835  
FXUS64 KHUN 170257  
AFDHUN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE HUNTSVILLE AL  
957 PM CDT SUN AUG 16 2026  
   
..NEW NEAR TERM, SHORT TERM, LONG TERM  
 
   
KEY MESSAGES  
 
UPDATED AT 956 PM CDT SUN AUG 16 2026  
 
- DANGEROUS HEAT WILL IMPACT THE TENNESSEE VALLEY THROUGH THE  
MIDDLE OF THIS WEEK, WITH MAJOR (LEVEL 3/4) TO EXTREME (LEVEL  
4/4) HEAT IMPACTS FORECAST.  
 
- A HEAT ADVISORY IS IN EFFECT FOR ALL OF NORTHERN ALABAMA AND  
SOUTHERN MIDDLE TENNESSEE THROUGH 7 PM MONDAY, WITH EXTENSIONS  
ON THE TABLE IN FUTURE UPDATES THROUGH POTENTIALLY MID-WEEK.  
 
- A SLIGHT (2 OUT OF 5) RISK FOR SEVERE THUNDERSTORMS IS FORECAST  
MONDAY ACROSS EASTERN FRANKLIN COUNTY TENNESSEE AND PORTIONS  
OF FAR NORTHEAST ALABAMA, WITH A MARGINAL (1 OUT OF 5) RISK  
THROUGH MOST OF THE AREA.  
 
 
   
NEAR TERM  
 
(REST OF TONIGHT AND MONDAY)  
ISSUED AT 956 PM CDT SUN AUG 16 2026  
 
TRANQUIL WEATHER ACROSS THE TENNESSEE VALLEY THIS EVENING, WITH  
HIGH PRESSURE PROMOTING CLEAR/CALM CONDITIONS. DESPITE THIS,  
EXPECT ANOTHER VERY WARM NIGHT WITH LOWS ONLY DROPPING INTO THE  
MID 70S IN MOST LOCATIONS. THE HEAT WILL AGAIN BE A CONCERN ON  
MONDAY, WITH GOOD HEATING IN THE MORNING ALLOWING HIGHS TO CLIMB  
INTO THE MID TO PERHAPS UPPER 90S BY THE EARLY AFTERNOON. COMBINED  
WITH DEWPOINTS IN THE 70S, THIS WILL CREATE HEAT INDEX VALUES  
BETWEEN 105-110 DEGREES IN MOST LOCATIONS. A HEAT ADVISORY REMAINS  
IN EFFECT FOR THE ENTIRE REGION UNTIL 7 PM MONDAY.  
 
IN ADDITION TO THE HEAT THREAT, A WEAK FRONT WILL DROP SOUTH INTO  
THE REGION ON MONDAY, SERVING AS A FOCUS FOR LOW TO MEDIUM  
(30-50%) CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS. THE  
THERMODYNAMIC ENVIRONMENT WILL BE FAVORABLE FOR SOME OF THESE  
STORMS TO BECOME SEVERE, WITH MLCAPE VALUES AROUND 2500 J/KG, LOW-  
LEVEL LAPSE RATES AROUND 8.5 TO 9 C/KM, AND DCAPE VALUES AS HIGH  
AS 1200-1400 J/KG. LOCALIZED DAMAGING WINDS IN THE FORM OF  
DOWNBURSTS WILL BE THE PRIMARY THREAT, ALONG WITH LOCALLY HEAVY  
HEAVY RAINFALL (PWATS AROUND 2").  
 
 
   
SHORT TERM  
 
(MONDAY NIGHT THROUGH WEDNESDAY)  
ISSUED AT 956 PM CDT SUN AUG 16 2026  
 
CONVECTION WILL WANE IN THE EVENING HOURS AS THE BOUNDARY DROPS  
SOUTH OF THE REGION. SOME PATCHY FOG MAY DEVELOP IN LOCATIONS THAT  
RECEIVE RAINFALL LATE MONDAY, BUT OTHERWISE IT SHOULD BE A FAIRLY  
TRANQUIL NIGHT. AN EVER SO SUBTLE CHANGE TO THE AIR MASS MAY TAKE  
PLACE TUESDAY AS DEWPOINTS WILL RUN A LITTLE LOWER AND  
SUBSEQUENTLY HEAT INDEX VALUES IN THE 100-105 DEGREE RANGE WILL BE  
MORE COMMON. STILL, MODERATE (LEVEL 2/3) TO MAJOR (LEVEL 3/4)  
HEAT IMPACTS ARE FORECAST AND EVERYONE SHOULD STILL OBSERVE COMMON  
SENSE HEAT SAFETY. HEAT IMPACTS WILL TEMPORARILY CREEP BACK INTO  
THE REGION ON WEDNESDAY AS HIGHS RETURN TO THE MID TO UPPER 90S  
AND DEWPOINTS IN THE 70S PUSH PEAK HEAT INDEX VALUES ABOVE 105  
DEGREES OVER MUCH OF THE AREA.  
 
 
   
LONG TERM  
 
(WEDNESDAY NIGHT THROUGH SUNDAY)  
ISSUED AT 956 PM CDT SUN AUG 16 2026  
 
AFTER WEDNESDAY, THE UPPER-RIDGE WILL BEGIN TO FLATTEN AND SHIFT  
BACK TO THE WEST OVER THE SOUTHERN ROCKIES AND GREAT BASIN. THIS  
WILL PLACE THE TENNESSEE VALLEY INTO NORTHWEST FLOW ALOFT, OPENING  
US UP TO A COUPLE OF SHORTWAVES THAT WILL PUSH THROUGH THE AREA  
THURSDAY AND FRIDAY, RESULTING IN MEDIUM (30-60%) CHANCES FOR  
SHOWERS AND THUNDERSTORMS BOTH AFTERNOONS. A FRONT WILL SAG SOUTH  
OF THE AREA BY THE WEEKEND, KEEPING THE BETTER CHANCES FOR SHOWERS  
AND STORMS DISPLACED TO SOUTH OF US ACROSS CENTRAL AND SOUTH  
ALABAMA. THIS WILL ALSO GIVE US A RELATIVE BREAK FROM THE HEAT AS  
HIGHS WILL DROP TO THE UPPER 80S TO LOWER 90S, WITH OVERNIGHT LOWS  
IN THE 60S BY THE WEEKEND.  
 
 
   
AVIATION  
 
(00Z TAFS)  
ISSUED AT 616 PM CDT SUN AUG 16 2026  
 
VFR CONDITIONS WILL PREVAIL AT EACH TERMINAL THROUGH MUCH OF THE  
PERIOD. HOWEVER, SHRA/TSRA WILL DEVELOP ALONG A FRONT MONDAY  
AFTERNOON WHICH COULD RESULT IN LOCALIZED MVFR CONDITIONS DUE TO  
REDUCED VISIBILITIES/CEILINGS. HAVE HANDLED THIS WITH A PROB30  
FOR NOW BETWEEN 19-00Z. AWWS AND AMENDMENTS MAY BE NEEDED DURING  
THIS TIMEFRAME.  
 
 
   
HUN WATCHES/WARNINGS/ADVISORIES  
 
AL...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR ALZ001>010-016.  
 
TN...HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR TNZ076-096-097.  
 
 
 
 
 
NEAR TERM...AMP.24  
SHORT TERM....AMP.24  
LONG TERM....AMP.24  
AVIATION...AMP  
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