Area Forecast Discussion
Issued by NWS Sioux Falls, SD
Issued by NWS Sioux Falls, SD
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118 FXUS63 KFSD 022247 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 547 PM CDT Sun Jun 2 2024 .KEY MESSAGES... - Scattered severe storms are still anticipated late this afternoon and tonight. A few supercells will be possible mainly near and west of the James River from about 4 pm to 8 pm, then some question marks arise as to evolution this evening into overnight. The big question is will there be a linear nature to the storms or will then remain more scattered with less coverage of strong winds. The latter seems to make the most sense given no east to west instability gradient. - Tuesday may be the next chance for severe weather, but will be dependent on recovery from scattered morning convection and timing of a cold front pushing through the region. Favored area for an isolated severe threat is along and east of the MN/IA Highway 60 corridor. - Quiet weather and seasonable temperatures are expected to prevail mid to late week. Possibly some breezy periods, especially Thursday and Friday. && .DISCUSSION... Issued at 211 PM CDT Sun Jun 2 2024 Still some question marks regarding the evolution of the convection tonight. Still plenty of instability, roughly 2000-2500 J/kg, with moderate deep layer shear around 40 knots. This is plenty to support isolated supercells capable of producing golf ball sized hail and wind gusts to 70 mph. One thing to watch late this afternoon and early this evening is whether or not a marginally low LFC and some decent turning in the low level winds could support isolated tornadoes. The best chance for supercells, large hail and isolated tornadoes will be west of I-29 and likely around the James Valley and points west. Showers and thunderstorms will progress eastward through the evening and overnight. Without a stronger east to west instability gradient and no LLJ really impinging on the area storms may remain more scattered instead of forming into a distinct line of storms. This may limit the extent of the wind threat and keep it more isolated. A linear system is not impossible, but maybe a little less likely. After about 9z most of the activity will be out of the area. The next wave of interest moves onto the Plains Monday night and should bring an area of showers and thunderstorms through. Given marginal instability of about 1000 to 1500 J/kg and weak to moderate shear severe storms should remain isolated. There is a bit of a dry layer below about 700 mb which could aid in supporting some stronger wind gusts. This threat will linger through the morning, then with the faster timing of the front areas near and east of highway 60 in southwest MN and northwest IA will see a short window around mid afternoon when a few stronger storms could develop but a good chance most severe weather in the afternoon and evening will be east of the area. Wednesday should be warm and windy behind the exiting wave. Suspect wind gusts around 35 mph with highs from the mid 70s to lower 80s. Thursday through Sunday should prove to be seasonally warm and mainly dry. A deepening low pressure over the Great Lakes and increasing upper level ridging across the Rockies leaves the area in northwest flow. Suspect with the deep northwest flow each day should be a touch breezy, especially Thursday and Friday when some upper level energy rotates around the backside of the low pressure over the Great Lakes. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/... Issued at 545 PM CDT Sun Jun 2 2024 Latest hi-res guidance suggests a complex of storms, some possibly severe, pushing eastward west of Interstate 29 from 00Z-04Z, then east of Interstate 29 from 04Z-08Z. With winds going light later tonight and precipitation exiting the area, there will be some potential for patchy fog on Monday morning. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ DISCUSSION...08 AVIATION...JM