366  
FXUS64 KHUN 140543  
AFDHUN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE HUNTSVILLE AL  
1243 AM CDT FRI AUG 14 2026  
   
..NEW AVIATION
 
 
   
KEY MESSAGES
 
 
UPDATED AT 1007 PM CDT THU AUG 13 2026  
 
- A HEAT ADVISORY REMAINS IN EFFECT FOR THE ENTIRE FORECAST AREA  
THROUGH SUNDAY, WITH EXTENSIONS LIKELY INTO THE MIDDLE OF NEXT  
WEEK.  
 
- THERE WILL BE A LOW (10-30%) CHANCE FOR A FEW THUNDERSTORMS  
EACH AFTERNOON/EVENING THROUGH SATURDAY. A COUPLE OF STORMS MAY  
BECOME STRONG TO MARGINALLY SEVERE WITH LOCALIZED DAMAGING  
WINDS, FREQUENT LIGHTNING AND HEAVY RAINFALL THE MAIN IMPACTS.  
 

 
   
NEAR TERM
 
 
(THIS EVENING THROUGH FRIDAY)  
ISSUED AT 1007 PM CDT THU AUG 13 2026  
 
A MID-LEVEL SUBTROPICAL HIGH (INITIALLY CENTERED ACROSS THE  
EASTERN GULF) WILL STRENGTHEN OVER THE COURSE OF THE NEAR TERM  
PERIOD AS IT BUILDS NORTH-NORTHWESTWARD (BECOMING CENTERED ACROSS  
THE LOWER MS VALLEY BY 0Z SATURDAY AND EXPANDING WESTWARD INTO THE  
SOUTHERN PLAINS AND EASTWARD OFF THE SOUTHEASTERN ATLANTIC  
COAST). AS THIS OCCURS, WNW FLOW ALOFT OF 10-20 KNOTS WILL WEAKEN  
CONSIDERABLY OVERNIGHT AND TOMORROW, BUT DUE TO THE ORIENTATION OF  
THE HIGH, A PAIR OF CONVECTIVELY-ENHANCED WAVES ALOFT WILL DRIFT  
SLOWLY SOUTHEASTWARD FROM NORTHERN PARTS OF THE TN VALLEY INTO  
AL/GA.  
 
IN THE LOW-LEVELS, OUR FORECAST AREA WILL REMAIN WITHIN A LIGHT  
SW FLOW REGIME BETWEEN A LEE CYCLONE IN THE OK PANHANDLE VICINITY  
AND A RIDGE OF HIGH PRESSURE EXTENDING FROM THE SOUTHWESTERN NORTH  
ATLANTIC INTO THE CENTRAL GULF. HOWEVER, WITHIN THE PREVAILING  
SOUTHWESTERLY FLOW, A REMNANT MESOSCALE BOUNDARY EXTENDS FROM  
NORTHERN MS SOUTHEASTWARD INTO CENTRAL AL AND MAY INITIATE A FEW  
SHOWERS AND THUNDERSTORMS THROUGHOUT THE NIGHT AIDED BY A WSW LOW-  
LEVEL JET OF 10-20 KNOTS. WITH THIS FEATURE PREDICTED TO LIFT  
SLOWLY NORTHWARD EARLY FRIDAY MORNING, DEVELOPMENT OF A FEW  
NOCTURNAL CONVECTIVE CELLS MAY OCCUR IN OUR REGION (PARTICULARLY  
SOUTH OF THE TN RIVER AND IN THE 8-14Z TIMEFRAME), AND FOR THIS  
REASON WE WILL RETAIN A 15-20% POP. OCCASIONAL LIGHTNING AND BRIEF  
HEAVY RAIN WOULD BE THE MAIN IMPACTS WITH ANY THUNDERSTORM  
ACTIVITY. OTHERWISE, WE EXPECT A PARTLY CLOUDY, WARM AND HUMID  
NIGHT WITH LOWS IN THE M-U 70S AND ONLY A LOW CHANCE FOR  
DEVELOPMENT OF PATCHY MIST/FOG (PRIMARILY IN LOCATIONS THAT  
RECEIVED RAINFALL EARLIER TODAY AND NEAR LARGE WATER SOURCES).  
 
TEMPERATURES WILL BEGIN TO WARM QUICKLY AFTER SUNRISE TOMORROW,  
SUPPORTING A RAPID INCREASE IN ATMOSPHERIC INSTABILITY THROUGH THE  
LATE MORNING HOURS. AS THE SECOND IN A PAIR OF SUBTLE  
DISTURBANCES ALOFT BEGINS TO DRIFT SOUTH-SOUTHEASTWARD INTO THE  
REGION, A FEW THUNDERSTORMS MAY DEVELOP BY LATE MORNING ACROSS  
SOUTHERN MIDDLE TN, WHICH WOULD TRACK SLOWLY SOUTHEASTWARD INTO  
NORTHEAST AL DURING THE AFTERNOON. ADDITIONAL STORMS MAY EVOLVE IN  
THE VICINITY OF THE REMNANT MESOSCALE BOUNDARY ACROSS WEST-  
CENTRAL GA BY EARLY AFTERNOON, AND DEPENDING ON THE EXTENT OF THIS  
ACTIVITY, NORTHWESTWARD- MOVING OUTFLOW MAY INITIATE NEW CELLS  
ACROSS NORTHEAST AL LATE IN THE AFTERNOON. THUS, POPS WILL BE  
SLIGHTLY HIGHER (20-30%) IN THE EASTERN PART OF THE CWFA COMPARED  
TO THE WEST (10%), BUT REGARDLESS OF STORM COVERAGE, VERY STEEP  
LOW-LEVEL LAPSE RATES COUPLED WITH MLCAPE OF 2000-3000 J/KG AND  
PWATS OF 1.8-2" WILL SUPPORT A RISK FOR DAMAGING DOWNBURST WINDS  
AND FREQUENT LIGHTNING. PRIOR TO ANY CONVECTIVE IMPACTS TEMPS WILL  
REACH THE MID 90S ONCE AGAIN, WITH RESULTANT HEAT INDICES IN THE  
105-110F RANGE FOR MANY VALLEY LOCATIONS.  
 

 
   
SHORT TERM
 
 
(FRIDAY NIGHT THROUGH SUNDAY NIGHT)  
ISSUED AT 1007 PM CDT THU AUG 13 2026  
 
THERE IS EXPECTED TO BE NO CHANGE IN THE EITHER THE INTENSITY OR  
POSITION OF A STRONG 500-MB RIDGE ENCOMPASSING MUCH OF THE SOUTH-  
CENTRAL AND SOUTHEASTERN CONUS ON FRIDAY NIGHT OR SATURDAY. THUS,  
EVEN WITH A FEW AFTERNOON SHOWERS AND THUNDERSTORMS POTENTIALLY  
LINGERING FOR A COUPLE OF HOURS BEYOND 0Z SATURDAY (PARTICULARLY  
ACROSS NORTHEASTERN PARTS OF THE FORECAST AREA), DRY BUT  
WARM/MUGGY CONDITIONS APPEAR LIKELY TO EXIST FOR MUCH OF THE  
NIGHT. THERE ARE STILL INDICATIONS THAT THE NORTHERN PORTION OF AN  
EASTERLY WAVE (TRACKING ACROSS FL AND INTO THE EASTERN GULF) MAY  
INDUCE A GREATER SPATIAL COVERAGE OF SEABREEZE AND OUTFLOW- DRIVEN  
CONVECTION ON SATURDAY FROM THE CENTRAL GULF COAST NORTHEASTWARD  
INTO SC, WHICH COULD POTENTIALLY GENERATE A FEW STORMS IN  
NORTHEAST AL AS WELL. SHOULD THIS OCCUR, IT WOULD LIKELY BE LATE  
IN THE AFTERNOON, WITH A SIMILAR RISK FOR DAMAGING DOWNBURST WINDS  
AND FREQUENT LIGHTNING COMPARED TO PREVIOUS DAYS.  
 
DURING THE TIMEFRAME FROM SATURDAY NIGHT-SUNDAY NIGHT, THE CENTER  
OF THE INTENSE SUBTROPICAL HIGH ALOFT WILL SLOWLY MIGRATE  
WESTWARD (BECOMING POSITIONED ACROSS NORTH-CENTRAL TX BY 12Z  
MONDAY). ALTHOUGH THIS EVOLUTION WILL GRADUALLY REDUCE THE IMPACTS  
FROM DEEP-LAYER SUBSIDENCE AND ALLOW FOR A MINOR INCREASE IN WNW  
FLOW ALOFT BY LATE SUNDAY/SUNDAY NIGHT, EFFICIENT MIXING AND  
DRYING OF THE BOUNDARY LAYER WILL ACTUALLY LOWER CAPE AS PWAT  
VALUES FALL INTO THE 1.3-1.5" RANGE. THUS, WE EXPECT DRY  
CONDITIONS TO PREVAIL DURING THIS PERIOD WITH VERY HOT AFTERNOON  
TEMPERATURES IN THE 95-100F RANGE BOTH SATURDAY AND SUNDAY. IF  
DEWPOINTS INDEED MIX OUT INTO THE L-M 60S (POTENTIALLY U50S)  
ACROSS WESTERN PARTS OF THE FORECAST AREA ON SATURDAY AND REGION-  
WIDE ON SUNDAY, THIS WILL CERTAINLY HAVE A FAVORABLE IMPACT ON  
BOTH AFTERNOON HEAT INDEX AND OVERNIGHT LOW TEMPS (MAINLY IN RURAL  
LOCATIONS). HOWEVER, THIS TREND HAS NOT YET BEEN CAPTURED BY  
BLENDED MODEL GUIDANCE, AND WITH APPARENT TEMPS STILL EXPECTED TO  
REACH 105-110F, A HEAT ADVISORY WILL REMAIN IN EFFECT THROUGH THE  
WEEKEND.  
 

 
   
LONG TERM
 
 
(MONDAY THROUGH THURSDAY)  
ISSUED AT 1007 PM CDT THU AUG 13 2026  
 
THE 5H RIDGE WILL REMAIN IN PLACE ACROSS THE SOUTHERN U.S. NEXT  
WEEK, WITH WEST-NORTHWEST FLOW ACROSS THE CENTRAL PLAINS INTO THE  
OH AND TN VALLEYS. THE QUESTION IS HOW AMPLIFIED AND IT'S EASTWARD  
INFLUENCE INTO THE TN VALLEY AND SOUTHEAST U.S. THE ECMWF IS A  
BIT MORE AMPLIFIED WITH THE RIDGE IN THE ROCKIES AND PLAINS WHICH  
COULD INFLATE CONVECTIVE CHANCES AND SOME HEAT RELIEF AT TIMES DUE  
TO A MORE NORTHWESTERLY FLOW IF THIS VERIFIES. FOR NOW, FORECAST  
HIGHS IN THE MIDDLE TO UPPER 90S ON MONDAY MAY DROP INTO THE LOWER  
TO MIDDLE 90S IN VALLEY AREAS TUESDAY THROUGH THURSDAY (UPPER 80S  
TO AROUND 90 ATOP THE HIGHER CUMBERLAND PLATEAU AREAS). OVERNIGHT  
LOWS IN THE MIDDLE TO UPPER 70S WILL DIP INTO LOWER TO MIDDLE  
70S. FOR NOW, POPS REMAIN LOW ON A DAY TO DAY BASIS NEXT WEEK, BUT  
THIS CERTAINLY COULD WAIVER UPWARD DEPENDING ON THE EVOLUTION OF  
THE RIDGE AND NORTHWESTERLY FLOW/MCS CLUSTER TRACKS AROUND THE  
PERIPHERY OF THE RIDGE.  
 

 
   
AVIATION
 
 
(06Z TAFS)  
ISSUED AT 1243 AM CDT FRI AUG 14 2026  
 
VFR CONDITIONS WILL CONTINUE EARLY THIS MORNING BENEATH A BKN  
LAYER OF CI. ALTHOUGH CONDITIONS WILL BE FAVORABLE FOR THE  
DEVELOPMENT OF PATCHY BR/FG BTWN 9-13Z, THIS IS MOST LIKELY TO  
OCCUR NEAR WATER SOURCES AND IN LOCATIONS THAT HAVE RECENTLY  
EXPERIENCED WETTING RAINFALL, AND WE WILL NOT INCLUDE MVFR VSBY  
REDUCTIONS IN THE TAFS ATTM. DEVELOPMENT OF A DIURNAL CU FIELD IS  
PREDICTED TO OCCUR BY 15Z, WITH A FEW TSRA POSSIBLE AT VARIOUS  
POINTS IN THE REGION BTWN 20-2Z. HOWEVER, DUE TO LOW ANTICIPATED  
COVERAGE, WE WILL NOT INCLUDE PROB30 GROUPS ATTM. A LGT SW FLOW  
WILL PREVAIL EARLY THIS MORNING, BEFORE BECOMING LGT/VRBL AFTER  
SUNRISE.  
 

 
   
CLIMATE
 
 
ISSUED AT 157 PM CDT WED AUG 12 2026  
 
THE CLIMATE PREDICTION CENTER HAS INCLUDED MUCH OF NORTHERN  
ALABAMA IN A HIGH RISK FOR MUCH ABOVE NORMAL TEMPERATURES AND MUCH  
OF SOUTHERN MIDDLE TENNESSEE AND FAR NORTHEAST ALABAMA IN A  
MODERATE RISK FOR MUCH ABOVE NORMAL TEMPERATURES ON AUGUST 20TH  
AND 21ST.  
 
ALL OF NORTHERN ALABAMA AND SOUTHERN MIDDLE TENNESSEE IS ALSO  
INCLUDED IN A MODERATE RISK FOR MUCH ABOVE NORMAL TEMPERATURES  
AUGUST 22ND AND 23RD.  
 
THEREFORE, THERE IS A 40-60% CHANCE IN THE MODERATE RISK  
LOCATIONS AND A 60-80% CHANCE FOR THOSE IN THE HIGH RISK AREAS FOR  
TEMPERATURES ABOVE 95 TO 97 DEGREES F AND HEAT INDEX VALUES ABOVE  
105 TO 110 DEGREES F DURING THIS PERIOD.  
 
MORE INFORMATION ON THE CPC U.S. HAZARDS OUTLOOK CAN BE FOUND AT:  
 
HTTPS://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/PREDICTIONS/THREATS/THREATS.PHP  
 

 
   
HUN WATCHES/WARNINGS/ADVISORIES
 
 
AL...HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR ALZ001>010-016.  
 
TN...HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR TNZ076-096-097.  
 

 
 

 
 
NEAR TERM...70/DD  
SHORT TERM...70/DD  
LONG TERM...17  
AVIATION...70/DD  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab AL Page
The Nexlab TN Page Main Text Page