Area Forecast Discussion
Issued by NWS Birmingham, AL
Issued by NWS Birmingham, AL
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846 FXUS64 KBMX 040608 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 108 AM CDT Thu Jul 4 2024 ...New AVIATION... .SHORT TERM... (Tonight through Friday) Issued at 735 PM CDT WED JUL 3 2024 Right at this writing, there was a small chance that a shower or storm may develop over Central Alabama. This small chance covers much of the area and the duration would be relatively short. Clouds will increase towards sunrise and linger for a few hours. Due to the low level moisture content, lows remain mild and in the 70s. Heat Indices will jump up again into the potentially dangerous zone and a Heat Advisory remains in effect. Overall, very little in the way of changes to ongoing forecast into Independence Day. 75 Previous short-term discussion: (This evening through Thursday) Issued at 1255 PM CDT WED JUL 3 2024 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 106 PM CDT WED JUL 3 2024 Based on today`s guidance suite, no major changes have been introduced to the long-term forecast. Highest rain chances remain in the forecast during the day on Friday, associated with the shortwave trough and surface front that will be approaching from the northwest. Moisture pooling out ahead of the surface front will lead to dewpoints only mixing down into the mid 70s during the afternoon. If we`re able to get high temps up into the low and mid 90s, we should easily see heat indices rise at or above 105 degrees. However, the widespread nature of convective activity and clouds that are being advertised by guidance will certainly help counteract the heat in some locations. We`ll have to see how much in the way of convective activity will be present during the morning hours. Widespread showers and storms will slowly move southward through the evening hours with the potential for scattered storms to linger through the overnight hours. As the synoptic front continues to move southward, rain chances will be confined to the southern half of the area on Saturday with slightly drier dewpoints in the 60s advecting southward close to the I-85 corridor. The front is still expected to move back northward by Monday, with scattered to numerous showers and storms returning to the forecast each day through the end of the forecast period. 56/GDG Previous long-term discussion: (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... (06Z TAFS) Issued at 108 AM CDT THU JUL 4 2024 A shower or two remains across portions of southeast Central Alabama tonight, with cigs between 3k-5kft. However, conditions at all forecast terminals are VFR. There is a chance of lower cigs around sunrise, mainly across the far south, with heights falling to 4k-5kft at MGM. Isolated to scattered showers and storms are expected Thursday by mid day through the afternoon. For now, have included PROB30s at all terminals. Winds will be light, less than 6kts, through the forecast period. 14 && .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 95 74 93 71 / 30 20 80 60 Anniston 93 76 92 74 / 40 20 80 60 Birmingham 93 77 93 74 / 30 20 80 60 Tuscaloosa 94 76 93 74 / 40 20 80 60 Calera 92 77 92 74 / 30 20 80 60 Auburn 91 76 92 75 / 50 20 70 60 Montgomery 94 76 94 75 / 30 20 70 60 Troy 94 74 93 74 / 40 20 70 50 && .BMX WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 9 PM CDT this evening 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 this morning to 9 PM CDT this evening for the following counties: Calhoun-Cherokee-Etowah. && $$ SHORT TERM...75 LONG TERM....56 AVIATION...14