271 FXUS64 KBMX 221212 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 612 AM CST Sun Dec 22 2019 .UPDATE... For 12Z Aviation. && .SHORT TERM... /Updated at 0245 AM CST Sun Dec 22 2019/ Through Tonight. Widespread light to moderate rainfall is falling across Central Alabama this morning, and will continue through much of the next 24 hours. Additionally, wind speeds will increase with occasional strong gusts east of I-65. A closed upper level low over eastern Texas this morning will move eastward along the northern Gulf Coast, with a surface low shifting northeastward into the eastern Floridan panhandle by tonight. Central Alabama will remain in a favorable area for isentropic and synoptic lift, along with the continuous feed of moisture. Will maintain widespread rain coverage through this evening, with rain chances tampering off from south to north late tonight as mid level drier air begins to wrap around the upper low. Temperatures currently are in the mid to upper 40s, and expect highs to only warm into the upper 40s to mid 50s. Tonight, lows will be in the mid to upper 40s. Many hi-res model solutions have trended stronger with wind speeds just above the surface. With the surface low to our south and a weakening wedge to our northeast, a tightened pressure gradient will result in increased surface winds and gusts. In addition, winds at 1-2kft above the surface will be quite strong at 35-45kt across the east. Conditions are not ideal for these winds to mix down, but an occasional strong gust especially on ridge tops in the east is possible through this evening. A wind advisory will be in effect through midnight tonight for counties along and east of I-65. Rainfall amounts so far have ranged from around 0.75 inches in the far west to as low as a tenth of an inch in the east. Expect an increase in rainfall intensity today with the approach of the upper low, and an additional 1.5 to 2.5 inches of rainfall is possible over the next 24 hours. This should not case widespread flash flooding or areal flooding concerns. Poor drainage areas and low lying areas where water typically accumulates should be monitored. 14 .LONG TERM... /Updated at 0245 AM CST Sun Dec 22 2019/ Monday through Sunday. The surface low should be positioned just south-southeast of our area beginning Monday morning and will continue to lift east- northeastward through the day. We'll likely still be dealing with widespread light rain for much of the area Monday morning due to the wrap-around moisture on the backside of the departing low. The winds may also be noticeably breezy at times in the early morning, but gusts should be well below advisory levels by Monday. The wrap- around moisture and associated light rain will continue to push eastward Monday afternoon, giving the best rain chances generally east of I-65. By the evening hours, any significant rain chances are well east of Central AL. Ridging builds in across the Southeastern CONUS Tuesday and Wednesday leading to dry weather and a general warming trend. Meanwhile, a deep trough is over much of the Western CONUS with a couple of low pressure systems dropping south out of the Gulf of Alaska and through the base of the trough. The second of these will help shift the trough eastward Thursday into Friday and eventually continue eastward across the MS Valley next weekend. As this occurs, a cold front will move through the area bringing our next chance for rain. At this time, guidance differs on the timing and evolution of this low pressure system as it traverses the CONUS, so I'll keep PoPs around 50% Saturday and Sunday until we start seeing better consistency in the long-range models. 25/Owen && .AVIATION... 12Z TAF Discussion. Widespread rainfall and reduced cigs are expected through the forecast period. Cigs have fallen to IFR at all forecast sites except BHM and ANB. Expect cigs at these two sites to lower over the next couple hours. With moist low levels and persistent rainfall, conditions might vary between LIFR and MVFR at times, but generally, IFR heights should prevail through the remainder of the forecast period, with visibilities not causing further reductions in flight conditions. Surface winds will be from the northeast through the forecast period and strong, with gusts up to 28-30kts. Low level winds increase at 2kft AGL, resulting in low level wind shear at most terminals. Winds should diminish some this evening, but remain at 7-11kts overnight. 14 && .FIRE WEATHER... A prolonged rain event continues across central Alabama with high humidity levels and rainfall totals of 2 to 3 inches through Sunday night. Surface winds will increase from the east today and tonight, with sustained speeds 10-20 kts and gusts up to 30 kts in the east and especially on ridge tops. The rain will decrease in coverage from west to east on Monday. Minimum relative humidity values remain well above critical levels through at least midweek despite rainfree conditions. && .PRELIMINARY POINT TEMPS/POPS... Gadsden 50 46 57 43 67 / 100 100 80 10 0 Anniston 51 46 57 45 69 / 100 100 80 10 0 Birmingham 51 48 57 45 68 / 100 100 70 0 0 Tuscaloosa 52 48 59 44 68 / 100 100 50 0 0 Calera 51 46 56 45 68 / 100 100 70 0 0 Auburn 51 47 55 49 67 / 100 100 70 30 0 Montgomery 54 48 59 48 69 / 100 100 60 10 0 Troy 55 48 59 49 68 / 100 90 40 10 0 && .BMX WATCHES/WARNINGS/ADVISORIES/... Wind Advisory until midnight CST tonight for the following counties: Autauga...Barbour...Blount...Bullock...Calhoun... Chambers...Cherokee...Chilton...Clay...Cleburne...Coosa... Elmore...Etowah...Jefferson...Lee...Lowndes...Macon... Montgomery...Pike...Randolph...Russell...Shelby...St. Clair... Talladega...Tallapoosa. && $$