textproduct: Huntsville

KEY MESSAGES

Updated at 1130 AM CDT Sat Oct 3 2026

- Pockets of light-moderate rain will persist across the northern half of the forecast area through early this afternoon, with an increasing risk for thunderstorms by mid-afternoon across the southeastern counties. Lightning and locally heavy rainfall will be the main storm impacts.

- After a break this evening, rain (and some embedded thunderstorms) will redevelop prior to sunrise on Sunday. Rain will become widespread in coverage (and potentially heavy in a few locations) late Sunday morning before gradually ending during the late afternoon and evening. A low risk for flash and areal flooding will exist during this period.

- A cold front will usher a drier airmass into the region on Monday, which will remain in place for the rest of the week.

NEAR TERM

(Rest of Today and Tonight) Issued at 224 PM CDT Sat Oct 3 2026

There have been no significant changes to near term forecast reasoning since the update earlier this morning. Current thinking is that a nearly stationary surface trough (bisecting the CWFA from SW-to-NE) will remain the focus for convective initiation for the rest of the afternoon, particularly across Cullman, Marshall, and Dekalb counties (where temps warming into the l-m 80s have already led to an increase in SBCAPE per SPC Mesoanalysis). To the north of the boundary, the kinematic environment will become increasingly less favorable for light-moderate rain through sunset. Afternoon convection should dissipate around 0Z, with dry but warm/muggy conditions anticipated this evening. However, deep- layer lift will begin to strengthen after Midnight as a mid- level trough digs southeastward, and this will result in redevelopment of stratus clouds and rain (along with some embedded thunderstorms) prior to sunrise tomorrow. Overnight lows will once again be rather mild and in the 65-70F range.

Previous Discussion: Over the course of the near term period, a strengthening surface high (initially across the Great Lakes) will spread eastward into northern New England as a broad area of low pressure remains nearly stationary across the southwestern Gulf and Bay of Campeche. A surface trough/effective cold front extending northeastward off the low remains oriented in a SW-to-NE fashion from the Lower MS Valley through the TN Valley and into southeastern TN this morning, but will likely begin to retreat slowly northwestward late this afternoon as a northern stream trough and related surface low track across southern MB. Although light-moderate NE flow to the north of the low-level streamline confluence axis is advecting slightly cooler/drier surface parcels southwestward, the thermal/moisture gradient will become increasingly diffuse with time across TN/KY.

Shallow ascent (driven by veering flow up to 5000 ft AGL to the immediate north of the boundary) will continue to result in low stratus clouds pockets of light-moderate rain on its cool side for the remainder of the morning, but a gradual diminishing trend in precipitation is expected this afternoon. However, across the southeastern portion of the forecast area (where less cloud cover will permit stronger insolation and highs in the m80s), MLCAPE may reach 500-1000 J/kg, leading to an increase in the coverage of showers and thunderstorms across this region. Due to these factors, we will be lowering the high temperature forecast for the northern half of the CWFA to represent max values in the m-u 70s. Due to weak vertical wind shear and anticipated lack of storm organization, the main impacts from storms will be lightning and convective rainfall rates which could contribute to flash/areal flooding given PWAT values around or slightly in excess of 2".

Current thinking is that afternoon convection (primarily focused across the southeastern zones) will dissipate this evening with the onset of the diurnal cooling cycle. However, as a northern stream trough begins to deepen while crossing southern OT, the surface trough will retreat further northwestward as a weak non- tropical low forms near the southeastern LA coast. Strengthening deep-layer WAA (aided by mid-level WSW flow increasing to 15-25 knots) will support redevelopment of low stratus clouds and light rain region-wide between 6-9Z, with a few embedded convective elements possible as well. Overnight lows will be mild once again, with temperatures only falling into the 65-70F range.

SHORT TERM

(Sunday through Monday night) Issued at 1130 AM CDT Sat Oct 3 2026

Latest short term model solutions suggest that the southern flank of a deepening northern stream trough will advance southeastward toward the TN Valley on Sunday, with sufficiently strong ascent amidst tropical moisture expected to support a rapid increase in both coverage and intensity of precipitation across our region during the late morning hours. Although UVMs will be fairly weak and driven by deep-layer WAA, PWAT values in excess of 2" will support an increasing risk for flash/areal flooding during this timeframe and CAPE up to 500 J/kg may result in a few embedded thunderstorms within the broader stratiform precipitation regime. Precipitation is expected to gradually come to an end from NW-to- SE beginning late Sunday afternoon as the mid-level trough axis slowly shifts southeastward over the region and surface high pressure in its wake builds southeastward into the OH Valley. However, the risk for flooding may linger well into the evening across our southeastern zones as this is where antecedent rainfall will likely be heaviest and precipitation will end last (perhaps not until the early morning hours on Monday).

During the timeframe from Monday-Monday night, a surface high will migrate east-southeastward from the Upper MS Valley into the central Appalachians, with strengthening N-NE flow advecting a drier airmass (featuring dewpoints in the u40s-l50s) into the northwestern half of the forecast area. Across the southeastern portion of the region, a narrow tongue of low-level moisture will remain in place, and this could support the development of a few showers Monday afternoon/evening as low-level easterly flow becomes established with a developing CAD event across VA/NC. However, with the bulk of this activity expected to be concentrated across northern GA, we will only mention POPs in the 5-10% range and advertise an increase in low clouds region-wide Monday night. After only reaching the m-u 70s tomorrow, afternoon highs will return to the l-m 80s on Monday, followed by overnight lows in the 50s.

LONG TERM

(Tuesday through Friday) Issued at 951 PM CDT Fri Oct 2 2026

Dry weather looks to reign for remainder of the work week, as high pressure to our north builds southward and controls the general weather pattern. With more sun than clouds, daily highs should rise to around 80 Tue and Wed, and in the mid 80s Thu and Fri. With longer nights as we progress through the fall season, lows will be a bit cooler, ranging from the mid/upper 40s sheltered valleys to the low/mid 50s near large bodies of water.

AVIATION

(18Z TAFS) Issued at 1238 PM CDT Sat Oct 3 2026

Pockets of lgt-mod RA and low stratus clouds will continue thru early-mid aftn along and north of a surface trough bisecting the forecast area. With the risk for TSRA expected to be higher to the immediate SE of both terminals, we will not mention convection in the current forecast. However, MVFR cig/vsby reductions may occur in heavier rainfall. After brief improvements this evening, low stratus clouds and lgt RA will begin to overspread the region once again btwn 6-9Z as an upper-level disturbance approaches from the NW and interacts with tropical moisture. Rain (and perhaps some embedded TSRA) will become widespread and potentially heavy in a few spots btwn 12-18Z, with an extended period of IFR cigs and MVFR vsby reductions anticipated during this timeframe. Sfc winds will remain from the NE at 5-10 kts today, before becoming lgt/vrbl overnight.

HUN WATCHES/WARNINGS/ADVISORIES

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