908 FXUS63 KFSD 132257 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 557 PM CDT Fri Jun 13 2025 .KEY MESSAGES... - Isolated showers or weak thunderstorms remain possible (20-30% chance) through this evening, mainly across Southwest Minnesota and far northern Iowa. - Areas of fog are again expected along the Buffalo Ridge and Hwy 14 corridor tonight into early Saturday resulting in reduced visibility. - An active pattern looks to bring continued chances for showers and storms for the weekend and at least early next week. While finer details remain uncertain, continue to monitor the forecast for strong to severe storms and heavy rain potential. && .DISCUSSION... Issued at 218 PM CDT Fri Jun 13 2025 Rest of Today: Boundary currently draped from roughly north of Windom to just north of Sioux City, near this boundary (mainly in SW Minnesota) a few showers or weaker thunderstorms are possible into the evening hours. While unlikely, NST parameter of 1-3 and low level CAPE/surface vorticity overlap leave at least some remote chance for any developing shower/storm to develop a funnel cloud or landspout. Tonight: Could again see some fog leak down the Buffalo Ridge of SW Minnesota and perhaps the higher elevations of Jerauld and Beadle county. Also not impossible for some showers or weaker thunderstorms to develop along the next WAA push although chances of measurable precipitation at any one location currently look low (<20%). Saturday: Weak wave moves from west to east through northern South Dakota and thus will carry some shower and thunderstorm chances (30- 50%) north of I-90 during the daytime hours with lesser chances south of there. Synoptic boundary looks to get hung up somewhere near Hwy 14 with next wave sinking into southeast South Dakota. This would likely bring a bit better chance (50-70%) of thunderstorms by the evening and overnight hours with probably still the overall better focus being north of I-90. This would also likely be the period to watch for an isolated stronger storm with a current Marginal risk from SPC. Baring any convective contamination, high temperatures in the 80s look likely for most locations with lower 90s toward the MO River Valley. Sunday through Wednesday: An unsettled pattern continues through the first half the week but also one that carries daily uncertainty with many of the drivers for convection chances dependent on what occurs in the previous day(s). While the finer details of where and when are still murky, pattern recognition, initial SPC outlooks and machine learning probabilities/analogs suggest this period will carry daily regional severe weather risks. At this time, would suspect that the better chances for any more widespread severe thunderstorms would be Monday night into Tuesday and then again Tuesday night and early Wednesday as better waves lift through the area within the broader southwest flow. With potential for multiple rounds of convection and PWATs climbing near or above the 90th percentile of climatology, will also want to monitor for potential flash flood/flood related issues during this timeframe. This is confirmed by some signal in 5 Day National Water Model guidance. Wednesday through Friday: Main trough finally lifts through the local area sometime Wednesday with building ridging by the end of the work week. Cooler conditions with temperatures back into the 70s behind the system Wednesday, quickly recovering to the 80s or even lower 90s by next weekend. && .AVIATION /00Z TAFS THROUGH 00Z SUNDAY/... Issued at 555 PM CDT Fri Jun 13 2025 Isolated showers and thunderstorms over southwest MN and northwest IA will continue to push to the east through the evening. This should lead to a primarily dry period until later tonight into Saturday morning when isolated showers and thunderstorms could redevelop. MVFR/IFR stratus presently located through the Highway 14 corridor may also sink southward into the Interstate 90 corridor by late tonight. In addition, there will be patchy fog development into Saturday morning, focused primarily through the Buffalo Ridge area - though cannot completely rule out some development at KHON and KFSD. Slightly better rain chances (~30%) will return on Saturday afternoon and evening. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ DISCUSSION...Kalin AVIATION...JM