766  
FXUS64 KMRX 290513  
AFDMRX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
113 AM EDT SUN JUN 29 2025  
   
..NEW SHORT TERM, LONG TERM, AVIATION
 
 
   
SHORT TERM
 
 
(TODAY AND TONIGHT)  
ISSUED AT 1258 AM EDT SUN JUN 29 2025  
 
KEY MESSAGES:  
 
1. ISOLATED SHOWERS AND THUNDERSTORMS AGAIN THIS AFTERNOON, MAINLY  
ACROSS THE HIGHER ELEVATIONS.  
 
2. SUMMER HEAT CONTINUES WITH HEAT INDEX VALUES NEAR 100F.  
 
DISCUSSION:  
 
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO  
DEVELOP AGAIN THIS AFTERNOON. THE GREATEST COVERAGE WILL BE ACROSS  
THE MOUNTAINS AND PLATEAU WITH ISOLATED COVERAGE ACROSS THE  
VALLEY. THE CURRENT RAP SHOWS HIGHEST INSTABILITY GENERALLY SOUTH  
AND WEST OF KNOXVILLE WHERE LOW-LEVEL MOISTURE IS HIGHEST, SO THE  
SOUTHERN PLATEAU AND CHATTANOOGA WILL LIKELY HAVE HIGHER CHANCES  
OF THUNDERSTORMS DURING THE AFTERNOON HOURS THAN FURTHER NORTHEAST  
ACROSS THE VALLEY. PW VALUES WILL REMAIN NEAR 2.0 INCHES WITH  
LOCALLY HEAVY RAIN RATES AND THE POTENTIAL FOR ISOLATED FLASH  
FLOODING ISSUES.  
 

 
   
LONG TERM
 
 
(MONDAY THROUGH SUNDAY)  
ISSUED AT 1258 AM EDT SUN JUN 29 2025  
 
KEY MESSAGES:  
 
1. THUNDERSTORMS CONTINUE MONDAY AND TUESDAY, MAINLY DURING THE  
AFTERNOON HOURS. HIGH PW VALUES WILL LEAD TO THE POTENTIAL FOR  
SOME HEAVY RAIN RATES AND FLASH FLOODING.  
 
2. DRIER AIR EXPECTED WEDNESDAY THROUGH FRIDAY BEHIND A FRONTAL  
BOUNDARY.  
 
3. LOW CHANCES OF DIURNAL CONVECTION START TO REAPPEAR IN THE  
FORECAST AS BETTER MOISTURE RETURNS NEXT WEEKEND.  
 
DISCUSSION:  
 
DIURNAL CONVECTION CONTINUES EARLY THIS WEEK WITH AFTERNOON MLCAPE  
VALUES APPROACHING 2000 TO 2500 J/KG EACH AFTERNOON FOR PORTIONS  
OF THE AREA. SOME OF THE STRONGER STORMS WILL BE CAPABLE OF  
DAMAGING WINDS AND FREQUENT LIGHTNING. HEAVY RAIN RATES WILL ALSO  
BE A PRIMARY CONCERN AS PW VALUES INCREASE TO NEAR 2.2 INCHES  
WHICH WILL RESULT IN FLASH FLOODING CHANCES ACROSS THE REGION.  
SOME AREAS COULD SEE SOME 3 TO 4+ INCH PER HOUR RAIN RATES IN THE  
HEAVIEST DOWNPOURS.  
 
SHORTWAVE TROUGH MOVES EAST OF THE REGION TUESDAY NIGHT AS A  
FRONT MOVES SOUTHEAST ACROSS THE REGION. SUBSIDENCE AND DRIER AIR  
BUILD IN FROM THE NORTHWEST ON WEDNESDAY AND THURSDAY WITH MOSTLY  
DRY CONDITIONS EXPECTED AREA-WIDE. LOW CHANCES OF RAIN AND  
THUNDERSTORMS WILL CONTINUE ON WEDNESDAY ACROSS OUR FAR SOUTHERN  
AREAS CLOSE TO THE FRONT.  
 
AS MOISTURE BEGINS TO INCREASE AND THE RIDGE WEAKENS NEXT WEEKEND,  
CHANCES OF STANDARD SUMMER-TIME DIURNAL CONVECTION BEGIN TO  
INCREASE ONCE AGAIN.  
 

 
   
AVIATION
 
 
(06Z TAFS)  
ISSUED AT 1258 AM EDT SUN JUN 29 2025  
 
VFR CONDITIONS FORECAST TO PREVAIL WITH VCFG TONIGHT NEAR ALL  
SITES. SOME FOG IMPACTS ARE MOST LIKELY AT TRI EARLY THIS MORNING  
PRIOR TO CLEARING OUT BY 14Z. VCSH AND PROB30 THUNDERSTORM CHANCES  
ARE EXPECTED AFTER 19Z WITH THE HIGHEST CHANCES FOR THUNDERSTORM  
IMPACTS AT CHA.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
CHATTANOOGA AIRPORT, TN 90 72 88 72 / 50 30 80 50  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 90 71 89 72 / 50 30 80 60  
OAK RIDGE, TN 89 70 87 71 / 50 30 80 60  
TRI CITIES AIRPORT, TN 88 68 87 70 / 60 30 70 60  
 

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

 
 

 
 
SHORT TERM...JB  
LONG TERM....JB  
AVIATION...JB  
 
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