047  
FXUS64 KMRX 160656  
AFDMRX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MORRISTOWN TN  
256 AM EDT SUN AUG 16 2026  
   
..NEW DISCUSSION, AVIATION
 
 
   
KEY MESSAGES
 
 
UPDATED AT 236 AM EDT SUN AUG 16 2026  
 
- VERY HOT HEAT INDEX'S CONTINUE TODAY AND MONDAY, ESPECIALLY  
SOUTH AND CENTRAL VALLEY AREAS. THEN IT WILL REMAIN ON THE HOT  
SIDE THROUGH THE WEEK BUT LIKELY A BIT LESS OPPRESSIVE.  
 
- NEXT WEEK, BEST CHANCE FOR SHOWERS AND STORMS WILL BE MONDAY  
WITH SOME POSSIBLY BEING STRONG TO SEVERE WITH DRIER WEATHER  
EXPECTED MIDWEEK.  
 

 
   
DISCUSSION
 
 
ISSUED AT 236 AM EDT SUN AUG 16 2026  
 
THE MID/UPPER LEVEL RIDGE WILL RETROGRADE AND FLATTEN OUT TOMORROW,  
KEEPING THE MCS ACTIVITY ACROSS THE OHIO VALLEY AND GREAT LAKES.  
THIS SHIFT IN THE RIDGE SHOULD BRING IN SLIGHTLY DRIER AIR, WITH PW  
VALUES FALLING TO AROUND 1.5 INCHES. FORECAST SOUNDINGS ALSO  
INDICATE A STRONGER CAP SUGGESTING LESS AFTERNOON CONVECTIVE  
DEVELOPMENT COMPARED TO RECENT DAYS. A FEW ISOLATED SHOWERS OR  
THUNDERSTORMS REMAIN POSSIBLE ACROSS SOUTHWEST VA AND THE TN  
MOUNTAINS.  
 
WITH FEWER CLOUDS AND A LOWER RAIN CHANCE, DIURNAL HEATING WILL  
ALLOW TEMPERATURES TO CLIMB INTO THE 90S FOR MOST LOCATIONS.  
ALTHOUGH BOUNDARY LAYER MIXING SHOULD LOWER AFTERNOON DEWPOINTS  
SOMEWHAT INTO THE LOWER TO MIDDLE 70S. HEAT INDEX VALUES OF 105+  
DEGREES ARE STILL EXPECTED ACROSS THE CENTRAL AND SOUTHERN TN  
VALLEY. THESE CONDITIONS CAN LEAD TO HEAT RELATED ILLNESS,  
ESPECIALLY FOR THOSE SPENDING EXTENDED TIME OUTDOORS. LIMIT  
STRENUOUS ACTIVITY DURING THE HOTTEST PART OF THE DAY, DRINK PLENTY  
OF WATER, AND TAKE FREQUENT BREAKS IN AIR CONDITIONING OR SHADE.  
 
ON SUNDAY NIGHT, SOME CAMS INDICATE REMNANT MCS CONVECTION MOVING  
ACROSS WEST VIRGINIA, POTENTIALLY CLIPPING PORTIONS OF SOUTHWEST  
VIRGINIA. GIVEN THE OVERNIGHT TIMING, THE SEVERE THREAT LOOKS  
LIMITED.  
 
MONDAY WILL SEE HEAT INDEX VALUES WITHIN THE BALLPARK OF WHAT WE'VE  
EXPERIENCED THIS WEEKEND. THERE'S A CHANCE THAT THE BOUNDARY LAYER  
MIXING ON MONDAY BRINGS IN LOWER DEW POINTS AND THE HUMIDITY IS NOT  
TECHNICALLY HEAT ADVISORY CRITERIA... BUT IT'S STILL GOING TO BE HOT.  
WILL GO AHEAD AND EXTEND THE HEAT ADVISORY THROUGH MONDAY FOR ONE  
MORE DAY.  
 
A SHORTWAVE TROUGH AND SURFACE COLD FRONT WILL MOVE THROUGH KENTUCKY  
MONDAY MORNING, SPARKING OFF CONVECTION AS THE SYSTEM APPROACHES THE  
PLATEAU DURING THE AFTERNOON. THE AIR MASS AHEAD OF THE FRONT SHOULD  
REMAIN CAPPED INTO THE EARLY AFTERNOON WHILE HELPING TO INCREASE  
INSTABILITY. SOME SHEAR WILL ALSO BE PRESENT, PARTICULARLY ACROSS  
NORTHERN TN AND SOUTHWEST VA, WITH THE NAM SHOWING APPROXIMATELY 30-  
40 KT OF DEEP LAYER SHEAR. AN INVERTED V PROFILE, STEEP LAPSE RATES,  
AND A DEEP BOUNDARY LAYER WOULD SUPPORT STRONG DOWNDRAFTS AND  
DAMAGING WIND GUSTS. DCAPE VALUES OF 1000+ J/KG FURTHER SUPPORT THIS  
CONCERN. THE RRFS DEPICTS A FAIRLY INTENSE CONVECTIVE LINE MOVING  
THROUGH THE AREA BETWEEN ROUGHLY 7 PM AND 11 PM.  
 
GIVEN THESE FACTORS, THE POTENTIAL EXISTS FOR A MORE SIGNIFICANT  
SEVERE WEATHER EVENT MONDAY AFTERNOON AND EVENING, WITH DAMAGING  
STRAIGHT LINE WINDS BEING THE PRIMARY CONCERN. LARGE HAIL AND AN  
ISOLATED TORNADO CANNOT BE COMPLETELY RULED OUT. THOSE WITH OUTDOOR  
PLANS SHOULD HAVE A RELIABLE WAY TO MONITOR CHANGING WEATHER  
CONDITIONS.  
 
THE SURFACE FRONT WILL PUSH THROUGH THE AREA MONDAY NIGHT, BRINGING  
SLIGHTLY COOLER TEMPERATURES AND LOWER DEWPOINTS FOR TUESDAY. THIS  
SHOULD END THE DANGEROUS HEAT POTENTIAL, ALTHOUGH TEMPERATURES WILL  
REMAIN NEAR NORMAL.  
 
THE RIDGE WILL CONTINUE TO RETROGRADE THROUGH THE REMAINDER OF THE  
WEEK, RESULTING IN A BROAD TROUGH ACROSS THE EASTERN CONUS. THIS  
PATTERN WILL INCREASE RAIN CHANCES THROUGH THE WEEK AS EMBEDDED  
SHORTWAVES MOVE THROUGH THE LARGER SCALE TROUGH AND THE JET STREAM  
SETTLES INTO THE OHIO VALLEY. SHOWERS AND THUNDERSTORMS WILL  
THEREFORE REMAIN POSSIBLE, WITH LOCALLY HEAVY RAINFALL AND LIGHTNING  
CONTINUING TO BE THE PRIMARY CONCERNS WITH STRONGER STORMS.  
 
OVERALL, THE MOST NOTABLE HAZARDS THROUGH THE FORECAST WILL BE  
DANGEROUS HEAT THROUGH MONDAY, LOCALIZED FLOODING FROM REPEATED  
THUNDERSTORMS, AND A POTENTIALLY MORE SIGNIFICANT SEVERE WEATHER  
THREAT MONDAY AFTERNOON AND EVENING.  
 

 
   
AVIATION
 
 
(06Z TAFS)  
ISSUED AT 236 AM EDT SUN AUG 16 2026  
 
DENSE FOG ONCE AGAIN POSSIBLE AT TRI VERY EARLY THIS MORNING. <6SM  
AND BKN CIG ALREADY BEING REPORTED THERE. TYS AND CHA LIKELY TO  
REMAIN CALM UNDER SKC OR HIGH CIG. LATER TODAY TRENDS DRY WITH  
VERY LOW CHANCES OF SHOWERS OR STORMS, THEREFORE NO MENTIONING IN  
TAF. RATHER LIGHT SW-WLY WINDS THIS AFTERNOON AT ALL TERMINALS.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
CHATTANOOGA AIRPORT, TN 98 77 99 76 / 0 0 40 20  
KNOXVILLE MCGHEE TYSON AIRPORT, TN 96 76 95 73 / 0 0 70 50  
OAK RIDGE, TN 95 74 94 72 / 0 0 60 30  
TRI CITIES AIRPORT, TN 90 71 89 69 / 10 30 60 40  
 

 
   
MRX WATCHES/WARNINGS/ADVISORIES
 
 
NC...NONE.  
TN...HEAT ADVISORY UNTIL 8 PM EDT /7 PM CDT/ MONDAY FOR ANDERSON-  
BLEDSOE-BRADLEY-HAMILTON-KNOX-LOUDON-MARION-MCMINN-MEIGS-  
MORGAN-NORTH SEVIER-NORTHWEST BLOUNT-NORTHWEST MONROE-RHEA-  
ROANE-SEQUATCHIE-WEST POLK.  
 
VA...NONE.  

 
 

 
 
DISCUSSION...  
AVIATION...KS  
 
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