755  
FXUS64 KMRX 231848  
AFDMRX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
248 PM EDT WED SEP 23 2026  
   
..NEW DISCUSSION
 
 
   
KEY MESSAGES
 
 
UPDATED AT 247 PM EDT WED SEP 23 2026  
 
- NUMEROUS SHOWERS AND STORMS WILL CONTINUE THIS AFTERNOON INTO THE  
EVENING. LOCALIZED FLOODING DUE TO HEAVY RAINFALL IS POSSIBLE, IN  
ADDITION TO GUSTY WINDS.  
 
- COOLER AND DRIER CONDITIONS ARE EXPECTED THROUGH THE WEEKEND  
BEFORE A WARMING TREND EARLY NEXT WEEK.  
 

 
   
DISCUSSION
 
 
ISSUED AT 247 PM EDT WED SEP 23 2026  
 
CURRENTLY, A SHORTWAVE IS MOVING THROUGH THE AREA OVERHEAD WITH AN  
UPSTREAM JET APPROACHING FROM THE WEST AND INVERTED SURFACE  
TROUGHING. THIS HAS PUT THE REGION IN THE LEFT-EXIT REGION OF THE  
JET, LEADING TO LARGE-SCALE LIFT. WHEN COMBINED WITH PWAT VALUES OF  
1.3 TO 1.4 INCHES, THIS HAS AND WILL CONTINUE TO PROVIDE SUPPORT FOR  
SHOWERS AND STORMS DURING THE AFTERNOON AND EVENING. MORNING  
CONVECTION AND CLOUDS HAS LIMITED HEATING AND DESTABILIZATION IN  
SOME AREAS, BUT UP TO 1,000 J/KG OF MLCAPE IS EXPECTED. WITH  
FREEZING LEVELS OF 14,000 FEET OR HIGHER AND RECENT RAIN FOR SOME,  
EFFICIENT WARM RAIN PROCESSES CONTINUE TO EMPHASIZE LOCALIZED FLASH  
FLOODING AS THE MAIN CONCERN. SOME GUSTY WINDS ARE POSSIBLE BUT NOT  
TO THE SAME DEGREE AS FLOODING. CAMS DIFFER ON HOW MUCH COVERAGE  
LASTS OVERNIGHT, BUT INTENSITY WILL BE LESSENED AS INSTABILITY IS  
LOST. BY THURSDAY, TROUGHING WILL HAVE MOVED OFF TO OUR EAST,  
LEADING TO LESS UPPER SUPPORT. STILL, INVERTED SURFACE TROUGHING AND  
LINGERING MOISTURE WILL KEEP AT LEAST LOW-END CHANCES FOR RAIN IN  
THE AREA. DURING THIS TIME, A LOW IN THE ATLANTIC WILL BE DEEPENING  
AS UPPER TROUGHING MOVES OVERHEAD.  
 
BY FRIDAY, THE LOW IN THE ATLANTIC WILL DEEPEN INTO A NOR'EASTER AS  
IT MOVES ALONG THE NEW ENGLAND COAST. THIS WILL LEAD TO BROAD  
NORTHWESTERLY FLOW ACROSS THE REGION, PULLING DOWN COOLER AND DRIER  
AIR ASSOCIATED WITH HIGH PRESSURE TO THE NORTH. DRY AND MORE FALL-  
LIKE WEATHER CAN BE EXPECTED WITH WIDESPREAD HIGHS IN THE 70S  
EXPECTED THROUGH THE WEEKEND. RADIATIONAL COOLING, ESPECIALLY FRIDAY  
NIGHT, WILL ALLOW LOWS TO DROP INTO THE 50S AND UPPER 40S IN THE  
NORTHEAST. ANOTHER WARMING TREND IS EXPECTED EARLY NEXT WEEK AS  
HEIGHTS RISE AND ANOTHER SURFACE LOW DEVELOPS IN THE GREAT PLAINS,  
LEADING TO A SOUTHERLY SHIFT IN WINDS.  
 

 
   
AVIATION
 
 
(18Z TAFS)  
ISSUED AT 100 PM EDT WED SEP 23 2026  
 
THE MAIN AVIATION IMPACT THROUGH THE PERIOD WILL BE CONTINUED  
SHOWERS AND STORMS, ALREADY BEING SEEN TO THE WEST OF TRI AND TYS.  
ALL SITES HAVE IMPROVED BACK TO VFR WITH THESE CONDITIONS EXPECTED  
TO REMAIN FOR AT LEAST A COUPLE OF HOURS BEFORE RAIN FILLS BACK IN  
THROUGH THE AFTERNOON. TIMING WILL BE EARLIEST AT CHA AND LATEST  
AT TRI BUT WITH A POTENTIALLY SHORTER DURATION AT CHA. ACTIVITY  
WILL CONTINUE INTO THE EVENING AND POSSIBLY OVERNIGHT AT TRI,  
LEADING TO PROLONGED MVFR REDUCTIONS. FOG IS ALSO POSSIBLE AT TRI  
AND TYS WITH MVFR OR LOWER LIKELY AT ALL SITES BY EARLY MORNING.  
CONDITIONS WILL GRADUALLY IMPROVE INTO THURSDAY.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
CHATTANOOGA AIRPORT, TN 64 80 61 80 / 70 30 20 0  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 63 76 58 75 / 80 40 0 0  
OAK RIDGE, TN 62 76 57 76 / 80 40 0 0  
TRI CITIES AIRPORT, TN 57 70 49 72 / 90 30 0 0  
 

 
   
MRX WATCHES/WARNINGS/ADVISORIES
 
 
NC...NONE.  
TN...NONE.  
VA...FLOOD WATCH UNTIL 10 PM EDT THIS EVENING FOR LEE-WISE.  
 

 
 

 
 
DISCUSSION...BW  
AVIATION...BW  
 
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