863
FXUS64 KHUN 201141
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
641 AM CDT THU AUG 20 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 237 AM CDT THU AUG 20 2026
- THERE IS A LOW CHANCE FOR STRONG TO SEVERE STORMS THIS
AFTERNOON INTO THE EVENING WITH THE MAIN THREAT BEING DAMAGING
WINDS AND QUARTER-SIZED HAIL.
NEAR TERM
(TODAY)
ISSUED AT 237 AM CDT THU AUG 20 2026
AN UPPER RIDGE THAT IN PART BROUGHT VERY WARM TO HOT CONDITIONS TO
THE REGION HAS SHRUNK IN AREAL SIZE, NOW WAS SITUATED OVER THE
DESERT SW. A DEEP UPPER LOW OVER NORTHERN QUEBEC HAS INDUCED LARGE
SCALE TROUGHING OVER THE EASTERN CONUS. IN A WESTERLY FLOW ALOFT,
A DISTURBANCE MOVING EASTWARD ACROSS THE WESTERN OHIO VALLEY WAS
BRINGING NUMEROUS SHOWERS/THUNDERSTORMS ACROSS THE WESTERN TO
CENTRAL KY/TN BORDER, WITH OTHER ACTIVITY HEADING EASTWARD ACROSS
NORTHERN ARKANSAS. OTHERWISE ACROSS THE TENNESSEE VALLEY, DRY
WEATHER WAS CONTINUING. AND DESPITE A LIGHT SE FLOW, PATCHY FOG
WAS BEING REPORTED AT A NUMBER OF METAR SITES. GIVEN THAT DRY
BULB/DEWPOINT TEMPERATURE SEPARATION WAS 2-5 DEGREES AT MOST
SPOTS, FOG MAY NOT BECOME AN ISSUE UNTIL AROUND DAYBREAK. WARM
CONDITIONS HAVE RETURNED WITH 2 AM TEMPERATURES IN THE LOW/UPPER
70S.
PER THE CONVECTION TO OUR NW. IT WAS HEADING A BIT TO THE SOUTH
OF DUE EAST. THIS WOULD SUGGEST THAT THE STRONGER ACTIVITY NW OF
NASHVILLE SHOULD REMAIN NORTH OF THIS AREA IN THE OVERNIGHT. AM
NOT SO CERTAIN WITH THE ACTIVITY OVER NORTHERN ARKANSAS, IT COULD
REACH NW ALABAMA OR OUR TENNESSEE COUNTIES AROUND DAYBREAK. STRONG
WIND GUSTS AND HEAVY DOWNPOURS ARE THE MAIN THREAT WITH STORMS
THAT MAKE IT HERE THIS MORNING.
FORECASTER CONFIDENCE IS LOW REGARDING MORE PRECISELY WHAT COULD
OCCUR LATER TODAY GIVEN A VARIETY OF OUTPUTS FROM THE MODELS. MOST
OF THE GUIDANCE WAS SHOWING CONVECTION WANING AS WE GO INTO THE
LATE MORNING AND EARLY AFTERNOON. AFTERWARDS, BUSINESS WILL LIKELY
PICK UP AS ANOTHER UPPER LEVEL DISTURBANCE NEARS THE AREA. THIS
DISTURBANCE ARRIVING DURING THE PEAK HEATING TIME, OF A MOIST AND
CONDITIONALLY UNSTABLE ATMOSPHERE WILL BRING SCATTERED TO NUMEROUS
SHOWER AND THUNDERSTORM ACROSS THE AREA. HEATING OF THIS MOIST
ATMOSPHERE WILL BOOST CAPES TO 1500-2500 J/KG. SOME OF THE STORMS
COULD BECOME STRONG TO SEVERE WITH DAMAGING OUTFLOW WIND GUSTS,
DOWNBURST-TYPE IS THE MAIN THREAT THANKS TO A DRY MID LAYER.
PRECIPITABLE WATER AMOUNTS FROM 1.8" TO 2.1" SUPPORT TORRENTIAL
DOWNPOURS WITH PONDING OF WATER AND A LOW RISK OF FLASH FLOODING.
FREEZING LEVELS OF 11-12KFT COULD ALLOW SEVERE HAIL FROM THE
STRONGEST STORMS. BEFORE STORMS COMMENCE, EXPECT ANOTHER VERY WARM
TO HOT DAY, AS HIGH TEMPERATURE SOAR INTO THE LOW/MID 90S.
DEWPOINTS IN THE MID 70S WILL PRODUCE HEAT INDEX (HI) VALUES ABOVE
105 DEGREES IN A NUMBER OF PLACES. BUT WITH A LIMITED COVERAGE OF
THE HOTTEST TEMPERATURES, MORE MIXING THAT THE MODELS DO NOT CATCH
THAT LOWERS THE HI, AND MORE CLOUDS FORMING, WE WILL HOLD OFF ON A
HEAT ADVISORY.
SHORT TERM
(TONIGHT THROUGH SATURDAY)
ISSUED AT 1010 PM CDT WED AUG 19 2026
ALTHOUGH THE SEVERE THREAT IS EXPECTED TO COME TO AN END BY LATE
TOMORROW AFTERNOON/EVENING, LOW TO MEDIUM CHANCES FOR RAIN AND
THUNDERSTORMS WILL CONTINUE TOMORROW NIGHT THROUGH FRIDAY AS THE
AFOREMENTIONED WAVE SLOWLY MOVES EAST OF THE AREA AND HIGH
PRESSURE BEGINS TO PUSH SOUTHWARD FROM THE LOWER OH RIVER AND MID
MS RIVER VALLEYS. THIS WILL ULTIMATELY LEAD TO A DRIER PATTERN FOR
THE FIRST HALF OF THE WEEKEND WITH SLIGHTLY LESS OPPRESSIVE
AFTERNOON HEAT INDICES. TEMPS WILL FALL CLOSER TO SEASONAL NORMS
WITH AFTERNOON HIGHS IN THE UPPER 80S TO LOWER 90S WITH HEAT
INDICES BELOW 105 DEGREES. OVERNIGHT LOWS WILL FALL TO THE UPPER
60S/LOWER 70S WITH MOSTLY CLEAR/SUNNY SKIES AFTER FRIDAY MORNING.
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
(12Z TAFS)
ISSUED AT 641 AM CDT THU AUG 20 2026
A PASSING BOUNDARY HAS HELPED INITIATE ISOLATED TO SCATTERED
CONVECTION ACROSS THE PARTS OF THE TN VALLEY THIS MORNING. THIS
ACTIVITY WAS MOVING NE AROUND 20KT. THIS ACTIVITY SHOULD WIND DOWN
DURING THE COURSE OF THE MORNING. STRONG DAYTIME HEATING AND
ANOTHER SYSTEM NEARING THE AREA WILL BRING BETTER CHANCES OF
CONVECTION LATER THIS AFTERNOON AND TONIGHT. SOME OF THOSE STORMS
COULD BECOME SEVERE WITH WIND GUSTS GREATER THAN 50KT AND
TORRENTIAL DOWNPOURS. DEPENDING UPON WHERE AND HOW MUCH RAINFALL
OCCURS, LIGHT WINDS LATE TONIGHT WOULD BE FAVORABLE FOR FOG
FORMATION. GIVEN UNCERTAINTY, DID NOT MENTION FOG IN THE LATTER
PORTION OF THE TAF.
HUN WATCHES/WARNINGS/ADVISORIES
AL...NONE.
TN...NONE.
NEAR TERM...RSB
SHORT TERM....25
LONG TERM....HC
AVIATION...RSB
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