716 FXUS63 KFSD 022347 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 647 PM CDT Mon Jun 2 2025 .KEY MESSAGES... - Thunderstorms will develop from southwest to northeast late this afternoon into the evening. Weak shear and moderate instability should lead towards a few storms producing hail as large as 2 inches and wind gusts to 70 mph. - Locally heavy rainfall is likely as well with a few stripes of 2- 5". Most locations south of a Wagner to Sioux Falls to Marshall MN line should receive 0.50" with the better chances for 1-2" south of a Yankton to Jackson MN line. - Could see a brief return of Canadian wildfire smoke behind today`s cold frontal passage. Minor deterioration in visibility and air quality will be possible during the late evening hours mainly across southeastern South Dakota and portions of southwestern MN. - Temperatures return to seasonal normals for the remainder of the week into the weekend, with some potential for scattered (20-40% chance) diurnal showers/thunderstorms each day. Currently the severe threat during this times looks low. && .UPDATE... Issued at 634 PM CDT Mon Jun 2 2025 Thunderstorms continue across northwestern IA into northern NE, with additional thunderstorms across central MN. Narrow corridor of instability keeps the severe threat in place for the next couple of hours, and should wane toward sunset. Main hazards are 2 inch hail and 70 mph winds. Have received a few reports of localized flooding as well rainfall rates of 1-2+ inches per hour and storms through the overnight hours will be capable of producing heavy rainfall. Additionally, we are seeing wildfire smoke mixing down behind the front, with reported visibility as low as 2 miles. && .DISCUSSION... Issued at 234 PM CDT Mon Jun 2 2025 A quick moving mid level wave/MCV moving along highway 14 is speeding up the low level front a bit this afternoon. If storm development holds off until 6-7 pm, this may push the stronger development a bit farther south. Environmentally, scattered severe storms remain likely with about 2000 J/kg instability and only weak shear. Suspect that the initial updrafts will have the potential for golf ball to ping pong ball hail, but overall wind gusts around 65 mph and locally heavy rain should be the main threats. The best chance for these strong to severe storms will be south of I-90 then into parts of southwest MN. Low level boundary orientation relative to the mid and upper level flow indicate some training of cells is possible and given PWAT values around 1.5" and a warm cloud depth of about 12 kft, 2-4" per hour rainfall rates will be likely, just localized. After sunset a wave to the south will work east and bring additional rain and isolated thunderstorms to the area. For the most part severe weather after about 3z should remain very isolated, with some localized heavy rain the biggest threat, especially in northeast NE and northwest IA. Rain will gradually come to an end from west to east on Tuesday morning, leading to a cooler and marginally breezy day. Highs should be in the upper 60s to lower 70s most locations. Near to slightly below normal temperatures will continue Wednesday and Thursday as westerly flow aloft allows for additional weak waves and periodic chances for showers and isolated thunderstorms. Right now any thunderstorm activity does not look to be severe. Saturday through Monday low pressure develops along the Canadian border and will swing a couple of weak waves southward through the area. This will bring spotty chances for showers and thunderstorms with fairly low chances for severe weather. With west to northwest flow aloft, mild temperatures near to above normal are expected, generally highs in the 70s to lower 80s. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 634 PM CDT Mon Jun 2 2025 Strong to severe storms continue over northwestern IA into northern NE through the evening hours, and should begin to weaken toward sunset tonight. Otherwise, expect additional showers and thunderstorms to develop this evening and overnight back to the west toward the James River Valley. Expect MVFR to IFR conditions with convection. Additionally, wildfire smoke is sinking to the surface behind the front with the return of northwesterly winds. Visibility with the smoke is dropping to as low as 2 miles. Not sure how long this will last, but have included mention at all three sites. Southerly winds ahead of the front continue to gust to around 35+ knots, with northwesterly winds behind the front gusting to 35 knots at times. Expect winds to begin to weaken overnight, with continuing gusts around 20-25 knots through the period. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ UPDATE...SG DISCUSSION...08 AVIATION...SG