849
FXUS62 KCAE 140705
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
305 AM EDT SAT MAR 14 2026
WHAT HAS CHANGED
THE FORECAST REMAINS ON TRACK, WITH THE EXCEPTION OF POTENTIAL
STRONG STORMS ON SUNDAY AFTERNOON. CONTINUE TO EXPECT SEVERE
THUNDERSTORMS MONDAY. AVIATION DISCUSSION UPDATED FOR 06Z TAFS.
KEY MESSAGES
- 1. STRONG THUNDERSTORMS APPEAR POSSIBLE ON SUNDAY
AFTERNOON/EVENING.
- 2. A ROBUST WEATHER SYSTEM WILL APPROACH ON MONDAY, WITH SEVERE
THUNDERSTORMS AND STRONG, NON-THUNDERSTORM WIND GUSTS
EXPECTED.
- 3: A POTENTIALLY HARD FREEZE LOOKS LIKELY ON TUESDAY NIGHT
AND EARLY WEDNESDAY.
DISCUSSION
KEY MESSAGE 1: STRONG THUNDERSTORMS APPEAR POSSIBLE ON SUNDAY
AFTERNOON/EVENING.
SUNDAY LOOKS POTENTIALLY ACTIVE IN ITS OWN RIGHT, AS A SHORTWAVE
OVER THE GULF PUSHES NORTHEASTWARD ATOP A MOISTENING AIRMASS. AN
INTENSE SYNOPTIC SCALE SYSTEM IS EXPECTED TO RAPIDLY DEVELOP DURING
THE DAY SUNDAY AS A 100+ KNOT 500 HPA JET STREAK RAPIDLY DIGS INTO
THE CENTRAL ROCKIES AND EMERGES ACROSS THE MID MISSISSIPPI VALLEY BY
SUNDAY EVENING. HEIGHT FALLS ARE EXPECTED ACROSS A BROAD AREA OF THE
EASTERN CONUS AS A RESULT, WITH SOUTHWESTERLY FLOW BECOMING
INCREASINGLY DOMINANT. AS THIS OCCURS, A BROAD SHORTWAVE ACROSS THE
NORTHEASTERN GULF WILL GET CAUGHT UP IN THE OVERALL AMPLIFICATION OF
THE PATTERN, PUSHING NORTHEASTWARD SLOWLY DURING THE DAY ON SUNDAY.
AS THE SAME TIME, SOUTHEASTERLY SURFACE FLOW WILL INCREASE IN
STRENGTH DURING THE DAY RESULTING IN FAIRLY ROBUST LOW-LEVEL
MOISTURE ADVECTION. SURFACE BASED CAPE OF 500+ J/KG (OR MORE,
RRFS/HRRR GUIDANCE IS PARTICULARLY AGGRESSIVE WITH >1000 J/KG OF
CAPE) IS FORECAST TO DEVELOP BY SUNDAY AFTERNOON AND EVENING BENEATH
40-50 KNOTS OF 0-6KM SHEAR VECTORS. LOOKING AT SOME PROXIMITY
SOUNDINGS, IT IS CONCERNING THAT MANY PIECES OF GUIDANCE SHOW
SCATTERED THUNDERSTORMS DEVELOPING SUNDAY EVENING IN A MODESTLY
UNSTABLE AND WELL SHEARED ENVIRONMENT. THERE EXISTS A CONDITIONAL
THREAT FOR SEVERE THUNDERSTORMS ON SUNDAY AFTERNOON CAPABLE OF LARGE
HAIL, DAMAGING WINDS, OR TORNADOES. WE WILL NEED TO SEE THE
INSTABILITY DEVELOP ACROSS THE AREA FOR THIS TO MANIFEST ITSELF, AND
THIS HAS RESULTED IN A MARGINAL RISK FOR SEVERE STORMS BEING ADDED
TO THE AREA ON SUNDAY AFTERNOON AND EVENING.
KEY MESSAGE 2: A ROBUST WEATHER SYSTEM WILL APPROACH ON MONDAY,
WITH SEVERE THUNDERSTORMS AND STRONG, NON-THUNDERSTORM WIND
GUSTS EXPECTED.
BY MONDAY MORNING, THE AFOREMENTIONED COLD FRONT WILL BE QUICKLY
APPROACHING THE FORECAST AREA FROM THE WEST. GUIDANCE REMAINS IN
GOOD AGREEMENT THAT ROBUST 500 HPA HEIGHT FALLS WILL OVERSPREAD A
MOISTURE RICH BOUNDARY LAYER (MID 60S TD'S, 0-3KM MIXING RATIOS
~9G/KG) AND YIELD CAPE VALUES NEAR 1000 J/KG ALONG AND AHEAD OF THE
FRONT. THE COLD FRONT LOOKS LIKE IT MAY FEATURE A TEMPERATURE
GRADIENT OF 20F-25F ALONG IT, WITH STRONG SYNOPTIC SCALE FORCING
ALONG THE FRONT ITSELF. DEEP LAYER SHEAR OF 50-60 KNOTS & STRONG LOW
LEVEL SHEAR WILL FAVOR THE MAINTENANCE OR REDEVELOPMENT OF A STRONG
QLCS ACROSS THE AREA. WITH LOW-LEVEL WINDS AROUND 45-55 KNOTS,
WIDESPREAD DAMAGING WIND GUSTS ARE POSSIBLE WITH THIS LINE OF
CONVECTION. LOW-LEVEL INSTABILITY AND SHEAR LOOKS STRONG ENOUGH TO
FAVOR QLCS TORNADOES, AS WELL. SPC HAS PLACED MUCH OF THE AREA IN A
SLIGHT OR ENHANCED RISK FOR SEVERE THUNDERSTORMS TO ACCOUNT FOR THIS
THREAT. THE PRIMARY TIMEFRAME LOOKS TO BE BETWEEN 9A AND 2P ACROSS
THE FORECAST AREA, WITH HIGHEST CONFIDENCE IN SEVERE THUNDERSTORMS
ALONG AND EAST OF A LINE FROM LANCASTER TO COLUMBIA TO BARNWELL. IN
ADDITION TO THIS, IT APPEARS THAT STRONG, NON-THUNDERSTORM WIND
GUSTS WILL BE A MAJOR THREAT BOTH AHEAD OF THE FRONT AND BEHIND IT.
AHEAD OF THE FRONT, LOW-LEVEL INSTABILITY WILL FAVOR STRONG WIND
GUSTS OF 30+ MPH MIXING TO THE SURFACE. INTENSE COLD ADVECTION IS
FORECAST BEHIND THE FRONT, WITH 40+ MPH WINDS EXPECTED WITH THIS
PERIOD OF WINDINESS. A WIND ADVISORY IS LIKELY NEEDED ON MONDAY TO
ACCOUNT FOR ALL OF THIS, WITH CONFIDENCE BOLSTER BY HIGH ECE EFI
WIND GUSTS VALUES.
KEY MESSAGE 3: A POTENTIALLY HARD FREEZE LOOKS LIKELY ON
TUESDAY NIGHT AND EARLY WEDNESDAY.
BEHIND THE FRONT ON MONDAY, A STRONG, ARCTIC HIGH PRESSURE SYSTEM IS
FORECAST TO SHIFT EASTWARD INTO THE EASTERN CONUS. ON TUESDAY, IT
SHOULD PUSH QUICKLY OVER THE APPALACHIANS AND SETTLE ACROSS THE
CENTRAL CAROLINAS BY TUESDAY NIGHT. STRONG COLD ADVECTION SHOULD
CONTINUE MONDAY NIGHT AND INTO EARLY TUESDAY, WITH TEMPS FALLING
FROM THE LOW 70S MONDAY MORNING TO THE LOW 30S BY TUESDAY MORNING.
GUIDANCE IS TYPICALLY A BIT TOO AGGRESSIVE WITH LOWS IN THIS REGIME
AS SURFACE WINDS REMAIN HIGH AND KEEP US FROM REACHING OUR FULL TEMP
POTENTIAL. STILL, LOW 30S ARE EXPECTED BY TUESDAY MORNING. FROST IS
UNLIKELY WITH THIS FIRST NIGHT OF COLD TEMPS, BUT A FREEZE IS STILL
POSSIBLE WITH A COUPLE OF HOURS TEMPS AT OR BELOW 32F. THE COLD
NIGHT IS EXPECTED TUESDAY NIGHT AND INTO WEDNESDAY MORNING. LREF AND
NBM GUIDANCE CONTINUES TO HONE IN ON AN EXTENDED PERIOD OF FREEZING
TEMPS TUESDAY NIGHT, WITH MANY AREAS SEEING A HIGH PROBABILITY OF
LOW TEMPS BELOW 28F. AS SUCH, A HARD FREEZE IS ABSOLUTELY ON THE
TABLE FOR THIS PERIOD. IDEAL RADIATIONAL COOLING CONDITIONS COMBINED
WITH A VERY DRY AIRMASS SHOULD YIELD THIS, AND CONFIDENCE REMAINS
HIGH IN THIS OCCURRING. IF YOU HAVE AGRICULTURAL INTERESTS, BE SURE
TO PREPARE FOR A FREEZE ON MON NIGHT/TUES MORN AND AGAIN ON TUES
NIGHT/WED MORNING. TEMPS WILL GRADUALLY MODERATE TOWARDS THE END OF
THE WEEK.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
OUTSIDE OF RIVER FOG, VFR CONDITIONS CONTINUE THROUGH THE TAF
PERIOD....
HIGH PRESSURE REMAINS FIRMLY IN CONTROL OF THE REGION TONIGHT
WITH CLEAR SKIES AT THE TERMINALS BARRING A FEW PASSING
CIRRIFORM CLOUDS. GUIDANCE SUGGESTS THAT LOW CLOUDS AND/OR FOG
WILL DEVELOP TONIGHT ALONG THE COASTAL PLAIN. WILL MONITOR TO
SEE IF THESE CLOUDS CAN REACH INTO OGB. OTHERWISE, THE ONLY
OTHER THREAT OF RESTRICTIONS TONIGHT COMES FROM TRANSIENT RIVER
FOG NEAR OGB/AGS. A TEMPO HAS BEEN ADDED TO BOTH TAF SITES AS
RH VALUES APPROACH 100 PERCENT AT THOSE LOCATIONS, SUGGESTING
FOG MAY FORM SOON. ONCE ANY FOG BURNS OFF, LIGHT WINDS AND
MAINLY CLEAR SKIES CONTINUE THROUGH THE END OF THE CURRENT TAF
PERIOD.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS ARE POSSIBLE ON SUNDAY
AFTERNOON AND EVENING FROM SCATTERED SHOWERS AND THUNDERSTORMS.
A COLD FRONT MOVING THROUGH ON MONDAY LIKELY BRINGS
RESTRICTIONS IN SHOWERS AND/OR THUNDERSTORMS, BOTH AHEAD OF AND
BEHIND THE BOUNDARY. A RETURN TO VFR CONDITIONS IS THEN
ANTICIPATED FOR TUESDAY ONWARD.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
DISCUSSION...PL
AVIATION...7
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