745  
FXUS64 KMRX 270020  
AFDMRX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
820 PM EDT FRI JUL 26 2024  
   
..NEW UPDATE
 
 
   
UPDATE
 
 
ISSUED AT 809 PM EDT FRI JUL 26 2024  
 
NO SIGNIFICANT CHANGES WERE MADE TO THE FORECAST FOR TONIGHT  
DURING THE EVENING UPDATE. A STATIONARY BOUNDARY IS NEAR THE KY/TN  
BORDER. SHOWERS HAVE DISSIPATED ACROSS THE REGION AND POPS WILL BE  
LOW OVERNIGHT. A FEW STRAY SHOWERS CANNOT BE RULED OUT ESPECIALLY  
IN THE SOUTHERN TENNESSEE VALLEY AND NORTH CAROLINA COUNTIES.  
 

 
   
SHORT TERM
 
 
(THIS EVENING THROUGH SATURDAY)  
ISSUED AT 221 PM EDT FRI JUL 26 2024  
 
KEY MESSAGES:  
 
1. SHOWERS AND THUNDERSTORMS CONTINUE THIS AFTERNOON WITH THE  
GREATEST COVERAGE LIKELY TO BE SOUTH OF I-40.  
 
2. ANOTHER ROUND OF SHOWERS AND POSSIBLY THUNDERSTORMS WILL OCCUR  
TOMORROW.  
 
DISCUSSION:  
 
CURRENTLY THE INITIAL ROUND OF LIGHT SHOWERS MOVING THROUGH THE  
CENTRAL VALLEY IS RUNNING INTO THE DRIER AIRMASS IN NORTHEAST TN AND  
SOUTHWEST VA. EXPECT THIS TREND TO CONTINUE WITH ONLY ISOLATED  
DRIZZLE EXPECTED NORTH OF INTERSTATE 40. MORE ROBUST CONVECTION IS  
MOVING ALONG NEAR THE SOUTHERN TN BORDER. THERE IS SOME ENHANCED  
MOISTURE CONVERGENCE AND SLIGHTLY BETTER SYNOPTIC FORCING ON THE  
SOUTHERN EDGE OF THE TROUGH MOVING THROUGH. WITH SOME CLEARING IN  
THE CLOUDS ACROSS SOUTHEAST TN THIS AFTERNOON THESE STORMS COULD  
MOVE INTO SOME ENHANCED INSTABILITY AS THEY MOVE FURTHER TO THE  
EAST. MLCAPE VALUES COULD EXCEED 1,000 J/KG IN THIS AREA. BIGGEST  
THREATS WITH THE STRONGEST STORMS WOULD LIKELY BE GUSTY WINDS AND  
BRIEF HEAVY DOWNPOURS LEADING TO LOCALIZED FLOODING OF POOR  
DRAINAGE AREAS.  
 
MOVING INTO THE OVERNIGHT HOURS EXPECT THE CONVECTION TO QUICKLY DIE  
OFF ONCE THE SUN BEGINS TO SET LEADING TO A FAIRLY CALM OVERNIGHT  
PERIOD. EXPECT ANOTHER ROUND OF PATCHY FOG IN OUR REGION WITH THE  
HIGHER DEW POINTS AND RECENT RAINFALLS. TOMORROW WILL SEE ANOTHER  
WARM AND HUMID DAY WITH AFTERNOON SHOWERS AND THUNDERSTORMS POSSIBLE  
ONCE AGAIN.  
 

 
   
LONG TERM
 
 
(SATURDAY NIGHT THROUGH NEXT FRIDAY)  
ISSUED AT 221 PM EDT FRI JUL 26 2024  
   
LONG TERM
 
(SATURDAY NIGHT THROUGH FRIDAY)  
 
KEY MESSAGES:  
 
1. AN UNSETTLED PATTERN WITH DAILY CHANCES OF SHOWERS AND STORMS IS  
EXPECTED THROUGH THE LONG TERM.  
 
2. LOCALIZED FLOODING IS POSSIBLE DUE TO REPEATED, POTENTIALLY HEAVY  
RAINFALL, ESPECIALLY MONDAY.  
 
DISCUSSION:  
 
COME SUNDAY, WE WILL FIND OURSELVES UNDER BRIEF RIDGING SQUISHED  
BETWEEN SHORTWAVE TROUGHING TO OUR WEST AND A DEVELOPING CUTOFF LOW  
OFF THE EAST COAST. THIS WILL ALLOW FOR INCREASING MOISTURE  
ADVECTION INTO THE REGION WITH PWAT INCREASING TO UPWARDS OF 2  
INCHES IN PORTIONS OF THE CENTRAL AND SOUTHERN VALLEY. VORT MAXIMA  
AND ISENTROPIC LIFT WILL LEAD TO NUMEROUS TO WIDESPREAD SHOWERS AND  
STORMS SUNDAY AND MONDAY. MODEL DERIVED SOUNDINGS SUGGEST TALL &  
SKINNY CAPE PROFILES WITH FREEZING LEVELS BETWEEN TO 13 TO 14KFT MAY  
VERY WELL PROMOTE PERIODS OF EFFICIENT WARM RAIN PROCESSES. THIS  
WILL LEAD TO INCREASED FLOODING POTENTIAL, ESPECIALLY FOR MONDAY, IN  
WHICH A LARGE PORTION OF OUR AREA OF RESPONSIBILITY REMAINS  
HIGHLIGHTED IN A SLIGHT RISK ERO. A LIMITING FACTOR TO THE FLOODING  
THREAT MAY BE FAIRLY MEAGER MLCAPE VALUES LESS THAN 1000J/KG,  
HOWEVER, SOUNDINGS ALSO SUGGEST CORFIDI UPSHEAR VALUES LESS THAN  
10KTS ARE POSSIBLE AND POTENTIAL FOR SLOW MOVING OR BACK BUILDING  
STORMS WILL NEED TO BE MONITORED.  
 
QUASI-ZONAL FLOW WITH BOUTS OF UPPER LEVEL DISTURBANCES IS EXPECTED  
TUESDAY ONWARDS. THIS WILL PROMOTE CONTINUED DAILY CHANCES OF  
SHOWERS AND STORMS THROUGH THE EXTENDED PERIOD. A CONTINUED THREAT  
OF FLOODING IS A LITTLE LESS CLEAR GIVEN A LACK OF REAL SIGNIFICANT  
UPPER LEVEL FEATURES BUT POOR ANTECEDENT CONDITIONS MAY ALLOW THE  
FLOODING THREAT TO PERSIST THROUGHOUT THE WEEK AS WELL. TEMPERATURES  
MID TO LATE WEEK WILL ALSO BE TRENDING WARMING, WITH THERMODYNAMIC  
PROFILES BECOMING INCREASINGLY FAVORABLE FOR MORE THUNDERSTORM  
ACTIVITY AND POTENTIAL GUSTY WINDS AND SMALL HAIL WITH STRONGER  
STORMS. SLIGHTLY ABOVE NORMAL TEMPERATURES ARE EXPECTED TO RETURN IN  
 

 
   
AVIATION
 
 
(00Z TAFS)  
ISSUED AT 721 PM EDT FRI JUL 26 2024  
 
MOSTLY VFR CONDITIONS ARE EXPECTED THIS TAF CYCLE. SOME FOG  
DEVELOPMENT IS POSSIBLE IN THE EARLY MORNING HOURS, MAINLY NEAR  
TRI WHERE CLEARING IS EXPECTED. HIGH CLOUDS WILL HANG AROUND  
LONGER FOR TYS/CHA. HIT AND MISS SHOWERS ARE LIKELY MAINLY NEAR  
TYS/CHA IN THE AFTERNOON.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
CHATTANOOGA AIRPORT, TN 71 88 73 87 / 20 50 10 70  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 68 88 71 88 / 20 40 10 60  
OAK RIDGE, TN 68 88 70 86 / 10 40 10 60  
TRI CITIES AIRPORT, TN 65 87 65 88 / 10 20 0 30  
 

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

 
 

 
 
SHORT TERM...  
LONG TERM....KS  
AVIATION...MCD  
 
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