textproduct: NWS Birmingham

KEY MESSAGES

Issued at 253 PM CDT TUE OCT 6 2026

- Dry conditions are expected through the end of the week with cool mornings and warm to hot afternoons.

- A tropical system is expected to lift northward from the Gulf by this weekend, but timing and details of impacts remains uncertain as the system has not formed yet.

- At this time the highest confidence potential impact is heavy rainfall which may lead to flash flooding, followed by the potential for breezy conditions causing at least scattered downed trees and power outages.

DISCUSSION

(This afternoon through Monday) Issued at 253 PM CDT TUE OCT 6 2026

Easterly surface winds between high pressure to our north/northeast and a developing tropical system in the Gulf will provide a feed of dry air for the rest of the week, with cool mornings but warm to hot afternoons expected. Showers and thunderstorms over the Bay of Campeche (SW Gulf) are gradually increasing in organization with falling surface pressures. NHC indicates a near 100% chance of development which may occur very soon. Meanwhile a developing broad southern stream trough over Texas will cause this potential tropical system to lift northward later this week. This trough and the associated subtropical jet will cause this tropical system to be sheared, though may also actually aid in some synoptic forcing for intensification. Until a closed circulation forms with this system, there will continue to be high uncertainty, and it's important not to focus on individual model runs.

Taking a look at the latest physical and AI model ensembles, there continues to be fairly good agreement on the system eventually lifting northward towards the MS/AL vicinity. However, there continues to be large spread along the track regarding how quickly the system moves to the north. In general many of the AI ensemble members are faster and potentially stronger than the physical model ensembles. If the system develops quicker, conditions will be more favorable for intensification with a little less shear, and more time for intensification than if it is slow to develop. Right now the most likely scenario is for the highest impacts to be Saturday and Saturday night on the faster end of the solutions. There is an alternative scenario where the system slows down into Sunday, or a low probability scenario where the system remains in the Gulf longer than that. Given the wind shear, this will be a "lopsided"/asymmetric system with the largest impacts along and east of the track, though as it becomes post-tropical synoptic forcing will cause an increase in precipitation on the west side of the track. With a "lopsided" system, however, it's important to note that impacts can be displaced far away from the center, and it's important not to focus on the exact track of the system.

For Central Alabama, the highest confidence impact at this time is heavy rainfall and potential for flash flooding. The next highest impact will be the potential for windy conditions and possible downed trees/power outages. The lowest confidence impact will be the potential for tropical tornadoes. More details on these threats will be included below.

Heavy Rainfall/Flash Flooding:

Drought remains ongoing over the area, but some areas did receive beneficial rainfall last weekend, especially our far southwest and far southeast counties. Streamflows remain below normal to well below normal for this time of year across West Alabama, while streamflows are closer to normal for this time of year (though normal is fairly low this time of year) elsewhere. Still, with copious tropical moisture transport we will be closely monitoring the potential for flash flooding. It's too early to focus on rainfall amounts quite yet, as they will be dependent on the speed, strength, and track of the system, but WPC does have a higher-end slight risk of excessive rainfall across much of Central Alabama.

Gradient/Tropical Winds:

The magnitude of the wind threat will be highly dependent on the strength and track of the system. One thing to keep an eye on is the 1032mb high pressure area in the vicinity of New York City resulting in a cold air damming wedge. This will tighten up the pressure gradient and cause easterly winds to be quite breezy as the system approaches. At minimum, would expect at least a wind advisory with this system and associated potential for downed trees and power outages.

Severe Weather/Tropical Tornadoes:

Unsurprisingly, low-level shear and helicity values are high as the tropical system moves in. Mid-level winds/deep-layer shear values are higher than normal for a tropical system due to phasing with the upstream shortwave trough. The main limiting factor as it often is as we move into the cool season is instability. The cold air damming wedge and associated easterly winds resulting in evaporative cooling from isentropic lift driven rainfall will be the primary limiting factor for surface- based instability, unless pressure falls with the system are strong enough. There's always a fine line between "high shear low CAPE" and "high shear no CAPE", so while the "high shear no CAPE" may be the most likely scenario for most of the area, we will have to keep an eye on anywhere some weak surface-based instability can develop. Typically the northeast quadrant is the favored quadrant, though will still need to keep an eye on the southeast quadrant later on in the event as the system becomes extratropical.

32/JDavis

AVIATION

(18Z TAFS) Issued at 1209 PM CDT TUE OCT 6 2026

VFR conditions are expected through the period, as a wedge of dry air moves in from the east. There is a very low (10-20%) chance of low clouds at the southern terminals, but the more likely scenario is that low clouds stay south of the terminals closer to a stalled frontal boundary. Winds will be easterly this afternoon and a little gusty at times, becoming lighter overnight, then picking back up tomorrow morning.

32/JDavis

FIRE WEATHER

Dry conditions are expected through Friday. RH values will be generally in the 30 to 40 percent range this afternoon and tomorrow afternoon, with higher values in far eastern and southeastern portions of the area. RH values drop into the 25 to 35 range for most areas Thursday and Friday afternoons. Fire danger may be a little elevated Friday as winds begin to pick up ahead of an approaching tropical system.

PRELIMINARY POINT TEMPS/POPS

Gadsden 51 85 52 88 / 0 0 0 0 Anniston 54 86 54 88 / 0 0 0 0 Birmingham 57 87 57 89 / 0 0 0 0 Tuscaloosa 59 91 59 93 / 0 0 0 0 Calera 58 86 57 89 / 0 0 0 0 Auburn 60 83 58 84 / 0 0 0 0 Montgomery 60 87 57 87 / 0 0 0 0 Troy 60 84 57 84 / 0 0 0 0

BMX WATCHES/WARNINGS/ADVISORIES

None.