889   
FXUS64 KMRX 222348 AAA  
AFDMRX  
  
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
748 PM EDT MON SEP 22 2025  
   
..NEW AVIATION  
  
   
KEY MESSAGES  
  
UPDATED AT 744 PM EDT MON SEP 22 2025  
  
 -  SCATTERED SHOWERS AND STORMS BOTH TODAY AND TUESDAY. A FEW    
    STORMS MAY PRODUCE STRONG GUSTY WINDS.  
  
 -  INCREASING CHANCES OF SHOWERS AND STORMS ARE EXPECTED  
    WEDNESDAY AND ESPECIALLY THURSDAY. A FEW STRONG TO SEVERE   
    STORMS WILL BE POSSIBLE, AND THERE WILL BE POTENTIAL FOR   
    LOCALLY HEAVY RAINFALL CAPABLE OF PRODUCING LOCALIZED   
    FLOODING.   
  
 -  THE WEEKEND INTO MONDAY WILL TREND DRIER, WITH SLIGHTLY BELOW  
    NORMAL TEMPERATURES TRENDING TOWARD NORMAL BY MONDAY.  
  
  
   
DISCUSSION  
  
ISSUED AT 107 PM EDT MON SEP 22 2025  
  
WE REMAIN UNDER QUASI-ZONAL FLOW ALOFT TODAY, WITH ANOTHER WEAK   
SHORT WAVE APPROACHING FROM THE WEST. THIS SHORT WAVE WILL MOVE   
OVER OUR AREA TONIGHT. MODELS SHOW AN AREA OF UPPER LEVEL JET   
FORCED DIVERGENCE THAT CLIPS AT LEAST OUR NORTHWESTERN COUNTIES   
LATE TODAY OR EARLY TONIGHT. CONVECTIVE ENERGY THIS AFTERNOON IS   
MODEST AND MIDLEVEL LAPSE RATES WEAK, WHILE EFFECTIVE SHEAR SHOWS   
A VERY SLIGHT UPTICK TO AROUND 15KTS. THE BEST CHANCE FOR STRONG   
TO SEVERE STORMS LOOKS TO BE ACROSS AND NEAR OUR PLATEAU COUNTIES   
AS WELL AS NEAR THE TN/KY/VA BORDERS LATER TODAY INTO THIS   
EVENING ASSOCIATED WITH THE AREA OF BETTER FORCING, WITH DAMAGING   
WINDS THE PRIMARY THREAT. WE WILL SEE CONVECTION LINGERING DURING   
THE NIGHT AS THE SHORT WAVE MOVES ACROSS.   
  
TUESDAY WILL SEE A SIMILAR ENVIRONMENT TO TODAY OVERALL ALTHOUGH   
FORCING LOOKS TO BE MORE LACKING AND EFFECTIVE SHEAR A BIT HIGHER.   
IN ADDITION, LINGERING CLOUD COVER AND MORNING PRECIPITATION   
ASSOCIATED WITH THE EXITING SHORT WAVE WILL LIKELY LIMIT CONVECTIVE   
ENERGY ESPECIALLY NORTHERN HALF OF THE AREA. WE WILL SEE   
SCATTERED SHOWERS AND STORMS AGAIN, AND A FEW MAY BECOME STRONG TO  
MARGINALLY SEVERE WITH DAMAGING WINDS AGAIN THE PRIMARY THREAT.   
  
THE PATTERN WILL BE SHIFTING FOR WEDNESDAY AND THURSDAY AS AN UPPER   
TROUGH STRETCHING FROM THE GREAT LAKES TO THE CENTRAL PLAINS PIVOTS   
SOUTHEAST INTO THE OHIO AND MISSISSIPPI RIVER VALLEYS. THE   
ASSOCIATED COLD FRONT WILL PUSH THROUGH OUR AREA THURSDAY INTO   
THURSDAY NIGHT.  INCREASING SOUTHWESTERLY FLOW WILL BRING INCREASING   
MOISTURE AHEAD OF THIS SYSTEM, WITH THE NAEFS DATA STILL SHOWING   
PWAT VALUES AROUND OR EXCEEDING THE 90TH PERCENTILE VALUES FOR THIS   
TIME OF YEAR FOR MUCH OF THE WEDNESDAY INTO THURSDAY TIME FRAME. WE   
WILL SEE AN INCREASE IN SHOWERS AND THUNDERSTORM COVERAGE FOR   
WEDNESDAY AND ESPECIALLY THURSDAY, AND LOCALIZED FLOODING WILL   
BECOME MORE OF A CONCERN ESPECIALLY IN AREAS THAT SEE REPEATED   
ROUNDS OF HEAVY RAINFALL. IN ADDITION, BULK SHEAR WILL BE INCREASING   
TO AROUND 30 TO 40 KTS, WHICH SUGGESTS THE CHANCES FOR SEVERE STORMS   
WILL BE ENHANCED ASSUMING ENOUGH CONVECTIVE ENERGY. THE AMOUNT OF   
CAPE THAT THE CONVECTION WILL HAVE TO WORK WITH IS DEFINITELY A   
QUESTION MARK, ESPECIALLY GIVEN UNCERTAINTIES IN HOW MUCH CLOUD   
COVER AND PRECIPITATION WILL INHIBIT SOLAR HEATING AS WELL AS THE   
TIMING OF THE BETTER FORCING. THIS WILL BEAR WATCHING.    
  
HOW QUICKLY DRIER AIR WILL PUSH IN IS STILL IN QUESTION GIVEN THE   
POOR CONSISTENCY IN THE MODELS, BUT RIGHT NOW IT LOOKS LIKE FRIDAY   
WILL TREND A BIT DRIER AS THE TROUGH AND FRONT SHIFTS EAST. THE   
WEEKEND AND MONDAY LOOK TO BE MOSTLY DRY, ESPECIALLY SUNDAY AND   
MONDAY. TEMPERATURES SATURDAY WILL LIKELY BE SLIGHTLY BELOW SEASONAL   
NORMALS, TRENDING CLOSER TO NORMAL BY SUNDAY AND MONDAY.    
  
  
   
AVIATION  
  
(00Z TAFS)  
ISSUED AT 744 PM EDT MON SEP 22 2025  
  
MULTIPLE ROUNDS OF SHRA/TSRA ARE EXPECTED TO AFFECT EASTERN TN  
OVERNIGHT AND INTO TOMORROW MORNING. HAVE TEMPO GROUPS IN FOR THE  
MOST LIKELY TIMES, NAMELY THE LINE OF CONVECTION EXPECTED TO  
ARRIVE BETWEEN ROUGHLY 11Z-14Z. MAY SEE A BREAK FROM MIDDAY INTO  
THE AFTERNOON HOURS BEFORE DAYTIME HEATING KICKS OFF MORE  
SCATTERED STORMS. FOG POTENTIAL FOR TONIGHT IS HIGHLY UNCERTAIN  
GIVEN THE AMOUNT OF CLOUD COVER EXPECTED. CHOSE TO LEAVE IT OUT OF  
ALL TERMINALS FOR THE TIME BEING BUT IF CLOUDS CLEAR OUT A RAPID  
ONSET OF FOG WOULD BE LIKELY.  
  
  
   
PRELIMINARY POINT TEMPS/POPS  
  
CHATTANOOGA AIRPORT, TN             87  68  87  68 /  30  20  30  30   
KNOXVILLE MCGHEE TYSON AIRPORT, TN  86  66  85  68 /  30  30  40  40   
OAK RIDGE, TN                       85  66  83  66 /  40  40  50  40   
TRI CITIES AIRPORT, TN              84  63  80  63 /  40  40  50  40   
  
  
   
MRX WATCHES/WARNINGS/ADVISORIES  
  
NC...NONE.  
TN...NONE.  
VA...NONE.  
  
  
  
  
DISCUSSION...99  
AVIATION...CD  
 
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