846  
FXUS64 KMRX 052335  
AFDMRX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
735 PM EDT SAT SEP 5 2026  
   
..NEW AVIATION
 
 
   
KEY MESSAGES
 
 
UPDATED AT 722 PM EDT SAT SEP 5 2026  
 
- ISOLATED SEVERE STORMS POSSIBLE THROUGH EARLY EVENING, MAINLY  
ALONG AND SOUTH OF INTERSTATE 40. DAMAGING WINDS AND FREQUENT  
LIGHTNING ARE THE MAIN CONCERNS.  
 
- HEAT INDICES OF 100+ ACROSS THE SOUTHERN TENNESSEE VALLEY BUT  
BELOW CRITERIA FOR A HEAT ADVISORY FOR SUNDAY.  
 
- SCATTERED STORMS AGAIN SUNDAY, MAINLY EAST OF INTERSTATE 75, AND  
TODAY, AND ISOLATED STORMS MONDAY, MAINLY ALONG AND WEST OF  
INTERSTATE 75.  
 
- DRIER CONDITIONS RETURN FOR MUCH OF NEXT WEEK, UNTIL THE LATER  
HALF.  
 

 
   
DISCUSSION
 
 
ISSUED AT 230 PM EDT SAT SEP 5 2026  
 
CURRENTLY, AN OUTFLOW BOUNDARY IS MOVING SOUTH ACROSS THE SOUTHERN  
HALF OF THE TENNESSEE VALLEY AND SOUTHERN PLATEAU. SCATTERED STORMS  
CONTINUE TO DEVELOP ALONG THIS BOUNDARY. MLCAPES OF 2500 AND DCAPES  
OF 900-1100. MICROBURSTS PARAMETER OF 5-7 SO ISOLATED DAMAGING WINDS  
FROM THESE STORMS ARE POSSIBLE.  
 
SATELLITE AND SPC MESO-ANALYSIS SHOWS AIRMASS HAS STABILIZED OVER  
EAST KENTUCKY, NORTHERN HALF OF TENNESSEE, SOUTHWEST VIRGINIA SO  
EXPECT THESE AREAS TO REMAIN DRY THE REST OF TODAY.  
 
AREAS ALONG AND SOUTH OF THE OUTFLOW BOUNDARY REMAIN VERY HOT WITH  
HEAT INDICES OVER 100 DEGREES. NORTH OF THE BOUNDARY CONDITIONS  
ARE MUCH BETTER. HOWEVER, GIVEN THE OUTSIDE EVENTS WE WILL  
CONTINUE THROUGH EXPIRATION.  
 
MOST CLEAR SKY, CALM WIND, AND RECENT RAINS WILL ALLOW FOR AREAS OF  
FOG DEVELOPMENT TONIGHT SOME DENSE, ESPECIALLY NEAR AREA WATERWAYS.  
 
FOR SUNDAY, ANOTHER MCV OR SHORT-WAVE WILL MOVE SOUTHEAST ACROSS THE  
AREA. ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS  
ANTICIPATED MAINLY ALONG AND EAST OF INTERSTATE 75. AIRMASS WILL BE  
FAVORABLE FOR LOCALIZED DAMAGING WINDS, FREQUENT LIGHTNING AND  
LOCALLY HEAVY RAINS.  
 
FOR MONDAY, AN INVERTED SURFACE TROUGH ACROSS THE PLATEAU AND  
WESTERN TENNESSEE VALLEY WILL SUPPORT ISOLATED CONVECTION MAINLY  
ALONG AND WEST OF INTERSTATE 40. AGAIN, STRONG/GUSTY WINDS AND  
FREQUENT LIGHTNING WILL BE THE MAIN CONCERN.  
 
FOR TUESDAY AND WEDNESDAY, UPPER RIDGING BUILDS BACK OVER THE  
TENNESSEE VALLEY AND SOUTHERN APPALACHIANS PRODUCING HOT AND DRY  
CONDITIONS. DEWPOINTS WILL BE IN THE MIDDLE AND UPPER 60S WHICH WILL  
LIMIT THE HEAT INDICES BELOW HEAT ADVISORY CRITERIA.  
 
THE UPPER RIDGE FLATTENS FOR THURSDAY AS A SHORT-WAVES AND FRONTAL  
BOUNDARY APPROACHES THE AREA. SCATTERED SHOWERS AND STORMS ARE  
EXPECTED. THE BOUNDARY MOVES SOUTH OF THE AREA FOR FRIDAY.  
 
FOR SATURDAY, RETURN SOUTHERLY FLOW AROUND SURFACE RIDGE EAST OF THE  
APPALACHIANS WILL BRING MOISTURE AND INSTABILITY BACK INTO THE AREA.  
 

 
   
AVIATION
 
 
(00Z TAFS)  
ISSUED AT 722 PM EDT SAT SEP 5 2026  
 
A FEW SHOWERS AND STORMS ARE LINGERING NEAR TYS BUT ACTIVITY IS  
DECREASING. A FEW ISOLATED SHOWERS AND STORMS WILL BE POSSIBLE  
THIS EVENING AND OVERNIGHT. SOME FOG DEVELOPMENT IS LIKELY NEAR  
TRI. THERE IS SOME UNCERTAINTY ABOUT HOW LOW VISIBILITY WILL GET.  
SHOWERS AND STORMS WILL BE ISOLATED TOMORROW. THE BEST CHANCE WILL  
BE NEAR TRI BUT OVERALL CHANCES ARE LOW.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
CHATTANOOGA AIRPORT, TN 74 96 72 91 / 20 10 20 40  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 71 91 69 89 / 20 20 0 40  
OAK RIDGE, TN 71 91 68 89 / 20 20 0 40  
TRI CITIES AIRPORT, TN 67 86 65 85 / 20 30 10 0  
 

 
   
MRX WATCHES/WARNINGS/ADVISORIES
 
 
NC...NONE.  
TN...HEAT ADVISORY UNTIL 8 PM EDT /7 PM CDT/ THIS EVENING FOR  
ANDERSON-BLEDSOE-BRADLEY-CAMPBELL-CLAIBORNE-GRAINGER-  
HAMBLEN-HAMILTON-HANCOCK-HAWKINS-JEFFERSON-KNOX-LOUDON-  
MARION-MCMINN-MEIGS-MORGAN-NORTH SEVIER-NORTHWEST BLOUNT-  
NORTHWEST COCKE-NORTHWEST GREENE-NORTHWEST MONROE-RHEA-  
ROANE-SCOTT TN-SEQUATCHIE-UNION-WEST POLK.  
 
VA...NONE.  

 
 

 
 
DISCUSSION...DH  
AVIATION...MCD  
 
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