725  
FXUS64 KMRX 112341  
AFDMRX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
741 PM EDT TUE AUG 11 2026  
   
..NEW AVIATION  
 
   
KEY MESSAGES  
 
UPDATED AT 737 PM EDT TUE AUG 11 2026  
 
- SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EACH DAY THROUGH THE  
END OF THE WORK WEEK, WITH THE BEST CHANCE OF RAIN DURING EACH  
AFTERNOON.  
 
- THERE WILL BE POTENTIAL FOR A FEW STORMS TO BECOME STRONG TO  
SEVERE EACH AFTERNOON WITH DAMAGING WINDS AND LOCALIZED FLOODING  
THE MAIN THREATS.  
 
- TEMPERATURES WILL BE NEAR NORMAL THROUGH FRIDAY, BUT TRENDING  
SLIGHTLY ABOVE NORMAL FOR THE WEEKEND.  
 
 
   
DISCUSSION  
 
ISSUED AT 218 PM EDT TUE AUG 11 2026  
 
THE REGIONAL RADAR MOSAIC SHOWS MULTIPLE AREAS OF CONVECTION  
UPSTREAM OVER THE OHIO VALLEY AND SOUTHERN GREAT LAKES. THE EXACT  
EVOLUTION OF THESE STRUCTURES IS UNCERTAIN, BUT THE LIKELIHOOD OF  
ONE OF THESE STRUCTURES TO IMPACT OUR AREA IS HIGH. THERE ARE A FEW  
ISOLATED THUNDERSTORMS DEVELOPING ACROSS THE SOUTHWEST VA AHEAD OF  
THE MAIN MCS OVER N KY AND W WV. THESE STORMS COULD PRODUCE ISOLATED  
WINDS AND HEAVY RAINFALL. IF WE SEE REPEATED ROUNDS OF STORMS AND  
SHOWERS OVER ANY AREA, THE POTENTIAL FOR FLOODING AND FLASH FLOODING  
WILL INCREASE AND MAY REQUIRE FLOOD HEADLINES IN THE FUTURE.  
FORECAST SOUNDINGS ACROSS SW VA & NE TN HIGHLIGHT 2000-3000+ J/KG  
CAPE WITH ~20 KNOTS OF SHEAR. THIS IS PLENTY FOR CLUSTERS OF  
THUNDERSTORMS TO DEVELOP AND PRODUCE ISOLATED HAIL/WIND DAMAGE.  
FORECAST SOUNDINGS FURTHER WEST IN SE TN HIGHLIGHT SIGNIFICANT  
INSTABILTY AVAILABLE FOR THUNDERSTORMS TO TAP INTO. THE GENERAL  
CONSENSUS IS THAT WE'LL SEE THE MCS OR A PORTION OF THE MCS UPSTREAM  
FOLLOW THE INSTABILITY GRADIENT THAT GOES THROUGH OUR EASTERN  
FORECAST AREA OF SW VA/NE TN. THE INSTABILITY IN PLACE WILL BE  
PLENTY FOR MCS MAINTENANCE AND THE STRUCTURE ITSELF WILL LIKELY BE  
ABLE TO ENHANCE THE LOCAL SHEAR ENVIRONMENT TO A MORE FAVORABLE  
SITUATION. THE TIMING APPEARS TO BE BETWEEN 4 TO 8PM FOR OUR NE AREA  
WITH UNCERTAINTY ON HOW FAR SOUTH/WEST IT'LL CONTINUE. ADDITIONAL  
MCS OVER CENTRAL INDIANA SHOULD CONTINUE TO MOVE SOUTH-SOUTHEAST AND  
SHOULD ARRIVE IN OUR NORTHERN AREA THIS EVENING. THE EXACT EVOLUTION  
OF THIS IS EVEN MORE UNCERTAIN DUE TO THE UNKNOWNS WITH THIS  
AFTERNOON'S POTENTIAL CONVECTION. THERE IS REASON TO BELIEVE THAT  
THE SECOND ROUND SHOULD MAINTAIN SOME INTENSITY AND BRING ANOTHER  
ROUND OF THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WINDS AND HEAVY  
RAIN. THIS STRUCTURE DOES HAVE SOME MID LEVEL SUPPORT AS AN IMPULSE  
TRANSITS THROUGH THE OHIO VALLEY THIS EVENING/TONIGHT. THIS SHOULD  
MOVE THROUGH THE AREA THIS EVENING AND INTO TONIGHT BEFORE WE BEGIN  
TO DRY OUT. GIVEN THE GENERAL UNCERTAINTY AND LOWER-THAN-NORMAL  
CONFIDENCE WITH THIS FORECAST, PLEASE MONITOR THE FORECAST IF YOU  
HAVE ANY OUTDOOR WORK OR ACTIVITIES PLANNED THIS AFTERNOON - EVENING.  
 
WEDNESDAY THROUGH FRIDAY... THIS PERIOD REMAINS UNSETTLED WITH THE  
POTENTIAL FOR ADDITIONAL SHOWERS AND THUNDERSTORMS EACH AFTERNOON. A  
STRONG RIDGE REMAINS OFF TO OUR WEST AND A TROUGH TO OUR EAST OVER  
THE NE CONUS. THIS PLACES US IN A FAVORABLE AREA FOR DAILY  
SHOWER/THUNDERSTORM CHANCES THROUGH FRIDAY EVENING. THERE WILL BE A  
NON-ZERO CHANCE FOR A FEW OF THESE STORM TO BECOME STRONG TO SEVERE  
AND ABLE TO PRODUCE HEAVY RAINFALL. THERE ISN'T A CLEAR SIGNAL FOR  
ANY ONE AREA BUT RATHER A BROAD BRUSH APPROACH GIVEN THE UNSTABLE  
AIRMASS AND NORTHWEST FLOW ALOFT. THE FINER DETAILS WON'T BE  
RESOLVED LIKELY UNTIL THE DAY OF GIVEN THE LOWER CONFIDENCE TIED TO  
THIS PATTERN.  
 
SATURDAY THROUGH EARLY NEXT WEEK... THE WESTERN RIDGE AXIS WILL  
BUILD INTO THE AREA THIS WEEKEND. THIS WILL ALLOW WARMER  
TEMPERATURES TO SETTLE IN THROUGH THE START OF NEXT WEEK.  
PRECIPITATION CHANCES WILL CONTINUE THROUGH THE WEEKEND, BUT THE  
CHANCE OF ANY ORGANIZED CONVECTION WILL BE MUCH LOWER. IF THE RIDGE  
BUILDS IN FURTHER EAST, WE MAY EVEN STAY MOSTLY DRY SATURDAY/SUNDAY,  
WHICH WOULD WELCOMED.  
 
 
   
AVIATION  
 
(00Z TAFS)  
ISSUED AT 737 PM EDT TUE AUG 11 2026  
 
AN MCS IS SPREADING INTO NORTHERN TN THIS EVENING, WITH TRI THE  
MOST LIKELY CULPRIT TO SEE STRONG GUSTY WINDS AS THE LINE OF  
SHOWERS AND STORMS MOVES THROUGH IN THE NEXT HOUR OR TWO. FREQUENT  
LIGHTNING AND HEAVY RAIN WILL ALSO ACCOMPANY THIS ACTIVITY.  
CONVECTION IS EXPECTED TO WEAKEN BUT MAY MAINTAIN ENOUGH OF A PRESENCE  
TO BRING HEAVY RAIN AND LIGHTNING TO TYS AND CHA LATER IN THE  
EVENING, THOUGH, CONFIDENCE IS LOWER IN THESE LOCATIONS. HREF  
PROBABILITIES PAINT 40% CHANCE FOR TRI EXPERIENCE MVFR CIGS EARLY  
WEDNESDAY MORNING. ADDITIONAL ROUNDS OF SHOWERS AND STORMS ARE  
POSSIBLE WEDNESDAY BUT CONFIDENCE IN EXACT LOCATION AND TIMING IS  
TOO LOW TO INCLUDE ANY MENTIONS AT THIS TIME.  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
CHATTANOOGA AIRPORT, TN 73 93 74 94 / 40 30 20 20  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 73 90 73 91 / 40 40 30 30  
OAK RIDGE, TN 72 90 72 91 / 40 30 30 30  
TRI CITIES AIRPORT, TN 68 86 69 87 / 60 40 50 40  
 
 
   
MRX WATCHES/WARNINGS/ADVISORIES  
 
NC...NONE.  
TN...NONE.  
VA...NONE.  
 
 
 
 
DISCUSSION...BH  
AVIATION...KRS  
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