402 FXUS64 KBMX 160620 AFDBMX Area Forecast Discussion National Weather Service Birmingham AL 120 AM CDT Sun Oct 16 2022 ...New SHORT TERM, AVIATION... .SHORT TERM... (Today through Monday) Issued at 119 AM CDT SUN OCT 16 2022 A frontal boundary remains to our north. It has actually lifted northward over the past few hours as a warm front with a surface low in western Oklahoma. The low will swing eastward through the morning and be near the Missouri Bootheel by midday. A secondary front will be sliding southward quickly this morning as well, and should merge with this first front around the same time. The stronger front will then begin to move southward this afternoon and move into northern portions of Central Alabama around Midnight. Isolated to scattered showers and a few embedded storms will be possible in the northwest late afternoon and then slide south and east through the evening. Looks like the best coverage will be in the north and northeast after sunset through Midnight ahead of the front. Activity will diminish in coverage after Midnight, but a stray shower can not be ruled out overnight. Isolated showers and perhaps a storm will be possible in the southern half of the area through midday, and then southeast through Monday afternoon, or until the upper level boundary works out of the region. Highs will be in the 80s today, with lows tonight into Monday morning in the 50s to low 60s. A stark difference will be in place on Monday with highs in the 60s and low low 70s north of I-20, low to mid 70s to the I-85 corridor and upper 70s to a few near 80s in the southeast. 16 && .LONG TERM... (Sunday night through next Friday) Issued at 240 PM CDT SAT OCT 15 2022 Long term forecast trends remain the same this afternoon, as we could be dealing with record cold October temperatures as we approach Wednesday and Thursday of next week. First off, slight chance PoPs remain in the forecast Sunday night through the day on Monday as the highly advertised strong cold front quickly moves south through the area. A few light showers can't be ruled out, but moisture continues to appear very limited. Most locations should remain dry through the day on Monday. All eyes will then be looking toward the arrival of some of the coldest air we've seen on record during the month of October across the Southeast. The highly amplified upper level pattern across the eastern CONUS continues to trend colder and drier on each subsequent global model run. An arctic airmass will dive southward across much of the eastern half of the country Tuesday through Thursday of this upcoming week. Low temperatures have trended even colder on this afternoon's forecast update and many locations will most certainly see the first freeze of the season both Wednesday and Thursday mornings. Widespread frost can be anticipated, especially on Thursday morning as the surface ridge settles across the region and winds are mainly calm with ideal radiational cooling conditions. See the climate section below for upcoming records going into next week. Temperatures could finally begin to modify by the end of next week, but very dry air will remain in place. Elevated fire danger conditions will need to be monitored with dewpoints dropping down into the low to mid 20s. I wouldn't be surprised to see guidance trending toward the teens for dewpoints over the next couple of days given the arctic nature of the air headed southward. 56/GDG Previous long-term discussion: (Sunday night through Friday) Issued at 311 AM CDT SAT OCT 15 2022 A mid-level speed max will push through the area Sunday evening, but the cold front will lag behind, not arriving in the northern counties until after midnight Sunday night. Moisture and lift are very limited with the front, and will just keep in some slight chance PoPs across the far north Sunday night. Lows will be relatively mild in the pre-frontal air mass. The cold front continues to move through the area Monday. Some lower 60s dew points may lift up into the far southern counties, and will continue to mention slight chance PoPs across the south with the front. Strongest cold air advection lags behind the front, so most areas except the far northern counties should reach the 70s for highs. A highly amplified pattern remain in place for much of the week with strong ridges over the western CONUS and Greenland and a deep trough over the eastern CONUS, with a deep upper low near the Great Lakes. This will allow an unseasonably chilly air mass from high latitudes to invade much of the eastern CONUS. Strong cold air advection may result in a light freeze along our northern border late Monday night/Tuesday morning and will add a low confidence mention to the HWO, but winds this night should be strong enough to prevent frost formation. 850mb temps will be in the 1st percentile on Tuesday, as cold as -4C, resulting in high temperatures near record "low highs" in the 50s to low 60s far southeast, and the breezy northerly winds will make it feel cooler than that. Despite the cool temperatures, very low dew points associated with the modified Arctic air mass will result in RH values below 25 percent. Winds will remain a little under red flag warning criteria, but fire danger will still be somewhat elevated. The cool dry air mass will set the stage for an earlier than normal first freeze of the season Tuesday night and Wednesday night. Winds may stay up enough to prevent ideal radiational cooling except in the northern/northeastern counties Tuesday night, but should go calm Wednesday night with a ridge axis overhead and widespread frost also expected. There are some interesting differences between the deterministic NBM low temperatures guidance and the probabilistic NBM low temperature guidance, with the probabilistic being much cooler. This appears to be due to different bias correction methods with other bias- corrected guidance being very cool as well. For now have lows in the upper 20s in the typically cooler spots across the north with low 30s elsewhere, which is still near record lows, but it's possible these could trend downward as we get closer given the tendency for low temperatures to over-perform (be cooler than guidance) in these dry air masses. ECMWF Extreme Forecast Index for both high and low temperatures also indicates the potential for anomalous values. See the climate section for record lows and record cool highs that may be in jeopardy. 32/Davis && .AVIATION... (06Z TAFS) Issued at 119 AM CDT SUN OCT 16 2022 Overall VFR conditions conditions for the next 24 hours. A front may bring some showers and storms to the northeast after 00z. Included VCSH at BHM after 1z. Better chances at ANB and ASN so included a prob30 here for showers after 1z as well. A thunderstorm can not be ruled out, but chances remain low at this time to include in the set of TAFS. 16 && .FIRE WEATHER... RH values are expected to increase slightly during the day on Sunday to 30 to 35 percent south of I-20, and 35 to 45 percent north of I-20. 20ft winds will be southwest 4-7 mph over the weekend. A strong cold front will push through Central Alabama on Monday with much drier air moving southward. Very limited moisture can be expected as the front moves through. && .CLIMATE... Issued at 311 AM CDT SAT OCT 15 2022 Record "cool high" temperatures for October 18: Birmingham: 55 (1955) Tuscaloosa: 58 (1966) Anniston: 54 (1955) Montgomery: 60 (2009) Record lows for October 19: Birmingham: 29 (1948) Tuscaloosa: 28 (1948) Anniston: 30 (1948) Montgomery: 34 (1948) Record lows for October 20: Birmingham: 32 (1964,1913) Tuscaloosa: 32 (1989,1948) Anniston: 29 (1948) Montgomery: 32 (1989) && .PRELIMINARY POINT TEMPS/POPS... Gadsden 84 56 71 33 / 10 40 10 0 Anniston 84 57 72 37 / 0 30 10 0 Birmingham 84 59 71 38 / 0 20 10 0 Tuscaloosa 84 60 73 40 / 0 20 10 0 Calera 84 59 73 40 / 0 20 10 0 Auburn 84 61 76 43 / 0 10 20 0 Montgomery 87 61 78 43 / 0 10 20 0 Troy 87 61 79 45 / 0 10 20 0 && .BMX WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...16 LONG TERM....56 AVIATION...16