452  
FXUS64 KMRX 220605  
AFDMRX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
205 AM EDT TUE SEP 22 2026  
   
..NEW DISCUSSION, AVIATION
 
 
   
KEY MESSAGES
 
 
UPDATED AT 159 AM EDT TUE SEP 22 2026  
 
- SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TONIGHT THROUGH  
WEDNESDAY. A FEW STRONG TO SEVERE STORMS CAPABLE OF DAMAGING  
WINDS AREN'T OUT OF THE QUESTION, BUT OVERALL SEVERE CHANCES ARE  
LOW. ADDITIONALLY, SOME LOCALIZED FLOODING COULD ALSO OCCUR,  
BUT AGAIN CHANCES ARE RELATIVELY LOW.  
 
- TUESDAY WILL BE THE LAST DAY WITH WELL ABOVE NORMAL  
TEMPERATURES. WEDNESDAY WILL FEATURE NEAR-NORMAL TEMPERATURES  
AS A PATTERN SHIFT OCCURS, WITH BELOW NORMAL TEMPERATURES  
EXPECTED THURSDAY ONWARD.  
 

 
   
DISCUSSION
 
 
ISSUED AT 159 AM EDT TUE SEP 22 2026  
 
OVER THE NEXT 48 HOURS A REX BLOCK PATTERN WILL TAKE SHAPE OVER THE  
EASTERN CONUS, WITH AN UPPER LOW DEEPENING OVER THE OHIO VALLEY AND  
CENTRAL APPALACHIAN REGION AND THE UPPER HIGH TO ITS NORTH  
STRENGTHENING OVER THE CANADIAN SIDE OF THE GREAT LAKES REGION.  
MEANWHILE, SURFACE HIGH PRESSURE DEVELOPS BENEATH THE RIDGE OVER THE  
GREAT LAKES WHICH WILL HELP TO PUSH A WEAK FRONT, WHICH WAS SITUATED  
FROM WEST VIRGINIA SOUTHWEST INTO THE CUMBERLAND PLATEAU THIS  
EVENING, SOUTHWARD THROUGH THE AREA SOMETIME LATE TUESDAY AFTERNOON  
AND EVENING. ALL OF THIS WILL RESULT IN CONTINUED SCATTERED TO  
NUMEROUS SHOWER AND THUNDERSTORM ACTIVITY ACROSS THE REGION THROUGH  
LATE WEDNESDAY EVENING, WITH THE BEST COVERAGE DURING DIURNALLY  
FAVORED DAYTIME HOURS BUT ALSO WITH LINGERING CONVECTION DURING THE  
OVERNIGHT HOURS. FOR TUESDAY, WITH THE BOUNDARY SLOWLY SHIFTING  
SOUTH, THE THREAT OF ANY STRONG TO SEVERE STORMS SHOULD LARGELY BE  
RELEGATED TO THE FAR SOUTHERN TN VALLEY AND OUR WESTERN NC COUNTIES.  
HOWEVER, PWATS WILL REMAIN ELEVATED THROUGH WEDNESDAY, AND STORM  
MOTIONS VERY SLOW, SO AN ISOLATED FLOODING THREAT COULD EXIST  
VIRTUALLY ANYWHERE THROUGH THAT PERIOD, THOUGH IN GENERAL THE  
RISK OF FLOODING SHOULD SHIFT SOUTH WITH TIME AS WELL.  
 
SPEAKING OF WEDNESDAY, THE PATTERN CHANGE REALLY GETS UNDERWAY LATE  
WEDNESDAY. THE UPPER LOW ASSOCIATED WITH THE REX BLOCK PATTERN,  
DIVES EAST SOUTHEAST TO THE COASTAL CAROLINA REGION WEDNESDAY NIGHT  
INTO THURSDAY, ALLOWING FOR PERSISTENT NORTHERLY FLOW TO SPREAD  
ACROSS THE CWA, USHERING IN SIGNIFICANTLY COOLER AND DRIER AIR.  
WE'LL STILL BE WARM ON WEDNESDAY, WITH HIGHS IN THE MID TO UPPER 80S  
SOUTH OF I-40. BUT THURSDAY THROUGH THE WEEKEND WILL SEE HIGHS  
TOPPING OUT LARGELY IN THE 70S, EXCEPT THE FAR SOUTHERN TN VALLEY  
WHICH MAY STILL MANAGE TO BEST THE 80 DEGREE MARK EACH DAY. PERHAPS  
THE MORE IMPORTANT NOTE WILL BE OVERNIGHT LOWS IN THE 40S AND 50S  
FRIDAY NIGHT ONWARD.  
 

 
   
AVIATION
 
 
(06Z TAFS)  
ISSUED AT 159 AM EDT TUE SEP 22 2026  
 
SCATTERED THUNDERSTORMS WILL IMPACT TYS AND TRI FOR THE FIRST FEW  
HOURS OF THE TAF. CHA SHOULD REMAIN VFR AS STORMS REMAIN NORTH OF  
THE TERMINAL OVERNIGHT. AFTER SHOWERS AND STORMS EXIT, THERE COULD  
BE A SHORT WINDOW OF FOG AT TRI JUST PRIOR TO SUNRISE, BUT ANY  
CLEARING IN SKY COVER MAY SUPPORT SUB-MVFR VSBY. ADDITIONAL  
THUNDERSTORMS DEVELOP THIS AFTERNOON AND WILL BE SCATTERED IN  
COVERAGE. ADDITIONAL TAFS WILL REFINE THE TIMING FOR EACH  
TERMINAL. SHOWERS AND STORMS LINGER UNTIL TUESDAY EVENING BEFORE  
DISSIPATING. VFR CONDITIONS RETURN FOR THE LAST FEW HOURS OF THE  
TAF.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
CHATTANOOGA AIRPORT, TN 91 68 86 65 / 70 30 60 40  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 87 67 82 64 / 70 50 80 80  
OAK RIDGE, TN 86 66 82 63 / 70 40 70 50  
TRI CITIES AIRPORT, TN 82 63 77 58 / 80 70 80 60  
 

 
   
MRX WATCHES/WARNINGS/ADVISORIES
 
 
NC...NONE.  
TN...NONE.  
VA...NONE.  

 
 

 
 
DISCUSSION...CD  
AVIATION...BH  
 
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