325 FXUS64 KHUN 240504 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 1204 AM CDT Wed Mar 24 2021 .UPDATE... For 06Z TAFS. && .NEAR TERM...(Tonight) Issued at 819 PM CDT Tue Mar 23 2021 Radar trends have shown all precipitation exiting our area late this afternoon and early this evening. We had already lowered the PoP this evening to slight chance, and now we have removed completely through 06Z. Will lower our PoP to slight chance after 06Z, although I'm seeing very little support for much at this point. The 00Z sounding at BMX has dried out significantly in mid levels behind the precipitation. A wake low has grazed our southeast counties this evening with brief wind gusts of 20-30kt, but those appear to have subsided looking at subhourly observations. Lower clouds will continue to fill back in overnight, and possibly lower as well. .SHORT TERM...(Wednesday through Thursday Night) Issued at 233 PM CDT Tue Mar 23 2021 Much of the same will continue into the day on Wednesday with the cold front to the west and a real lack of any forcing across the forecast area. PW values remain around an inch and again hard to go with a dry forecast. Expect most areas will remain dry but continued with low end PoPs around 20-30 percent. If precipitation does develop, there is some weak instability that would lead to a few rumbles of thunder in the afternoon. However, based on model trends, could see these PoPs potentially removed all together for Wednesday if the trends continue. Regardless, expects skies to be partly to mostly cloudy with highs in the low to mid 70s. Things get much more interesting going into Wednesday night into Thursday. An upper level trough will move out of the Desert Southwest into the Southern Plains. Models support a coupled jet with divergence from the left exit region of the southern jet and from the right entrance region from the northern jet. This will help the surface low deepen with strong divergence aloft. The low track is still uncertain but latest models have trended further north with the track of the surface low. This go around, surface high pressure to the north and east, is not as much of a factor preventing the warm front from lifting through the area. However, do expect a good bit of rain along the warm front as it tries to lift northwards Wednesday night into Thursday morning. This rain may act to enhance the warm frontal boundary and will also make the atmosphere more stable. The question becomes just how much the atmosphere may destabilize later in the morning and into the afternoon as the upper level trough races to the northeast. The low-level jet will strengthen is response to the mass divergence aloft. This will lead to elongated hodographs and a favorable low-level shear profile for rotating updrafts. Due to this, want to highlight the tornado threat a little more with this forecast package. Probabilistic guidance for SBCAPE values over 1,000 J/Kg continue to creep up as well. Overall, thinking that all modes of severe weather will be possible including tornadoes, damaging winds, hail, and heavy rainfall Thursday afternoon into the overnight period. Speaking of heavy rainfall, PW values will climb to anomalous high of 1.6-1.8 inches. This saturated atmosphere will be capable of producing extremely heavy rainfall. After the heavy rainfall last week, expect flash flooding will be possible Thursday into early Friday morning. The only thing that may help the flooding threat is that the system will be moving rather quickly with rain chances ending early Friday morning. .LONG TERM...(Friday through Monday) Issued at 233 PM CDT Tue Mar 23 2021 Friday should be dry as the front departs to the south and east. The front will stall to the south of the forecast area along the northern Gulf Coast as the main upper level trough exits to the northeast. This break in the showers, storms, and severe weather chances will be short-lived. The warm front will push back northwards into the Tennessee Valley on Saturday with southwesterly flow aloft. Models do not show any strong synoptic forcing along this boundary but forecast soundings show rather impressive instability and mid-level lapse rates. If storms do form, these storms could easily become strong to severe. Due to this, went ahead and adding the mention of strong to severe storms into the HWO for Saturday. This threat will continue into Saturday night and Sunday as an upper level trough passes to the north and pushes the front back southward through the area as a cold front. Again, there is still tons of model uncertainty at this time, this does not appear to be as big of a threat as Thursday, but the pattern will remain active. Finally, drier weather is forecast on Monday with cooler conditions behind the front. Lows Monday morning are currently forecast to be in the low mid 40s with highs in the mid to upper 60s. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1204 AM CDT Tue Mar 23 2021 Ceilings of 015-025agl (MVFR) are expected to lower below 010agl by 09Z as moist southeast flow continues. Ceilings will lift into the 015-020agl range (MVFR) by ~15Z. There is a small chance of -SHRA, but uncertainty is great enough to leave out of the TAFs. Clouds will either lift to or above 030agl or scatter out by 17-18Z with VFR conditions expected. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ NEAR TERM...17 SHORT TERM...MA LONG TERM...MA AVIATION...17 For more information please visit our website at weather.gov/huntsville.