Area Forecast Discussion
Issued by NWS Huntsville, AL
Issued by NWS Huntsville, AL
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892 FXUS64 KHUN 251935 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 235 PM CDT Sat May 25 2024 ...New NEAR TERM, SHORT TERM... .NEAR TERM... (Rest of Today and Tonight) Issued at 235 PM CDT Sat May 25 2024 The rest of today still remains somewhat uncertain regarding the potential for strong to severe storms. Our morning convection has made it well southeast of here, however outflow from the system has triggered at least one storm currently in Birmingham`s area. With this outflow storm initiating so far south of us, it is less likely this specific boundary will trigger storms in our area. The corridor we will be watching through the afternoon currently resides in NW AL in the form of a broken line of scattered cumulus. Should any boundaries interact with this, it would likely be enough to trigger storm initiation. If no boundaries move into it, it will likely just remain as a Cu field. Any storms that do develop will pose a threat for gusty winds, hail, and frequent lightning. Sunset should aid in squandering any storms that do develop with a very calm night anticipated. While winds won`t be entirely calm, very small dew point depressions may allow for some shallow ground fog in sheltered valleys and along water ways to develop. A system passing to our north near sunrise Sunday morning may support some very light showers yet as the sun rises this will aid in dissipating any lingering fog or ongoing showers. && .SHORT TERM... (Sunday through Tuesday) Issued at 235 PM CDT Sat May 25 2024 Before any mention of severe weather, we must discuss the high temperatures on Sunday! We have a very high chance of seeing our first 90 degree day at several locations. This has been well represented in nearly all of the HIRES models. Unfortunately this will only aid in destabilizing the boundary layer throughout the day tomorrow and prime the environment for overnight storms. After very sunny peak heating hours, CAMS indicate 1500-2000+ J/KG of CAPE lingering into the overnight hours for storms to take advantage of. Our severe threat comes from a surface low pressure system passing just to the NW of us. A broken line of storms will move through the area ahead of an attached cold front Sunday night into Monday morning, bringing all modes of severe weather and warranting a slight risk (2/5) from SPC. As we entered into CAM coverage this morning, models have been very consistent with harsh environmental parameters being present Sunday night. The aformentioned CAPE will support strong updrafts with 50-60+ KTS of bulk shear favoring organized convection and yielding a low but non zero tornado threat. Steep lapse rates from 7-8 C/KM will support a hail threat and the orientation of the line will be very favorable for damaging winds, which will likely prevail as our primary threat. While CAMS have been consistent in showing the line and favorable parameters, they have yet to align on timing. What appears clear right now is that the HIRES models favor a earlier arrival of the line and a faster departure as compared to previously used global models. Current models have the line entering NW AL Sunday night as early as 8 pm but as late as midnight. Current exit times look to be around mid morning on Monday. Timing is one of two aspects we will continue to refine in subsequent forecasts. The second aspect is the potential for scattered storm development ahead of the line. Models have not necessarily picked up on this yet but the environment Sunday afternoon and evening will be supportive of all modes of severe weather should anything develop ahead of the line. After the line exits our area, clear and dry conditions will develop in its wake throughout the day on Monday. These conditions will prevail for the remainder of the short term as high pressure will begin to build in from the NW. Highs will be slightly cooler than Sunday only reaching the mid to high 80s Monday and Tuesday. && .LONG TERM... (Tuesday night through Friday) Issued at 359 AM CDT Sat May 25 2024 Sfc high pressure allows for dry weather to settle over the region through the mid week. Upper level shortwaves will allow a very low chance of showers (10% or less) during this time, however, confidence is low in this occurring. High temperatures during this period are forecast to be in the 80s with overnight lows in the 50s/60s. && .AVIATION... (18Z TAFS) Issued at 1224 PM CDT Sat May 25 2024 There will be two periods of concern that will pose a threat to otherwise VFR conditions. This afternoon there will be a chance for scattered thunderstorm development. With very low confidence on location and timing, TS has been left out of the TAF for now. Tomorrow morning there are some indicators of fog and or low clouds. This is shown in the TAF as the ceilings are lowered significantly however confidence on the development of MVFR conditions is also low at this time and thus it has been left out of the TAF for now. Both TS chances and MVFR chances will be refined in further TAF issuances. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...RAD SHORT TERM....RAD LONG TERM....HC AVIATION...RAD