textproduct: Huntsville

KEY MESSAGES

Updated at 1105 AM CDT Mon Jun 22 2026

- Conditions appear favorable for both locally heavy rainfall and flooding and strong-severe storms, with damaging winds and a tornado or two this afternoon into this evening. Expect this main threat period for any severe storms and flooding to be between 3 PM and 11 PM.

- After a period of drier conditions Tuesday into Wednesday morning, chances for showers and storms increase to 40-60% from Wednesday afternoon into Thursday.

NEAR TERM

(Rest of Today and Tonight) Issued at 228 PM CDT Mon Jun 22 2026

The biggest update to today's forecast is the earlier issuance of a Severe Thunderstorm Watch for all of our counties until 7pm tonight. The edge of the MCV is currently pushing through north central AL, Southern Middle TN and into NE AL. Storms so far have produced heavy rainfall along with wind gusts of at least 40 mph as well as frequent lightning. There have also been segments in the line that have shown rotation early this afternoon, along with cell mergers. This trend will likely continue through the remainder of the afternoon into this evening, as Hi-Res model guidance shows an increase in SRH to between 100-200 m2/s2 especially over north Alabama and into central Alabama.

Thus, the low chance of tornadoes will persist through at least early this evening, as well as the damaging wind threat from bowing segments. With storms moving at a decent clip, flooding has not been as much of a concern so far, but this will be monitored for training storms through this evening. Stay weather aware this afternoon and if a Severe Thunderstorm or Tornado Warning is issued for your location, take shelter immediately!

Previous Discussion: Persistent rainfall from a cold pool boundary has stayed mainly north of the TN River this morning, producing heavy rainfall and batches of frequent lightning. This is good for our AL counties, however not so much for Lincoln and Moore Co in TN. Starting off on a drier note in most places will help with hydro concerns for this afternoon. Regardless, we will keep a keen eye rainfall rates today, and if any backbuilding occurs to increasing flooding concerns across the board.

On the heels of this batch of rainfall, there is a MCV that has developed in AR and sliding eastward. The eastern portion of the MCV will reach the MS/AL border in the next hour or two. On top of this, there is a shortwave upstream of the MCV that will arrive later this afternoon as well. Our counties haven't been worked over this morning and ahead of these features, CAPE values will be 1-2,000 J/kg, PWATS 2.0-2.2" (99th percentile), bulk shear up to 30kts right ahead of the line and a LLJ up to 50kts later this afternoon into this evening. Thunderstorms this afternoon will be capable of producing strong to damaging wind gusts, heavy rainfall that could produce flooding concerns, and a tornado threat. Will note the tornado threat is a little bit higher than previous forecast. This is noted in SPC's latest convective outlook as well. We remain in a Slight Risk Convective Outlook (Level 2/5), and a Slight Risk ERO. Strong to severe timing looks to be just a tad slower, moving into NW AL 2-4pm and moving out of NE AL 10-11pm.

Once this moves through, precip chances will drop off fairly quickly. A cold front will slip into the TN Valley between midnight and early morning Tuesday, but not sure on exactly how far it will make it into the CWA before slowing down. Lows will be in the upper 60s.

SHORT TERM

(Tuesday through Thursday) Issued at 1105 AM CDT Mon Jun 22 2026

It's still uncertain exactly where the cold front will stall out on Tuesday, but it should be just south of us. If it makes it all the way through, there will be northerly winds in the wake of the front and a slow erosion of cloud cover. Highs will be in the lower 80s. Drier conditions will linger into Wednesday before the next round of rainfall returns Wednesday afternoon (15-30%) as a short wave swings through. The previously mentioned cold front should lift back northward on Thursday, creating low to medium shower/storm chances (30-60%). Daytime highs will be in the mid to upper 80s each day with lows around 70.

LONG TERM

(Thursday through Sunday) Issued at 1026 PM CDT Sun Jun 21 2026

We continue in a generally wet pattern through the beginning of the long term period, with at least low chances (30%) of showers and thunderstorms daily. With high pressure over the southeastern US and low pressure over the Great Lakes region, the TN Valley will remain wedged between with an upper level shortwave forecast to push eastward into the area by Thursday into Friday. As this occurs, rainfall chances will increase to medium (40-60%) both Thursday and Friday afternoons with the assistance of a lingering frontal boundary south of the area as well as southwesterly flow. There remains some model disagreement in the potential environment based on placement/track of aforementioned upper level shortwave, however, southwesterly flow will likely contribute to a moist environment with PWATs reaching around 1.7-1.8" (just below 90th percentile sounding climatology per BMX). The majority of rainfall/flash flood potential will likely remain to our west in areas where the Weather Prediction Center has already highlighted in a Marginal (risk level 1 of 4) Outlook for Excessive Rainfall. Rain chances will gradually decrease as we head into the weekend as sfc high pressure begins working in from the west. Heat will be a concern towards the end of the week as well as highs are forecast to reach the upper 80s to low 90s with heat index values around 100 degrees by Saturday and Sunday. If you have outdoor interests at the end of the work week, be sure to check back in for updates.

AVIATION

(18Z TAFS) Issued at 1240 PM CDT Mon Jun 22 2026

A relatively low confidence forecast regarding timing details with expected additional rounds of SHRA/TSRA to occasionally impact the KHSV and KMSL TAF sites through the afternoon/evening. The bulk of the activity may tend to occur early in the TAF period (highest confidence due to existing obs in KHTX/KGWX radars). The heavier TSRA/SHRA will initially pass mostly north of KHSV but sufficiently close to warrant VCTS in TAFs. Further development and expansion of SHRA/TSRA is anticipated as an upr- lvl low traverses the area, bringing the potential for MVFR/IFR ceiling/vis conditions. Winds aloft should be high enough to warrant LLWS mention in the KMSL TAF (NW areas most prone) through ~22Z. Clearing on the backside of the upr low is anticipated and generally supported by ongoing satellite obs and NWP guidance after ~02-05Z.

HUN WATCHES/WARNINGS/ADVISORIES

AL...None. TN...None.