476
FXUS62 KCAE 191021
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
521 AM EST WED FEB 19 2025
SYNOPSIS
MOISTURE WILL SLOWLY INCREASE TODAY AHEAD OF A DEVELOPING LOW
PRESSURE SYSTEM IN THE WESTERN GULF. THE LOW WILL TRACK EAST
ALONG THE GULF COAST WITH RE-DEVELOPMENT OFF THE COAST OF SC.
THIS WILL LEAD TO WIDESPREAD RAIN TODAY WITH SOME WINTRY PRECIP
POSSIBLE ACROSS THE NORTHERN MIDLANDS AND PEE DEE. WITH
LINGERING MOISTURE ON THURSDAY AND VERY COLD AIR SPREADING IN
FROM THE NORTHWEST ON STRONG GUSTY WINDS, A FEW SNOW SHOWERS ARE
POSSIBLE MAINLY IN THE NORTH/CENTRAL MIDLANDS. A VERY COLD AIR
MASS WILL SETTLE OVER THE AREA BY FRIDAY MORNING WITH
TEMPERATURES WELL BELOW NORMAL.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGE(S):
- CHILLY, WITH WIDESPREAD SHOWERS EXPECTED TODAY AND SOME WINTRY
PRECIP LIKELY IN THE NORTHERN MIDLANDS AND PEE DEE.
-WINTER WEATHER ADVISORY EXPANDED TO ALSO INCLUDE SUMTER AND
CLARENDON COUNTIES.
UPPER TROUGH CONTINUES TO PUSH EASTWARD THIS MORNING, WITH A
STRENGTHENING SURFACE LOW AFFECTING THE DEEP SOUTH. PWAT VALUES ARE
STILL QUITE LOW, BUT MOISTURE WILL CONTINUE TO INCREASE THROUGH THE
MORNING. CLOUDS NOW COVER THE AREA AND BASES ARE BEGINNING TO LOWER.
RADAR RETURNS ARE AS CLOSE AS NORTHWEST GA TO THE GA/FL BORDER, AND
MOVING NORTHEAST AT A DECENT CLIP. THERE IS A LOW END CHANCE OF RAIN
IN THE CSRA TOWARDS DAYBREAK, BUT THE MAJORITY OF THE PRECIPITATION
SHOULD HOLD OFF UNTIL AFTER SUNRISE. TEMPERATURES REMAINED A BIT
WARMER THAN EXPECTED WITH THE CLOUD COVER AND INCREASING MOISTURE
LEVELS (DEWPOINTS NOW IN THE LOW TO MID 30S), SO LOWS THIS MORNING
WILL GENERALLY END UP IN THE MID 30S TO LOW 40S FROM THE NORTHERN
MIDLANDS TO THE CSRA/SOUTHERN MIDLANDS.
WEAK WARM ADVECTION AND ISENTROPIC ASCENT WILL STEADILY INCREASE OUR
PRECIP CHANCES THIS MORNING AS PWATS INCREASE TO OVER 0.8". RECENT
GUIDANCE AND CAM SOLUTIONS KEEP THE BULK OF PRECIP WEST OF OUR AREA
UNTIL LATER ON THIS MORNING WHEN THE BEST LIFT MOVES OVER THE AREA.
THOUGH THE STRONGEST SYNOPTIC FORCING WILL LIKELY REMAIN TO OUR
EAST, WE'LL STILL HAVE A FEW FAVORABLE DYNAMICS OVERHEAD HELPING
ENHANCE PRECIP DEVELOPMENT. THE SURFACE LOW CURRENTLY OFF THE
SOUTHEAST TX COAST WILL CONTINUE TO TRACK ALONG THE NORTHERN GULF
THROUGH THE DAY, AND EVENTUALLY A SECONDARY LOW WILL FORM OFF THE SC
COAST. THIS WILL RAMP UP RAIN CHANCES THIS AFTERNOON IN PARTICULAR.
TEMPERATURES WILL BE QUITE CHILLY TODAY WITH COLD ADVECTION
CONTINUING AND A LACK OF SUNSHINE, SO ONLY EXPECTING HIGHS TO REACH
THE UPPER 30S ACROSS THE NORTHERN MIDLANDS TO PERHAPS THE MID 40S
ACROSS THE SOUTHERN FA. THE CLOUD DEPTH AND TEMPERATURE WILL BE
SUFFICIENT FOR ICE GROWTH, BUT A PERSISTENT WARM NOSE WILL MOST
LIKELY PREVENT SNOW ACROSS THE NORTHERN TIER. PRECIP IS EXPECTED TO
REMAIN ALL LIQUID THROUGH AT LEAST MID-AFTERNOON.
AS THE OFFSHORE LOW MOVES UP THE COAST TONIGHT, WE'LL TAP INTO THAT
EXTRA SYNOPTIC LEVEL FORCING. AS THE WARM NOSE WILL REMAIN ABOVE THE
SURFACE, TEMPERATURES WILL BEGIN TO FALL AND SO A PERIOD OF FREEZING
RAIN IS POSSIBLE ACROSS THE NORTH AND NORTHEASTERN MIDLANDS. WE
EXTENDED THE WINTER WEATHER ADVISORY TO NOW ALSO INCLUDE SUMTER AND
CLARENDON COUNTIES, AS IT APPEARS THERE WILL BE A THREAT FOR A
GLAZE OF ICE ACROSS PARTS OF THOSE COUNTIES AS WELL AS THE
OTHER NORTHERN COUNTIES ALREADY IN THE ADVISORY. THE SETUP WILL
BE VERY SENSITIVE TO SMALL CHANGES IN SURFACE TEMP AND MOISTURE.
OVERALL, IMPACTS WILL REMAIN LIMITED FROM THIS EVENT AND THE
COLUMBIA METRO AND AREAS SOUTH AND WEST ARE UNLIKELY TO SEE ANY
IMPACTFUL FROZEN PRECIP. SOME CLEARING IS LIKELY LATE THIS
EVENING AND OVERNIGHT AS THE LOW PULLS AWAY AND THE TROUGH AXIS
TRANSLATES THROUGH. WE'LL THEN BEGIN TO SEE THE SURGE OF ARCTIC
AIR INTO THE AREA FROM THE NORTHWEST AS HIGH PRESSURE BUILDS
ACROSS THE CENTRAL CONUS. LOW TEMPS TONIGHT WILL BE ABOUT 8-12
DEGREES COOLER, REACHING THE MID 20S TO LOW 30S.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/
KEY MESSAGE(S):
- THE SLIGHT CHANCE FOR WINTRY PRECIP CONTINUES EARLY THURSDAY.
- VERY COLD TEMPERATURES EXPECTED ON THURSDAY AND FRIDAY, WITH A
COLD WEATHER ADVISORY POSSIBLE FRIDAY MORNING.
COLD ADVECTION IS EXPECTED TO BE QUICK AND ROBUST ON THURSDAY AS OUR
WEATHER MAKER DEPARTS TO THE EAST. HOWEVER, WE HAVE TO GET BEYOND
THURSDAY MORNING BEFORE WE TRULY CAN LOOK AT SOME QUIET WEATHER.
THERE IS A PERSISTENT SIGNAL FOR SOME LIGHT RAIN/SNOW SHOWERS
DEVELOPING IN THE MID TO LATE MORNING HOURS ON THURSDAY, ESPECIALLY
ALONG AND NORTH OF I20. THIS LOOKS TO OCCUR AS THE TROUGH CONTINUES
TO PROGRESS EASTWARD AND A STRONG 700 HPA SHORTWAVE COMBINES WITH A
SECONDARY FRONTAL PASSAGE THROUGH THE AREA. ADDITIONALLY, 850 HPA
TEMPS LOOK TO FALL RAPIDLY ON THURSDAY MORNING WHICH SHOULD HELP
CREATE STEEP LOW-LEVEL LAPSE RATES AS THE LAST BIT OF FORCING
ARRIVES. MODEL SOLUTIONS RANGE FROM FLURRIES/LIGHT RAIN SHOWERS TO
MORE INTENSE SNOW SHOWERS (HRRR). THE HRRR SHOWING A PERSISTENTLY
MORE INTENSE SIGNAL THAN OTHER GUIDANCE IS NOTABLE AS IT DOES WELL
WHEN IT GOES TO AN ISLAND LIKE THIS BY ITSELF. MODEL SOUNDINGS ARE
FAVORABLE FOR SOME KIND OF MIX OF SNOW/GRAUPEL IF PRECIPITATION DOES
DEVELOP, SO WE NEED TO WATCH MODEL TRENDS CLOSELY TODAY TO SEE IF
THE WINTER WEATHER ADVISORY NEEDS TO BE EXTENDED IN TIME.
REGARDLESS, THIS DOESN'T LOOK LIKE IT WILL CAUSE ANY MAJOR ISSUES
ACROSS THE AREA AS ACCUMULATIONS SHOULD BE LIGHT. BEHIND THIS, WINDS
SHOULD STAY BREEZY THROUGH THE AFTERNOON HOURS AS COLD ADVECTION
FOSTERS EFFICIENT MIXING. LOOK FOR WELL BELOW NORMAL HIGHS IN THE
LOW 40S, WITH LOWS ON THURSDAY NIGHT IN THE UPPER TEENS OR LOWER
20S. FRIDAY LOOKS COLD, TOO, AS HIGH PRESSURE CONTINUES TO PUSH INTO
THE SOUTHEASTERN CONUS. DRY AIR SHOULD REMAIN IN PLACE, WITH SUNNY
SKIES DECEIVING HOW CHILLY TEMPERATURES ARE FORECAST TO BE
AGAIN. EXPECT HIGHS IN THE THE MID OR UPPER 40S, WITH OVERNIGHT
LOWS IN THE LOW 20S.
LONG TERM /SATURDAY THROUGH TUESDAY/
KEY MESSAGE(S):
- QUIET WEATHER THROUGH THE PERIOD, WITH A SLOW MODERATION OF
TEMPERATURES EXPECTED.
QUIET WEATHER IS THE STORY IN THE LONG TERM, AS THE PATTERN LOOKS TO
SETTLE DOWN FOR A LITTLE BIT. THE EXPANSIVE SURFACE HIGH SHOULD
CONTINUE SETTLING INTO THE SOUTHEASTERN CONUS OVER THE WEEKEND,
GRADUALLY WEAKENING AS IT DOES SO. GENERAL UPPER LEVEL
TROUGHING SHOULD REMAIN FAVORED BUT EVEN WEAK SHORTWAVES PASSING
THROUGH THE FLOW SHOULDN'T RESULT IN MUCH ACROSS THE AREA. PWS
SHOULD REMAIN ABOUT 50% OF NORMAL, WITH ONLY MID/HIGH LEVEL
CLOUDS EXPECTED THROUGH THE PERIOD. AS THE SURFACE HIGH SHIFTS
TO OUR SOUTH, A GRADUAL WARM UP IS EXPECTED TO BEGIN SATURDAY
AND LAST THROUGH THE MIDDLE OF NEXT WEEK. EACH DAY, THE AIRMASS
WILL MODIFY A BIT MORE, WITH MON/TUES/WED EACH LOOKING NEAR TO
ABOVE NORMAL TEMPERATURE WISE. THIS LOOKS REASONABLE RIGHT NOW
AS THE OVERALL PATTERN SUPPORTS AN INCREASE IN SOUTHERLY FLOW BY
THAT POINT, ALLOWING US TO WARM UP A BIT. OVERALL, THE LONG
TERM LOOKS QUIET, WITH OUR NEXT REAL RAIN CHANCE LIKELY NOT
ARRIVING UNTIL AFTER THE END OF THE PERIOD.
AVIATION /09Z WEDNESDAY THROUGH SUNDAY/
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH AT LEAST 19/15Z THIS
MORNING. DETERIORATING CONDITIONS WITH MVFR/IFR CIGS DURING THE
AFTERNOON/EVENING HOURS.
BKN-OVC HIGH CLOUDS THIS MORNING WITH MID AND LOWER LEVEL CLOUDS
STARTING TO DEVELOP TOWARD SUNRISE. LIGHT ELY WINDS AT 5 KNOTS OR
LESS BECOMING MORE NELY AFTER 19/12Z AND INCREASING SPEEDS TO 5-10
KTS. MVFR CIG RESTRICTIONS DEVELOP AROUND 19/15Z-17Z ALONG WITH THE
ONSET OF -RA. CIGS THEN CONTINUE TO FALL TO IFR AFTER 19/20Z WITH
MVFR VSBYS ALSO BEGINNING AROUND THAT TIME. ANY WINTRY PRECIPITATION
LOOKS TO STAY NORTH OF THE TERMINALS DURING THIS FORECAST PERIOD.
PRECIP SHOULD END STARTING AT THE AGS/DNL TERMINALS AND CLEAR FROM
WEST TO EAST AFTER 20/00Z. LINGERING RESTRICTIONS THEN PERSIST
THROUGH THE END OF THE TAF PERIOD, WITH SOME PATCHY AND BRIEF LIFR
NOT OUT OF THE QUESTION.
EXTENDED AVIATION OUTLOOK...LOW PRESSURE SYSTEM MOVING OFF THE COAST
OF SC WILL RESULT IN PRECIPITATION AND RESTRICTIONS THROUGH THURSDAY
MORNING. STRONG, GUSTY NORTHWEST WINDS EXPECTED THURSDAY AFTERNOON.
NO RESTRICTIONS EXPECTED FRIDAY THROUGH THE WEEKEND.
CAE WATCHES/WARNINGS/ADVISORIES
SC...WINTER WEATHER ADVISORY FROM 11 AM THIS MORNING TO 5 AM EST
THURSDAY FOR SCZ016-022-029-031-038-115-116.
GA...NONE.
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