


Area Forecast Discussion
Issued by NWS Aberdeen, SD
Issued by NWS Aberdeen, SD
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898 FXUS63 KABR 230539 AAC AFDABR Area Forecast Discussion...UPDATED National Weather Service Aberdeen SD 1239 AM CDT Mon Jun 23 2025 .KEY MESSAGES... - Severe storm threat has diminished across the area but showers and thunderstorms remain in the forecast through daybreak across parts of the region. - Much cooler temperatures move in the first half of the week with several chances for showers and thunderstorms across the area Tuesday through Thursday. Marginal risk (level 1 of 5) for severe storms over southern SD Tuesday/Tuesday night. && .UPDATE... Issued at 1235 AM CDT Mon Jun 23 2025 The aviation discussion has been updated for the 06Z TAFS. UPDATE Issued at 725 PM CDT Sun Jun 22 2025 Allowed the heat advisory to expire this evening. Temperatures and heat indices are quickly falling behind the front this evening. UPDATE Issued at 620 PM CDT Sun Jun 22 2025 The front is now east of I-29 this evening with the trailing low center just east of Aberdeen. Will continue to monitor a few areas for storms this evening, focusing for now on the storms moving into SD out of central NE. && .DISCUSSION... Issued at 322 PM CDT Sun Jun 22 2025 Surface low is approaching the James River this afternoon and is rather evident on obs/satellite. Surface frontal boundary also shows up nicely on radar, so fairly east to track these features this afternoon. Unstable air mass across the region, with MLCAPE values around 2000-3000 J/KG. Still capped across a good portion of the CWA, but may be eroding it along the frontal boundary as witnessed by latest mesoscale analysis. Still a bit unclear on how convection pans out in our CWA, with better potential for supercellular activity across eastern ND into northern MN where a Tornado Watch is currently in effect. Seeing post-frontal convection across central ND, evident of increasing lift in that region. Once that area of lift pushes eastward over the next couple hours, will see if any convection can get going across the CWA. Otherwise, may have to wait until later this evening/tonight with whatever emerges across western NE and moves northeast across southern/southeast SD. Heat Advisory remains in effect until 00Z this evening. Still seeing hot and humid conditions along and east of the James River, with many areas between 100 and 105 heat index. That said, with the way the frontal boundary is moving across Brown county, heat indices may cool below criteria earlier than the set expiration time, especially northern and western parts of Brown. Monday will be cooler and much less humid compared to the past few days. In the post-frontal air mass, 850mb temps cool down to around +8c to +12C across the CWA. Northwest breezes will also be felt, with dewpoints only forecast to be in the 40s by afternoon for most areas. Southwest flow aloft continues into mid-week, with a northward movement of a surface frontal boundary Tuesday into Tuesday night. By Wednesday morning, GEFS/GEPS/ENS agree fairly well in showing the frontal position along the SD/NE border, or just into southern SD. With passing disturbances mid-week, shower and thunderstorm chances (60-80%) are best Tuesday night into Wednesday morning. But, it appears additional opportunities arise Wednesday night as well. Parameters/setup do seem to support at least a marginal risk for severe storms Tuesday night over southern SD, which seems to line up with the current Day 3 outlook. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1235 AM CDT Mon Jun 23 2025 Terminals KABR,KATY,KPIR,KMBG Post frontal showers and thunderstorms are moving northeast through the region tonight. Thunderstorms will be near KPIR and KATY at times tonight. There is also MVFR stratus. Expect both thunderstorms and cigs to improve after 12z leaving VFR conditions and breezy west to northwest winds through afternoon. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...20 DISCUSSION...TMT AVIATION...20/Vipond