105
FXUS62 KCAE 192002
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
302 PM EST SUN JAN 19 2025
SYNOPSIS
A STRONG COLD FRONT IS MOVING THROUGH THE AREA, BRINGING STRONG
GUSTY WINDS IN ITS WAKE THROUGH THE REST OF THE AFTERNOON.
BEHIND THE FRONT, VERY COLD AIR BEGINS TO SPREAD ACROSS THE
REGION. WELL BELOW NORMAL TEMPERATURES ARE EXPECTED THROUGH THE
WEEK AS AN ANOMALOUSLY DEEP TROUGH AND SURFACE HIGH PUSHES AN
ARCTIC AIR MASS INTO THE CENTRAL AND EASTERN US. ON TUESDAY, A
COASTAL LOW IS EXPECTED MOVE THROUGH ALONG THE SOUTHEAST, LIKELY
INCREASING PRECIPITATION CHANCES WITH WINTRY POTENTIAL, BUT
SOME UNCERTAINTY REMAINS.
NEAR TERM /UNTIL 6 AM MONDAY MORNING/
KEY MESSAGE(S):
- A STRONG COLD FRONT WILL BRING BREEZY CONDITIONS INTO THIS
EVENING.
- THE COLDEST AIRMASS SO FAR THIS SEASON WILL MOVE IN TONIGHT WITH
TEMPERATURES AND DEWPOINTS FALLING RAPIDLY.
SHOWERS ASSOCIATED WITH A LOW PRESSURE SYSTEM HAVE MOVED EAST OF THE
AREA THIS AFTERNOON. SKIES ARE STARTING TO BREAK UP, WITH BITS OF
SUNSHINE FILTERING THROUGH. A TIGHT PRESSURE GRADIENT BEHIND THE LOW
IS RESULTING IN BREEZY TO WINDY CONDITIONS AS EXPECTED, WITH MANY
SITES GUSTING TO BETWEEN 30 AND 40 MPH. A LAKE WIND ADVISORY REMAINS
IN EFFECT UNTIL 11 PM THIS EVENING. SOME DOWNSLOPING AHEAD OF A COLD
FRONT HAS WARMED TEMPERATURES THIS AFTERNOON INTO THE MID AND UPPER
50S. HOWEVER, THIS IS EXPECTED TO BE SHORT-LIVED, WITH TEMPS
DROPPING SHARPLY THIS EVENING BEHIND THE FRONT. THE FRONT CURRENTLY
REMAINS NORTHWEST OF THE UPSTATE WHERE THERE IS A NOTABLE WIND SHIFT
TO THE NORTHWEST IN ADDITION TO MUCH LOWER TEMPERATURES (LOW TO MID
30S) AND DEWPOINTS (20S AND LOW 30S).
STRONG COLD ADVECTION CONTINUES OVERNIGHT, BUT WINDSPEEDS WILL
REMAIN ELEVATED FOR AT LEAST THE FIRST PART OF THE PERIOD. AGAIN,
THIS MAY HINDER COOLING JUST SLIGHTLY, BUT OVERNIGHT LOWS STILL
SHOULD FALL INTO THE MID 20S, PARTICULARLY BY DAWN WHEN WINDSPEEDS
REALLY DROP OFF. WIND CHILL TEMPS WILL BE IN THE 20S MOST OF THE
NIGHT BUT MAY FALL INTO THE TEENS BRIEFLY FOR A PERIOD AROUND
DAYBREAK. THIS MAY BE CLOSE TO COLD WEATHER ADVISORY THRESHOLDS, BUT
WITH THE SPOTTINESS AND BRIEF DURATION, NO HEADLINES HAVE BEEN
ISSUED.
SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/
KEY MESSAGE(S):
- HIGH CONFIDENCE IN THE BEGINNING OF A LONG DURATION COLD
TEMPERATURE EVENT WITH OVERNIGHT TEMPERATURES AND/OR WIND CHILL
VALUES EXPECTED TO FALL INTO THE 10F-15F RANGE.
A POTENT ARCTIC AIR MASS WILL SETTLE INTO THE EASTERN CONUS ON
MONDAY, WITH WELL BELOW NORMAL HIGH AND LOW TEMPERATURES EXPECTED.
COLD ADVECTION SHOULD CONTINUE THROUGH THE DAY UNDER CLEAR OR MOSTLY
CLEAR SKIES, WITH NORTH TO NORTHWEST WINDS IN THE 5-10 MPH RANGE
THROUGH AT LEAST MIDDAY. A PREVIOUSLY MENTIONED, THIS COULD GENERATE
A BRIEF PERIOD OF WIND CHILL VALUES THAT APPROACH COLD WEATHER
ADVISORY THRESHOLDS FOR A FEW HOURS AFTER SUNRISE. HOWEVER, ITS
BORDERLINE WITH LIMITED CONFIDENCE AND SO NO HEADLINES HAVE BEEN
ISSUED. HIGHS ARE ONLY EXPECTED TO REACH THE MID 30S NORTH TO AROUND
40 SOUTH. THEN, TEMPERATURES SHOULD BE VERY COLD MONDAY NIGHT AS
HIGH PRESSURE CONTINUES TO BUILD SOUTHEASTWARD. LOWS ON MONDAY NIGHT
ARE LIKELY TO GET DOWN INTO THE MID TO UPPER TEENS ACROSS THE
FORECAST AREA AND A COLD WEATHER ADVISORY IS LIKELY GOING TO BE
NEEDED.
LONG TERM /TUESDAY THROUGH SUNDAY/
KEY MESSAGE(S):
- MULTIPLE IMPACTFUL HAZARDS EXPECTED THIS WEEK.
1) HIGH CONFIDENCE IN A LONG DURATION COLD TEMPERATURES AS THE
COLDEST AIRMASS SINCE DECEMBER 2022 PUSHES INTO THE SOUTHEASTERN
US, LIKELY REQUIRING A LONG FUSED COLD WEATHER ADVISORY MONDAY NIGHT
INTO THURSDAY.
ARCTIC HIGH PRESSURE IS FORECAST TO CONTINUE BUILDING INTO THE AREA
TUESDAY THROUGH MUCH OF THE WEEK, BRINGING THE COLDEST AIR OF THE
SEASON TO THE AREA. LOOKING UPSTREAM, THERE ARE BITTERLY COLD
TEMPERATURES. IN FACT, CURRENT TEMPERATURES IN MINNESOTA (WHERE THIS
FORECASTER GREW UP) ARE IN THE -5 TO -10F RANGE. YES, YOU READ THAT
CORRECT, BELOW ZERO IN THE AFTERNOON. THIS IS THE AIRMASS THAT IS
EXPECTED TO MOVE INTO THE SOUTHEAST. ARE WE GOING TO BE SEEING THESE
TEMPERATURES LOCALLY? NO, BECAUSE THE AIR WILL MODIFY SOME AS IT
MOVES SOUTHEASTWARD. HOWEVER, IT GIVES AN IDEA OF THE TYPE OF
AIRMASS WE'RE DEALING WITH FOR MID TO LATE WEEK. TEMPERATURES ARE
FORECAST TO BE WELL BELOW NORMAL, WITH THE RECORD LOWS NOT OUT OF
THE QUESTION FOR THURSDAY MORNING. WITH THESE COLD TEMPERATURES IN
PLACE, WILL LIKELY BE NEEDING A LONG FUSED COLD WEATHER ADVISORY FOR
THAT TIME FRAME AS WIND CHILLS ARE LIKELY TO BE LESS THAN 15F FOR
TUESDAY, WEDNESDAY AND THURSDAY MORNINGS. DAYTIME HIGHS IN THE MID
TO LATE WEEK PERIOD ARE EXPECTED TO STRUGGLE TO GET TO 40F. WITH THE
PROLONGED PERIOD OF COLD TEMPERATURES, DANGEROUS CONDITIONS ARE
LIKELY FOR THOSE WITHOUT ADEQUATE SHELTER AND FROZEN PIPES ARE
POSSIBLE.
2) AN IMPACTFUL WINTER WEATHER SYSTEM REMAINS ON TRACK TO
AFFECT THE AREA TUES. AFTERNOON INTO WED. MORNING.
AH, THE JOYS OF FORECASTING A WINTER WEATHER SYSTEM. LATEST 12Z
GUIDANCE CONTINUES TO SUPPRESS THE FOOTPRINT OF THE HIGHER SNOW
AMOUNTS TOWARD THE COAST. HOWEVER, WE ARE STILL MODERATELY CONFIDENT
(50-70%) OF AT LEAST MINOR IMPACTS ACROSS MUCH OF THE FORECAST AREA
DUE TO THE SYSTEM. WITH THE COLD TEMPERATURES IN PLACE, CONFIDENCE
IS INCREASING THAT MOST, IF NOT ALL, THE PRECIPITATION THAT FALLS
WILL BE SNOW. CURRENT FORECAST IS ROUGHLY AN INCH NEAR THE I-95
CORRIDOR AND ABOUT HALF AN INCH ALONG THE I-20 CORRIDOR. THERE ARE
SOME CAVEATS TO THOSE AMOUNTS. THERE IS STILL A COUPLE OF DAYS
BEFORE THE SYSTEM ARRIVES, SO THERE REMAINS UNCERTAINTY IN THE EXACT
TRACK, WHICH COULD AFFECT THE AMOUNTS. ANOTHER FACTOR TO CONSIDER IS
THE AMOUNT OF DRY AIR NEAR THE SURFACE AND HOW FAST THAT SATURATES
TO ALLOW SNOW TO BEGIN TO ACCUMULATE. BECAUSE OF THIS DRY AIR, THERE
IS A GOOD CHANCE OF A SHARP CUTOFF BETWEEN ACCUMULATING SNOW AND NO
SNOW WHEN IT IS ALL SAID AND DONE.
AN ADDITIONAL FACTOR PLAYING INTO THIS SYSTEM IS HOW WELL A SOUTHERN
STREAM AND NORTHERN STREAM SHORTWAVE PHASE AS THEY MOVE TOWARD THE
REGION. GUIDANCE IS SPLIT A BIT ON THIS. THE MODEL SOLUTIONS THAT
FAVOR A PHASING OF THESE TWO FEATURES SHOW SLIGHTLY HIGHER SNOWFALL
AMOUNTS. OTHER MODEL SOLUTIONS SUGGEST THE NORTHERN STREAM WAVE
MOVES FASTER THAN THE SOUTHERN STREAM WAVE, WHICH FAVORS HIGHER
AMOUNTS FURTHER EAST. SO, THERE ARE STILL SOME DETAILS THAT NEED TO
BE IRONED OUT.
WITH THE LINGERING COLD AIR AFTER THE SYSTEM, ANY SNOW THAT DOES
ACCUMULATE WITH THIS SYSTEM IS LIKELY TO STICK AROUND FOR LONGER
THAN USUAL. SO, IMPACTS COULD LINGER FOR A FEW DAYS AFTER THE SNOW
ENDS.
AVIATION /20Z SUNDAY THROUGH FRIDAY/
IMPROVING CONDITIONS WITH GUSTY WINDS THIS AFTERNOON.
A COLD FRONT IS MOVING THROUGH THE AREA THIS AFTERNOON WITH
DRIER AIR FUNNELING INTO THE AREA BEHIND IT. THIS IS LEADING TO
CLEARING SKIES AND VFR CONDITIONS HAVE RETURNED TO ALL THE
TERMINALS. WITH THE PASSAGE OF THE FRONT, WINDS WILL REMAIN
SIGNIFICANTLY BREEZY WITH MAX GUSTS BETWEEN 25 TO 30 KNOTS OUT
OF THE WEST. WINDS WILL DECREASE INTO THIS EVENING, ALTHOUGH
GUSTS AROUND 20 KNOTS WILL CONTINUE TO BE POSSIBLE OVERNIGHT,
SHIFTING A BIT MORE WNW. AS A VERY DRY AIR MASS SETTLES OVER THE
AREA TOMORROW, CLEAR SKIES EXPECTED WITH WINDS OUT OF THE NW
BETWEEN 5 TO 10 KNOTS.
EXTENDED AVIATION OUTLOOK
RESTRICTIONS POSSIBLE LATE TUESDAY
INTO TUESDAY NIGHT AS MOISTURE INCREASES AND LOW PRESSURE MOVES
NEAR THE COAST.
CAE WATCHES/WARNINGS/ADVISORIES
SC...LAKE WIND ADVISORY UNTIL 11 PM EST THIS EVENING FOR SCZ016-018-
020>022-025>031-035-037-038-041-115-116-135>137.
GA...LAKE WIND ADVISORY UNTIL 11 PM EST THIS EVENING FOR GAZ040-
063>065-077.
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