360 FXUS63 KFSD 050346 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 1046 PM CDT Wed Jun 4 2025 .KEY MESSAGES... - Thursday afternoon and night will see rain move through central into northeast SD, with a 30-50% chance for more than a half an inch of rain roughly northwest of a Platte SD to Ivanhoe MN line. - Friday will see the potential for isolated funnel clouds in the afternoon. - Saturday afternoon and night will see a small threat for isolated severe storms. && .DISCUSSION... Issued at 223 PM CDT Wed Jun 4 2025 A weak wave with just enough saturation and very weak instability will being some patchy light rain to central SD late this afternoon into the evening. Any forcing from this wave weakens quickly through the evening, so precipitation chances should be mainly diurnal. The remainder of the night will see cloud cover linger which should bring milder lows in the lower 50s to most locations. A stronger wave will move in Thursday with only minor instability, but decent forcing and saturation in the dendritic layer. Persistent rainfall across central into northeast SD should bring some decent rainfall amounts to locations roughly northwest of a Platte SD to Ivanhoe MN line. The GEFS is more aggressive with the higher amounts, generally 30-50% chance for more than a half an inch and about a 10 percent chance for more than an inch. ECMWF is less aggressive but still indicating potential in the same general area. The severe threat is very low. This wave gradually moves to the north of the area through Friday morning, with a larger wave moving into western SD Friday afternoon and dropping southeast into Nebraska Friday night. The position of the wave on Friday to the north is farther north and a touch less conducive to funnel development as the wave to the west moves in. With the current trends the better chance for isolated funnels would be west of I-29 and mainly in the afternoon as the wave shears out and drifts eastward. The potential for steeper surface to 1-2km lapse rates is also a little farther south and west as the lower levels remain a bit more saturated in southwest MN and northwest IA during the day with persistent rain chances. Of note continues to be the lack of winds from 700 mb to the surface, generally less than 5 knots, which aids in the maintenance of these weak funnels. Friday night into Saturday morning this wave will continue to drift southeast with some weak ridging ahead of a much stronger wave expected Saturday afternoon. This should bring a lull in activity with some potential for showers and thunderstorms on Saturday afternoon and evening, possibly continuing into the night. Right now the model soundings do not indicate much in the way of instability, but this is a pretty strongly forced event, so if a bit better instability can evolve, the shear profile as well as moisture aloft does support a few discrete cells with inflow from the southwest and storm motion likely to the southeast. For now any severe threat looks very isolated unless models begin to introduce more instability. Of note, both the GEFS and EC Ensemble are showing a bit more instability so maybe this trend is starting to show up in the models. Long story short, Saturday afternoon and evening may see some scattered stronger updrafts with a few discrete severe updrafts. A strong upper level jet max dives south and shoves any unstable air eastward taking the main threat for showers and storms with it. Slightly cooler conditions are expected Sunday and Monday, but highs should still be roughly 70 to 75. Northwest flow aloft continues into Tuesday and then appears to give way to weak ridging and more westerly flow aloft. This may bring the threat for showers and thunderstorm back to the area mid to late week next week as well as warmer temperatures. && .AVIATION /06Z TAFS THROUGH 06Z FRIDAY/... Issued at 1044 PM CDT Wed Jun 4 2025 VFR conditions begin the TAF period. Light and variable winds are expected for the overnight hours before clouds thicken aloft by tomorrow morning. Winds will pick up out of the southeast during the morning hours as well. Cloud bases will reside at VFR levels during the afternoon hours as rain chances expand across the area. Ceilings and visibilities will remain mainly at VFR levels but could fall to MVFR thresholds in a heavier shower. An isolated rumble of thunder is possible in the showers as well. The showers and VFR/MVFR ceilings and visibilities will finish out the TAF period. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ DISCUSSION...08 AVIATION...Meyers