041
FXUS64 KHUN 202253
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
553 PM CDT THU AUG 20 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 222 PM CDT THU AUG 20 2026
- ALL OF NORTH ALABAMA AND MOST OF SOUTHERN MIDDLE TENNESSEE IS
OUTLOOKED IN A SLIGHT RISK OF SEVERE STORMS (LEVEL 2 OF 5) THIS
AFTERNOON/EVENING. THE MAIN HAZARD IS DAMAGING WINDS, BUT
HEAVY RAINFALL/FLOODING, FREQUENT LIGHTNING, AND HAIL ARE ALSO
THREATS.
NEAR TERM
(TONIGHT)
ISSUED AT 222 PM CDT THU AUG 20 2026
WE ARE CURRENTLY WATCHING SATELLITE TRENDS ALONG THE
MISSISSIPPI/TENNESSEE AND ALABAMA/TENNESSEE STATE BORDERS, AS SOME
STORMS HAVE TRIED TO DEVELOP IN THESE AREAS OVER THE PAST HOUR OR
SO. HOWEVER, THE STORMS THAT HAVE TRIED TO FORM HAVE BEEN SHORT-
LIVED. SO, WE ARE MONITORING TO SEE IF THIS CLOUD DECK IS
STABILIZING THESE AREAS, RESULTING IN A POTENTIALLY HIGHER
PROBABILITY OF A STRONG TO SEVERE STORM THREAT CONCENTRATED TO THE
SOUTH. EXPECTING MORE CONVECTION TO FIRE OVER THE NEXT HOUR OR
TWO, ESPECIALLY SOUTH OF THESE CLOUDS.
OVERALL, NOT TOO MUCH HAS CHANGED IN TERMS OF OUR OVERALL
THINKING AND TIMING (NOW THROUGH ~9PM) FOR STORMS. ATMOSPHERIC
PARAMETERS ARE IN PLACE FOR STRONG TO SEVERE STORMS TO DEVELOP.
SEE PREVIOUS DISCUSSION ATTACHED BELOW, BUT IN ADDITION TO THESE,
0-3KM LAPSE RATES ARE ALSO HIGH AT AROUND 8 DEGC/KM. DAMAGING WIND
GUSTS ARE THE MAIN HAZARD, BUT HEAVY RAIN/FLOODING, FREQUENT
LIGHTNING, AND HAIL ARE ALSO THREATS. IN ADDITION, SPC HAS
OUTLOOKED ALL OF NORTH ALABAMA AND MOST OF SOUTHERN MIDDLE
TENNESSEE IN A SLIGHT RISK OF SEVERE STORMS. HAVE MULTIPLE WAYS OF
RECEIVING WARNINGS AND STAY WEATHER AWARE!
PREVIOUS DISCUSSION:
THE COMPLEX OF SHOWERS AND STORMS TO OUR NORTH IN TENNESSEE THAT
BROUGHT A FEW SHOWERS/STORMS TO OUR TN COUNTIES AND INTO NORTH-
CENTRAL AL EARLIER THIS MORNING CONTINUES TO DWINDLE AND MOVE
EAST. HOWEVER, MOST OF THIS ACTIVITY REMAINS TO OUR NORTH. THERE
HAS BEEN SOME DEVELOPMENT OF A FEW SHOWERS AND STORMS TO OUR
NORTHWEST OVER THE PAST HOUR. THIS WILL BE SOMETHING TO WATCH OVER
THE NEXT FEW HOURS, BUT HI-RES GUIDANCE SUGGESTS THAT THESE WILL
WANE AND NOT BE THE MAIN CONCERN. AS AN UPPER SHORTWAVE TROUGH
MOVES INTO THE OHIO AND TENNESSEE VALLEYS TODAY, THE MAIN SHOW IN
THE FORM OF A SORT OF BROKEN LINE OF SHOWERS/STORMS IS EXPECTED
THIS AFTERNOON. MOST GUIDANCE SHOWS THIS ACTIVITY STARTING AROUND
2PM AND MOVING FROM NORTHWEST TO SOUTHEAST OVER THE LOCAL AREA
THROUGH THIS EVENING.
TAKING A LOOK AT BULK SHEAR, MODEL VALUES RANGE BETWEEN 20-30
KNOTS WITH AMPLE INSTABILITY (1800-3000 J/KG CAPE). DCAPE VALUES
EXCEED 1000 J/KG AS WELL, SO DAMAGING WINDS WILL BE A MAIN HAZARD
WITH ANY STRONG TO SEVERE STORMS THAT DEVELOP. THIS COINCIDES WITH
AN AREA-WIDE MARGINAL RISK OF SEVERE STORMS FROM SPC. HOWEVER, WE
ARE NOT AS CONFIDENT WHEN IT COMES TO THE HAIL THREAT BECAUSE OF
THIS MORNING'S OBSERVED AND MODEL SOUNDINGS GIVING BETWEEN 14-15
KFT FOR THE FREEZING LEVEL. ULTIMATELY, HAIL CAN'T BE RULED OUT
ENTIRELY BUT IT DOESN'T SEEM TO BE THE BIGGER THREAT (LIKE
DAMAGING WINDS). ADDITIONALLY, OUR PWATS GENERALLY RANGE BETWEEN
1.75-2.0 INCHES TODAY, WITH VALUES GREATER THAN 2 INCHES IN SOME
LOCATIONS LATER TODAY INTO THIS EVENING. WITH THE 75TH PERCENTILE
(COMPARED TO BMX SOUNDING CLIMATOLOGY) AROUND 1.8 INCHES AND THE
90TH PERCENTILE RIGHT AROUND 2 INCHES, THIS MEANS THAT SHOWERS AND
STORMS WILL BE EFFICIENT RAINFALL PRODUCERS TODAY WHICH COULD
RESULT IN AT LEAST NUISANCE FLOODING. OVERALL, STAY WEATHER AWARE
TODAY AND TAKE SHELTER IF A WARNING IS ISSUED FOR YOUR LOCATION!
LIGHTNING IS ALSO HAZARDOUS, SO IF YOU'RE OUTSIDE AND YOU HEAR
THUNDER OR SEE LIGHTNING, HEAD INDOORS! IF YOU ENCOUNTER FLOODED
ROADS, TURN AROUND, DON'T DROWN!
AS FOR TEMPERATURES, IT WILL BE WARM TODAY WITH HIGHS TOPPING OUT
IN THE MID TO UPPER 90S. NE AL AND PORTIONS OF SOUTHERN MIDDLE TN
MAY BE A TOUCH COOLER, IN THE LOWER TO MID 90S. OVERALL, THINKING
THAT THE NBM IS A BIT TOO BULLISH WHEN IT COMES TO DEW POINTS
THROUGH THE DAY. MOST OTHER GUIDANCE SUGGESTS VALUES GENERALLY
BETWEEN UPPER 60S TO LOWER 70S (EVEN PERHAPS THE MID 70S IN A FEW
SPOTS). DECREASING OUR FORECAST DEW POINTS A BIT DID TEMPER OUR
HEAT INDEX VALUES DOWN TO BETWEEN 100-105 DEGREES FOR MOST OF THE
LOCAL AREA AS WELL. MORE URBAN SPOTS LIKE HUNTSVILLE OR MUSCLE
SHOALS MAY SEE VALUES CLOSER TO 105-106 DEGREES THOUGH. EVEN WITH
THIS IN ADDITION TO NWS HEATRISK AT THE MAJOR CATEGORY (LEVEL 3 OF
4) FOR A PORTION OF THE AREA (MOSTLY NORTH-CENTRAL ALABAMA), NOT
CONFIDENT IN ANY HEAT PRODUCTS DUE TO THE LOW TO MEDIUM (20-50%)
CHANCES OF SHOWERS AND STORMS THIS AFTERNOON. THIS WILL BE
MONITORED. REGARDLESS, PLEASE PRACTICE HEAT SAFETY. STAY HYDRATED
AND TAKE FREQUENT BREAKS IN THE SHADE IF YOU WORK OUTSIDE OR HAVE
OUTDOOR ACTIVITIES.
FOR TONIGHT, WHILE SOME SHOWER AND STORM ACTIVITY MAY LINGER INTO
THE OVERNIGHT PERIOD, THE SEVERE THREAT IS EXPECTED TO LARGELY
END AROUND 9PM THIS EVENING. THE CONCERN THEN TURNS TO CHANCES OF
PATCHY TO AREAS OF FOG (20-40%) WHERE THERE ARE BREAKS IN THE
CLOUDS TONIGHT. NOT EXPECTING WIDESPREAD DENSE FOG, BUT WITH LIGHT
TO CALM WINDS, THERE IS THE POTENTIAL FOR AT LEAST PATCHY FOG IN
RIVER VALLEYS, SHELTERED LOCATIONS, NEAR BODIES OF WATER, AND FOR
SPOTS THAT RECEIVE RAINFALL TODAY. LASTLY, EXPECT LOWS TO DIP INTO
THE UPPER 60S TO LOWER 70S.
SHORT TERM
(FRIDAY THROUGH SATURDAY)
ISSUED AT 1038 AM CDT THU AUG 20 2026
THERE IS A LOW CHANCE (10-15%) OF SOME LINGERING SHOWERS/STORMS
DURING THE DAY ON FRIDAY, BUT NO SEVERE WEATHER IS ANTICIPATED.
DRY CONDITIONS THEN RETURN ON SATURDAY AS AN UPPER RIDGE OVER THE
CENTRAL CONUS BUILDS EASTWARD INTO THE ARKLATEX AND SOUTHEASTERN
STATES. IN ADDITION, HIGHS ARE EXPECTED TO MAX OUT IN THE UPPER
80S TO LOWER 90S EACH DAY. FORTUNATELY, THE NWS HEATRISK DECREASES
TO BE IN THE MINOR CATEGORY, ALONG WITH HEAT INDEX VALUES ONLY
REACHING THE 90S. THUS, A SLIGHTLY COOLER WEEKEND IS ON TAP FOR
NORTH ALABAMA AND SOUTHERN MIDDLE TENNESSEE BY THE WEEKEND. ENJOY!
LONG TERM
(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 1010 PM CDT WED AUG 19 2026
THE LONG TERM SHOULD REMAIN FAIRLY TRANQUIL UNDER THE INFLUENCE OF
AN UPPER LEVEL RIDGE AND SUBSEQUENT SFC HIGH PRESSURE FROM THE NORTH.
HIGHS DURING THIS TIME ARE FORECAST TO CONTINUE TO REACH THE 90S
WITH HEAT INDICES UP TO 100 DEGREES, WHICH WILL KEEP US WITHOUT ANY
HEAT PRODUCTS ON THE TABLE. ONE THING TO WATCH WILL BE A SHORTWAVE
AND SUBSEQUENT SFC LOW WITH AN ACCOMPANYING FRONTAL BOUNDARY THAT MAY
CLIP THE WESTERN PORTION OF OUR AREA ON MONDAY INTO TUESDAY. FOR
NOW, HAVE KEPT POPS ALIGNED WITH BLENDED GUIDANCE DUE TO UNCERTAINTY
IN THE EVOLUTION AND SPEED OF THIS FRONT. THEREFORE, LOW CHANCES (20%
OR LESS) OF RAIN EXISTS MONDAY INTO TUESDAY. IF YOU HAVE OUTDOOR
INTERESTS EARLY NEXT WEEK, BE SURE TO CHECK BACK IN FOR FORECAST
UPDATES.
AVIATION
(00Z TAFS)
ISSUED AT 553 PM CDT THU AUG 20 2026
THERE REMAINS A LOW TO MEDIUM CHANCE OF TSRA THROUGH ~04Z, WITH A
RISK OF GUSTY WINDS, FREQUENT LIGHTNING AND +RA. PATCHY BR OR FG
WILL DEVELOP BY 10Z WITH A LOW CHANCE OF MVFR CONDITIONS AT KHSV
AND KMSL THROUGH 13Z. VFR CONDITIONS ARE THEN EXPECTED THROUGH THE
REST OF THE PERIOD.
HUN WATCHES/WARNINGS/ADVISORIES
AL...NONE.
TN...NONE.
NEAR TERM...26
SHORT TERM....26
LONG TERM....HC
AVIATION...17
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