207
FXUS64 KHUN 201621
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1121 AM CDT WED MAY 20 2026
..NEW NEAR TERM, SHORT TERM, LONG TERM
KEY MESSAGES
ISSUED AT 1120 AM CDT WED MAY 20 2026
- MEDIUM TO HIGH CHANCES (60-90%) OF SHOWERS AND THUNDERSTORMS
ARE FORECAST TODAY THROUGH EARLY NEXT WEEK. NO SEVERE WEATHER
IS FORECAST.
- LOCALLY HEAVY DOWNPOURS AND FREQUENT LIGHTNING MAY ACCOMPANY
ALL THUNDERSTORMS AND THOSE WITH OUTDOORS PLANS OR EVENTS
SHOULD MONITOR THE FORECAST.
NEAR TERM
(REST OF TODAY AND TONIGHT)
ISSUED AT 1120 AM CDT WED MAY 20 2026
A WEAKENING COLD FRONT WILL PUSH EAST INTO NORTHWESTERN ALABAMA
LATER THIS AFTERNOON. FORCING ALONG AND AHEAD OF THIS FEATURE
WILL LIKELY BE STRONG ENOUGH TO PRODUCE AN AREA OF SCATTERED TO
MORE NUMEROUS (MAINLY IN SOUTHERN MIDDLE TENNESSEE) SHOWERS AND
THUNDERSTORMS. SHEAR IS NOT VERY IMPRESSIVE AND FORECAST LAPSE
RATES ARE MAINLY BETWEEN 5.0 AND 6.0 IN MOST GUIDANCE. THOUGH
SBCAPE COULD BE BETWEEN 2000 AND 3000 J/KG, SEVERE STORMS ARE NOT
EXPECTED. SOME STRONGER STORMS WILL BE ABLE TO PRODUCE FREQUENT
LIGHTNING, GUSTY WINDS TO AROUND 45 MPH, AND HEAVY RAINFALL.
IT LOOKS LIKE STRONGEST AND MOST PERSISTENT FORCING WILL REMAIN
MOSTLY IN TENNESSEE NE INTO THE SOUTHERN OHIO VALLEY AND SOUTHWEST
OF THE AREA. ONE QUARTER TO AROUND HALF AN INCH IN SOUTHERN MIDDLE
TENNESSEE LOOKS REASONABLE FOR RAINFALL AMOUNTS THROUGH TONIGHT.
THE MAJORITY OF GUIDANCE PUSHES THE FRONT SOUTH OF THE TENNESSEE
RIVER LATE TONIGHT INTO THE DAYBREAK ON THURSDAY. WE SHOULD LOSE
INSTABILITY OVERNIGHT BEHIND THE FRONT. SOME POST-FRONTAL FORCING
WILL LIKELY PRODUCE SOME LINGERING LIGHT TO MODERATE RAIN OVER THE
AREA.
SHORT TERM
(THURSDAY THROUGH SATURDAY)
ISSUED AT 1120 AM CDT WED MAY 20 2026
DURING THE DAY ON THURSDAY, GUIDANCE PUSHES THE FRONT BACK TO THE
NORTHWEST. SHEAR REMAINS WEAK NEAR AND ALONG THIS FRONTAL BOUNDARY.
INSTABILITY IS FORECAST TO AGAIN CLIMB INTO THE 1000 TO 2000 J/KG
RANGE, MAYBE SLIGHTLY HIGHER. AGAIN LAPSE RATES AND DCAPE VALUES
LOOK FAIRLY MEAGER. OVERALL FORCING SHOULD BE BETTER, BUT SEVERE
THUNDERSTORMS DO NOT LOOK POSSIBLE. GENERAL TO STRONG THUNDERSTORM
ACTIVITY IS LIKELY THOUGH PRODUCING FREQUENT LIGHTNING, HEAVY
DOWNPOURS, AND GUSTY WINDS TO AROUND 45 MPH.
THE FRONTAL BOUNDARY CONTINUES TO MORE QUICKLY MOVE NORTHWARD
THURSDAY NIGHT INTO THE DAY ON FRIDAY. AT THE SAME TIME, MODELS
FORM A PRE-FRONTAL TROUGH AXIS THAT EXTENDS WSW FROM THE MID-
ATLANTIC THROUGH NORTHERN GEORGIA INTO CENTRAL MISSISSIPPI.
30 KNOTS OF 0-3 KM SHEAR IS FORECAST BY SEVERAL MODELS BY THE
LATE AFTERNOON INTO THE EARLY EVENING HOURS ALONG THIS FEATURE.
SBCAPE VALUES CLIMB IN THE AFTERNOON INTO THE 1000 TO 2500 J/KG
RANGE IN SEVERAL MODELS. LUCKILY, LAPSE RATES LOOK FAIRLY POOR
(5.0 TO 6.0 DEGREES/KM). DCAPE VALUES REMAIN LESS THAN 500 J/KG AS
WELL. ALL IN ALL, THERE MAY BE JUST ENOUGH SHEAR FOR A LOW END
ORGANIZED SEVERE THUNDERSTORM THREAT PRODUCING DAMAGING WINDS.
SOME ENHANCED FORCING ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE
MOVING ALONG THE PRE-FRONTAL TROUGH AXIS COULD PROVIDE THE SPARK
FOR A MORE ORGANIZED CLUSTER OF STORMS ALONG WITH THE MINIMAL
SHEAR. GIVEN FORCING AND HIGH PWAT VALUES BETWEEN 1.5 AND 1.7
INCHES, THIS COULD PRODUCE BETWEEN 0.5 AND 1.0 INCHES OF
ADDITIONAL RAINFALL OVER THE AREA. SOME LOCALLY HEAVIER AMOUNTS
CAN'T BE RULED OUT GIVEN FORCING AND SOME POSSIBLE BRIEF TRAINING
OF STORMS.
THIS PRE-FRONTAL TROUGH AXIS DOESN'T MOVE MUCH FRIDAY NIGHT INTO
SATURDAY. HOWEVER, WE MAY HAVE A SLIGHT BREAK FROM HEAVIER
RAINFALL. THE BASE OF THE SHORTWAVE TROUGH AXIS LOOKS TOO FAR
SOUTH FOR MUCH CONVECTION TO DEVELOP DESPITE A GOOD AMOUNT OF
INSTABILITY DEVELOPING IN THE AFTERNOON. IT LOOKS LIKE WE WILL BE
UNDER THE INFLUENCE OF MORE SUBSIDENCE. HOWEVER, WIDESPREAD CLOUD
COVER AND MAYBE SOME SHOWERS WILL LIKELY KEEP HIGHS IN THE UPPER
70S TO LOWER 80S.
LONG TERM
(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 1120 AM CDT WED MAY 20 2026
THE POSITION OF THE PRE-FRONTAL TROUGH AXIS CHANGES LITTLE THROUGH
EARLY NEXT WEEK. OCCASIONAL DISTURBANCES CONTINUE TO MOVE EAST
ACROSS IT AT TIMES THROUGHOUT THAT PERIOD. INSTABILITY BUILDS EACH
DAY IN THE AFTERNOON TO BETWEEN 1000 AND 3000 J/KG. NOT SEEING
SHEAR INCREASE, BUT FLOODING WILL LIKELY BECOME AN ISSUE IF IT
ALREADY ISN'T BY THE WEEKEND. AT THIS TIME, IT LOOKS LIKE THERE IS
ENOUGH OF A BREAK GIVEN THE PRIMARILY DIURNAL NATURE OF THE
CONVECTION TO KEEP A MORE SERIOUS FLASH FLOODING/FLOODING THREAT
FROM MATERIALIZING. HOWEVER, SOME LOW END FLASH FLOODING OR MINOR
RIVER FLOODING IS NOT OUT OF THE QUESTION THROUGH THAT PERIOD.
OVERALL, DAYTIME HIGHS WILL REMAIN BELOW NORMAL (UPPER 70S/LOWER
80S) DUE TO CLOUD COVER AND AFTERNOON CONVECTION. OVERNIGHT LOWS
WILL REMAIN FAIRLY WARM AND HUMID ONLY DROPPING INTO THE LOWER TO
MID 60S.
AVIATION
(12Z TAFS)
ISSUED AT 549 AM CDT WED MAY 20 2026
VFR CONDITIONS WILL PREVAIL AT BOTH TERMINALS EARLY THIS MORNING,
BEFORE CLOUDS INCREASE AND CEILINGS DROP LATE THIS MORNING INTO
THE AFTERNOON. A FRONT WILL MOVE INTO THE REGION, BRINGING MEDIUM
TO HIGH CHANCES OF SHOWERS AND STORMS. HAVE ADDED A TEMPO DURING
THE MAIN WINDOW OF TSRA ACTIVITY (20-00Z). AWWS AND AMENDMENTS
MAY BE NEEDED DURING THIS TIMEFRAME. AFTER SUNSET, MVFR CONDITIONS
WILL DEVELOP AS LOW STRATUS SETTLES IN AFTER CONVECTION WANES.
HUN WATCHES/WARNINGS/ADVISORIES
AL...NONE.
TN...NONE.
NEAR TERM...KTW
SHORT TERM....KTW
LONG TERM....KTW
AVIATION...AMP
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