Area Forecast Discussion
Issued by NWS Birmingham, AL
Issued by NWS Birmingham, AL
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108 FXUS64 KBMX 031756 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 1256 PM CDT Wed Jul 3 2024 ...New SHORT TERM... .SHORT TERM... (This evening through Thursday) Issued at 1255 PM CDT WED JUL 3 2024 This afternoon. Broad elongated ridging in the mid levels currently extends from over the Southeast Atlantic Coast westward to over far Southwest Texas. Surface high pressure extended southwest from over Nova Scotia into the Carolinas while a weak surface front was analyzed along far eastern Georgia, delineating cumulus development to the west and mostly clear skies to the east. Additionally, a weak Theta-E gradient exists in local analysis fields, separating some more humid conditions to the south and west from slightly drier air to the north and east. Skies were partly cloudy generally areawide at this writing while mostly cloudy skies were observed on visible satellite across portions of the East-Central and South-Central Counties. Partly cloudy skies are expected areawide with some thicker clouds across the South-Central areas just to the east of a weak surface trough. Chances for some showers and a few thunderstorms will exist generally encompassing areas near and southeast of the Interstate 59 corridor with better chances across the South- Central Counties and extending eastward into the East-Central and Southeast areas this afternoon into early evening. Winds will be from the southeast at 5-10 mph. High temperatures will range from around 90 in the higher elevations east to the upper 90s across the far west. The combination of heat with the humidity has prompted heat advisories to remain in effect until 7 pm tonight for all but our east-central counties that are in the higher terrain areas. Peak eat index values could reach to near 108 degrees far west and northwest this afternoon. Tonight. The elongated mid-level ridging will remain in place overnight with surface high pressure extending southwest generally along the Eastern Seaboard further southwest across the Central Florida Panhandle. A residual wedge front will be positioned across portions of eastern South Georgia while a surface cold front remains to northwest, extending from New York State southwest across the Central Plains. Look for partly cloudy skies overnight with a few lingering showers and a storm or two across the southern third of the area through early evening. Overnight, some lower clouds may affect portions of the South-Central and Southeast counties before sunrise on Independence Day. Winds will be from the south at 2-4 mph. Lows will range from the lower 70s in the higher elevations east to the mid 70s elsewhere. Independence Day. Mid-level ridging looks to contract and migrate westward on Thursday, with the ridging becoming centered over Louisiana. The surface front to our northwest remains in place as waves of low pressure develop along the front across the Midwest while surface high pressure continues to extend southwest from Offshore of New England southwest across the Northern Florida Panhandle. Partly cloudy skies with isolated shower and thunderstorm activity is forecast with best chances across portions of the southwest and east. Winds will be from the south to southwest at 5-10 mph. High temperatures will range from the low 90s in the higher elevations east and northeast to readings in the upper 90s west and northwest. The combination of heat with humidity will continue to require heat advisories across the area with heat index values potentially reaching around 107 degrees across portions of our western and central counties during the afternoon hours. 05 && .LONG TERM... (Thursday night through next Tuesday) Issued at 310 AM CDT WED JUL 3 2024 Key messages: - Numerous to widespread showers and storms are expected Friday. A couple strong storms with gusty winds are possible. There is uncertainty as to whether heat indices will reach 105 degrees depending on how quickly storms develop. - Some drier air may push into northern portions of Central Alabama over the weekend. Otherwise, a wetter pattern is expected next week with heat indices decreasing to just below 105 degrees. Subtropical ridging will weaken and become centered near the Southeast Atlantic Coast through much of the period, while troughing amplifies over the Central CONUS downstream of a strong ridge over California. A seasonally strong shortwave will be moving through the Midwest and Great Lakes Thursday night and Friday along with an associated surface low. An associated cold front will reach the Mid-South by Friday morning. Any lingering showers and storms at sunset Thursday night should quickly diminish, but it seems prudent to mention slight chance PoPs during the evening outdoor activities. Convection will remain ongoing ahead of the front late Thursday night with a slight chance that any convection makes it into our northern counties during the overnight hours. The front will be approaching from the northwest Friday while a pre-frontal trough may develop further south over Central Alabama. Westerlies along the base of the trough will begin to extend down into North Alabama. Forcing from these features and any boundaries from Thursday night`s convection along with PWATs above 2 inches will result in numerous to widespread showers and storms developing by Friday afternoon. Some guidance suggests an MCS could develop as early as Friday morning but this remains uncertain. 0-6km bulk shear around 15 to 20 kts and any expanding cold pools could result in some strong storms with gusty winds though a lack of dry air aloft and weak mid-level lapse rates will be a limiting factor for getting anything much stronger. Uncertainty regarding timing of convection results in an uncertain heat index forecast, but if storms hold off long enough then heat indices would reach 105 in the persistent humid air mass. Latest guidance has trended a bit more aggressive with the southward progress of the front before it stalls, indicating some drier (but still warm) air may make it down into some of the northern half of Central Alabama over the weekend. Meanwhile, a moist airmass will result in continued scattered to numerous showers and storms across at least the southern half of the area along and south of the front, along with potential for heat indices near 105 in the southeast counties. The front will lift back to the north on Monday. A weakness in the ridge over the south-central CONUS and a moist air mass will result in scattered to numerous showers and storms with heat indices mainly staying just under 105. The most likely scenario for Hurricane Beryl per the latest NHC forecasts and ensembles is for it to dissipate over southern Texas or northern Mexico, with less and less ensemble members showing any remnants curving towards us. Were this low probability scenario to occur, the sensible weather forecast for Central Alabama probably wouldn`t be that much different, however. 32/Davis && .AVIATION... (18Z TAFS) Issued at 1225 PM CDT WED JUL 3 2024 VFR conditions will prevail through this cycle. Isolated showers and a few storms will be possible across portions of our south and east counties this afternoon into early evening, but potential was too low to include at any terminal location. Scattered to broken low clouds will are expected over the south and portions of the eastern counties tonight into Independence Day. Isolated to scattered showers with some storms are expected through Thursday with chances high enough to include at the southern and eastern sites generally after 15z. 05 && .FIRE WEATHER... Hot and humid conditions are expected over the coming days. Scattered showers and storms are possible today mainly in far southern portions of Central Alabama. Scattered showers and storms are possible each afternoon and evening heading into the weekend. 20-foot winds will average less than 10 mph, from the southeast to southwest. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 74 94 74 94 / 10 40 20 90 Anniston 74 93 76 92 / 10 40 20 80 Birmingham 76 95 78 93 / 10 30 20 90 Tuscaloosa 76 96 77 93 / 20 40 20 90 Calera 75 94 77 93 / 20 30 20 80 Auburn 75 91 76 92 / 30 40 10 70 Montgomery 76 96 76 94 / 40 30 10 70 Troy 74 94 74 94 / 40 30 10 70 && .BMX WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 9 PM CDT Thursday for the following counties: Autauga-Barbour-Bibb-Blount-Bullock-Chilton-Coosa- Dallas-Elmore-Fayette-Greene-Hale-Jefferson-Lamar-Lee-Lowndes- Macon-Marengo-Marion-Montgomery-Perry-Pickens-Pike-Russell- Shelby-St. Clair-Sumter-Talladega-Tallapoosa-Tuscaloosa-Walker- Winston. Heat Advisory from 10 AM to 9 PM CDT Thursday for the following counties: Calhoun-Cherokee-Etowah. && $$ SHORT TERM...05 LONG TERM....32 AVIATION...05