Area Forecast Discussion
Issued by NWS Sioux Falls, SD
Issued by NWS Sioux Falls, SD
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462 FXUS63 KFSD 280807 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 307 AM CDT Fri Jun 28 2024 .KEY MESSAGES... - Rivers across the area have crested or are presently at crest. Expect rivers to slowly trend downward, even with any rain early this morning. - A small threat for severe weather exists this afternoon over parts of northwest IA. An isolated strong storm will also be possible in central SD this evening. - Below normal temperatures continue today into Monday, with the coolest temperatures Saturday through Monday. - Stronger westerly flow aloft develops Monday through the end of the week which should bring a bit busier pattern next week. && .DISCUSSION... Issued at 305 AM CDT Fri Jun 28 2024 Showers and thunderstorms will roll across the area this morning, but severe weather is unlikely as the convection moves into more stable air. Two more pieces of energy move through the area today. One will be over mainly northeast NE into northwest IA early this afternoon. Any severe weather will remain isolated and somewhat limited as the timing of the lower level front moves through fairly quickly. Another piece of energy is the stronger upper level low pressure which will dip into northern SD tonight and swing through a stronger cold front. Some very isolated stronger thunderstorms will be possible with the surge of colder air and wind would be the main threat. Instability is not overly high at around 500 J/kg but very strong mid and upper level winds could support some stronger wind gusts at the surface. Temperatures will warm a touch ahead of this colder surge with highs from the upper 70s to lower 80s. High pressure slides through the area this weekend bringing well below normal temperatures Saturday and Sunday. Highs Saturday will be in the upper 60s to lower 70s with highs Sunday in the lower to mid 70s. Low temperatures on Sunday morning may fall into the 45 to 50 degree range in some locations. While temperatures remain below normal on Monday, they will rebound back into the mid 70s to lower 80s in most locations, a touch warmer in central SD. This is in response to a trough digging into the Northern Rockies. Instability does try to rebound into the area, but similar to yesterday we may see mainly sub severe showers and thunderstorms late Sunday night into Monday, then a better chance for severe weather Monday night as instability tries to build up the Western High Plains into the area. Scattered showers and thunderstorms remain Tuesday with the next better chance for storms Thursday. Temperatures will likely rebound back closer to normal but may come up just a touch short in many locations. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1115 PM CDT Thu Jun 27 2024 Area of showers with isolated thunder over northwest Iowa at the start of the period will slowly shift east through daybreak. Main focus will be on line of strong to severe storms in central SD which will push east through areas near/north of I-90 through the overnight into Friday morning. Expect this line to gradually weaken as it progresses farther east, but may still be producing 40+kt gusts as it approaches the James River/KHON. Will carry a few hours of thunder at KHON and KFSD as this line moves through prior to 12Z Friday. Additional storms may develop ahead of a cold front across northwest Iowa Friday late morning/afternoon with a low (30%) probability for KSUX. Stout southerly low level jet will produce areas of low level wind shear through daybreak, though still seeing occasional surface gusts to around 25kt as well. Cold front will bring a wind shift to west and northwest winds as it progresses east across the area on Friday. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ DISCUSSION...08 AVIATION...JH