


Area Forecast Discussion
Issued by NWS Aberdeen, SD
Issued by NWS Aberdeen, SD
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727 FXUS63 KABR 082310 AAA AFDABR Area Forecast Discussion...UPDATED National Weather Service Aberdeen SD 610 PM CDT Tue Jul 8 2025 .KEY MESSAGES... - Marginal/Slight risks for severe storms across the region Wednesday and Thursday. Hail up to 2 inches in diameter possible over central/north central SD on Wednesday (10% or greater probability within 25 miles of a point). - Heat and humidity return Wednesday/Thursday (especially James River westward), with highs in the 90s and heat indices approaching 100 degrees on Wednesday over central SD. && .UPDATE... Issued at 608 PM CDT Tue Jul 8 2025 The forecast remains on track this evening. No major changes are planned. && .DISCUSSION... Issued at 324 PM CDT Tue Jul 8 2025 Surface high pressure is anchored over eastern SD this afternoon, bringing mostly sunny skies and light winds to the region. Overnight, this high shifts east and allows for south-southeast return-flow winds to develop. There`s a weak low-level jet (25- 30kts) that develops late tonight into early Wednesday morning over central/south central SD. MUCAPE values generally from 1000-2000 J/KG (HREF ensemble mean), but with minimal shear. CAMs/paintball output show just a few blips of elevated convection over the southern CWA, so added slight chance (20%) PoPs for this. Otherwise, focus will then shift to Wednesday/Wednesday night with increasing heat, and chances for storms once again. By 00Z Thursday, 850mb temps rise to around +20C across the James River valley, to as warm as +28C across central SD. 90+ degrees looks probable from the James River westward, with highs more into the mid/upper 90s over central SD. Dewpoints will also be creeping up there into the mid/upper 60s to around 70 degrees. Latest iteration of heat indices brings values close to 100 over parts of central SD, but as of now it seems too brief/marginal to issue a headline for heat (100+ degree heat indices), although something to monitor. Will also be watching convection chances by late afternoon Wednesday as CAMs/paintball output continue to target the west-river counties of the CWA seeing initiation between 21-00Z along a frontal boundary. With rich low-level moisture (60s dewpoints) streaming northward into central SD, moderate/strong instability sets up by late afternoon as MLCAPE values peak around or just above 3000 J/KG. Shear is not overly strong, but models indicating perhaps 25-35kts. Whatever coverage of storms that develop across central SD late Wednesday afternoon/evening will push east-southeast across the CWA into the nighttime hours, likely waning in severe intensity as it does so. Looking at more potential for strong to severe storms Thursday/Thursday night also, while we remain in an active weather pattern across the Northern Plains. Looking further ahead, GEPS/GEFS/ENS all in good agreement in showing a cold front moving through the area on Friday, bringing cooler temperatures to the region after widespread 80s/90s Wednesday and Thursday. At 12Z Friday, all three camps of ensembles are in generally good agreement in showing the cold front position just exiting the CWA. 850mb temps on Friday off the Grand Ensemble range from about +13C to +16C, several degrees cooler from the +20s C expected Wednesday/Thursday. We may see a bit of a break in the stormy pattern as well, with minimal chances for precip showing up this weekend into Monday. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 608 PM CDT Tue Jul 8 2025 Terminals KABR,KATY,KPIR,KMBG VFR conditions are expected through Wednesday afternoon. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...20 DISCUSSION...TMT AVIATION...20