Area Forecast Discussion
Issued by NWS Birmingham, AL
Issued by NWS Birmingham, AL
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873 FXUS64 KBMX 270914 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 414 AM CDT Thu Jun 27 2024 ...New SHORT TERM... .SHORT TERM... (Today through Friday) Issued at 408 AM CDT THU JUN 27 2024 We currently have a surface front extending from New Brunswick, Canada SWWD to DE then to the Carolinas and WWD to NW AL, continuing to dip beyond AL afterward into LA/TX with an associated low over NW AL. This front/low feature is expected to make a little more progress SEWD across C AL today. However, it is expected to stall and begin to weaken/fizzle before making it completely through the area, somewhere between the I20 and I85 corridors. In the upper levels, we currently have a shortwave deepening into a low extending out over MS/AL from the main longwave upper trough out of the ERN half of Canada. The main trough will move EWD tonight off toward Nova Scotia. This will allow the shortwave energy over the Deep South to break off as a weakened low. The flow gets stagnant over AL ending any push for our surface system resulting in it washing out. However, with a lingering boundary, pops will remain elevated into Friday with a somewhat more diurnal trend. With that said, with more cloud cover and high pops, our high temperatures should stay out of the record values through the short term. 08 && .LONG TERM... (Friday night through next Wednesday) Issued at 332 AM CDT THU JUN 27 2024 Key message: - Oppressively hot and humid conditions are expected this weekend, with dangerous heat possible on Sunday as heat indices rise above 105 degrees. A multi-day heat wave is expected to continue through much of next week. Best rain chances will exist Saturday through Sunday, with scattered showers and storms possible each afternoon through the end of the forecast period. Another prolonged period of oppressive heat will begin this weekend as the 500mb ridge begins to build and broaden from Texas all the way east through the Deep South. The big difference in this heat wave compared to the one we`ve recently experienced will be the addition of more tropical low-level moisture with dewpoints expected to remain in the 70s during the afternoon hours. Rain chances on Saturday will remain across the eastern and southeastern portions of Central Alabama, with higher PWATs and deeper 700mb moisture transport from the southwest. Although shower and storm coverage is expected to be scattered to numerous, temperatures aloft due to the 500mb ridge strengthening to 597 decameters will be quite warm. Therefore strong to severe storms are not expected at this time. Where it doesn`t happen to rain, heat indices will rise between 100 and 105 degrees Saturday afternoon as highs top out in the low to mid 90s. So, even though we may escape Saturday without issuing a Heat Advisory, all bets will be off on Sunday. As the ridge continues to strengthen but slightly retrograde off to our west, a shortwave trough is expected to move through the Great Lakes states Sunday morning. A cold front will be moving southward into northern Arkansas and Tennessee during that time, along with synoptic lift in the form of a 500mb vort max within the northwesterly flow. Convective development will be likely with strong surface instability as temperatures rise into the mid to upper 90s with dewpoints holding in the low to mid 70s. A Heat Advisory will be needed if current guidance trends hold, but widespread convective development (potentially in the form of an MCS) may throw a wrench in those trends if storms move through a bit earlier. As of now, heat indices Sunday afternoon should easily rise between 105 and 110 degrees for just about everyone. The cold front is currently progged to move southward on Monday, with a fresh fetch of dry air moving in from the north at 700mb. How far south the dry air at the surface can move southward is still in question, which will affect locations that may need another Heat Advisory Monday afternoon. For now, those locations appear to be along the U.S. 80/I-85 corridors and points southward with plenty of moisture pooling out ahead of the surface front. Scattered to numerous showers and storms can also be expected across the southern half of Central Alabama. The 500mb ridge is currently advertised to build back in over Deep South through Thursday, with isolated to scattered showers and storms possible during the peak heating of the day. As highs top out in the upper 90s each day, we could enter into a prolonged period where Heat Advisories may be needed for several days in a row. With this being said, we`ll also have to start keeping an eye on the dreaded Drought Monitor, with significant rain chances staying out of reach likely through the end of next week. 56/GDG && .AVIATION... (06Z TAFS) Issued at 120 AM CDT THU JUN 27 2024 All sites are currently VFR. MVFR cigs will spread across most of C AL from the NW after 9z lasting through midday as a surface low inches SE into the state. There will be chances for SHRA and TSRA across the area at times as the low drags a frontal boundary toward the I20 corridor by sunset and a little further SE toward the I85 corridor tonight/Thu night. Overall winds should be light outside of convection. Some reduced vsbys may occur briefly with heavier convection. 08 && .FIRE WEATHER... Scattered to numerous showers and storms can be expected today across much of Central Alabama, but widespread wetting rains are not expected. Min RH values this afternoon will be much higher than previous days, in the 55 to 65 percent range. Transport winds will remain light and variable at times through the afternoon today. Fortunately, we`re not expecting much in the way of gusty erratic winds with showers and storms today like what was observed on Wednesday. Scattered showers and storms will remain in the forecast for Friday, confined more to the southern half of Central Alabama. Transport winds are expected to increase out of the southwest between 10 and 15mph by Friday afternoon. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 87 69 91 72 / 50 20 50 20 Anniston 87 71 90 74 / 50 20 50 20 Birmingham 88 72 91 75 / 50 20 40 20 Tuscaloosa 89 72 91 75 / 50 20 40 10 Calera 89 73 92 75 / 50 20 50 20 Auburn 86 72 89 74 / 70 40 60 20 Montgomery 89 73 92 74 / 70 40 60 20 Troy 88 72 90 73 / 70 40 70 20 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...08 LONG TERM....56/GDG AVIATION...08