921
FXUS64 KHUN 300648
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
148 AM CDT TUE JUN 30 2026
..NEW NEAR TERM
KEY MESSAGES
UPDATED AT 148 AM CDT MON JUN 30 2026
- A HEAT WAVE WILL OCCUR THIS WEEK WITH A HEATRISK VALUE OF 3
OUT OF 4 (MAJOR CATEGORY) TO 4 OUT OF 4 (EXTREME CATEGORY).
AFTERNOON HIGHS IN THE MID TO UPPER 90S WILL BE COMMON, WITH
PEAK HEAT INDEX VALUES BETWEEN 105 TO 110 DEGREES
- A HEAT ADVISORY IS CURRENTLY IN EFFECT THROUGH 7 PM THURSDAY
FOR THE ENTIRE TENNESSEE VALLEY.
- POTENTIAL EXISTS ON WEDNESDAY FOR A FEW THUNDERSTORMS CAPABLE
OF PRODUCING STRONG WIND GUSTS
NEAR TERM
(TODAY)
ISSUED AT 148 AM CDT TUE JUN 30 2026
A STRONG MID/UPPER-LEVEL RIDGE WILL REMAIN CENTERED DIRECTLY OVER
THE TENNESSEE VALLEY, RESULTING IN ANOTHER HOT/HUMID DAY ACROSS
THE REGION. THE COMBINATION OF AMPLE SUNSHINE AND LIGHT SOUTHERLY
FLOW WILL ALLOW DAYTIME HIGHS TO REACH THE MID TO UPPER 90S. THESE
HOT TEMPERATURES COMBINED WITH DEWPOINTS IN THE LOW TO MID 70S
WILL CREATE MAXIMUM HEAT INDEX VALUES BETWEEN 105-110 DEGREES IN
MOST LOCATIONS BY THIS AFTERNOON. A MAJOR (LEVEL 3 OUT 4) HEAT
RISK WAS NOTED ACROSS THE ENTIRE REGION TODAY, WITH EXTREME VALUES
(LEVEL 4 OUT 4) FORECAST FOR MUCH OF THE REGION WEDNESDAY AND
THURSDAY. THUS, A HEAT ADVISORY REMAINS IN EFFECT FOR THE ENTIRE
TENNESSEE VALLEY THROUGH 7 PM THURSDAY. PLEASE PRACTICE HEAT
SAFETY TODAY -- STAY HYDRATED, TAKE FREQUENT BREAKS FROM THE HEAT,
AND NEVER LEAVE PEOPLE OR PETS IN VEHICLES!
ONE SMALL CAVEAT TO WATCH WILL BE THE POTENTIAL FOR A FEW SHOWERS
AND STORMS TO DEVELOP JUST TO THE SOUTH AND EAST OF AREA DUE TO A
WEAK IMPULSES OVER GEORGIA AND SOUTH ALABAMA. HAVE KEPT A 10% POP
FOR OUR NORTHEAST ALABAMA COUNTIES IN CASE ONE OR TWO
SHOWERS/STORMS IS ABLE TO BRIEFLY DRIFT NORTHWARD INTO AREA LATE
THIS AFTERNOON.
SHORT TERM
(TUESDAY NIGHT THROUGH THURSDAY)
ISSUED AT 1040 PM CDT MON JUN 29 2026
AS WE PROGRESS INTO WED/THU, THE RIDGE WILL TEND TO BECOME MORE
ELONGATED ALONG AN W-E AXIS, WHILE MOVING GRADUALLY INTO THE
CENTRAL APPALACHIAN REGION. THIS WILL RESULT IN A DEEPER EASTERLY
FLOW DEVELOPING ACROSS THE REGION. THE BROAD SUITE OF GLOBAL AND
REGIONAL/HI-RES GUIDANCE INDICATES A COHERENT SHORTWAVE WILL RIDE
SOUTH AND THEN WESTWARD ALONG THE EASTERN PERIPHERY OF THE BROAD
UPR RIDGE ON WED. THIS WILL BRING THE FEATURE INTO THE SRN
APPALACHIAN REGION, FURTHER INCITING VERTICAL COUPLING WITH THE
DEVELOPMENT OF LOWER-LEVEL VORTICITY, AND PRODUCING SHOWER/STORM
ACTIVITY. THE COVERAGE OF ANY ENSUING ACTIVITY IS UNCERTAIN AT
THIS TIME, WITH A RATHER WIDE RANGE IN THE GUIDANCE SUITE.
HOWEVER, GIVEN THE ROBUST STATE OF MOISTURE/INSTABILITY EXPECTED
ON WED, STRONG WIND GUSTS COULD OCCUR FROM ANY STRONGER CELLS.
STEEP LOW AND MID LEVEL LAPSE RATES, ALONG WITH HIGH MIXING RATIOS
AND VERY HIGH MAX/MIN THETA-E DIFFERENCES BETWEEN LOW/MID LEVELS
ALSO SUGGEST A POTENTIAL FOR DOWNBURSTS. THE TIMING OF THIS
ACTIVITY REMAINS A BIT UNCERTAIN, BUT APPEARS MOST PLAUSIBLE
DURING THE AFTERNOON. WITH THAT SAID, IF THE ACTIVITY HOLDS OFF
LONG ENOUGH ON WED, HEAT ADVISORY CRITERIA WOULD STILL BE MET,
WITH THE POTENTIAL FOR EVEN HIGHER HEATRISK (WIDESPREAD LEVEL 4)
THAN ON TUES, AND HEAT INDICES PERHAPS REACHING OR BREAKING 110 F.
THURSDAY MAY END UP BEING A NEAR CARBON-COPY OF WED, WITH THE
PROSPECTS FOR YET ANOTHER VORT MAX TO MOVE INTO THE REGION NEAR
PEAK HEATING. FROM AN INSTABILITY STANDPOINT, THE OVERALL
PARAMETER SPACE MAY BE A LITTLE LESS ROBUST ON THU, BUT COULD
AGAIN BE SUPPORTIVE OF SOME STRONG UPDRAFTS/DOWNDRAFTS IN THE
AFTERNOON. EITHER WAY, BOTH DAYS WILL BEAR SOME WATCHING. IN
SIMILAR FASHION TO WED, OUTSIDE OF SHOWER/STORM ACTIVITY, HEAT MAY
SURGE ONCE AGAIN DURING THE DAY ON THURSDAY IN THE MOISTURE-RICH
HUMID AIR MASS. DUE TO UNCERTAINTY WITH THE COVERAGE OF CLOUDS AND
SHOWERS/STORMS, THE HEAT ADVISORY WILL CONTINUE TO BE ADVERTISED
THROUGH THURSDAY.
LONG TERM
(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 1040 PM CDT MON JUN 29 2026
THE APEX OF THE UPPER LEVEL RIDGE WILL SHIFT OVER THE EASTERN
SEABOARD BY FRIDAY AND ALSO START TO FLATTEN AS RIPPLES OF SHORTWAVES
PROGRESS OVER THE MIDWEST, GREAT LAKES, AND UPPER OHIO VALLEY
REGIONS. SOME GLOBAL GUIDANCE SUGGESTS THAT A FEW OF THESE SHORTWAVES
WILL DIG TOWARDS THE SOUTHEAST LATE IN THE WEEKEND AND INTO EARLY
NEXT WEEK. MEANWHILE, SURFACE HIGH PRESSURE WILL PERSIST OVER THE
APPALACHIANS DOWN THROUGH THE ARKLAMISS REGION THROUGH SUNDAY;
HOWEVER, A COLD FRONT MAY APPROACH THE TENNESSEE VALLEY BY EARLY NEXT
WEEK, PUSHING THE HIGH PRESSURE TO THE SOUTHEAST.
OVERALL, EXPECT A DIURNAL PATTERN TO SET UP BY LATE WEEK, WITH DAILY
CHANCES OF SHOWERS AND STORMS (GENERALLY 20-40%) IN THE AFTERNOON
AND EVENING. WITH THE CONTINUED WARM AND HUMID CONDITIONS, ALONG WITH
DCAPE VALUES NEAR OR JUST OVER 1000 J/KG, WE'LL BE KEEPING AN EYE ON
DOWNBURST POTENTIAL DURING THIS TIME AS WELL. BY SUNDAY, AND
ESPECIALLY MONDAY, SHOWER AND STORM CHANCES THEN INCREASE AS THE
AFOREMENTIONED COLD FRONT APPROACHES THE REGION. WHILE THERE LOOKS TO
BE MORE THAN ENOUGH INSTABILITY FOR STORMS, BULK SHEAR VALUES ARE
FAIRLY WEAK (10 KNOTS OR LESS). THEREFORE, SEVERE WEATHER IS NOT
ANTICIPATED SUNDAY OR MONDAY AT THIS TIME.
AS FOR TEMPERATURES, FRIDAY AND SATURDAY WILL CONTINUE TO BE VERY
WARM WITH HIGHS IN THE LOWER TO UPPER 90S ALONG WITH HEAT INDEX
VALUES IN THE 98-106 DEGREE RANGE. NWS HEATRISK LOOKS TO MAINLY BE IN
THE MAJOR CATEGORY (LEVEL 3 OF 4) BY LATE WEEK, BUT WBGTS REMAIN IN
THE UPPER 80S TO AROUND 90. THEREFORE, HEAT PRODUCTS MAY NEED TO BE
EXTENDED INTO THE FIRST PART OF THE WEEKEND TO ACCOUNT FOR THE
LINGERING HEAT. MAKE SURE TO TAKE PRECAUTIONS FOR THE DANGEROUS HEAT!
WEAR LIGHT-COLORED, LOOSE-FITTING CLOTHING, STAY HYDRATED, AND TAKE
FREQUENT BREAKS IN THE SHADE IF YOU WORK OUTSIDE OR HAVE OUTDOOR
ACTIVITIES! LOOK BEFORE YOU LOCK - NEVER LEAVE PEOPLE OR PETS IN
VEHICLES! BY SUNDAY AND MONDAY, THE INCREASED PRECIPITATION CHANCES
WILL RESULT IN AN EVER SO SLIGHT COOLDOWN, WITH HIGHS TOPPING OUT IN
THE LOWER TO MID 90S ON SUNDAY AND IN THE UPPER 80S TO LOWER 90S ON
MONDAY.
AVIATION
(06Z TAFS)
ISSUED AT 1222 AM CDT TUE JUN 30 2026
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD, WITH LIGHT WINDS
AND MOSTLY CLEAR SKY.
HUN WATCHES/WARNINGS/ADVISORIES
AL...HEAT ADVISORY UNTIL 7 PM CDT THURSDAY FOR ALZ001>010-016.
TN...HEAT ADVISORY UNTIL 7 PM CDT THURSDAY FOR TNZ076-096-097.
NEAR TERM...AMP.24
SHORT TERM....KDW
LONG TERM....26
AVIATION...AMP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page