Area Forecast Discussion
Issued by NWS Birmingham, AL
Issued by NWS Birmingham, AL
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185 FXUS64 KBMX 011747 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 1147 AM CST Mon Dec 1 2025 ...New AVIATION... .KEY MESSAGES... Updated at 1140 AM CST MON DEC 1 2025 - Significant rain amounts of one to two inches on average are expected across central Alabama through Tuesday. Highest rainfall amounts are expected along the I-85 corridor. - Widespread freezing temperatures in the low to mid 20s will return Tuesday night through Wednesday morning. A few upper teens will likely be observed within colder valleys. - Another storm system is poised to arrive by the end of the upcoming week with an additional opportunity for soaking rains Thursday night through Friday night. && .DISCUSSION... (Tuesday through next Monday) Issued at 202 AM CST MON DEC 1 2025 Today through Tuesday: The cold front with modified arctic air to the north of it has slowly moved southward near the I-20 corridor early this morning. Temporary clearing of low clouds have occurred at TCL and BHM as the dry air has moved just enough to the south while all other locations south of I-20 remain socked in with low ceilings and overcast skies. Cold Air Advection is currently ongoing across Central Tennessee and northern Alabama with northerly winds gusting between 10 and 15 knots on some METARs. However, the coldest air still hasn`t been able to make it southward just yet, with lower 30s observed across northern Alabama and below freezing temperatures a little farther to the north. As a result, the hourly forecast for temperatures and dewpoints have been revised upward for locations north of I-20 through daybreak. For the rest of the CWA, temperatures will continue to fall a few degrees and lows should range from the upper 30s just south of I-20 to the upper 40s in Troy and Eufaula. The clearing across the northern half of the forecast area will be very short-lived as the next shortwave trough ejects eastward from the Four Corners states today, combined with a 500mb impulse originating from Mexico. Strong isentropic upglide will begin as early as this afternoon with a CAD wedge working in from Georgia and easterly to southeasterly flow at the surface. A 50 to 65 knot southwesterly jet at 500mb with a tropical plume of moisture headed north from the Gulf between 850 and 700mb will quickly develop widespread rains by this evening, spreading across much of the Deep South. Highs today will remain on the cooler side due to overcast conditions remaining in place, followed by rain developing by this afternoon. Mid 40s can be expected in Hamilton, while Eufaula will have a good chance of reaching the lower 60s with a warmer southeasterly surface flow. A soaking rainfall will develop overnight tonight as overrunning moisture continues to move northward and a surface low moves from just south of Pensacola to near Dothan by early Tuesday morning. 1 to 2 inch rainfall amounts on average should remain along and southeast of the I-59 corridor with heaviest rains concentrated along the I-85 corridor just north of the track of the surface low. A few rumbles of thunder certainly can`t be ruled out in these areas with localized heavier rainfall amounts. We`ll keep an eye out for localized flooding, especially within poor drainage areas. Recent falling leaves will also help to clog storm drains and ditches, likely leading to additional ponding of water on roadways. A non-diurnal temperature curve has been forecast across the CWA overnight as temperatures remain in the 50s closest to the surface low to the south, while temperatures drop behind the next cold front moving into western Alabama before daybreak Tuesday morning. All rainfall will be well to our east by Tuesday afternoon with another round of modified arctic air filtering into the region. Despite clearing skies, temperatures are advertised to struggle to reach the 40 degree mark in Marion and Winston Counties, with low to mid 50s south of I-85. Blustery northwest winds between 10 and 20mph will cause wind chills to perhaps stay in the upper 20s to lower 30s along and north of I-20. Tuesday Night through the Upcoming Weekend: Thankfully winds will diminish after sunset Tuesday as surface high pressure builds in across the Tennessee River Valley. Unfortunately that will also provide ideal radiational cooling conditions under clear skies and very dry air at the surface. A widespread freeze will occur as a result, with widespread low to mid 20s forecast for much of the area by sunrise Wednesday. We will likely see some upper teens in the colder valleys across the northeastern counties along the I-59 corridor northeast of Birmingham. Following a dry and mostly sunny day on Wednesday with chilly temperatures in the 50s, the next storm system is expected to arrive by Thursday. Guidance is presenting a very similar upper level pattern to what is currently ongoing now across the Deep South, with a more suppressed shortwave due to a stronger 592 decameter ridge building over Cuba. The result would be another round of widespread rains Thursday night through Friday night as another surface low moves from the Mississippi and Alabama coast to the Florida Panhandle by Friday afternoon. PoPs have been increased to categorical during that time frame as confidence in this solution continues to rise. Guidance solutions begin to diverge in terms of the 500mb pattern by the upcoming weekend and have kept a mainly persistence forecast in place through Sunday due to the lower forecast confidence. 56/GDG && .AVIATION... (18Z TAFS) Issued at 1147 AM CST MON DEC 1 2025 A band of MVFR cigs is currently located across MGM and AUO, with a low to medium chance that it will move northward to the northern terminals this afternoon. Light rain will also develop near the northern terminals this afternoon but shouldn`t have a significant impact on visibilities. By this evening, widespread steady light to moderate rain will overspread the area, along with IFR to LIFR cigs. Rain ends from west to east tomorrow morning, but expect IFR cigs to linger through at least midday. Behind a cold front, winds tomorrow will become northwesterly at 10 to 12 kts. 32/JDavis && .FIRE WEATHER... Another round of soaking rainfall is expected to move across Central Alabama this afternoon through early Tuesday morning. 1 to 2 inches of rainfall on average is anticipated along and south/east of the I-59 corridor. Dry weather returns late Tuesday through the mid-week period with MinRHs ranging from the mid 30s to upper 40s once again by Wednesday afternoon. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 52 42 45 21 / 40 100 30 0 Anniston 53 45 47 24 / 40 100 40 0 Birmingham 52 41 44 25 / 40 100 30 0 Tuscaloosa 52 41 43 25 / 50 100 20 0 Calera 53 43 46 25 / 40 100 30 0 Auburn 55 50 53 29 / 20 100 50 0 Montgomery 58 50 54 28 / 30 100 40 0 Troy 59 53 55 29 / 30 100 40 0 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...56/GDG AVIATION...32/JDavis