715  
FXUS62 KCAE 221159  
AFDCAE  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE COLUMBIA SC  
659 AM EST THU FEB 22 2024  
   
SYNOPSIS
 
 
DRY BUT SOME INCREASING CLOUD COVER EXPECTED THURSDAY AHEAD OF  
OUR NEXT WEATHER SYSTEM. SHOWERS AND POSSIBLY A FEW  
THUNDERSTORMS ARE LIKELY FRIDAY WITH SOME BREEZY WINDS. DRIER  
AND COOLER AIR FILLS IN FOR SATURDAY, BUT A FEW ISOLATED SHOWERS  
REMAIN POSSIBLE AS AN UPPER LEVEL SYSTEM SWINGS THROUGH. DRY AND  
CALM WEATHER EXPECTED SUNDAY INTO THE MIDDLE OF THE WEEK BEFORE  
A MAJOR WARM UP IS EXPECTED.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
MORNING ANALYSIS SHOWED GENERALLY ZONAL FLOW ACROSS THE COUNTRY  
WITH A SHORTWAVE MOVING ACROSS THE CENTRAL PLAINS WITH SOME  
WEAK DOWNSTREAM RIDGING OVER THE GULF COAST AND TN VALLEY. AT  
THE SURFACE, LOW PRESSURE WAS DEVELOPING OVER NORTHERN OKLAHOMA  
WHILE HIGH PRESSURE WAS LOCATED ALONG THE EASTERN SEABOARD. A  
RELATIVELY DRY AIR MASS OVER THE REGION WITH PWATS AROUND 0.4  
INCHES IS EXPECTED TO GRADUALLY MOISTEN THROUGH THE DAY AS  
SOUTHERLY FLOW DEVELOPS WITH WINDS FROM THE SOUTH AND GUSTY AT  
TIMES THROUGH THE AFTERNOON.  
 
A STRONGER SURGE IS MOISTURE IS EXPECTED AFTER 00Z AS THE UPPER  
TROUGH TO THE WEST MOVES EASTWARD AND DEEPENS A BIT AS SOME  
NORTHERN STREAM ENERGY DIGS SOUTH INTO THE GREAT LAKES AND OHIO  
VALLEY REGION. THE SURFACE LOW OVER OK WILL LIFT NORTHEASTWARD  
INTO THE WESTERN OHIO VALLEY AND DEEP SOUTHWESTERLY FLOW WILL  
DEVELOP ACROSS THE REGION DURING THE 00Z-06Z TIME FRAME AND  
PWATS ARE FORECAST TO RISE TO AROUND AN INCH BY 06Z WITH STRONG  
MOISTURE ADVECTION FROM A 35-45 KNOT 850MB LOW LEVEL JET. EXPECT  
A SCATTERED TO BROKEN LINE OF SHOWERS (50-70 PERCENT CHANCE OF  
RAIN) TO MOVE INTO THE FORECAST AREA FROM THE WEST AROUND 06Z  
AND SHIFT EASTWARD THROUGH THE REGION DURING THE PREDAWN HOURS.  
WHILE THERE WILL BE STRONG HEIGHT FALLS AS THE UPPER TROUGH  
APPROACHES THE FORECAST AREA, INSTABILITY IS GENERALLY NON-  
EXISTENT, BOTH SURFACE BASED AND ELEVATED, SO DECIDED TO REMOVE  
THE MENTION OF THUNDER THROUGH 12Z. OVERALL RAINFALL AMOUNTS ARE  
EXPECTED TO BE LIGHT THROUGH 12Z WITH MOST LOCATIONS RECEIVING  
LESS THAN A QUARTER INCH OF RAIN, BUT SOME LOCATIONS IN THE  
WESTERN MIDLANDS MAY GET A QUARTER TO THIRD OF AN INCH.  
 
TEMPERATURES SHOULD AGAIN BE MILD AND WELL ABOVE NORMAL AND  
SLIGHTLY WARMER TODAY WITH SOUTHERLY WINDS DEVELOPING AND EXPECT  
HIGHS TO RANGE FROM THE MID 60S NORTH TO THE UPPER 60S TO NEAR  
70 DEGREES SOUTHEAST MIDLANDS AND CSRA. OVERNIGHT LOWS TONIGHT  
SHOULD BE LIMITED BY A MIXED BOUNDARY LAYER WITH WINDS STAYING  
UP AND WIDESPREAD CLOUDS WITH LOWS IN THE LOWER TO MID 50S.  
 

 
   
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/
 
 
AS NOTED IN THE NEAR TERM DISCUSSION, BY 12Z FRIDAY THE BAND OF  
PREFRONTAL SHOWERS WILL BE PUSHING THROUGH THE AREA AS MOISTURE  
CONVERGENCE DRIVES PWAT'S TO 0.8-1.0". INSTABILITY LOOKS TO  
REMAIN FAIRLY LIMITED (LESS THAN 200 J/KG MUCAPE ACROSS THE  
HREF MEMBERS) THROUGH 15Z; THE STRONGEST CORE OF THE 850MB JET  
AHEAD OF THE FRONT WILL HOWEVER PUSH THROUGH WITH THIS BAND OF  
SHOWERS EARLY FRIDAY MORNING. SO THANKS TO THE DIURNAL TIMING,  
THE SHEAR AND THERMODYNAMIC PROFILES WILL IN ALL LIKELIHOOD NOT  
LINE UP FOR AN APPRECIABLE SEVERE THREAT FRIDAY MORNING, BUT A  
FEW WAVES OF GUSTY SHOWERS ARE LIKELY INTO THE LATE MORNING.  
RAIN CHANCES WILL THEN LINGER INTO THE AFTERNOON AS HEIGHTS  
RAPIDLY FALL ALOFT AS THE VORT MAX OF THE 500MB TROUGH NEARS THE  
AREA WITH DRIER AIR FILLING IN ALOFT. SURFACE MOISTURE HOWEVER  
WILL BE SLOWER TO SCOUR OUT AND WITH THE HEIGHT FALLS ALOFT,  
INSTABILITY WILL QUICKLY DEVELOP AHEAD OF THE SURFACE  
CONVERGENCE FROM THE COLD FRONT ITSELF; HREF MEMBERS PROG AROUND  
1000 J/KG AHEAD OF THE FRONT, WITH SURFACE DEW POINTS IN THE  
50'S STILL AND PWAT'S STILL AROUND 0.8". AT THIS POINT, THE LOW  
LEVEL SHEAR PROFILES WITH THE 50+ KNOT 850MB JET WILL HAVE  
SHIFTED EASTWARD (AN INVERSE OF THE MORNING WAVE OF SHOWERS).  
DEEP LAYER SHEAR WILL HOWEVER REMAIN SUFFICIENT WITH  
UNIDIRECTIONAL WESTERLY 0-6KM BULK SHEAR AROUND 50 KNOTS BY  
EARLY AFTERNOON. SO NO SURPRISE GIVEN THE INCREASING  
INSTABILITY, DRY AIR ALOFT TO SUPPORT ISOLATED CELLS, AND STRONG  
DEEP UNIDIRECTIONAL SHEAR, THE HRRR AND HI- RES NAM BOTH DEPICT  
SOME SUPERCELL-LIKE STRUCTURES PUSHING ACROSS THE MIDLANDS IN  
THE AFTERNOON WITH EVIDENT UH SWATHS; HAIL WOULD BE THE PRIMARY  
THREAT WITH ANY OF THESE CELLS THAT DEVELOP DUE TO CONVECTIVE  
MODE, HODOGRAPH TYPE, AND DRY AIR ALOFT. A BIG CAVEAT WITH THIS  
SETUP IS THE FAIRLY NARROW WINDOW FOR PARAMETERS TO LINE UP FOR  
STRONG CONVECTION. DRY AIR WILL BE RAPIDLY PUSHING IN ALOFT AND  
AT THE SURFACE, WHICH COULD ACT TO SUPPRESS ANY DEVELOPMENT IN  
THE FIRST PLACE IF ADVECTION IS FASTER AND/OR STRONGER THAN  
PROGGED IN THE HREF MEMBERS.  
 
REGARDLESS, BY FRIDAY EVENING DRY AIR WILL FILL IN AT  
THE SURFACE, DROPPING DEW POINTS DOWN IN THE 30'S BY SATURDAY  
MORNING WITH SOME WEAK COLD ADVECTION AND DOWNSLOPING FLOW.  
GUIDANCE CONTINUES TO BE FAIRLY BULLISH WITH A STRONG SHORTWAVE  
ROUNDING THE BASE OF THE TROUGH VORT MAX SATURDAY AFTERNOON,  
PROVIDING SOME FORCING AND ADDITIONAL HEIGHT FALLS FOR SCATTERED  
CONVECTION. THIS SETUP HOWEVER IS A MORE EXAGGERATED VERSION OF  
FRIDAY AFTERNOON'S WITH PWAT'S DOWN BELOW 0.6" AND SURFACE DEW  
POINTS IN THE 30'S. BUT LAPSE RATES WILL ESSENTIALLY BE DRY  
ADIABATIC UP THROUGH 700MB AND THE STEEP HEIGHT FALLS FROM  
700-500MB WILL ALLOW SOME WEAK INSTABILITY TO DEVELOP. OVERALL,  
ISOLATED SHOWER ACTIVITY IS EXPECTED SATURDAY AFTERNOON BUT  
LIKELY HIGHLY SUPPRESSED BY DRY AIR ALOFT. SOME GUSTY WINDS AND  
GRAUPEL, DUE TO LOW FREEZING LEVELS AND INSTABILITY ABOVE 0 C,  
ARE POSSIBLE IN ANY STRONG CELLS THAT DO DEVELOP HOWEVER BUT  
COVERAGE IS EXPECTED TO BE THIN.  
 

 
   
LONG TERM /SUNDAY THROUGH WEDNESDAY/
 
 
DRY HIGH PRESSURE WITH NORTHWEST FLOW ALOFT IS EXPECTED TO FILL  
IN SUNDAY FOLLOWED BY HIGH CONFIDENCE IN A STEADILY WARMING  
PATTERN THROUGHOUT NEXT WEEK. TEMPS ARE EXPECTED TO RISE FROM  
NEAR AVERAGE AT THE BEGINNING OF THE WEEK TO WELL ABOVE AVERAGE  
BY WEEK'S END AS DEEP RIDGING DEVELOPS ACROSS THE EASTERN CONUS;  
GEFS AND EC MEMBERS ARE IN VERY GOOD AGREEMENT OVERALL WITH  
BUILDING HEIGHTS ALOFT AND STEADILY INCREASING SOUTHWEST  
FLOW BELOW 700MB. GEFS PWAT'S JUMP BACK ABOVE AVERAGE BY THE  
MIDDLE OF THE WEEK AND PRECIP CHANCES START TO INCREASE WITH THE  
MOIST SOUTHWEST FLOW REGIME. NAEFS HIGHLIGHTS THIS PATTERN WELL  
WITH 90TH+ PERCENTILE HEIGHTS, TEMPS, AND MOISTURE FROM  
WEDNESDAY ONWARD; NBM SURFACE TEMPS CONSEQUENTLY ARE RUNNING  
10-15 DEGREES ABOVE AVERAGE BY THE END OF THE WEEK WITH A TIGHT  
DISTRIBUTION ACROSS MEMBERS.  
 

 
   
AVIATION /12Z THURSDAY THROUGH MONDAY/
 
 
VFR CONDITIONS EXPECTED THROUGH 06Z THEN SOME MVFR CIGS EXPECTED  
NEAR THE END OF THE FORECAST PERIOD. SOME EARLY FOG AT AGS/OGB  
AT START OF FORECAST.  
 
ANY LINGERING FOG THIS MORNING SHOULD BURN OFF BY 13Z. WINDS  
WILL PICK UP FROM THE SOUTH BY 15Z AHEAD OF AN APPROACHING COLD  
FRONT WITH WINDS EXPECTED TO INCREASE TO AROUND 10 TO 12 KNOTS  
WITH GUSTS TO 20 KNOTS LATE MORNING THROUGH THE AFTERNOON. GUSTS  
SHOULD SUBSIDE BY SUNSET BUT WINDS ARE EXPECTED TO STAY UP  
AROUND 8 TO 10 KNOTS AFTER 00Z AS THE COLD FRONT DRAWS CLOSER.  
SOME SCATTERED HIGH CLOUDS MAY KEEP PASSING OVER THE REGION  
THROUGH THE PERIOD BUT GRADUALLY WILL LOWER IN HEIGHT AFTER 00Z  
AS THE COLD FRONT APPROACHES FROM THE WEST. SOME MVFR CIGS  
EXPECTED AFTER 09Z AS LOWER CLOUDS PRECEDING THE FRONT ARRIVE.  
WINDS WILL PICK UP LATE TONIGHT WITH SOME GUSTS TO 20 KNOTS  
AFTER 06Z DUE TO A STRONG LOW LEVEL JET.  
 
EXTENDED AVIATION OUTLOOK...INCREASING CHANCE FOR RESTRICTIONS  
THURSDAY NIGHT INTO FRIDAY AS A COLD FRONT MOVES THROUGH THE REGION.  
 

 
   
CAE WATCHES/WARNINGS/ADVISORIES
 
 
GA...NONE.  
SC...NONE.  
 

 
 

 
 
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