087 FXUS63 KABR 131049 AFDABR Area Forecast Discussion National Weather Service Aberdeen SD 549 AM CDT Wed Aug 13 2025 .KEY MESSAGES... - Weak/isolated showers and thunderstorms will move west to east across the area this morning into the early afternoon. Severe weather is not anticipated with this round of moisture. - There is a slight risk (level 2 of 5) for central/south central South Dakota, and a marginal risk (1 out of 5) south of a line from Mobridge to Redfield and Watertown. Main threats in these outlook areas are large hail and winds of 60-70mph. Timing of severe weather is mainly evening and early overnight. - There is a slight (2 of 5) risk area for the northern tier of northeast South Dakota, and a marginal risk (1 of 5) in central South Dakota for storms on Thursday. Again, timing is evening to overnight and main threats are hail and winds. Coverage is expected to be more isolated. - Unsettled weather patten will continue for the end of the week into the weekend. - Hot and humid Thursday with highs/heat index values near 100 in central South Dakota. Temperatures will remain close to climatology (80s in central SD & 70s in the northeast) Friday through the weekend and into next week. && .DISCUSSION... Issued at 209 AM CDT Wed Aug 13 2025 Mid-level clouds associated with warm advection have already developed out west. There is a very subtle shortwave evident in deterministic 500mb analysis that will slowly traverse the forecast area through the course of the day. That, combined with about 100- 200j/kg of mid-level instability means we can anticipate high-based showers and weak storms to migrate from west to east through the course of the morning and early afternoon. The focus then shifts to this afternoon. cams indicate convective development out west around 00Z mainly out towards the hills but some of the cams also show some development out in the Pierre area. CAMS show the convective cluster migrates east southeast across primarily central South Dakota, Though a couple of the CAMS show more isolated coverage up along the northern tier of the state into the northeast by around midnight. CAMS also linger convection through about 12Z Thursday morning, likely thanks to a 35-45kt low level jet over the eastern Dakotas/Minnesota. The 25th 75th percentile range in CAPE from the HREF is approximately 1200 to 2500 joules per kilogram at about the time of convective initiation. 0-6km shear runs about 40 knots with a bulls eye of 50 knots in central South Dakota, With a majority of that being westerly unidirectional mid-level flow with southeasterlies in the boundary layer. Across central South Dakota LCLs will end up running around 8000 feet With dew point depressions running around 15 Celsius. Doesnt look like theres strong mid level drying in these profiles, but at 95 over 60 and bases AOA 6-8kft aside from the shear driven hail aspect, would also think winds are the primary threat for today. The heat and humidity is on for Thursday. NBM temperatures and heat indexes approach the century mark in central South Dakota. Does not appear at this time to be widespread enough to warrant a heat advisory. CAMS and Bufkit profiles hint theres still the potential for isolated convection to break the cap Despite the elevated mixed layer aloft, possible aided by enhanced flow aloft thanks to a trough to the north and ridging to the south. Uncertain if theres a wave embedded within that flow however, but there is a wave in the NAM/GFS and Canadian later for Friday morning. NBM has limited POPs but there is some mid level instability (1200 j/kg in NAM BUFKIT) to support elevated convection. The heat on Friday is also undercut by a backdoor cold front. The rest of the forecast is off and on again chances for moisture as the pattern is overall unchanged until we get into the middle of next week with a 4 corners ridge expected to build and project into the northern Rockies. && .AVIATION /12Z TAFS THROUGH 12Z THURSDAY/... Issued at 515 AM CDT Wed Aug 13 2025 Terminals KABR,KATY,KPIR,KMBG A little pocket of fog near KABR could briefly drop the VISBY to MVFR. Otherwise VFR conditions with potential for some light showers briefly this morning out of a mid level deck near KPIR. Focus is on storms this evening for all terminals. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ DISCUSSION...07 AVIATION...07