312
FXUS64 KHUN 200541
AFDHUN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HUNTSVILLE AL
1241 AM CDT MON JUL 20 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 1014 PM CDT SUN JUL 19 2026
- A HEAT ADVISORY WILL BE IN EFFECT FOR MOST OF THE TENNESSEE
VALLEY FOR THE MONDAY THROUGH TUESDAY TIMEFRAME.
- MODERATE (LEVEL 2/4) TO MAJOR (LEVEL 3/4) HEAT RISK WILL BUILD
INTO THE TENNESSEE VALLEY THROUGH THE MIDDLE OF THE WEEK, WITH
PEAK HEAT INDEX VALUES BETWEEN 100 TO 109 DEGREES LIKELY IN
SOME LOCATIONS MONDAY AND TUESDAY.
- DAILY THUNDERSTORM CHANCES WILL CONTINUE INTO EARLY NEXT WEEK.
A FEW STORMS COULD BECOME STRONG TO MARGINALLY SEVERE TUESDAY.
GUSTY TO DAMAGING WINDS, FREQUENT LIGHTNING, AND LOCALLY HEAVY
RAINFALL WILL BE THE MAIN THREATS.
NEAR TERM
(REST OF TONIGHT AND MONDAY)
ISSUED AT 1014 PM CDT SUN JUL 19 2026
NUMEROUS SHOWERS AND THUNDERSTORMS THAT EARLIER IMPACTED MUCH OF
THE TENNESSEE VALLEY HAVE FOR THE MOST PART DISSIPATED AND/OR
MOVED SOUTH OF THE AREA AS OF THE EARLY NIGHT-TIME. OTHERWISE
UNDER A MIX OF MOSTLY CLOUDY TO OVERCAST SKIES, 10 PM TEMPERATURES
HAVE COOLED INTO THE 70S, AFTER EARLIER REACHING HIGHS FROM THE
MID 80S TO MID 90S, WITH RAINFALL AMOUNTS OVER 2" IN A FEW SPOTS.
WITH PLENTY OF RESIDUAL MOISTURE, EVEN IN SPOTS THAT HAVE NOT
RECEIVED WETTING (> 0.10") RAINFALL, EXPECT MUGGY CONDITIONS FOR
THE OVERNIGHT WITH LOWS ONLY COOLING INTO THE LOWER 70S, WITH A
FEW SPOTS ONLY INTO THE MID 70S. THANKS TO LIGHT WINDS AND "CLEAR"
SKIES (THINNING HIGHER ALTITUDE CLOUDS), THERE IS A RISK FOR LATE
NIGHT FOG FORMATION, ESPECIALLY IN/NEAR THOSE MORE FOG FAVORED
SPOTS, AND IN LOCATIONS THAT RECEIVED WETTING RAINS.
NEWER MODEL GUIDANCE COMING CONTINUED TO SUGGEST LOWER RAIN
CHANCES FOR THE START OF A NEW WORK WEEK. A SYSTEM THAT IN PART
COULD INTERCEPTING MOISTURE FROM THE GULF REGION IS TROPICAL
DEPRESSION #2 LOCATED ABOUT 180 MILES SOUTH OF PANAMA CITY. THIS
SYSTEM IS EXPECTED TO TAKE A NW, THEN WEST TRACK TOWARDS THE
MISSISSIPPI BAYOU INTO TUE. THIS TROPICAL SYSTEM SHOULD HAVE
LITTLE IMPACT OVER THIS REGION INTO THE MID WEEK. UNDER MAINLY
PARTLY CLOUDY SKIES, HEAT COULD BECOME A PROBLEM ON MONDAY.
OUTSIDE OF SHOWER ACTIVITY, HIGH TEMPERATURES SHOULD RISE INTO THE
LOW/MID 90S. CORRESPONDING HEAT INDEX VALUES SHOULD RANGE FROM
THE UPPER 90S TO 107. AREAS COVERED BY 105 DEGREE OR HIGHER HEAT
INDEXES ARE SUFFICIENT TO PUT OUT A HEAT ADVISORY STARTING MONDAY
AT 10 AM FOR ALL AREAS EXCEPT DEKALB COUNTY. AREA RESIDENTS ARE
URGED TO TAKE PRECAUTIONS REGARDING THE HEAT AND HUMIDITY.
SCATTERED AFTERNOON SHOWER AND THUNDERSTORM CHANCES DO REMAIN
DESPITE LOWER MOISTURE CONTENT THAN TODAY. STORMS THAT DO FORM
SHOULD BE "SUB-SEVERE" BUT WILL BE CAPABLE OF PRODUCING STRONG
GUSTY WINDS, FREQUENT LIGHTNING STRIKES, AND TORRENTIAL DOWNPOURS.
AM EXPECTING SHOWER COVERAGE TO REMAIN ISOLATED TO AT TIMES
SCATTERED IN COVERAGE.
SHORT TERM
(MONDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 1014 PM CDT SUN JUL 19 2026
AS HAS BEEN THE CASE THE PAST FEW NIGHTS, SHOWERS THAT FORM SHOULD
FADE AS WE GO INTO MON NIGHT. WE CANNOT RULE OUT PATCHY LATER
NIGHT FOG IN AREAS THAT RECEIVE WETTING RAINFALL, AS WELL AS FOG
FAVORED SPOTS. ANOTHER MUGGY AND HUMID NIGHT WITH LOWS IN THE
LOW/MID 70S. THE MILDER LOWS IN THE MID 70S WOULD HELP SET THE
STAGE FOR MORE HEAT ISSUES TUE. INLAND DEEP MOISTURE TRANSPORT
FROM THE GULF OF AMERICA SHOULD BE LIMITED BY THE TROPICAL ENTITY,
THUS WITH LOWER RAIN CHANCES, HOT CONDITIONS WILL AGAIN RULE.
HIGH TEMPERATURES SHOULD WARM INTO THE LOW/MID 90S, WITH HEAT
INDEX VALUES FROM THE UPPER 90S TO 109 DEGREES. WILL HAVE THE HEAT
ADVISORY CONTINUING INTO EARLY TUE EVENING.
SULTRY CONDITIONS ARE EXPECTED TUE NIGHT, AS LOW TEMPERATURES
COOL ONLY INTO THE MID 70, WITH SOME UPPER 70S IN THE MORE
URBANIZED HEAT ISLANDS. DEPENDING UPON HOW MUCH OF THE AREA WILL
BE IMPACTED BY CLOUDS AND SHOWERS IN LATER FORECASTS, THE HEAT
ADVISORY MAY BE NEEDED FOR SOME OF THE AREA WED. VERY WARM UPPER
RIDGING THAT WAS POSITIONED OVER THE CENTRAL HIGH PLAINS EARLIER
IN THE WEEK, SHOULD WEAKEN SOMEWHAT AND BUILD MORE TOWARDS THE SW.
WHILE THIS OCCURS, A SYSTEM MOVING IN THE MAIN WESTERLIES OVER
CANADA WILL INDUCE MORE TROUGHING FROM THE GREAT LAKES TO THE MID
ATLANTIC IN THE MID WEEK. THIS WILL HELP BRING A SURFACE COLD
FRONT TOWARDS THE FORECAST AREA ON WED. LIFT PROVIDED BY THE
FRONT, ALONG WITH MEDIUM TO HIGH SHOWER AND THUNDERSTORM CHANCES
(GREATER RAIN CHANCES EAST) WILL HELP PROVIDE RELIEF FROM THE
HEAT. HIGHS SHOULD BE A TAD COOLER, FROM THE MID/UPPER 80S EAST TO
LOW/MID 90S WEST, WITH HEAT INDEX VALUES FROM THE MID 90S TO 105
IN A FEW SPOTS. CONDITIONS SHOULD COOL DOWN A LITTLE MORE WED
NIGHT WITH LOWS FALLING INTO THE UPPER 60S TO AROUND 70.
LONG TERM
(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 1014 PM CDT SUN JUL 19 2026
THE PASSAGE OF A COLD FRONT ON WEDNESDAY WILL MARK THE START OF
THE LONG TERM FORECAST WITH SLIGHTLY LOWER TEMPS AND DEW POINTS.
HIGHS THROUGH THE LONG TERM PERIOD WILL BE RELEGATED TO THE LOW
90S WITH DEW POINTS DROPPING BACK TO THE HIGH 60S TO LOW 70S. THE
PASSAGE OF THE COLD FRONT WILL MARK A PATTERN CHANGE WITH A
TROUGHING EAST/RIDGING WEST REGIME SETTING UP THROUGH THE LONG
TERM FORECAST. AS SUCH, WE WILL FIND OURSELVES SOLIDLY IN NW FLOW
AS WE HEAD INTO THE WEEKEND AND INTO EARLY NEXT WEEK. THIS WILL
KEEP MEDIUM RAIN CHANCES IN THE FORECAST AS SEVERAL SHORTWAVES
RIPPLE ALONG THE BASE OF THE TROUGH. THIS SET UP DOES FAVOR MCSS
DROPPING SOUTH ALONG THE BASE OF THE TROUGH, POTENTIALLY INTO OUR
AREA. AS THE SET UP DRAWS NEARER, WE WILL CONTINUE TO EVALUATE MCS
POTENTIAL AND ANY INCREASED THREATS FOR SEVERE WEATHER OR
FLOODING.
AVIATION
(06Z TAFS)
ISSUED AT 1241 AM CDT MON JUL 20 2026
HIGH ALTITUDE CLOUDS FROM EARLIER CONVECTION WERE FADING AS THEY
MOVED SOUTHWARD IN A NORTHERLY FLOW. THUS SKIES OVERNIGHT SHOULD
BECOME MOSTLY CLEAR WITH MAINLY HIGH LEVEL CLOUDS. SOME OF THE
MODELS REDEVELOP LOW/MID LEVEL CLOUDS IN THE OVERNIGHT. PATCHY FOG
DEVELOPMENT MAY OCCUR OVER AND NEAR AREAS THAT RECEIVED WETTING
RAINFALL ON SUN. VSBY REDUCTIONS TO IFR (LESS THAN 3SM) MAY OCCUR
LOCALLY. THE FORMATION OF MORE LOWER CLOUDS BEFOREHAND COULD
HAMPER FOG FORMATION. FOG THAT FORMS SHOULD FADE SHORTLY AFTER
SUNRISE, WITH VFR CONDITIONS RETURNING SHORTLY THEREAFTER. DAYTIME
HEATING COULD RESULT IN ISOLATED TO SCATTERED CONVECTION FORMING
IN THE AFTERNOON. GIVEN LOW CONFIDENCE, HAVE MAINTAINED VCSH FOR
MUCH OF THE AFTERNOON. ANY SHOWER ACTIVITY SHOULD FADE SHORTLY
AFTER SUNSET. LIGHT WINDS OVERNIGHT WILL BECOME LIGHT FROM S-SW IN
THE LATE MORNING AND AFTERNOON, THEN LIGHT AGAIN AFTER DUSK.
HUN WATCHES/WARNINGS/ADVISORIES
AL...HEAT ADVISORY FROM 10 AM THIS MORNING TO 8 PM CDT TUESDAY FOR
ALZ001>009-016.
TN...HEAT ADVISORY FROM 10 AM THIS MORNING TO 8 PM CDT TUESDAY FOR
TNZ076-096-097.
NEAR TERM...RSB
SHORT TERM....RSB
LONG TERM....RAD
AVIATION...RSB
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