572
FXUS64 KHUN 270245
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
945 PM CDT FRI JUN 26 2026
..NEW NEAR TERM, SHORT TERM, LONG TERM
KEY MESSAGES
UPDATED AT 945 PM CDT FRI JUN 26 2026
- THERE IS A MEDIUM (40-60%) CHANCE OF THUNDERSTORMS TOMORROW AND
TOMORROW EVENING, FOCUSED ACROSS SOUTHERN MIDDLE TN AND
NORTHEAST AL. A FEW STORMS WILL BE CAPABLE OF PRODUCING LOCALLY
DAMAGING WINDS UP TO 50-60 MPH. OTHERWISE, LIGHTNING AND HEAVY
RAINFALL WILL BE THE MAIN STORM IMPACTS.
- THE FIRST BIG HEAT WAVE OF THE SUMMER MOVES IN SUNDAY AND
CONTINUES THROUGH ALL OF NEXT WEEK. HEATRISK VALUES OF MAJOR
AND EXTREME (LEVELS 3 AND 4 OUT OF 4) INDICATE IMPACTFUL HEAT
ALL WEEK, COUPLED WITH HEAT INDEX VALUES OF 100-109 F.
NEAR TERM
(THIS EVENING THROUGH SATURDAY)
ISSUED AT 945 PM CDT FRI JUN 26 2026
IN THE MID/UPPER-LEVELS, A ZONALLY-ORIENTED RIDGE WILL EXTEND
FROM SUBTROPICAL PARTS OF THE EASTERN NORTH PACIFIC ACROSS THE
NORTHERN GULF AND INTO THE CENTRAL NORTH ATLANTIC FOR THE DURATION
OF THE NEAR TERM PERIOD. EMBEDDED WITHIN PREVAILING WNW FLOW
ALOFT OF 20-30 KNOTS (ALONG THE NORTHERN RIM OF THE RIDGE) A
SERIES OF WEAK VORTICITY MAXIMA (PERHAPS CONVECTIVELY-ENHANCED)
WILL SHIFT EASTWARD FROM THE SOUTHERN HIGH PLAINS THROUGH THE
OH/TN VALLEYS AND OFF THE MID-ATLANTIC COAST. ONE INITIALLY
PROMINENT DISTURBANCE WILL LOSE DEFINITION AS IT TRACKS EASTWARD
TO THE NORTH OF THE FORECAST AREA OVERNIGHT. HOWEVER, IT WILL
REMAIN SUFFICIENTLY ORGANIZED TO SUSTAIN A WEST-SOUTHWESTERLY LOW-
LEVEL JET OF 15-25 KNOTS, WITH THE RELATED INCREASE IN LOW-LEVEL
WARM ADVECTION SUPPORTING A THICK LAYER OF ALTOSTRATUS CLOUDS THAT
WILL REMAIN INTACT THROUGH AT LEAST EARLY TOMORROW AFTERNOON.
ISOLATED LIGHT SHOWERS WITHIN THIS REGIME MAY BRING A FEW
SPRINKLES OF RAIN TO NORTHWEST AL/SOUTHERN MIDDLE TN EARLY THIS
EVENING, BUT THIS WEAK CONVECTION IS LIKELY TO DISSIPATE BETWEEN
3-6Z. WELL TO OUR NORTHWEST, AN OUTFLOW BOUNDARY ORIGINATING FROM
STORMS EARLIER TODAY ACROSS SOUTHERN MO IS EXPECTED TO SPREAD
SOUTHEASTWARD WITH TIME AND MAY IGNITE NEW THUNDERSTORMS ACROSS
WESTERN PORTIONS OF KY/TN DURING THE PREDAWN HOURS. ALTHOUGH THE
SOUTHWARD EXTENT OF THIS REGIME IN THE 9-12Z TIMEFRAME IS UNCLEAR
AT THIS POINT, THE MAJORITY OF IMPACTS ACROSS OUR REGION ARE
LIKELY TO COME AFTER 12Z AND WE WILL ONLY LEAVE A 10-20% POP IN
PLACE ACROSS NORTHWEST AL/SOUTHERN MIDDLE TN. SHOULD ANY NOCTURNAL
CONVECTION IMPACT OUR REGION, IT IS NOT EXPECTED TO BE STRONG-
SEVERE, BUT WILL CERTAINLY BE CAPABLE OF PRODUCING LIGHTNING AND
LOCALLY HEAVY RAINFALL. OTHERWISE, THE COMBINATION OF INCREASINGLY
OVERCAST SKIES AND A LIGHT SW WIND WILL YIELD A WARM NIGHT WITH
LOWS IN THE L-M 70S.
DURING THE LATE MORNING HOURS TOMORROW, CONVECTIVE OUTFLOW FROM A
GROWING CLUSTER OF RAIN AND THUNDERSTORMS TO OUR NORTH WILL BEGIN
TO SPREAD VERY SLOWLY SOUTHWARD ACROSS THE AL-TN BORDER, PERHAPS
INITIATING DEVELOPMENT OF NEW CONVECTION ACROSS SOUTHERN MIDDLE
TN. HOWEVER, WITHIN A SYNOPTIC ENVIRONMENT CHARACTERIZED BY
GRADUAL 500-MB HEIGHT RISES (AND ONLY WEAK LOW-LEVEL ASCENT ALONG
AND IMMEDIATELY NORTH OF A SURFACE COLD POOL)WE ANTICIPATE A SHARP
GRADIENT IN PRECIPITATION COVERAGE, WITH LOCATIONS SOUTH OF THE
TN RIVER EXPECTED TO EXPERIENCE VERY LITTLE (IF ANY) RAIN, WHILE
LOCATIONS IN SOUTHERN MIDDLE TN AND NORTHEAST AL CURRENTLY HAVE
POPS IN THE 40-60% RANGE. REGENERATION OF THUNDERSTORMS IS
EXPECTED TO OCCUR ACROSS EASTERN AR/WESTERN TN BY MID-DAY AS
ANOTHER PROMINENT MID-LEVEL WAVE BEGINS TO TRACK EASTWARD AND
INTERACT WITH THE OUTFLOW BOUNDARY FROM MORNING STORMS, AND THIS
COULD RESULT IN ADDITIONAL STORMS THAT WOULD IMPACT THE SAME
PORTION OF OUR CWFA LATE TOMORROW AFTERNOON AND EVENING. THE LOCAL
STORM ENVIRONMENT WILL FEATURE CAPE AROUND 2000 J/KG AND STEEP
LOW-LEVEL LAPSE RATES AS TEMPS WARM INTO THE U80S-L90S. THIS,
ALONG WITH DEEP-LAYER SHEAR MARGINALLY CONDUCIVE FOR STORM
ORGANIZATION, WILL SUPPORT LOCALLY DAMAGING WINDS (UP TO 50-60
MPH), FREQUENT LIGHTNING AND HEAVY RAIN AS THE MAIN STORM IMPACTS.
ALTHOUGH LOW-LEVEL FLOW APPEARS TOO WEAK TO SUPPORT A RISK FOR
BRIEF TORNADOES, SHEAR IN THE 0-3KM LAYER MAY LEAD TO OCCASIONAL
MESOCYCLONE DEVELOPMENT WITH THE STRONGER UPDRAFTS.
SHORT TERM
(SATURDAY NIGHT THROUGH MONDAY NIGHT)
ISSUED AT 945 PM CDT FRI JUN 26 2026
SHOWERS AND THUNDERSTORMS WILL LIKELY BE ONGOING ACROSS PORTIONS
OF SOUTHERN MIDDLE TN AND NORTHEAST AL EARLY SATURDAY EVENING, AND
THIS REGIME COULD PERSIST INTO THE EARLY MORNING HOURS ON SUNDAY.
HOWEVER, THE AXIS OF CONVECTION WILL GRADUALLY SPREAD
NORTHEASTWARD AND OUT OF THE REGION BY SUNRISE, AS A MID-LEVEL
HIGH CENTERED ACROSS THE LOWER MS VALLEY AMPLIFIES NORTHWARD INTO
THE UPPER MS VALLEY DOWNSTREAM FROM A LONGWAVE TROUGH ACROSS THE
WESTERN CONUS. AS THE ANTICYCLONE ALOFT BEGINS TO STRENGTHEN AND
EXPAND NORTHEASTWARD INTO OUR REGION ON SUNDAY, MID/UPPER-LEVEL
WINDS WILL DIMINISH AND VEER TO THE NORTH, WITH AN INCREASING
INFLUENCE FROM BROAD SCALE SUBSIDENCE EXPECTED TO KEEP DIURNAL
CONVECTION CONCENTRATED TO OUR IMMEDIATE EAST ON BOTH SUNDAY AND
MONDAY AFTERNOONS. NEVERTHELESS, WE WILL MAINTAIN A VERY LOW
(10-20%) POP FOR OUR FAR EASTERN FORECAST ZONES TO ACCOUNT FOR
SOME UNCERTAINTY REGARDING THE PRECISE LOCATION OF THE 500-MB
HIGH.
BY THE END OF THE SHORT TERM PERIOD (MONDAY NIGHT), THE CENTER OF
THE SUBTROPICAL RIDGE IS PREDICTED TO MIGRATE NORTHEASTWARD INTO
WESTERN KY, PLACING THE LOCAL FORECAST AREA BENEATH STRENGTHENING
ENE FLOW ALOFT. THIS MAY ALLOW A FEW THUNDERSTORMS (DRIVEN BY BOTH
OUTFLOW AND A WEAK VORT MAX TRAVELING AROUND THE SOUTHEASTERN
FLANK OF THE RIDGE) TO SPREAD WESTWARD INTO THE FORECAST AREA
DURING THE EVENING HOURS. SHOULD THIS OCCUR, HIGH VALUES OF BOTH
CAPE AND DCAPE WILL SUPPORT A RISK FOR STRONG DOWNBURST WINDS WITH
THIS ACTIVITY. OTHERWISE, THE PRIMARY WEATHER IMPACT DURING THE
SHORT TERM PERIOD WILL BE EXCESSIVE HEAT, WITH AFTERNOON HIGHS
RISING INTO THE L-M 90S SUNDAY AND MID TO (PERHAPS) UPPER 90S ON
MONDAY. ALTHOUGH MIXING OF LOW-LEVEL MOISTURE ON A DAILY BASIS MAY
OCCASIONALLY RESULT IN DEWPOINTS FALLING INTO THE MID 60S, THIS
WILL NOT OCCUR EVERYWHERE AND HEAT INDEX WILL LIKELY REACH THE
100-105F RANGE FOR MOST OF THE VALLEY ON SUNDAY/MONDAY (WITH
105-110F POSSIBLE IN PORTIONS OF THE FORECAST AREA ON MONDAY).
LONG TERM
(TUESDAY THROUGH FRIDAY)
ISSUED AT 945 PM CDT FRI JUN 26 2026
THE LONG TERM FORECAST WILL BE INFLUENCED BY A PERSISTENT 594DAM
HIGH ALOFT, LEADING TO THE FIRST REAL HEAT WAVE WE HAVE SEEN THIS
YEAR. THIS HIGH WILL BE ANCHORED OVER THE OH VALLEY DOWN THROUGH
THE TN VALLEY THROUGH MUCH OF THE WORK WEEK AND WILL LIKELY KEEP
HEAT RELATED ADVISORIES IN PLACE OVER MULTIPLE DAYS. THE HEAT
THREAT WILL COME FROM THE COMBINATION OF TEMPS IN THE 90S (UPPER
90S SOME AFTERNOONS) AND DEWPOINTS IN THE LOW TO MID 70S THAT WILL
BRING HEAT INDICES TO THE 100-105 DEGREE RANGE. IN ADDITION,
OVERNIGHT LOWS IN THE MID TO UPPER 70S WILL PROVIDE VERY LITTLE
RELIEF FROM THE WARM AND HUMID CONDITIONS DURING THE DAY, KEEPING
US IN A MAJOR HEATRISK THROUGH THE LONG TERM PERIOD. WHILE THE
FORECAST LOOKS RELATIVELY DRY DURING THIS PERIOD, LOW (10-30%)
CHANCES FOR DIURNAL THUNDERSTORMS WILL EXIST EACH AFTERNOON AND
COULD KEEP SOME LOCATIONS FROM REACHING THE HIGHER HEAT INDICES
MENTIONED ABOVE. PLEASE KEEP UP WITH THE LATEST FORECAST AS WE
HEAD INTO NEXT WEEK. THOSE WITH OUTDOOR PLANS SHOULD PRIORITIZE
HEAT SAFETY BY STAYING HYDRATED, WEARING LIGHT COLORED CLOTHING,
TAKING FREQUENT BREAKS IN THE SHADE OR A/C, USING SUNSCREEN, AND
NEVER LEAVING PEOPLE OR PETS BEHIND IN VEHICLES.
AVIATION
(00Z TAFS)
ISSUED AT 732 PM CDT FRI JUN 26 2026
CURRENT SATELLITE IMAGERY SUGGESTS THAT THE COVERAGE AND DENSITY
OF MID-LEVEL AS WILL CONTINUE TO INCREASE THIS EVENING AND
THROUGHOUT THE MORNING HOURS ON SAT, WITHIN A STRENGTHENING LOW-
LEVEL WAA REGIME. ALTHOUGH A FEW LGT SHRA OR SPRINKLES OF RAIN
WILL BE POSSIBLE ACROSS NW AL/SOUTHERN MIDDLE TN EARLY THIS
EVENING (BEFORE WEAK CONVECTION CURRENTLY DEPICTED IN RADAR DATA
DISSIPATES), WE EXPECT NOCTURNAL SHRA/TSRA TO LARGELY REMAIN TO
OUR NW THRU 12Z. AS CONVECTIVE OUTFLOW DRIFTS SOUTHWARD INTO THE
REGION LATE SAT MORNING, PROSPECTS FOR SHRA/TSRA WILL INCREASE AT
BOTH TERMINALS, LIKELY BECOMING MAXIMIZED IN THE 14-20Z TIMEFRAME
(WHEN PROB30 GROUPS HAVE BEEN INCLUDED TO INDICATE THE POTENTIAL
FOR MVFR CIG/VSBY REDUCTIONS IN HEAVY RAIN AND LIGHTNING/STRONG
WIND GUSTS). HOWEVER, CONDITIONS SHOULD BEGIN TO IMPROVE LATE IN
THE TAF PERIOD. PREVAILING SFC FLOW WILL REMAIN FROM THE SW AT
5-10 KTS.
CLIMATE
ISSUED AT 605 PM CDT THU JUN 25 2026
MODERATE TO HIGH RISK FOR MUCH ABOVE NORMAL TEMPERATURES:
THE CLIMATE PREDICTION CENTER HAS INCLUDED THE TENNESSEE VALLEY
IN A HIGH RISK FOR MUCH ABOVE NORMAL TEMPERATURES FOR JULY 3.
THEREFORE, THERE IS A 60-80% CHANCE FOR TEMPERATURES ABOVE ABOVE
THE MID 90S AND HEAT INDEX VALUES ABOVE 105 DEGREES F DURING THIS
PERIOD.
THE CLIMATE PREDICTION CENTER HAS INCLUDED THE TENNESSEE VALLEY
IN A MODERATE RISK FOR MUCH ABOVE NORMAL TEMPERATURES FOR JULY 4.
THEREFORE, THERE IS A 40-60% CHANCE FOR TEMPERATURES ABOVE ABOVE
THE MID 90S AND HEAT INDEX VALUES ABOVE 105 DEGREES F DURING THIS
PERIOD.
MORE INFORMATION ON THE CPC U.S. HAZARDS OUTLOOK CAN BE FOUND AT:
HTTPS://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/PREDICTIONS/THREATS/THREATS.PHP
HUN WATCHES/WARNINGS/ADVISORIES
AL...NONE.
TN...NONE.
NEAR TERM...70/DD
SHORT TERM...70/DD
LONG TERM...25
AVIATION...70/DD
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