDAY AND
SUNDAY, CLASSIC COLD AIR DAMMING IS FORECAST TO SETUP ACROSS THE
CAROLINAS AND INTO GEORGIA, ANCHORED BY THE UPPER LEVEL JET STREAK
CORE TO OUR NORTH. THE INTENSIFYING RIGHT ENTRANCE REGION OF THE
THEN PHASED NORTHERN/SOUTHERN STREAM JETS IS THEN FORECAST TO SHIFT
EAST-NORTHEASTWARD, OVERSPREADING THE SOUTHEASTERN CONUS WITH WHAT
90-95TH PERCENTILE INTEGRATED VAPOR TRANSPORT VALUES (IVT). THIS
COMBINATION OF AN "ATMOSPHERIC RIVER" STREAMING ATOP THE COLD AIR
DAMMING IS A UNIQUE, IMPRESSIVE SETUP FOR SIGNIFICANT WINTER WEATHER
IN THIS PART OF THE COUNTRY.
12Z GUIDANCE IS CONTINUING THE TREND FROM THE OVERNIGHT
GUIDANCE IN STRENGTHENING THE ARCTIC HIGH PRESSURE SYSTEM
SHIFTING INTO THE NORTHERN PLAINS AND OHIO VALLEY LATER THIS
WEEK, YIELDING A ROBUST COLD AIRMASS ACROSS THE FORECAST AREA
THIS WEEKEND. THE UPPER LEVEL PATTERN REMAINS FAIRLY SIMILAR,
WITH SOME SLIGHT DELAY IN THE EJECTION OF THE UPPER LEVEL TROUGH
ACROSS THE SOUTHWESTERN US (GUIDANCE TENDS TO EJECT THESE
FEATURES A BIT TOO FAST IN THE LONGER RANGE SO THIS TREND MAKES
SOME SENSE). THIS IS A TREND SEEN AMONGST PHYSICS BASED MODELS
AND THEIR ENSEMBLES IN ADDITION TO THE AI GUIDANCE, INCREASING
CONFIDENCE IN WINTRY PRECIPITATION. ADDITIONALLY, WITH GUIDANCE
CONTINUING TO SHOW A ROBUST AND ANOMALOUS IVT SIGNAL, GUIDANCE
HAS CONTINUED TO TREND A BIT WETTER THAN IT WAS EVEN 24 HOURS
AGO. AS SUCH, SIGNIFICANT TOTALS OF SNOW/SLEET/FREEZING RAIN ARE
ALL POSSIBLE AT THIS STAGE. THERE IS TREMENDOUS UNCERTAINTY
REGARDING WHERE ALL OF THESE PRECIPITATION TYPES SET UP AND HOW
MUCH ACTUALLY FALLS OF EACH. REGARDLESS OF THAT, CONCERN IS
INCREASING THAT THIS WINTER STORM COULD BE SIGNIFICANT AND
IMPACTFUL ACROSS THE ENTIRE FORECAST AREA. THE PRIMARY TIMEFRAME
LOOKS IT COULD RUN FROM SATURDAY AFTERNOON THROUGH MONDAY
MORNING, WITH MULTIPLE ROUNDS OF HEAVY PRECIPITATION POSSIBLE IN
THIS TIME SPAN. PLEASE CONTINUE TO STAY ABREAST OF THE LATEST
FORECAST INFORMATION OVER THE COMING DAYS AND BEGIN TO REVIEW
YOUR WINTER WEATHER PREPAREDNESS PLAN.
AVIATION /00Z WEDNESDAY THROUGH SUNDAY/
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.
HIGH PRESSURE IS CENTERED OVER THE MID-ATLANTIC INTO THE
SOUTHEASTERN STATES THIS EVENING. SATELLITE IMAGERY SHOWING ONLY
A FEW PASSING CIRRUS CLOUDS ALTHOUGH CIRRUS COULD BECOME MORE
SCATTERED TO BROKEN ON WEDNESDAY. LIGHT AND VARIABLE TO CALM
WINDS EXPECTED TONIGHT BEFORE PICKING UP FROM THE SOUTHEAST
AROUND 4 TO 6 KNOTS LATE MORNING AFTER 16Z AND SHIFTING MORE
SOUTHERLY LATE IN THE AFTERNOON. ATMOSPHERE REMAINS WELL TOO DRY
TO SUPPORT FOG CONCERNS.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS LIKELY CONTINUE
INTO THURSDAY. THE NEXT STORM SYSTEM WILL LIKELY BRING
RESTRICTIONS AS EARLY AS FRIDAY, BUT MORE LIKELY SATURDAY AND
SUNDAY.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
DISCUSSION...07
AVIATION...23
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