Area Forecast Discussion
Issued by NWS Huntsville, AL
Issued by NWS Huntsville, AL
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085 FXUS64 KHUN 241105 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 605 AM CDT Fri May 24 2024 ...New AVIATION... .NEAR TERM... (Today) Issued at 247 AM CDT Fri May 24 2024 While the current radar is clear for the TN Valley, we are monitoring a few areas of ongoing convection that will track toward our area. The first is a convective complex to our west that will steadily track eastward throughout the morning hours. Additionally, a remnant outflow boundary draped from northern Mississippi through central Alabama will be a focus for additional shower/storm development this morning. The primary forcing for lift will be a weak shortwave trough rippling through the zonal flow aloft, which will provide extra synoptic scale support for ascent. For storm intensity, we will not be in a very favorable dynamic environment with weak wind shear values this morning. As is typical for this time of year, our thermodynamic profile becomes more supportive with diurnal heating. Therefore, while some stronger storms with wind gusts near 40 mph and small hail are on the table this morning, we would expect the potential for severe storms to peak in the late afternoon to evening hours. We will need to monitor radar trends closely for the potential multiple rounds of storms that will track over our area from the west. Primary threats at peak intensity time will be hail, damaging wind gusts, and a low chance for a tornado (best tornado probabilities will be in the Midwest). With weak shear present, a low end flooding threat comes to mind as weak corfidi vectors indicate the potential for backbuilding, on top of the multiple rounds of storms. For now, widespread 1-2" of rain are forecast but localized totals up to 3-4" may cause some nuisance flooding in low lying or poor drainage areas. && .SHORT TERM... (Tonight through Monday) Issued at 247 AM CDT Fri May 24 2024 If spending time outdoors at all this Memorial Day Weekend, be sure to know where you will go if there is a thunderstorm in your area. Unfortunately, we will have multiple rounds of storms to keep track of throughout the 3-day weekend. For Saturday, confidence in any strong or severe storms is low, but our main concern will be a weak zone of surface convergence moving in from the northwest on the southern flank of a surface high pressure system tonight. This will provide an area of focus for storms throughout the day Saturday with medium chances (40-60%) for the entire region. Timing remains a challenge based on when storms form to our west and what path they take, as well as how frequently they reinvigorate along a leading outflow boundary. If you don`t have a storm form over your area, you will likely be able to see one in the distance. A fairly deep fetch of southerly flow in low levels will advect in more Gulf moisture, as dew points surge into the low 70s on Sunday. With high temperatures in the low 90s, please be mindful of heat risks when spending time outdoors, particularly for sensitive groups. Attention on Sunday turns to a shortwave trough tracking through the Central Plains with an associated surface low that will push through the Mid-Mississippi Valley. While storm chances will be initially low on Sunday morning (10-30% chance), those will increase overnight as a line of strong to severe storms forms along a cold front. A recent trend has been for timing to push back, so while this initially looked to be Sunday evening/night, it now looks to be closer to midnight to early morning on Monday (60-80% chance). While not necessarily as favorable thermodynamically for severe weather, we will have a good wind profile in place with a LLJ of 30-40 kts to support a low end tornado threat. Over the next few days, this Sunday night/Monday morning round will be the one to keep an eye on. The most likely scenario is that the line of storms will race ahead of the cold front, lose that stronger forcing to maintain its severity, and then gradually weaken as it tracks across the area. Due to lower confidence in timing, we have kept rain chances in the forecast through Memorial Day on Monday. If the early morning storms outpace the front, then depending on how much the environment may recover on Monday, it is entirely feasible that additional storms could form Monday afternoon with the true frontal passage. It is not as likely at this time that any storms that do develop would become severe. && .LONG TERM... (Monday night through Thursday) Issued at 247 AM CDT Fri May 24 2024 A broader troughing pattern sets up Monday night for the eastern CONUS and will persist through the remainder of next week. While our next chance at storms is a lower end potential on Wednesday, the pattern overall looks to be drier with temperatures closer to daily average values in the low to mid 80s. && .AVIATION... (12Z TAFS) Issued at 605 AM CDT Fri May 24 2024 A line of very electrically active storms was moving toward AL from northern MS this morning. Current track puts this at MSL just after 12z and near HSV at 14Z. Expect a few hours of periodic thunderstorms with gusty winds; AWWs will be likely. Additional storms are likely in the afternoon, but confidence in timing remains too low for more than a PROB30 mention. Be prepared for periodic showers and thunderstorms this weekend through Monday afternoon. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...30 SHORT TERM....30 LONG TERM....30 AVIATION...30