FXUS63 KFSD 270320 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 1020 PM CDT Sun Oct 26 2025 .KEY MESSAGES... - Areas of rain develop west of I-29 Monday morning and move slowly east through Tuesday night. Potential for tow main areas, one from central to northeast SD and another roughly east of a Yankton to Marshall MN line. The second area has the better chance (30-60%) for a half an inch or more. - Cooler Tuesday into Thursday with temperatures back around normal Friday into next weekend. && .DISCUSSION... Issued at 231 PM CDT Sun Oct 26 2025 A trough of low pressure over the Northern Rockies will spread east into tomorrow. This energy will reach the eastern Dakotas late Monday morning through the night. This should swing a band of rainfall through the area. Thunderstorms are not expected with only very weak elevated instability expected. The forcing with this initial, shearing out wave to the north during the day may prove to only bring lighter rainfall with the better chances in central to northeast SD. By Monday evening a bit better piece of energy works into central NE and far southern SD, then northwest IA later in the evening and looks to have just a bit better instability, still likely not enough to produce any actual thunderstorms. Model soundings do indicate that some dry air will begin to work in at the mid levels and without much instability this could quickly diminish rainfall potential later at night. However, still a lot to work out with this system as a blocky upstream ridge will likely slow the progression of this wave and multiple models/members indicate that this wave will wrap up a bit into Tuesday and keep rainfall chances in place during this time, especially near and east of Interstate 29. Statistically, the latest GEFS and EC Ensemble show this split in precipitation chances pretty well with a decent chance for a tenth of an inch or more in central to northeast SD and another area near and east of a Yankton to Marshall MN line. One difference is the northern area has a less than 10 percent chance for more than a half an inch of rain while the southern area is showing a 30 to 60 percent chance for more than a half an inch, likely due to the slowing of the system Monday night into Tuesday. So for now the better chances for a more meaningful rainfall will be Monday evening into Tuesday morning, and especially in and around northwest IA. After this system wraps up to the southeast and moves out by Wednesday morning, northwest flow aloft will be the dominant flow through next weekend. This supports a mainly dry forecast with just smaller chances of lighter precipitation amounts. This will also help lock in cooler temperatures with mainly below normal temperatures Tuesday through Thursday. The models do have some marginal consistency in producing low pressure across ND Friday that drops southward into next weekend and could bring some precipitation chances, but confidence is low for now. If this pattern develops, deeper westerly flow could support mixy conditions and milder temperatures Friday into Sunday. && .AVIATION /06Z TAFS THROUGH 06Z TUESDAY/... Issued at 1015 PM CDT Sun Oct 26 2025 Mostly VFR conditions will transition to mainly MVFR conditions this TAF period. Taking a look at satellite imagery, low to mid level clouds continue to filter into the region from west to east this evening promoting occasional MVFR ceilings. Expect these MVFR ceilings to become more widespread after sunset as low hanging stratus surges eastwards with decreasing temperatures across the area. Otherwise, intermittent periods of showers will develop throughout the day as a as a cold front progresses through the region. Lastly, southerly surface winds will gradually decrease overnight before increasing again on Monday with gusts between 25-35 mph expected. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ DISCUSSION...08 AVIATION...05