


Area Forecast Discussion
Issued by NWS Sioux Falls, SD
Issued by NWS Sioux Falls, SD
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850 FXUS63 KFSD 110815 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 315 AM CDT Fri Jul 11 2025 .KEY MESSAGES... - Scattered showers and isolated storms will persist through the morning hours, mainly over the lower Missouri River Valley into northwest Iowa. Locally heavy downpours will be possible over that area through early morning. - A low end (level 1 of 5) risk of severe storms develops by late this afternoon, as a front brings scattered thunderstorms southward into the region. The main threats with the strongest storms will be up to quarter sized hail, strong winds up to 60 mph, and heavy downpours. - Temperatures cool Saturday, but heat and humidity build back in for Sunday through Tuesday. - Thunderstorm risks return for Tuesday into Wednesday, with some threat of severe storms possible. && .DISCUSSION... Issued at 307 AM CDT Fri Jul 11 2025 Scattered showers and isolated thunderstorms continue across the lower Missouri River Valley into northwest IA very early this morning - this in association with an upper level trough situated over the region. Latest guidance indicates a downward trend in shower coverage over that area through the morning into the early afternoon as the trough slowly shifts to the east, but will keep the flood watch in effect until 12Z for possible heavier downpours. Additional showers and thunderstorms are expected to develop over central SD by late afternoon - pushing eastward through the evening as a cold front moves slowly across the region. Although MLCAPE will be in the range of 1500-2000 J/KG by afternoon, 0-6 bulk shear looks to be generally less than 20 kts. In addition mid level lapse rates are not overly impressive at 6-7 C/KM, so the severe threat looks to remain on the low side - though cannot rule out a stronger storm with small hail and brief gusty winds. It will be another warm and muggy day with highs in the mid to upper 80s combined with dew points in the upper 60s to lower 70s. Could see a few lingering showers early tonight as another upper level trough moves through the region, though this activity will diminish later in the night with little additional rainfall accumulation expected. With cold air advection behind the aforementioned front, temperatures will fall into the upper 50s to lower 60s by Saturday morning. A much nicer day in store for Saturday as weak surface high pressure builds into the area and an 850 mb thermal trough swings through the region. Highs in the upper 70s to mid 80s will feel quite pleasant as dew points fall into the 50s to low 60s. The cooler conditions will be brief however, as high pressure pushes off to the east and a southerly flow returns to the region for Sunday into Tuesday of next week. With warming 850 mb temperatures, highs will climb back into the upper 80s and 90s each day. In addition, with a return of low level moisture dew points will push back into the 60s to lower 70s. Our next best chance of showers and storms will come on Tuesday into Wednesday as a strong cold front moves through the region. Too soon to get a handle on the severe storm potential for that period, though it will be something to keep an eye on. With the passage of the front, much cooler temperatures will drop back into the area for Wednesday and Thursday. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1035 PM CDT Thu Jul 10 2025 Showers and occasional thunderstorms will continue to train east near Yankton and Sioux City overnight. The strongest storms will bring MVFR visibility, heavy downpours, and small hail. Isolated showers and storms are possible further north at Huron and Sioux Falls, but confidence was too low to include in the TAF at this time. We`ll dry out heading into Friday morning before another round of scattered showers and storms develops Friday afternoon into evening. Light southerly winds persist overnight, gusting up to 20 kts during the day Friday. A passing front will shift winds to the north late Friday afternoon and evening. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...Flood Watch until 7 AM CDT this morning for IAZ031-032. NE...Flood Watch until 7 AM CDT this morning for NEZ013-014. && $$ DISCUSSION...JM AVIATION...BP