437
FXUS64 KHUN 081525
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1025 AM CDT TUE SEP 8 2026
..NEW NEAR TERM, SHORT TERM
KEY MESSAGES
UPDATED AT 1023 AM CDT TUE SEP 8 2026
- LOW CHANCES (20-30%) FOR A SHOWER/STORM DEVELOPING ACROSS THE
AREA THIS AFTERNOON.
- BETTER CHANCES (20-40%) OF SHOWERS AND STORMS THURSDAY AND
FRIDAY ALONG AND NORTH OF THE TN RIVER AS A FRONT SAGS SOUTH
TOWARD THE CWA.
- NWS HEAT RISK WILL REMAIN IN THE MINOR TO MODERATE CATEGORY
THROUGHOUT THE FORECAST PERIOD.
NEAR TERM
(REST OF TODAY AND TONIGHT)
ISSUED AT 1023 AM CDT TUE SEP 8 2026
THE FRONTAL BOUNDARY THAT TRAVERSED THE CWFA THIS PAST WEEKEND HAS
SINCE SHIFTED WELL SOUTH, CURRENTLY PLOTTED SPRAWLING WEST TO EAST
ACROSS THE NORTHERN GULF. SURFACE RIDGING ANCHORED OVER THE MID-
ATLANTIC WILL EXPAND WESTWARD ACROSS THE APPALACHIANS THROUGH THE
DAY, AND AS A RESULT, A FEW ISOLATED SHOWERS/STORMS (20-30%) MAY
BUBBLE UP THIS AFTERNOON. THIS WOULD FOLLOW CURRENT CLOUD-COVER
TRENDS ON THE LATEST SATELLITE IMAGERY, AS WELL AS INCREASED
MOISTURE POOLING ON THE WESTERN PERIPHERY OF THE RIDGING CENTERED
TO OUR EAST. GUSTY WINDS ~30-40MPH, LIGHTNING, AND LOCALLY HEAVY
RAINFALL WILL BE THE PRIMARY HAZARDS THIS AFTERNOON/EVENING.
MODELS ARE IN GOOD AGREEMENT THAT WHATEVER DEVELOPS WILL DISSIPATE
QUICKLY WITH SUNSET THIS EVENING. MORNING LOWS WEDNESDAY MORNING
START OUT IN THE UPPER 60S EAST/LOWER 70S WEST.
SHORT TERM
(WEDNESDAY THROUGH FRIDAY)
ISSUED AT 1023 AM CDT TUE SEP 8 2026
HIGH PRESSURE ALOFT AND AT THE SFC WILL KEEP A DRY FORECAST ON TAP
FOR WEDNESDAY FOR THE AREA, WITH DAYTIME HIGHS TOPPING OUT 2-3
DEGREES WARMER THAN TODAY. HIGHS WEDNESDAY RANGE FROM THE LOWER
90S EAST TO THE MIDDLE 90S WEST, BUT HEAT INDEX VALUES STILL
REMAIN BELOW 100F (WHICH IS A FAR CRY FROM THIS TIME LAST WEEK).
A PATTERN CHANGE IS IN THE WORKS FOR THURSDAY/THURSDAY NIGHT AS
RIDGING SHIFTS EASTWARD ALOFT, AND AT THE SAME TIME, AN UPPER LOW
TRAVERSES THE SRN CANADIAN PROVINCES. THIS WILL SEND A FRONT
SOUTHWARD, AND WITH IT, CLUSTERS OF SHOWERS AND STORMS ALONG THE
BOUNDARY. LOCATIONS ALONG AND N OF THE TN RIVER HAVE THE BEST SHOT
AT SEEING RAIN THURSDAY, BUT CHANCES DECREASE SIGNIFICANTLY THE
FARTHER SOUTH YOU GO IN THE CWA. RAIN CHANCES FOR US ARE HIGHEST
IN SRN MIDDLE TN (20-30%) AND ARE UPWARDS OF 60-70% OVER METRO
NASHVILLE. LOCALLY, IN CULLMAN COUNTY, RAIN CHANCES ARE LESS THAN
5%. AS WITH THIS PAST WEEKEND, GUSTY WINDS 30-40MPH, FREQUENT
LIGHTNING, AND LOCALLY HEAVY RAINFALL DUE TO SLOW MOVEMENT WILL BE
THE PRIMARY THREATS. LOWS THURSDAY NIGHT WILL BE MILD AND IN THE
LOWER/MIDDLE 70S, WITH DAYTIME HIGHS FRIDAY WILL TOP OUT IN THE
LOWER TO MIDDLE 90S AHEAD OF MEDIUM CHANCES (~40%) FOR DEVELOPING
SHOWERS AND STORMS.
LONG TERM
(FRIDAY THROUGH MONDAY)
ISSUED AT 1105 PM CDT MON SEP 7 2026
EXTENDED RANGE MODEL DATA SUGGESTS THAT A SUBTLE LOW-LEVEL
STREAMLINE CONFLUENCE AXIS (INITIALLY POSITIONED ACROSS THE TN
VALLEY) WILL LIFT NORTHWARD INTO THE OH VALLEY AND LOSE DEFINITION
DURING THE PERIOD FROM FRIDAY-SATURDAY NIGHT, IN RESPONSE TO
SURFACE PRESSURE FALLS ACROSS THE SOUTHERN HIGH PLAINS. THIS,
ALONG WITH SW FLOW ALOFT (PROVIDED BY A WEAK MID- LEVEL TROUGH
DRIFTING EASTWARD OVER THE LOWER MS VALLEY), WILL FORCE PWAT
VALUES BACK INTO THE 1.8-2" RANGE, LEADING TO A GENERAL INCREASE
IN THE COVERAGE OF SHOWERS AND THUNDERSTORMS BOTH DAYS. WITH NO
CLEAR EVIDENCE OF SYNOPTIC SCALE FORCING FOR ASCENT, SUBTLE DEEP-
LAYER WARM/MOIST ADVECTION AND MESOSCALE BOUNDARIES WILL LIKELY BE
THE SOURCE OF UNORGANIZED CONVECTION (LARGELY TIED TO THE DIURNAL
WARMING CYCLE, BUT WITH SOME POTENTIAL FOR CONVECTION TO PERSIST
AT NIGHT, AS WELL).
ON SUNDAY AND MONDAY, THERE ARE INDICATIONS THAT THE ATLANTIC
SUBTROPICAL RIDGE WILL BEGIN TO STRENGTHEN AS IT RETROGRADES
WESTWARD INTO THE SOUTHEASTERN CONUS. ALTHOUGH THIS COULD
POTENTIALLY HAVE A NEGATIVE INFLUENCE ON THE OVERALL COVERAGE OF
AFTERNOON CONVECTION, LOW-LEVEL MOISTURE RETURN WILL IMPROVE AS
SOUTHERLY FLOW BECOMES ESTABLISHED WITHIN THE WARM SECTOR OF A LOW
TRACKING NORTHEASTWARD INTO THE UPPER MS VALLEY. WITH DEWPOINTS
RETURNING TO THE L-M 70S, PWAT VALUES WILL CONTINUE TO RISE ABOVE
2" AND THIS COUPLED WITH COLLAPSING STEERING CURRENTS ALOFT MAY
ENHANCE THE RISK FOR LOCALLY HEAVY RAINFALL AND FLOODING DURING
THIS PERIOD. DUE TO INCREASED RAIN CHANCES, HIGHS WILL FALL BACK
INTO THE U80S-L90S, AS OVERNIGHT LOWS REMAIN IN THE U60S-L70S.
AVIATION
(12Z TAFS)
ISSUED AT 643 AM CDT TUE SEP 8 2026
A LOWER LEVEL MOISTURE RETURN HAS RESULTED IN SCATTERED TO BROKEN
LOWER CLOUDS ACROSS THE TN VALLEY. THESE CLOUDS HAD CLOUD BASES OF
2500-8000FT AGL. DAYTIME HEATING PRODUCING A MORE UNSTABLE
ENVIRONMENT SUPPORTS THE FORMATION OF ISOLATED SHOWERS MAINLY IN
THE AFTERNOON. CONFIDENCE ON TIMING AND COVERAGE OF SHOWER
ACTIVITY IS TOO LOW FOR INCLUSION IN THE TAF. OTHERWISE, LIGHT SE
WINDS SHOULD INCREASE TO 5-15KT THIS MORNING AND EARLY AFTERNOON,
BEFORE SUBSIDING TO AROUND 5KT TONIGHT.
HUN WATCHES/WARNINGS/ADVISORIES
AL...NONE.
TN...NONE.
NEAR TERM...12
SHORT TERM....12
LONG TERM....70
AVIATION...RSB
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