FXUS63 KFSD 081908 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 208 PM CDT Wed Jul 8 2026 .KEY MESSAGES... - The potential for strong to severe storms will return to the area from 4 pm to 10 pm. Large hail up to half dollar size and damaging winds to 65 mph are the main hazards. Locally heavy rain could result in ponding in low-lying/urban areas. - High temperatures remain on track to rise to the 90s to 100 degree mark towards this weekend and into early next week. && .DISCUSSION... Issued at 208 PM CDT Wed Jul 8 2026 A few light rain showers persist across mainly northwest Iowa this afternoon. A surface trough and associated cold front continue to track through the forecast area early this afternoon. The mid level clouds associated with these light rain showers continue to sit over mainly northwest Iowa and surrounding locations. This has prevented locations in this area from heating out. The cooler temperatures look to also delay new convective development as the cold front pushes into this area. Still, these clouds look to clear/break up enough to allow adequate instability to develop with a magnitude up to about 2,000 J/kg over the course of the afternoon timeframe. Vertical shear values will be on the weaker side of things with a magnitude of roughly 20-30 knots. Latest hi-res guidance shows that a small, bi-modal severe weather event is on the table for this afternoon and evening. Storms look to develop on both the pre- frontal trough and trailing cold front. Storm development looks to take place across mainly northwest Iowa and adjacent areas this afternoon with a timeframe from from about 4 pm to 10 pm. With the cold frontal forcing, storms look to grow into a line as they push out of the area this evening. While vertical shear magnitudes will be on the lower side, hodographs show a weak but classic veer-back profile. With weak cold advection aloft, lapse rates will steepen just a bit more and allow for a large hail threat. Soundings do show slightly more saturated profiles in the hail growth zone (HGZ) which will tone down the hail threat a bit, with some of the largest stones growing up to half dollar size. DCAPE values will be sufficient with values up to 800 to 1,000 J/kg, keeping a damaging wind threat in place with the strongest gusts up to 65 mph. The large hail threat will come with the initial storm development before transitioning to a damaging wind threat as storms grow upscale. Pockets of moderate to heavy rainfall could result in localized ponding in low lying/urban areas as storms roll through. The storm threat will end this evening, leaving mostly quiet conditions for the overnight hours. Low temperatures will fall to the 60s. Seasonable and mostly dry conditions will return for the end of the week with high temperatures remaining in the 80s to just touching 90F. Winds will be light, making for a pleasant Thursday and Friday. Heights begin to rise aloft on Saturday, beginning to warm temperatures with highs rising to the 80s and 90s. Sunday will kick off the first day of near to above normal temperatures as medium range and ensemble guidance show a 600 dam ridge building into the Northern Plains. This ridge looks to persist through the first half of next week, brining hot and humid conditions with it. The ensembles show a 60-100% chance for highs to exceed 90F Sunday through Tuesday near and west of I-29. Chances for exceeding 100F drop to 40-70% for the same period of time with Tuesday having the highest probabilities. The ensembles also show a broad 40-100% chance for dew points to exceed 60F as well. All these probabilities to say that hot and humid conditions are expected late this weekend and into early next week. A few ensemble members show the ridge beginningto flatten next Wednesday which could begin to trend temperatures down. There remains uncertainty regarding how long the ridge remains strong so something to keep an eye on heading forward. && .AVIATION /18Z TAFS THROUGH 18Z THURSDAY/... Issued at 1240 PM CDT Wed Jul 8 2026 Latest satellite shows a mix of mid/upper level clouds and low level stratus across the area this afternoon. The low level stratus is sitting at MVFR/IFR levels with no obstruction to visibility. This stratus has been persistent across KHON and continues to push southeast just behind an advancing cold front. Should see this stratus make it into KFSD just after the period begins. This front will also be responsible for new thunderstorm development later this afternoon and evening, primarily across parts of northwest Iowa and adjacent areas. As of now, the new storms may develop just east of both KFSD and KSUX. Have left only PROB30 groups in their TAFs but this may change as confidence in storm location increases. The storms will push out of the area this evening as winds turn northerly behind the front. Additional MVFR/IFR stratus looks to develop late tonight along and east of I-29. This new stratus looks to continue into the morning hours before dissipating to end the TAF period. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ DISCUSSION...Meyers AVIATION...Meyers