textproduct: Huntsville

KEY MESSAGES

Updated at 247 AM CDT Mon May 25 2026

- A Dense Fog Advisory has been issued for all counties in northern Alabama and southern middle Tennessee in the forecast area through 10 AM this morning.

- A Flood Watch for Flash Flooding has been issued from 10 AM today through 10 PM on Tuesday for Cullman, Morgan, Madison, Jackson, Marshall and Dekalb counties.

- Another excessive rainfall and flash flooding threat exists on Thursday into Friday.

NEAR TERM

(Today) Issued at 247 AM CDT Mon May 25 2026

Be careful driving this morning with the foggy conditions out there. With the calm winds and all the moisture in place, all local observations are seeing a reduction in visibilities with a few reporting dense fog conditions at this hour. There is a Dense Fog Advisory out until 10am for the entire TN Valley, so slow down and do not use high beams when driving.

Shower and thunderstorm chances will increase throughout the day today to bring yet another round of rainfall to the TN Valley. Afternoon highs will reach the upper 70s to lower 80s. An upper level shortwave anchored in eastern TX will continue to stream in rich moisture to the region and swing disturbances up into the TN Valley today. At the same time, the associated sfc low in Lower MS Valley will drift northward and tug a cold front into the TN Valley today. Just how far the front makes it through and where it gets hung up is still uncertain. This will have to be monitored as it will play a role in precip coverage and rainfall totals. Look for low chances (20-30%) of showers and thunderstorms to return later this morning with those values increasing this afternoon to mid to high chances (60-80%). With PWATS remaining in the 99th percentile for this time of year ~1.8", poor lapse rates and weak shear, the main hazard will be heavy rainfall. Rainfall can reduce visibility when driving, create an additional rises in rivers, creeks and streams, and flooding concerns. Given the saturated soils in place, especially those east of I-65 who have received the most rainfall the past few days, a Flood Watch is in effect starting at 10am Today until 10pm on Tuesday, for Cullman, Morgan, Marshall, Madison, Jackson, DeKalb counties. These locations could see rainfall totals reaching 2-4" by Tuesday night with locations elsewhere seeing 1-2".

Remember, if you encounter flood waters, Turn Around, Don't Drown.

SHORT TERM

(Monday night through Wednesday) Issued at 1146 PM CDT Sun May 24 2026

Though the surface front continues to move further northward Monday night into Tuesday, an additional trough axis through northern Alabama and southern middle Tennessee forms southward from this warm front. This should continue to focus forcing over the area. At this time, it looks like areas near and east of the I-65 corridor will be near/east of the trough axis. West of this trough axis may see less rainfall overall. For now, continuing the Flash Flood Watch for those same counties mentioned earlier. This should line up closely to locations near and east of the trough axis expected to develop on Tuesday. Luckily, not seeing much shear and instability should be limited (a few hundred to around 1000 J/KG primarily). Cannot rule out some thunderstorm activity, but it will remain sub-severe. Most guidance dissipates any convection and really drops off precipitation amounts after 10 PM on Tuesday. At least 2 to 4 inches of storm total rainfall with locally higher amounts look reasonable Monday and Tuesday.

Besides flash flooding concerns, river flooding will need to be monitored for area basins rising above flood stage. Again, cloud cover and precipitation will keep highs in the 75 to 80 degree range in the afternoon.

It looks like on Wednesday, the center of the trough axis moves east of the area in GA. This should shift the better forcing east of the area and put northern Alabama into southern middle Tennessee into a regime of subsidence and give us a break from rainfall activity. Temperatures might rebound a bit higher on Wednesday back into the 80 to 85 degree range in many areas, despite lingering cloud cover.

LONG TERM

(Wednesday night through Sunday) Issued at 1146 PM CDT Sun May 24 2026

As we go into Wednesday night, an upper low should be positioned over the Sierra Nevada range. Rather sharp, smaller synoptic scale ridging was also in place from the Deep south to the Upper Mississippi River Valley. But more upper lows over SE Canada was producing troughing along eastern seaboard from the Mid Atlantic and northward. The western trough should weaken as we go into the weekend, with upper ridging from the Gulf to south/central Canada holding strong. The SE Canadian trough not only persists, but guidance even further out from Sunday show it potentially amplifying further to the south.

By the midweek, a frontal boundary should be oriented in a west to east manner from the central Great Plains to the northern Delmarva. Because of upper troughing from eastern Canada, it will move more southward along the east coast across the Carolinas. But it should for the most part remain near to just north of our area in the latter half of the week.

A southerly flow from the Gulf will keep a moist environment in place across the Deep South. This moisture along with daytime heating will destabilize, and bring more showers and thunderstorms each day. Precipitable water amounts for this period range from 1.7" to 1.9" which will favor locally heavy rainfall in the heavier showers and storms. Given that heavy rainfall will have already fallen in previous convection, additional amounts will run off and could result in flooding, as well as rises in creek, stream and river water levels. Overall thunderstorm strength for the most parts should remain general, gusty outflow winds the main threat. Storms in these environments can become very electrically active, thus consideration to seek safe shelter should storms near your location. With more clouds than sun and elevated rain chances, daily high temperatures for the extended should range mostly in the lower 80s (with some mid 80s at times), and lows in the mid 60s.

AVIATION

(12Z TAFS) Issued at 639 AM CDT Mon May 25 2026

The development of light showers that are approaching the terminals this morning has interrupted the development of dense fog. MVFR or brief IFR CIGS can still be experienced, however those should be short lived this morning. Medium to high chances of rain move in this afternoon and will lessen in coverage by 06Z leaving low MVFR CIGS in place til the end of the TAF period.

HUN WATCHES/WARNINGS/ADVISORIES

AL...Dense Fog Advisory until 10 AM CDT this morning for ALZ001>010- 016.

Flood Watch from 10 AM CDT this morning through Tuesday evening for ALZ006>010-016.

TN...Dense Fog Advisory until 10 AM CDT this morning for TNZ076-096- 097.