439
FXUS62 KCAE 291155
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
755 AM EDT SAT MAR 29 2025
SYNOPSIS
MOISTURE CONTINUES TO INCREASE TODAY, WITH RAIN CHANCES RISING
VERY LATE TONIGHT AND SHOWERS AND THUNDERSTORMS POSSIBLE
SUNDAY. HIGHER CHANCES FOR SHOWERS AND THUNDERSTORMS ARRIVE ON
MONDAY AS A COLD FRONT APPROACHES FROM THE WEST. NEAR TO ABOVE
NORMAL TEMPERATURES EXPECTED TO CONTINUE THROUGH THE NEXT SEVEN
DAYS.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGE(S):
- INCREASING MOISTURE TODAY AND CONTINUED WARM
- LESSENED FIRE DANGER WITH INCREASING HUMIDITIES
AN UPPER LEVEL TOUGH MOVING INTO THE LOWER MS VALLEY WILL MOVE
TOWARDS THE FORECAST AREA AND DE-AMPLIFY BEFORE CROSSING THE
AREA OVERNIGHT. SATELLITE IMAGERY SHOWS WIDESPREAD HIGH CIRRUS
CLOUDS BLANKETING THE DEEP SOUTH AND CAROLINAS AND THIS SHOULD
CONTINUE TODAY. DEEP SOUTHERLY FLOW NOTED ON FORECAST SOUNDINGS
WILL YIELD MOISTURE ADVECTION INTO THE AREA AS PWATS CURRENTLY
AROUND 0.8 INCHES SHOULD RISE OVER AN INCH BY THIS AFTERNOON AND
PEAK OVERNIGHT AROUND 1.5 INCHES (NEARLY 200% OF NORMAL).
THEREFORE, EXPECTING CUMULUS CLOUD DEVELOPMENT BY EARLY
AFTERNOON ALONG WITH THE HIGHER CLOUDS TO RESULT IN PARTLY TO
MOSTLY CLOUDY SKIES. WARM ADVECTION WILL OFFSET THE DIMINISHED
SOLAR INSOLATION FROM CLOUD COVER AND STILL EXPECT HIGH
TEMPERATURES TO BE SIMILAR TO SATURDAY WITH HIGHS IN THE LOWER
80S. MOISTURE ADVECTION CONTINUES SATURDAY NIGHT WITH SOME LIGHT
SHOWERS ASSOCIATED WITH THE APPROACHING WEAKENING SHORTWAVE
REACHING THE FAR WESTERN MIDLANDS AND UPPER CSRA AROUND 12Z
SUNDAY. CLOUD COVER AND LIGHT SOUTHERLY FLOW SHOULD LIMIT
RADIATIONAL COOLING AND EXPECT LOWS IN THE UPPER 50S TO AROUND
60 DEGREES.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/
KEY MESSAGE(S):
- SHOWERS AND THUNDERSTORMS POSSIBLE SUNDAY AND SUNDAY
AFTERNOON.
- STRONG TO SEVERE THUNDERSTORMS POSSIBLE ON MONDAY
AN ACTIVE SHORT TERM PERIOD IS EXPECTED, WITH MUCH NEEDED
RAINFALL FORECAST ACROSS THE AREA BOTH SUNDAY AFTERNOON AND
AGAIN ON MONDAY. COMPLEX SYNOPTIC PATTERN OVER THE CONUS IS
FORECAST TO UNFOLD DURING THE PERIOD. A DEAMPLIFYING SOUTHERN
STREAM SHORTWAVE IS FORECAST TO APPROACH THE AREA LATE TONIGHT
AND INTO SUNDAY. THIS WILL CONTINUE TO DEAMPLIFY AND LIFT
NORTHWARD AS A STRONGER SHORTWAVE EJECTS EASTWARD FROM THE
ROCKIES ON SUNDAY. MOISTURE RETURN IS FORECAST TO BE ROBUST
THROUGH THE DAY ON SUNDAY, WITH WIDESPREAD DEWPOINTS IN THE 60S
AND PWS RISING WELL ABOVE THE 90TH PERCENTILE BY SUNDAY
AFTERNOON. GUIDANCE HAS BEEN CONSISTENT (OUTSIDE OF THE NAM
SOLUTION) IN SHOWING WIDESPREAD SHOWERS AND THUNDERSTORMS
DEVELOPING SUNDAY AFTERNOON AND EVENING EVEN IN THE WAKE OF THE
WEAKENING TROUGH AXIS. THIS SETUP IS SLIGHTLY ODD; HOWEVER, WITH
STRONG MOISTURE ADVECTION ON THE WESTERN SIDE OF A LOW-LEVEL
RIDGE OF HIGH PRESSURE & PLENTIFUL MOISTURE, STILL THINK THAT
PRECIPITATION IS LIKELY. THERE WILL PROBABLY BE A BIT OF A
GRADIENT IN RAIN CHANCES FROM WEST TO EAST, WITH THE BEST
CHANCES OF SHOWERS/STORMS GENERALLY WEST OF I-77. ANY RAIN
SHOULD DIMINISH ON MONDAY NIGHT AS SUBSIDENCE INCREASES WITH
INCREASING SHORTWAVE RIDGING.
MONDAY LOOKS TO BE A POTENTIALLY ACTIVE DAY. SHORTWAVE TROUGH
OVER THE PLAINS IS EXPECTED TO CONTINUE TO PUSH EASTWARD, WITH
GUIDANCE HONING IN ON A MORE FOCUSED SHORTWAVE DEVELOPING IN THE
TENNESSEE VALLEY AND SHIFTING TOWARDS US ON MONDAY AFTERNOON. A
BROAD RESERVOIR OF INSTABILITY AND ROBUST LOW-LEVEL MOISTURE IS
FORECAST TO EXIST TO OUR SOUTHWEST DURING THIS PERIOD AND LIKELY
WILL BE ADVECTED INTO THE CAROLINAS THROUGH THE DAY ON MONDAY.
FORECAST MODELS CONSISTENTLY HAVE BEEN CHARACTERIZING THIS
AIRMASS TO FEATURE 750-1250 J/KG OF CAPE WITH INCREASING SHEAR
ON THE ORDER OF 35-45 KNOTS BY MONDAY AFTERNOON. THERE IS SOME
EXPECTATION THAT A REMNANT AREA OF CONVECTION SHOULD BE CENTERED
SOMEWHERE TO OUR WEST AND IN THE TENNESSEE RIVER VALLEY BY
MONDAY MORNING. OUR SEVERE THREAT IS GOING TO BE LARGELY
MODULATED BY THIS FEATURE, AS IT COULD BE COME A ROBUST MCS AND
DIVE INTO THE GREATER INSTABILITY ALONG THE GULF COAST AND
PREVENT ANY ROBUST MOISTURE ADVECTION ON MONDAY. HOWEVER, IF
THIS FEATURE IS SOMEWHAT ATTACHED TO THE COLD FRONT TO OUR WEST
BY MONDAY MORNING, A PRETTY ROBUST SEVERE THREAT COULD
MATERIALIZE BY MONDAY AFTERNOON. STRONG, DAMAGING WINDS LOOK TO
BE THE PRIMARY THREAT BUT EMBEDDED TORNADOES (ESPECIALLY WITHIN
A POTENTIAL QLCS) CANNOT BE RULED OUT BY MONDAY AFTERNOON. THE
INSTABILITY/SHEAR COMBO IS ONE WE HAVEN'T REALLY SEEN YET THIS
YEAR, SO WE WILL NEED TO WATCH CONVECTIVE TRENDS AND FORECASTS
CLOSELY OVER THE NEXT 36-48 HOURS. SPC MAINTAINS A SLIGHT RISK
OVER THE AREA TO ACCOUNT FOR THE THREAT. HIGHS ON MONDAY WILL
LIKELY BE IN THE UPPER 70S OR LOWER 80S. THE RAIN THREAT SHOULD
QUICKLY SHIFT EASTWARD ON MONDAY NIGHT AS DRIER AND COOLER AIR
FILTERS IN BEHIND THE COLD FRONT.
LONG TERM /TUESDAY THROUGH FRIDAY/
KEY MESSAGE(S):
- WELL ABOVE NORMAL TEMPERATURES ARE LIKELY BY THE END OF THE
PERIOD
GUIDANCE, IN GENERAL, IS A BIT MORE ON THE SAME PAGE AS WE
MOVE BEYOND THE MONDAY SYSTEM. THE EVOLUTION OF THE PATTERN
STILL REMAINS COMPLEX AND COMPLICATED AS THE SYSTEM MODULATING
IT ALL WILL REMAIN OVER THE NORTHEASTERN PACIFIC/GULF OF ALASKA
THROUGH MUCH OF THE PERIOD. THE GFS/GEFS SOLUTION HAVE TRENDED
TOWARDS THE EC/ECE SOLUTION (WHICH REMAINS LARGELY UNCHANGED
FROM LAST NIGHT). BASICALLY, TRANSIENT SURFACE HIGH PRESSURE AND
TROUGHING IS EXPECTED TO PASS THROUGH THE AREA ON TUESDAY. THIS
SHOULD QUICKLY SHIFT EASTWARD BY WEDNESDAY, WITH SOUTHERLY AND
SOUTHEASTERLY FLOW AGAIN COMMENCING AS HEIGHTS BEGIN TO RISE
ACROSS THE AREA. THIS MAY BE OUR PRIMARY CHANCE FOR RAIN DURING
THE UPCOMING WEEK, AS GUIDANCE DOES SHOW SOME ROBUST MOISTURE
CONVERGENCE ACROSS THE AREA ON WEDNESDAY NIGHT. I'M SOMEWHAT
SKEPTICAL OF OVERALL RAIN CHANCES GIVEN THE RISING HEIGHTS BUT
KEPT SOME POPS IN THERE TO ACCOUNT FOR THE THREAT CURRENTLY.
AS ALL OF THIS OCCURS, MULTIPLE SHORTWAVES ARE EXPECTED TO
ESTABLISH A DEEP TROUGH ACROSS THE DESERT SOUTHWEST BY THE
MIDDLE OF THE WEEK. MULTIPLE SHORTWAVES ARE FORECAST TO PASS
NORTHEASTWARD IN THE FLOW, WITH STRONG UPSTREAM BLOCKING OVER
THE NORTH ATLANTIC HELPING RESULT IN A STRONG, ANOMALOUSLY
STRONG MID-LEVEL RIDGE ACROSS THE SOUTHEASTERN CONUS. AS A
RESULT, CONFIDENCE IS BEGINNING TO INCREASE IN A PERIOD OF NEAR
RECORD HIGHS IN THE THUR-SAT PERIOD OF THIS LONG TERM FORECAST.
THE COMBINATION OF GUIDANCE SHOWING VERY HIGH HEIGHTS, STRONG
SUBSIDENCE BENEATH THE RIDGE KEEPING AFTERNOON SHOWER/STORM
CHANCES AT BAY, AND ANTECEDENT DRYNESS IS LEADING TO ABOVE
NORMAL FORECASTER CONFIDENCE IN VERY WARM TEMPS. THE RECORD
HIGHS AT CAE DURING THIS PERIOD ARE PRETTY ATTAINABLE (LOW 90S
EACH DAY) AND MAY END UP BEING EXPLICITLY FORECAST, ESPECIALLY
SINCE THE DETERMINISTIC NBM SOLUTION TENDS TO STRUGGLE WITH OUR
FIRST WARM SPELL OF THE YEAR. OTHERWISE, SENSIBLE WEATHER LOOKS
FAIRLY QUIET AS THE STRONG RIDGE WILL TEND TO SUPPRESS ANYTHING
OUTSIDE OF WARM TEMPS.
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
VFR CONDITIONS PERSIST MUCH OF THE PERIOD BEFORE EXPECTED
STRATUS DEVELOPMENT TOWARD END OF PERIOD BRINGING POSSIBLE IFR
CONDITIONS.
AN UPPER DISTURBANCE OVER THE MS VALLEY WILL CONTINUE TO LIFT
NORTHEASTWARD TOWARD THE REGION TODAY AND TONIGHT. SOME PATCHY
FOG AND LOW STRATUS DEVELOPED THIS MORNING AT OGB AND THUS
TEMPORARY IFR TO LIFR RESTRICTIONS WILL BE POSSIBLE HERE UNTIL
AROUND 13-14Z BEFORE THIS MIXES OUT, BUT ALL OTHER SITES HAVE
REMAINED AT VFR CONDITIONS. THE REST OF THE PERIOD CONTINUES TO
SEE HIGH CLOUDS STREAM INTO THE REGION AS MOISTURE CONTINUES TO
INCREASE WHERE SOME SCATTERED TO BROKEN CUMULUS ARE THEN
POSSIBLE THIS AFTERNOON WITH WINDS OUT OF THE SOUTH TO SOUTHEAST
AT 5-10 KTS GENERALLY. AS MOISTURE CONTINUES TO INCREASE TOWARD
THE END OF THE PERIOD, LOW STRATUS AND POSSIBLE PATCHY FOG IS
EXPECTED TO FORM AFTER 7-9Z AND INTO SUNDAY MORNING WHERE IFR
CONDITIONS WILL BE POSSIBLE.
EXTENDED AVIATION OUTLOOK...THE NEXT CHANCE OF RESTRICTIONS AND
RAINFALL CONTINUES TO BE ON SUNDAY WITH MORE RESTRICTIONS
POSSIBLE MONDAY AS MORE RAIN CHANCES ACCOMPANY A PASSING COLD
FRONT.
FIRE WEATHER
THE SOUTH CAROLINA FORESTRY COMMISSION HAS ISSUED A STATEWIDE
BURN BAN UNTIL FURTHER NOTICE.
MOISTURE CONTINUES TO INCREASE TODAY WITH MINIMUM RH VALUES
EXPECTED TO BE NEAR 35-40 PERCENT DURING THE AFTERNOON WITH
SOUTH TO SOUTHEAST WINDS OF 5-10 MPH WITH SOME ISOLATED GUSTS
TOWARD 15-20 MPH POSSIBLE. AS OUR NEXT SYSTEM APPROACHES,
MOISTURE AND RAIN CHANCES CONTINUE TO INCREASE INTO SUNDAY AND
MONDAY.
CAE WATCHES/WARNINGS/ADVISORIES
SC...NONE.
GA...NONE.
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