textproduct: NWS Birmingham

KEY MESSAGES

Issued at 150 PM CDT MON MAY 18 2026

- Warm conditions are expected today and tomorrow with highs near 90 degrees.

- Chances for showers and storms will be above average Wednesday through the weekend, with the highest (40-70%) chances in northern and western portions of Central Alabama during the afternoon and evening hours.

DISCUSSION

(This afternoon through Sunday) Issued at 150 PM CDT MON MAY 18 2026

Temperatures are warming up nicely across the area with many areas approaching 90 degrees. A mid-level trough is located over the western CONUS, while mid-level ridging is generally in place over the Gulf, Southeast CONUS, and western Atlantic, though there is a broad upper low near the Bahamas. At the surface, low pressure is located over Kansas with a Bermuda high over the western Atlantic. Overall we are in a summer-like pattern, indicating the beginning of the summer convective season. Showers are already developing in southern Alabama, in an area of 1.5 inch GOES-derived PWAT values lifting northward. Latest HREF guidance indicates isolated to scattered showers and storms lifting northward late this afternoon and into the early evening, aided by this enhancement in moisture and weak confluence on the west side of the Bermuda high. However, ridging aloft and a lack of higher PWAT values will be a limiting factor for coverage. MLCAPE values will be around 1000-1500 J/kg this afternoon with weak mid-level lapse rates and weak shear. This should limit overall updraft intensity, with severe storms being unlikely, but with DCAPE over 1000 J/kg there will be a risk for gusty winds with any stronger storms.

Heights increase slightly on Tuesday while some lower PWATs advect in from the east. The daytime hours look to be mainly dry and warm across Central Alabama. Convection will develop ahead of the stalling cold front over Mississippi aided by some weak vorticity maxima in southwest flow aloft. Some of the activity and its outflow boundaries may move into our northwest counties Tuesday night. CAMs generally indicate this activity more or less falling apart, but low to medium (20-40%) rain chances will continue through the overnight hours Tuesday night.

Wednesday through the end of the week a quasi-stationary frontal boundary will remain stalled to our northwest, with elevated PWATs in the 1.7-1.9 inches lingering through the extended period, highest far northwest. Positively tilted troughing will be located to our north and west, with ridging being suppressed to the Gulf. This will place Central Alabama under southwest flow aloft with several shortwaves moving through and continued low- level southerly flow off of the Gulf. Chances for showers and storms will remain above climatology for much of the rest of the period in the 40-70% range, lower than that in the southeast counties. We are not expecting a washout, but occasional periods of showers and storms, with details dependent on outflow boundaries and MCVs from previous days. 0-6 km bulk shear values around 20-25kts may be sufficient for multicells at times, with convection being of the "pulse" variety. While widespread severe weather is not expected, some isolated to widely scattered instances may occur. Overall rainfall amounts should mostly be beneficial, though if some areas get several rounds of heavy rainfall then some minor flooding could occur.

32/JDavis

AVIATION

(18Z TAFS) Issued at 1231 PM CDT MON MAY 18 2026

VFR conditions are expected the next 24 hours outside of any convection. Sufficient moisture and weak confluence on the west side of the Bermuda high will result in isolated to scattered SHRA/TSRA initially in the vicinity of MGM, then potentially northward to BHM/EET. However, coverage will be limited by ridging aloft. PROB30s are included at MGM/EET/BHM, while at AUO/TCL probabilities are only 20 percent and will not be mentioned. Variable gusty winds may occur with any TSRA.

32/JDavis

FIRE WEATHER

Isolated to scattered showers and storms are forecast this afternoon, with mainly dry conditions expected Tuesday afternoon. Min RH values will be in the 40-50% range both afternoons. Rain chances increase by mid week and continue into the weekend as a front stalls near the region, with higher Min RH values.

PRELIMINARY POINT TEMPS/POPS

Gadsden 65 88 65 87 / 10 10 10 70 Anniston 65 88 66 86 / 10 0 10 60 Birmingham 70 89 70 87 / 30 0 10 70 Tuscaloosa 69 90 69 88 / 20 0 20 50 Calera 67 90 67 88 / 30 0 10 60 Auburn 67 89 68 88 / 10 0 0 30 Montgomery 68 90 69 89 / 20 0 10 40 Troy 66 90 68 89 / 20 0 10 40

BMX WATCHES/WARNINGS/ADVISORIES

None.