textproduct: Huntsville

KEY MESSAGES

Updated at 954 PM CST Tue Nov 18 2025

- A broken line of multicell showers and thunderstorms will move through the area overnight tonight with lightning and gusty winds being the main threat.

- High (60-90%) rain and storm chances will return to the forecast Friday night with the passage of our next system. - Mostly dry conditions are forecast through the later half of the weekend, with additional rain chances returning early next week.

NEAR TERM

(Tonight and Tomorrow) Issued at 954 PM CST Tue Nov 18 2025

Our near term forecast will be driven by a weakening cut off low moving through the Ohio Valley. An associated surface cyclone currently located in the southern tip of Illinois with its trailing cold front off to the SW, will follow a similar weakening trend as both the surface cyclone and front progress east. Currently, supercell and multicell clusters can be seen along the TN/KY border along a prefrontal trough axis. These storms are supported by 1000+ J/KG of CAPE and 40+ KTS of shear. While these storms are forecast to continue SE through the night, the supporting thermodynamics will wane as the storms enter the area. The lingering question is how much they will wane.

With a very moist late fall airmass in place, as seen by dew points in the 50-60 range, it won't take much to support showers and thunderstorms as the pre frontal trough moves through. CAMs show storms entering the area around midnight and continuing SE through sunrise tomorrow. They will likely move through as a broken line of multicell clusters. 40-50 KTs of bulk shear look to remain through the night making instability our limiting factor as the trough axis moves through. We currently have a few hundred J/KG of CAPE, highest in NW AL. While CAPE will decrease through the night, it is likely 100-300 J/KG of CAPE will be present when storms enter the area allowing from some stronger storms. With CAPE decreasing through the night and as storms move SE, the stronger storm threat should be very short lived, ending during the early morning hours. Stronger storms will be capable of some well defined mesocyclones making damaging winds the primary threat with heavy rainfall and lightning being secondary threats. By 8Z storms should have waned in intensity with general showers and thunderstorms continuing SE, exiting the forecast area by the start of the work day tomorrow.

While rain chances will drop off quickly off of 12Z, cloud cover will remain through a majority of the day as the front stalls just to our north. This will create rather muggy conditions with temps in the mid 70s and dew points in the mid 60s.

SHORT TERM

(Thursday through Saturday) Issued at 954 PM CST Tue Nov 18 2025

Ridging will briefly build in the mid levels from Wednesday night through Thursday ahead of our next system. At the surface the aformentioned frontal boundary will hang out through Thursday and prompt overcast conditions. Rain chances don't look to return until Thursday afternoon when the frontal boundary finally pushes through with a low chance of thunder due to the prolonged overcast conditions. Low rain chances (20-40%) will remain in the forecast from Thursday evening through Friday morning for areas north of the TN River.

Our attention will then shift to Friday when our next system looks to pass through the area. Through the end of the week, a mid level low pressure system will eject from the SW CONUS through the Ohio Valley, dampening as it does so. An associated surface low and cold front will mirror this march across the CONUS. Locally, the front looks to move through the area Friday evening through Saturday morning bringing with it high rain and storm chances. Along and ahead of the front, boundary layer moisture will remain high with dew points in the 60s. This will support a gradual increase in rain chances through the day on Friday from west to east as the front draws closer. Prolonged overcast conditions will likely limit instability on Friday making CAPE our limiting factor again as we head into the overnight hours. LREF models maintain a few hundred J/KG of MUCAPE overnight. This paired with 40-50 KTS of bulk shear will be supportive of some strong to potentially severe storms as the front moves through. Damaging winds would likely be the main threat however additional HIRES model coverage will aid in identifying any secondary threats. Through the coming days as this system moves into HIRES coverage we will begin to refine forecast details regarding timing, threats, and intensity.

Low rain chances (20-30%) look to linger behind the front as well as overcast conditions through most of the day on Saturday. The winds will veer slightly to the NW, no significant airmass changes will take place leaving our high temps in the 70s.

LONG TERM

(Saturday night through Wednesday) Issued at 954 PM CST Tue Nov 18 2025

During the later part of the weekend, sfc high pressure will contribute to mostly dry conditions over the Tennessee Valley. Zonal flow will begin to shift by the early work week (likely Tuesday) as an upper level trough and subsequent low pressure system shift eastward into the area from the Deep South. In turn, rain chances increase into the medium range (~40%) ahead of a frontal boundary. Have stuck with blended guidance due to this system still being a week out and some minor model disagreement. If you have outdoor interests early next week, be sure to check back in for updates. High temperatures are forecast to reach the mid 60s to low 70s during this time with overnight lows in the upper 40s to lower 50s.

AVIATION

(06Z TAFS) Issued at 1140 PM CST Tue Nov 18 2025

Low to medium chances of showers and storms are forecast between 7-11Z tonight at both terminals. These may bring reductions in VIS and CIGs in the heavier showers. In addition, LLWS (from the southwest at 40 knots) will be a concern through much of the overnight until about 10-11Z. Outside of any storms, expect southwesterly to westerly winds between 5-10 knots through most of the TAF period. MVFR to IFR CIGs are anticipated early Wednesday morning, improving back to VFR by mid to late afternoon.

HUN WATCHES/WARNINGS/ADVISORIES

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