770  
FXUS64 KMRX 021804 AAA  
AFDMRX  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
204 PM EDT TUE SEP 2 2025  
   
..NEW DISCUSSION, AVIATION  
 
   
DISCUSSION  
 
ISSUED AT 131 PM EDT TUE SEP 2 2025  
 
KEY MESSAGES:  
 
1. INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS WEDNESDAY AND  
THURSDAY. MAIN CONCERNS WILL BE LOCALLY HEAVY RAINFALL AND A  
MARGINAL THREAT OF SEVERE STORMS ON THURSDAY.  
 
DISCUSSION:  
 
THROUGH THE REST OF THE AFTERNOON AND EVENING, SHOWER ACTIVITY IS  
EXPECTED TO BE MAINLY WEST OF I-75, AHEAD OF AN APPROACHING  
SHORTWAVE TROUGH AND A SURFACE TROUGH. A FEW ISOLATED SHOWERS MAY  
LINGER PAST SUNSET, MAINLY IN THE NORTHERN HALF.  
 
A BROAD MID/UPPER LEVEL TROUGH WILL MAINTAIN ITS POSITION OVER THE  
EASTERN CONUS FOR THE NEXT FEW DAYS. SHORTWAVE SDISTURBANCES IN  
THE CYCLONIC FLOW WILL BRING ENHANCED RAIN CHANCES TO OUR AREA,  
FIRST ON WEDNESDAY AND AGAIN ON THURSDAY. THE VORT MAX NOW LOCATED  
OVER IL WILL DROP SE AND TRACK ACROSS KY TONIGHT AND TOMORROW  
MORNING, AND SW VA TOMORROW AFTERNOON. LIFT AHEAD OF THIS VORT  
MAX WILL BE FOCUSED ACROSS OUR NORTHERN SECTIONS, AND MAINLY  
BETWEEN 12-18Z. INSTABILITY IS QUITE WEAK, WITH MLCAPE MAXING OUT  
AT 600-700 J/KG IN NORTHERN SECTIONS, SO THUNDERSTORMS SHOULD BE  
ISOLATED AT BEST.  
 
A SECOND SHORTAVE TROUGH PACKS A LITTLE MORE PUNCH ON THURSDAY,  
ENHANCED BY A JET ENTRANCE REGION AND A BETTER DEFINIED SURFACE  
COLD FRONT. BETTER DEEP LAYER SHEAR AND MLCAPE IN THE 1000-1500  
J/KG RANGE WILL PROVIDE A MORE FAVORABLE ENVIRONMENT FOR  
THUNDERSTORMS, ESPCIALLY IN NORTHERN SECTIONS CLOSER TO THE UPPER  
LEVEL JET FORCING. SOME STORMS WILL STRONG WIND GUSTS WILL BE  
POSSIBLE THURSDAY AFTERNOON AND EVENING.  
 
THE THURSDAY COLD FRONT APPEARS TO HANG UP JUST NORTH OF OUR AREA,  
LINGERING THERE THROUGH FRIDAY UNTIL ANOTHER SHORTWAVE TROUGH  
MOVES AROUND THE LONGWAVE TROUGH ON SATURDAY. FRIDAY LOOKS DRY,  
FOLLOWED BY A COLD FRONT/TROUGH PASSAGE THAT BRINGS RAIN CHANCES  
ON SATURDAY. AT THIS TIME, MOISTURE AND INSTABILITY LOOKS TOO  
LIMITED FOR MUCH OF A SEVERE THREAT, BUT THIS WILL BEAR WATCHING.  
SUNDAY APPEARS DRIER AND SLIGHTLY COOLER IN THE POST-FRONTAL AIR  
MASS, BUT THIS MAY BE SHORT LIVED AS THE ATLANTIC RIDGE BEGINS TO  
ASSERT ITSELF AGAIN ACROSS THE SOUTHEAST ON MONDAY.  
 
 
   
AVIATION  
 
(18Z TAFS)  
ISSUED AT 131 PM EDT TUE SEP 2 2025  
 
A FEW SHOWERS WILL GET CLOSE TO CHA AND TYS IN THE NEXT FEW  
HOURS, WITH TYS HAVING THE BEST CHANCE OF LIGHT RAIN WITH MVFR  
CONDITIONS. LOW CIGS ARE EXPECTED TO FORM TONIGHT IN THE NORTHERN  
TN VALLEY, ESPCIALLY WHERE RAIN FALLS THIS AFTERNOON AND TONIGHT.  
SHOWERS MAY SPREAD INTO TRI LATE TONIGHT AND TOMORROW MORNING,  
ACCOMPANIED BY MVFR CIGS THAT MAY PERSIST UNTIL THE END OF THIS  
TAF PERIOD.  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
CHATTANOOGA AIRPORT, TN 63 84 63 86 / 20 20 10 40  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 62 81 63 83 / 30 40 10 50  
OAK RIDGE, TN 61 80 61 82 / 30 30 10 60  
TRI CITIES AIRPORT, TN 58 75 57 79 / 40 60 10 60  
 
 
   
MRX WATCHES/WARNINGS/ADVISORIES  
 
NC...NONE.  
TN...NONE.  
VA...NONE.  
 
 
 
 
DISCUSSION...DGS  
AVIATION...DGS  
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