textproduct: Huntsville

KEY MESSAGES

Updated at 252 AM CDT Wed Jul 2 2026

- An Extreme Heat Warning remains in effect through 7 PM Thursday due to a combination of afternoon temperatures in the mid- upper 90s and heat indices of 110-114F. A Heat Advisory will remain in effect from 7 PM Thursday-7 PM Friday.

- Strong to severe thunderstorms will impact portions of the region once again on Thursday and Friday (mainly from late afternoon into the evening). These will feature a risk for locally damaging downburst winds, small hail and excessive lightning.

- The coverage of afternoon/evening showers and thunderstorms will begin to increase this weekend and will remain in the 40-60% range through the middle of next week.

NEAR TERM

(Today) Issued at 253 AM CDT Thu Jul 2 2026

A dangerous heatwave continues today as a strong mid/upper ridge remains centered near the Tennessee Valley. Today will essentially be a repeat of yesterday with dangerous heat impacts coupled with medium chances for afternoon thunderstorms (some which could be severe). Early this morning we'll have to watch for some patchy fog in areas that received rainfall due to the moist boundary layer conditions. Any fog and/or low clouds that do develop will quickly dissipate after sunrise. Ample morning sunshine will warm temperatures into the mid to upper 90s in most locations again today. These hot temperatures, combined with dewpoints in the low to mid 70s, will create heat index values as high as 110-114 degrees across the region today. NWS Heat Risk highlights Level 3 of 4 (Major Risk) to Level 4 of 4 (Extreme Risk) across the region again today. Thus, an Extreme Heat Warning remains in effect for the entire Tennessee Valley through 7 PM this evening. Please practice heat safety today -- stay hydrated, take frequent breaks from the heat, and never leave people or pets in vehicles!

As mentioned above afternoon thunderstorms are expected to develop thanks to a weak perturbation rounding the southern flank of the ridge. Similar to yesterday, the storm environment will most definitely favor downbursts given very steep low-level lapse rates of around 9 C/km, DCAPE values of 1000-1500 J/kg, MLCAPE values of 3000-4000 J/kg, PWATs around 2", and a pronounced inverted-v profile noted on model soundings. Any storms that can develop may become quickly severe, with damaging stright-line winds being the main threat.

SHORT TERM

(Thursday night through Saturday night) Issued at 1121 PM CDT Wed Jul 1 2026

During the period from Thursday night-Friday night, a strong subtropical high (initially across the central Appalachians) will begin to weaken and shift eastward into VA/NC as a northern stream trough digs southeastward across Ontario/Quebec. This will occur as the axis of a low-level ridge shifts southward into the Gulf, and for this reason, steering currents will become progressively weaker as we move forward through the short term period. A small complex of thunderstorms will likely be in progress across the region early tomorrow evening, but should dissipate between 2-4Z, leaving another warm/muggy night featuring lows in the l-m 70s Friday morning and patchy fog in locations that experience late afternoon/evening rainfall. Redevelopment of thunderstorms is anticipated once again early Friday afternoon across the higher terrain to our north/east, with some of this activity likely to be propelled westward into our CWFA later in the afternoon. However, due to weaker deep-layer flow, coverage may be confined to a smaller portion of northeast AL/southern Middle TN before dissipation occurs Friday evening. With a similar thermodynamic environment (compared to previous days) this activity should once again carry a risk for locally damaging downburst winds, small hail and excessive lightning.

By Saturday and Saturday night, the subtropical ridge will continue to weaken off the coast of NC, and with less impacts from subsidence aloft, the local environment will become more conducive for a greater spatial coverage of showers and thunderstorms. This activity may also begin earlier in the day on Saturday (perhaps aided by ascent from a more defined easterly wave that will approach the southeastern Atlantic Coast tomorrow and lift northwestward into AL/MS this weekend) and could also extend further into Saturday night as outflow-driven convection from storms across MO/IL/IN may spread southeastward into the TN Valley during the evening. Fortunately, mid-level lapse rates will weaken with time as light southwesterly flow becomes established to the west of the 500-mb ridge and to the east of a weak shortwave trough across the southern Plains, and this will lessen the risk for strong-severe downbursts. However, gusty winds, locally heavy rainfall and lightning will still be a concern. With afternoon highs gradually falling back into the l-m 90s by Saturday, we will not make any changes to the expiration time of the Heat Advisory.

LONG TERM

(Sunday through Wednesday) Issued at 1121 PM CDT Wed Jul 1 2026

Global models are in general agreement that a subtropical high in the mid-levels (located off the southeastern Atlantic Coast) will begin to slowly strengthen once again early next week before eventually retrograding westward into the northeastern Gulf. This configuration will maintain light to moderate deep-layer SW to WSW flow, providing abundant moisture for development of showers and thunderstorms as a series of smaller scale waves travel along the edge of the ridge. Although a gradual increase in subsidence aloft may keep overall coverage of showers and thunderstorms a bit lower at our latitude, we will advertise a 40-60% POP (mainly focused during the afternoon/early evening) each day from Sunday- Wednesday. The anticipated combination of shear and instability suggests that convection will be unorganized and sub-severe, with lightning and heavy downpours the primary impacts. Due to clouds and precipitation, afternoon highs will fall back into the u80s-l90s by Wednesday, with Heat Risk diminishing as we move toward the middle of next week.

AVIATION

(12Z TAFS) Issued at 606 AM CDT Thu Jul 2 2026

VFR conditions will be the predominant flight category at each terminal through the period. A low chance of TSRA is forecast this afternoon and have added PROB30 to account for this at both terminals between 21-01z. Should a TSRA impact either terminal, localized IFR/MVFR conditions may occur and AWWs and amendments may be needed.

HUN WATCHES/WARNINGS/ADVISORIES

AL...Extreme Heat Warning until 7 PM CDT this evening for ALZ001>010- 016.

Heat Advisory from 7 PM this evening to 7 PM CDT Friday for ALZ001>010-016.

TN...Extreme Heat Warning until 7 PM CDT this evening for TNZ076-096- 097.

Heat Advisory from 7 PM this evening to 7 PM CDT Friday for TNZ076-096-097.