Area Forecast Discussion
Issued by NWS Birmingham, AL
Issued by NWS Birmingham, AL
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804 FXUS64 KBMX 250548 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 1248 AM CDT Sat May 25 2024 ...New AVIATION... .SHORT TERM... (This evening through Saturday) Issued at 129 PM CDT FRI MAY 24 2024 The first storms of the afternoon are currently firing across northern portions of Central Alabama and also across eastern Mississippi. These storms are developing along an old outflow boundary that is moving southeastward from previous MCS activity that occurred in Tennessee early this morning. We`ve got plenty of instability to work with this afternoon, with 3000-3500 J/kg of SBCAPE, 40-50 knots of effective westerly bulk shear, and steep lapse rates aloft. LI`s are coming in between -5 and -8 along and west of the I-65 corridor. Uncertainties currently exist in terms of overall coverage of storms this afternoon, but it would not be out of the question for another MCS or multiple clusters of storms to develop and move southeast through this evening. The best chance of this occurring would be where the severe storm has currently developed in Monroe County, MS. With unidirectional shear profiles, damaging straight-line winds and large hail will be the main hazards with these storms. RAP analysis indicates the highest amount of DCAPE across western and southwestern counties, which could also help produce a better-defined cold pool boundary. We`ll see how trends evolve as we go through the afternoon. In the meantime, likely PoPs will remain in the forecast for the northern half of the area through this afternoon, with high PoPs continuing to the southeast before diminishing into the overnight hours. With westerly flow aloft continuing overnight, upper level shortwave activity will help develop additional clusters of showers and storms across southern Arkansas and northern Mississippi. We`ll watch those storms as they move east between midnight and 7am, as some of those could be on the strong side depending on how much available instability is still left from today`s activity. PoPs have been updated to high chance probability due to the uncertainty in placement of the storms, but may need to be increased into the likely category before all is said and done. Strong to isolated severe storms will remain in the forecast Saturday afternoon through Saturday night as another shortwave impulse moves eastward. Scattered to perhaps numerous showers and storms are possible if enough daytime heating occurs behind the morning activity. In terms of the CAMs, some are showing more convective development than others, but we should have enough support in the synoptic scale for storm development. Hail and gusty winds will be the main hazards through Saturday, which will be conditional based on mesoscale conditions. 56/GDG && .LONG TERM... (Saturday night through next Thursday) Issued at 229 PM CDT FRI MAY 24 2024 Model trends continue to keep MCS activity to our north on Sunday. If outflow boundaries push into north Central Alabama and interact with an airmass characterized by more than 1800 J/kg CAPE and bulk shear of 35kts, a few strong to severe storms are possible. With a slight increase in midlevel heights, it will take some focus or boundary interaction to kick convection off. By Sunday night, a weak front and convective line/cluster approaches the Tennessee Valley. There`s some uncertainty on whether the line is weakening as it moves into north Central Alabama Monday morning, as upper level support lifts away from the area. This would leave boundaries to interact with an unstable airmass through the day, with scattered thunderstorms expected. If a more organized line of storms pushes southward Monday morning, it is unlikely there will be airmass recovery to support strong storms during the afternoon. For now will not post threats for Monday, and wait to see how model trends evolve. Troughing moves to the east by Tuesday, with mid level flow becoming northwesterly. This will allow a slightly cooler and drier airmass to settle over the area through mid week. 14 && .AVIATION... (06Z TAFS) Issued at 1241 AM CDT SAT MAY 25 2024 VFR conds thru 11Z with mainly mid to high level clouds and light winds. MVFR cigs will develop around 12Z at most TAF sites with IFR cigs likely at KTOI between 10Z and 13Z. Cigs will rise above 3000 ft agl by 16Z. Sct tstms will develop across west-central Alabama by 13Z and track southeast. Included PROB30 groups at all TAF sites. TSTM activity should dissipate by 01Z. 58/rose && .FIRE WEATHER... Several opportunities for rain and storms through Monday, as several impulses provide focus for convection. Enhanced coverage is expected during the afternoon and evening, especially across northern counties. 20 foot winds will be from the south to southwest at less than 5 mph Saturday, increasing to 6-12mph on Sunday. Min RH value will be near or above 45 percent through Monday, with overnight recoveries near 100%. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 88 67 91 68 / 40 20 20 30 Anniston 88 69 90 70 / 40 20 20 20 Birmingham 89 71 91 71 / 40 20 20 20 Tuscaloosa 91 71 92 71 / 40 10 10 20 Calera 88 71 90 71 / 40 20 10 10 Auburn 86 70 88 71 / 30 10 10 0 Montgomery 90 71 92 72 / 30 10 0 0 Troy 90 70 91 71 / 30 10 0 0 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...56 LONG TERM....14 AVIATION...58/rose