980  
FXUS64 KMRX 242326  
AFDMRX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
726 PM EDT THU JUL 24 2025  
   
..NEW AVIATION
 
 
   
SHORT TERM
 
 
(THIS EVENING THROUGH FRIDAY)  
ISSUED AT 1245 PM EDT THU JUL 24 2025  
 
KEY MESSAGES:  
 
1. MOSTLY DRY THIS EVENING AND FRIDAY AFTERNOON. ISOLATED SHOWERS  
AND STORMS WILL MAINLY BE ACROSS THE MOUNTAINS.  
 
2. HOT AND HUMID CONDITIONS CONTINUE.  
 
DISCUSSION:  
 
UPPER-LEVEL RIDGE WILL CONTINUE TO PRODUCE SYNOPTIC CONDITIONS  
UNFAVORABLE TO WIDESPREAD CONVECTION WITH POOR LAPSE RATES AND  
LIMITED INSTABILITY, EVEN WITH THE HOT AND HUMID SURFACE  
CONDITIONS. THIS RIDGING AND WARMER AIR ALOFT WILL RESULT IN VERY  
WARM SURFACE TEMPERATURES IN THE LOW TO MID 90S TODAY AND TOMORROW  
WITH HEAT INDEX VALUES APPROACHING 100F.  
 
PATCHY FOG IS EXPECTED TONIGHT, ESPECIALLY FOR AREAS THAT RECEIVE  
ANY RAINFALL THIS AFTERNOON. SOME FOG MAY BE DENSE, BUT IT SHOULD  
BE LOCALIZED AND PATCHY IN NATURE.  
 

 
   
LONG TERM
 
 
(FRIDAY NIGHT THROUGH NEXT THURSDAY)  
ISSUED AT 1245 PM EDT THU JUL 24 2025  
 
KEY MESSAGES:  
 
1. RIDGING INCREASES THIS WEEKEND WITH LOW PROBABILITY DIURNAL  
SHOWERS/THUNDERSTORMS.  
 
2. HEAT AND HUMIDITY WILL PUSH HEAT INDEX VALUES INTO THE LOW 100S  
OVER THE WEEKEND.  
 
3. WEAK COLD FRONT AND WEAKNESS IN THE RIDGE MAY BRING INCREASING  
SCATTERED CONVECTION TO THE REGION TOWARDS THE MIDDLE OF NEXT  
WEEK.  
 
DISCUSSION:  
 
UPPER RIDGE WILL RETROGRADE ACROSS THE REGION THIS WEEKEND WITH  
THE 597-598 DAM 500MB RIDGE CENTERED ACROSS THE TENNESSEE AND  
LOWER MISSISSIPPI VALLEYS. SYNOPTIC SUBSIDENCE ALONG THE NORTHERN  
AND EASTERN SIDE OF THE RIDGE, ALONG WITH WARM AIR ALOFT, WILL  
LIMIT CONVECTIVE COVERAGE. ISOLATED CONVECTION WILL BE POSSIBLE  
EACH AFTERNOON, MAINLY ACROSS THE HIGHER ELEVATIONS, BUT  
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE NOT EXPECTED. THIS  
ANOMALOUS RIDGING WILL BE NEAR THE MAX OF CLIMATOLOGY ACCORDING TO  
NAEFS FORECAST PERCENTILES. WHILE IT WILL BE TOUGH TO REACH RECORD  
HIGHS, WE WILL BE WITHIN A FEW DEGREES OVER THE WEEKEND.  
 
DAILY RECORD HIGH MAXIMUM TEMPERATURES  
 
DATE CHATTANOOGA KNOXVILLE TRI-CITIES OAK RIDGE  
07-24 101(1952) 101(1934) 97(2016) 98(1993)  
07-25 101(1952) 101(1934) 98(2016) 97(2016)  
07-26 103(1993) 99(1993) 96(2016) 100(1993)  
07-27 104(1952) 103(1952) 99(1952) 102(1952)  
07-28 106(1952) 103(1952) 102(1952) 105(1952)  
07-29 105(1952) 101(1952) 102(1952) 103(1952)  
07-30 99(1999) 98(1995) 96(1995) 100(1995)  
 
HEAT INDEX VALUES WILL BE APPROACHING 100F-105F ON SATURDAY AND  
SUNDAY AFTERNOON, ESPECIALLY ACROSS THE SOUTHERN VALLEY BETWEEN  
CHATTANOOGA AND KNOXVILLE.  
 
THE UPPER RIDGE CONTINUES TO RETROGRADE WESTWARD WITH A WEAK FRONT  
POTENTIALLY MOVING SOUTHEAST TOWARDS THE SOUTHERN APPALACHIANS ON  
WEDNESDAY/THURSDAY OF NEXT WEEK. THERE'S SIGNIFICANT UNCERTAINTY  
WITH HOW FAR SOUTH THIS FRONT WILL MOVE, AND EVEN IF IT DOES MAKE  
IT THIS FAR SOUTH, CONVECTION MAY BE MORE SPOTTY AND LIMITED IN  
COVERAGE TO LOCATIONS DIRECTLY ALONG THE PRIMARY LINE OF FRONTAL  
FORCING.  
 
THE MAIN CONCERN THROUGHOUT THE SHORT TERM AND EXTENDED IS THE  
HEAT AND HUMIDITY WHICH WILL POSE A HEALTH RISK. THOSE SPENDING  
TIME OR WORKING OUTDOORS ARE ENCOURAGED TO REMAIN HYDRATED, TAKE  
FREQUENT BREAKS IN SHADE OR AIR CONDITIONING, AND PLAN TO WORK  
DURING THE COOLER HOURS OF THE DAY IN THE MORNING AND LATE  
EVENING. REMEMBER THAT HEAT INDEX VALUES ARE CALCULATED IN THE  
SHADE, THEY DON'T ACCOUNT FOR DIRECT SUNLIGHT. URBAN, PAVED AREAS  
ALSO RETAIN ADDITIONAL HEAT AND CAN OFTEN BE MUCH WARMER THAN  
OFFICIAL TEMPERATURE MEASUREMENTS. HEAT RELATED ILLNESS AND DEATHS  
ARE PREVENTABLE; TAKE PRECAUTIONS TO MITIGATE THE RISK TO YOU AND  
YOUR LOVED ONES.  
 

 
   
AVIATION
 
 
(00Z TAFS)  
ISSUED AT 723 PM EDT THU JUL 24 2025  
 
UPPER RIDGING ACROSS THE TENNESSEE VALLEY AND SOUTHERN  
APPALACHIANS WILL LIMIT CONVECTION TO MAINLY THE TERRAIN FEATURES.  
GROUND FOG AND SCATTERED 500 FEET CLOUDS POSSIBLE AT TRI AND TYS,  
OTHERWISE, VFR CONDITIONS ANTICIPATED AT ALL TAF SITES.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
CHATTANOOGA AIRPORT, TN 74 93 75 94 / 0 30 0 30  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 73 94 74 94 / 0 40 10 30  
OAK RIDGE, TN 72 94 73 93 / 0 30 10 40  
TRI CITIES AIRPORT, TN 68 92 71 91 / 0 20 10 40  
 

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

 
 

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