368
FXUS64 KHUN 041739
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1239 PM CDT SAT JUL 4 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 1123 AM CDT SAT JUL 4 2026
- A HEAT ADVISORY REMAINS IN EFFECT THROUGH 7 PM TODAY, WITH SOME
HEAT INDEX VALUES REACHING UP TO 106F.
- AFTER A SLIGHTLY LOWER COVERAGE OF PRECIPITATION TODAY,
CHANCES FOR AFTERNOON/EVENING SHOWERS AND STORMS WILL INCREASE
TO 40-80% FROM SUNDAY-FRIDAY (HIGHEST ON MONDAY/TUESDAY).
- A LOW RISK OF FLASH FLOODING OR RIVER FLOODING MAY DEVELOP NEXT
WEEK.
NEAR TERM
(REST OF TODAY AND TONIGHT)
ISSUED AT 1123 AM CDT SAT JUL 4 2026
A SHORTWAVE CONTINUES TO MOVE ENE ACROSS NORTHEASTERN TN. THIS IS
DRAGGING SOME MUCH WEAKER CONVERGENCE SOUTHWEST OF THAT DISTURBANCE
INTO NORTHERN ALABAMA THIS MORNING. THIS HAS MANAGED TO SPARK A
SHOWER OR TWO IN NORTHERN ALABAMA. SBCAPE IS MUCH LOWER TODAY
GIVEN MORNING CLOUD COVER. HOWEVER, SUNNY SKIES HAVE RETURNED AT
THIS HOUR TO MOST OF THE AREA (SOME HIGH CLOUDS LINGERING IN NE
AL), SO INSTABILITY WILL INCREASE.
HOWEVER, BELIEVE THE CONVERGENCE HAS PUSHED INTO NW GEORGIA
ALREADY. THIS LOOKS TO LIKELY MERGE WITH A BOUNDARY THAT CURRENTLY
EXTENDS FROM FAR EASTERN TENNESSEE INTO WESTERN NORTH CAROLINA.
THIS BOUNDARY IS A STRONGER CONVERGENCE BOUNDARY AND EXTENDS
SOUTHWEST INTO NORTH CENTRAL GEORGIA AND CENTRAL ALABAMA.
HIRES-ARW, WHICH HAS HANDLES CONVECTION INITIATION VERY WELL OVER
THE PAST FEW DAYS, SEEMS TO DEVELOP 30 TO 60 PERCENT COVERAGE OF
SHOWERS AND THUNDERSTORMS NEAR THAT BOUNDARY TOWARDS 1 TO 3 PM,
BUT KEEPS IT MAINLY IN NORTHERN GEORGIA. WHETHER THAT BOUNDARY
WILL EXTEND INTO NE ALABAMA OR NOT IS A BIT OF A QUESTION.
HOWEVER, DID INCREASE POP A BIT AFTER 18Z IN NE AL TO BETWEEN 20
AND 40 PERCENT. THOUGH WE WILL BECOME MORE UNSTABLE LATER THIS
AFTERNOON (2000-3000 J/KG), THETA E DIFFERENCES IN THE ATMOSPHERIC
PROFILE ARE NOT NEARLY AS CONDUCIVE FOR DAMAGING MICROBURST
(15-20 TODAY). LOW LEVEL LAPSE RATES ARE NOT AS IMPRESSIVE AND MID
LEVEL LAPSE RATES ARE PRETTY WEAK. THESE OVERALL LAPSE RATES ARE
NOT FORECAST TO REALLY STEEPEN AS IN PAST DAYS. DCAPE VALUES LOOK
VERY MARGINAL FOR STRONGER MICROBURSTS. WE WILL HAVE ENOUGH
INSTABILITY TO PRODUCE THUNDERSTORMS THAT CREATE FREQUENT
LIGHTNING, HEAVY RAINFALL AND GUSTY WINDS, BUT NO SEVERE
CONVECTION IS EXPECTED. HIGHS LOOK TO BE TEMPERED AS WELL WITH
THE UPPER RIDGE TO OUR ENE WEAKEN EVEN MORE SIGNIFICANTLY AS AN
UPPER LEVEL TROUGH AXIS MOVES EAST TOWARDS THE AREA THIS
AFTERNOON. HIGHS IN THE 90 TO 95 DEGREE RANGE (MAYBE ONLY LOWER
90S IN NE WITH CLOUD COVER), LOOK REASONABLE. NOT SURE WE WILL SEE
POOLING OF HIGHER DEWPOINTS IN THE EARLY MID AFTERNOON HOURS, WHEN
TEMPERATURES WILL BE THE HIGHEST. HEAT INDEX VALUES WILL STILL
REACH THE 100 TO 106 DEGREE RANGE IN SOME LOCATIONS. THUS, LEFT
THE HEAT ADVISORY IN EFFECT THROUGH 7 PM TODAY. HOWEVER, 105 OR
106 HEAT INDEX VALUES MAY NOT BE AS WIDESPREAD AS PREVIOUSLY
THOUGHT.
EXPECT SHOWER AND THUNDERSTORM COVERAGE TO INCREASE IN NW ALABAMA
TOWARDS SUNSET. AGAIN NOT EXPECTING ANY OF THIS ACTIVITY TO BE
SEVERE. THIS ACTIVITY SHOULD PUSH EAST AHEAD OF AN APPROACHING
UPPER LEVEL TROUGH AXIS THIS EVENING. HOWEVER, ACTIVITY WILL
LIKELY LAST THROUGH AT LEAST 10 PM IF NOT CLOSER TO MIDNIGHT
BEFORE DISSIPATING. EXPECTING FOG DEVELOPMENT OVERNIGHT INTO EARLY
SUNDAY MORNING. IT COULD BE DENSE IN SOME AREAS. LOWS WILL REMAIN
WARM, ONLY DROPPING INTO THE 70 TO 73 DEGREE RANGE.
SHORT TERM
(SUNDAY THROUGH MONDAY NIGHT)
ISSUED AT 1123 AM CDT SAT JUL 4 2026
THE FAIRLY AMPLIFIED LONGWAVE TROUGH AXIS PUSHES FURTHER EAST INTO
THE OHIO VALLEY SOUTHWEST INTO EASTERN ARKANSAS/EXTREME WESTERN
TN SUNDAY INTO MONDAY. THIS SHOULD FOCUS STRONG LIFT OVER THE
AREA STARTING IN THE EARLY MORNING HOURS ON SUNDAY. SHEAR REMAINS
EXTREMELY WEAK THOUGH, SO NO INCREASE IN THUNDERSTORM INTENSITY
IS EXPECTED. THIS TROUGH AXIS DOES NOT MOVE VERY QUICKLY EASTWARD
THROUGH MONDAY NIGHT. THIS WILL KEEP KEEP SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS IN THE FORECAST DURING THAT PERIOD.
HIGHEST PRECIPITATION CHANCES WILL BE IN THE MIDDAY TO EARLY
EVENING PERIOD MOSTLY WITH MORE SCATTERED CHANCES IN THE OVERNIGHT
PERIOD. HIGH PWATS WILL BE IN PLACE, SO FLASH FLOODING RISK WILL
INCREASE DURING THAT PERIOD. SOME MINOR RIVER FLOODING MAY BE
POSSIBLE. THIS WET PATTERN WILL KEEP HIGHS MUCH MORE PLEASANT
(UPPER 80S TO LOWER 90S). THOUGH IT WILL STILL BE HUMID, SO HEAT
INDEX VALUES WILL REMAIN IN THE 96 TO 103 DEGREE RANGE MOSTLY. SO
MAKE SURE TO REMAIN HYDRATED IF WORKING OUTSIDE, EVEN THOUGH HIGH
TEMPERATURES WILL BE MUCH LOWER.
LONG TERM
(TUESDAY THROUGH FRIDAY)
ISSUED AT 1109 PM CDT FRI JUL 3 2026
THE WARM AND HUMID AIRMASS WILL CONTINUE INTO NEXT WEEK AS AN
UPPER TROUGH AXIS EXITS TO THE EAST AND UPPER RIDGING BUILDS OVER
THE AREA TOWARD THE MID-LATE WEEK PERIOD. FORTUNATELY THIS RIDGE
LOOKS TO BE A LITTLE WEAKER THEREFORE TEMPS AND HEAT INDICES WON'T
BE QUITE AS HOT AS WE HAVE SEEN THIS PAST WEEK. AN AXIS OF HIGHER
MOISTURE WILL BE POSITIONED OVER THE TN VALLEY OVER MUCH OF THE
LONG TERM PERIOD AND WILL LEAD TO MEDIUM CHANCES (40-60%) FOR RAIN
AND THUNDERSTORMS EACH DAY, PEAKING DURING THE AFTERNOON HOURS.
PWATS WILL CLIMB BACK TO THE 2-2.2" RANGE AND WILL BRING AN
INCREASED RISK FOR LOCALIZED FLOODING, ESPECIALLY OVER AREAS THAT
RECEIVE CONSECUTIVE DAYS OF HEAVY RAINFALL. FOR NOW, ORGANIZED
SEVERE WEATHER IS NOT ANTICIPATED BUT SOME THUNDERSTORMS COULD BE
STRONG TO MARGINALLY SEVERE GIVEN AFTERNOON INSTABILITY. DAILY
HIGHS WILL TOP OUT IN THE UPPER 80S/LOWER 90S WITH HEAT INDICES
REACHING THE MID 90S TO LOW 100S.
AVIATION
(18Z TAFS)
ISSUED AT 1239 PM CDT SAT JUL 4 2026
VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH 22Z AT KHSV AND
23Z AT KMSL. THEN SCATTERED TSRA COULD AFFECT EITHER TERMINAL
(KHSV FROM 22Z TO 04Z/KMSL FROM 23Z TO 02Z). THERE IS HIGHER
CONFIDENCE OF THIS OCCURRING AT KMSL THAN KHSV, THUS A TEMPO GROUP
DURING THE PERIOD FOR KMSL WAS INCLUDED AND ONLY A PROB30 GROUP
FOR KHSV. DURING THESE PERIODS, AT LEAST MVFR CIGS/VSBYS WILL BE
MET (POTENTIALLY LOWER THRESHOLDS). EXPECT FOG TO FORM AFTER 06Z
BETWEEN 9Z AND 12Z PRIMARILY. FOR NOW, ONLY INCLUDED VSBY
REDUCTION TO MVFR, BUT THE POTENTIAL FOR IFR OR LOWER WILL NEED TO
BE MONITORED IN FUTURE ISSUANCES.
HUN WATCHES/WARNINGS/ADVISORIES
AL...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ALZ001>010-016.
TN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR TNZ076-096-097.
NEAR TERM...KTW
SHORT TERM....KTW
LONG TERM....25
AVIATION...KTW
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