598  
FXUS64 KHUN 191545  
AFDHUN  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE HUNTSVILLE AL  
1045 AM CDT SAT SEP 19 2026  
   
..NEW NEAR TERM, SHORT TERM  
 
   
KEY MESSAGES  
 
UPDATED AT 1045 AM CDT SAT SEP 19 2026  
 
- CONDITIONS WILL BE FAVORABLE FOR STRONG-SEVERE THUNDERSTORMS  
EACH AFTERNOON TODAY-TUESDAY, WITH THE GREATEST SPATIAL  
COVERAGE OF STORMS EXPECTED MONDAY AND TUESDAY. LOCALLY  
DAMAGING DOWNBURST WINDS, FREQUENT LIGHTNING AND HEAVY RAINFALL  
WILL BE THE MAIN STORM IMPACTS.  
 
- HOT TEMPERATURES WILL CONTINUE FROM TODAY-MONDAY, WITH HIGHS IN  
THE MID-UPPER 90S IN THE VALLEY. A HEAT ADVISORY REMAINS IN  
EFFECT THROUGH 8 PM CDT TODAY.  
 
- A SLIGHTLY COOLER AND DRIER AIRMASS WILL ARRIVE LATE IN THE  
FORECAST PERIOD, WITH HIGHS DROPPING BACK INTO THE 80S ON  
THURSDAY/FRIDAY.  
 
 
   
NEAR TERM  
 
(REST OF TODAY AND TONIGHT)  
ISSUED AT 1045 AM CDT SAT SEP 19 2026  
 
A NUMBER OF CHANGES WERE NOTED WITH THE UPPER LEVEL PATTERN IN  
COMPARISON TO EARLIER THIS WEEK. A FORMER "MEGA" UPPER RIDGE THAT  
HELPED BRING THE HEAT TO MUCH OF THE CENTRAL, SOUTHERN, AND  
EASTERN LOWER-48 HAS WEAKENED WITH MAXIMUM 500MB HEIGHTS AROUND  
593 DECAMETERS OVER THE AR-LA-TX-OK REGION. A TUTT TYPE UPPER  
LOW WAS MOVING WESTWARD ACROSS THE FAR NE GULF OF AMERICA. THIS  
TROPICAL UPPER TROPOSPHERIC TROUGH FEATURE SHOULD REMAIN OVER THE  
EASTERN GULF INTO EARLY NEXT WEEK. A WEAKER UPPER DISTURBANCE OVER  
EASTERN KENTUCKY WAS PRODUCING WEAK TROUGHING EXTENDING SOUTHWARD  
ALONG THE AL/GA BORDER. OTHERWISE, MAINLY SUNNY SKIES PREVAILED  
AT 10 AM WITH TEMPERATURES CLIMBING THROUGH THE 80S WITH LIGHT  
WINDS.  
 
STRONG DAYTIME HEATING AND RESULTANT INSTABILITY WILL RESULT IN  
SCATTERED TO AT TIMES BROKEN FIELDS OF CU AND SOME TCU. MODERATELY  
HIGH PRECIPITABLE WATER OF AMOUNTS FROM 1.6-1.8" WITH HEATING WILL  
RESULT IN MOST UNSTABLE CAPES RISING 1500-2200 J/KG LATE THIS  
MORNING AND EARLY THIS AFTERNOON. THUS LOW/MEDIUM CHANCES OF  
SHOWERS AND THUNDERSTORM WILL BE REALIZED MAINLY IN THE AFTERNOON.  
PER CONVECTIVE OUTLOOKS FROM THE SPC; SOME OF THE STORMS OVER OUR  
MORE EASTERN AREAS COULD BECOME STRONG TO SEVERE. THE MAIN THREAT  
FROM THE STRONGER STORMS WILL BE DOWNBURST-TYPE OUTFLOW WIND  
GUSTS. THE BEST CHANCES FOR THE STRONGER STORMS WILL BE MORE TO  
OUR EAST. WINDEX NUMBERS AND AN INVERTED-V SIGNATURE FROM FORECAST  
SOUNDINGS CONFIRM A STRONG OUTFLOW WIND POTENTIAL.  
 
HEAT IS ANOTHER CONCERN FOR TODAY. BEFORE SHOWERS COMMENCE, EXPECT  
ANOTHER HOT DAY WITH HIGHS RISING INTO THE MID/UPPER 90S, WITH A  
100 DEGREE READING OVER NW ALABAMA. OVER THE PAST FEW DAYS, STRONG  
SURFACE HEATING HAS MIXED DEWPOINTS FROM THE 70S INTO THE 60S,  
WHICH HAS PUT A DAMPER ON HEAT INDEXES RISING INTO THE ADVISORY  
AREA. UNLESS NEWER GUIDANCE SUGGESTS OTHERWISE, WE ARE PLANNING TO  
LET THE HEAT ADVISORY EXPIRE AT 8 PM THIS EVENING. AFTER SHOWER  
ACTIVITY ENDS THIS EVENING, EXPECT ANOTHER MUGGY NIGHT WITH LOWS  
FROM NEAR 70 EAST TO THE LOW/MID 70S NEAR LARGE BODIES OF WATER.  
AS WE GO TO THE END OF THE SUMMER SEASON, LONGER NIGHTS UNDER  
MOSTLY CLEAR SKIES COULD ALLOW THE DEVELOPMENT OF FOG BEFORE  
DAYBREAK SUNDAY, AND MAINLY IN/NEAR AREAS THAT RECEIVE WETTING  
(GREATER THAN 1/10") RAINFALL AND/OR IN FOG FAVORED AREAS.  
 
 
   
SHORT TERM  
 
(SUNDAY THROUGH TUESDAY)  
ISSUED AT 1045 AM CDT SAT SEP 19 2026  
 
THE UPPER DISTURBANCE TO OUR NE WILL MOVE FURTHER TO THE EAST ON  
SUN, WHILE THE UPPER RIDGE TO OUR WEST AND LOW OVER THE NE GULF  
REMAINS. THUS ANOTHER HOT DAY EXPECTED. HIGHS SHOULD RISE INTO THE  
LOW 90S EAST TO MID/UPPER 90S WEST. DEWPOINTS IN THE 70S AGAIN  
SHOULD MIX DOWN INTO THE 60S, THUS ARE EXPECTING HEAT INDEXES TO  
REMAIN LESS THAN 105 DEGREES. DESPITE NO ADVISORY, AREA RESIDENTS  
SHOULD MAINTAIN AWARENESS FOR THE HEAT. THE MIXING SHOULD ALSO  
LOWER SHOWER/THUNDERSTORM CHANCES IN THE AFTERNOON. WILL KEEP LOW  
CHANCES OF AFTERNOON CONVECTION FOR OUR MORE EASTERN AREAS, THAT  
WILL BE HELPED BY MORE RUGGED TERRAIN. SIMILARLY MILD/WARM SUN  
NIGHT WITH LOWS IN THE LOW/MID 70S.  
 
A SYNOPTIC SCALE SYSTEM FORMING TO OUR WEST WILL APPROACH THE  
TENNESSEE VALLEY ON MONDAY. THIS SYSTEM WILL BRING LOW/MEDIUM  
CHANCES OF SHOWERS/THUNDERSTORMS. WITH BETTER FORCING FROM THIS  
SYSTEM, STORMS THAT FORM COULD BECOME STRONG TO SEVERE, WITH MORE  
DOWNBURST-TYPE OUTFLOW WIND GUSTS THE MAIN THREAT. THIS RISK HAS  
BEEN NOTED BY THE SPC, WITH MOST OF THE AREA IN A MARGINAL (1 OUT  
OF 5) RISK FOR SEVERE STORMS. BEFORE SHOWERS BEGIN, EXPECT  
SIMILARLY HOT CONDITIONS WITH HIGHS MAINLY IN THE 90S (LOWER 90S  
EAST TO MID/UPPER 90S WEST). IT SHOULD BE BIT COOLER MON NIGHT  
WITH LOWS FROM THE MID 60S EAST TO LOWER 70S NEAR LARGE BODIES OF  
WATER. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE  
FORECAST TUESDAY, WITH HIGHS FROM THE UPPER 80S EAST TO MID 90S  
WEST. CONFIDENCE IS TOO LOW THIS FAR OUT TO EXACTLY DISCERN STORM  
STRENGTH; CANNOT RULE OUT STRONGER STORM CHANCES TUE. LASTLY, THE  
AUTUMN 2026 SEASON BEGINS TUE EVENING AROUND 704 PM CDT.  
 
 
   
LONG TERM  
 
(TUESDAY THROUGH FRIDAY)  
ISSUED AT 1057 PM CDT FRI SEP 18 2026  
 
LATEST EXTENDED RANGE FORECAST DATA SUGGEST THAT A WEAK NORTHERN  
STREAM TROUGH WILL ADVANCE SLOWLY EASTWARD FROM THE MID-MS VALLEY  
INTO THE NORTHERN MID-ATLANTIC STATES NEXT WEEK, AS IT WILL LIKELY  
BE BLOCKED BY RIDGING TO ITS NORTH. AT THE SURFACE, A TROUGH  
(INITIALLY EXTENDING FROM CENTRAL PARTS OF MS/AL NORTH-  
NORTHEASTWARD INTO THE UPPER OH VALLEY) IS PREDICTED TO REMAIN  
NEARLY STATIONARY ON TUESDAY, AND WILL LIKELY FOCUS DEVELOPMENT OF  
ADDITIONAL SHOWERS AND THUNDERSTORMS ACROSS OUR REGION BOTH  
DURING THE DAY AND AT NIGHT. IN SIMILAR FASHION TO MONDAY, A FEW  
STRONG-SEVERE THUNDERSTORMS MAY OCCUR DURING THE AFTERNOON AND  
EVENING HOURS, AIDED BY HIGH CAPE AND INCREASING W-NW FLOW ALOFT.  
 
ALTHOUGH THERE IS SOME UNCERTAINTY REGARDING PRECISELY WHEN THIS  
WILL OCCUR, THE SURFACE TROUGH IS EXPECTED TO SHIFT SLOWLY  
SOUTHEASTWARD AT SOME POINT WEDNESDAY/THURSDAY, ALLOWING A  
COOLER/DRIER AIRMASS (ORIGINATING FROM AN ANTICYCLONE ACROSS  
SOUTHERN QC) TO SPREAD SOUTHEASTWARD INTO THE REGION. THIS COUPLED  
WITH 20-30 KNOT W-NW FLOW ALOFT AND DRY ADVECTION THROUGH THE  
DEPTH OF THE TROPOSPHERIC COLUMN WILL ALLOW RAIN CHANCES TO  
DECREASE CONSIDERABLY ON THURSDAY/FRIDAY. AFTERNOON HIGHS WILL  
FALL BACK INTO THE L-M 80S BY THE END OF THE WORK WEEK, WITH  
OVERNIGHT LOWS THURSDAY NIGHT/FRIDAY MORNING IN THE U50S-L60S.  
 
 
   
AVIATION  
 
(12Z TAFS)  
ISSUED AT 617 AM CDT SAT SEP 19 2026  
 
LOW CHANCES OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AROUND  
19-01Z AT BOTH TERMINALS. STORMS WILL BE CAPABLE OF PRODUCING  
LIGHTNING AND STRONG TO DAMAGING WIND GUSTS, ALONG WITH A  
VIS REDUCTION TO MVFR.  
 
 
   
HUN WATCHES/WARNINGS/ADVISORIES  
 
AL...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ALZ001>010-016.  
 
TN...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR TNZ076-096-097.  
 
 
 
 
 
NEAR TERM...RSB  
SHORT TERM....RSB  
LONG TERM....70/DD  
AVIATION...JMS  
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