269 FXUS63 KFSD 110334 AFDFSD Area Forecast Discussion National Weather Service Sioux Falls SD 1034 PM CDT Thu Apr 10 2025 .KEY MESSAGES... - A very pleasant Friday with lighter winds, plenty of sunshine and highs in the 60s. - Strong winds return Saturday and Sunday along with warm temperatures which will lead to elevated to potentially critical fire weather conditions. - A small threat (20-30% chance) for showers and isolated thunderstorms exists Saturday night into Sunday. - Windy on Monday with rain or snow showers possible. Overall impacts should be minor. && .DISCUSSION... Issued at 218 PM CDT Thu Apr 10 2025 Strong northwest winds will subside this evening as high pressure builds south into the area. A few models indicating some fog potential, but antecedent conditions not very supportive given dry soils. So will mention nothing more than patchy potential. Cool overnight lows given light winds, generally 30 to 35 degrees. Friday should prove to be an extremely pleasant day with lighter winds in place as the surface high pressure shifts east. A few gusts from the south to 15 to 20 mph in central SD in the afternoon, otherwise most other locations will see wins remain below 15 mph. Highs will be similar or a touch warmer than today, ranging from near 60 in parts of southwest MN and northwest IA to the lower 70s in central SD. While drier conditions are again expected, critical fire weather conditions are not expected. However areas near and west of the James should be high to very high at times with lower humidities. Upper level ridging will give way to a more westerly flow aloft Friday night into the weekend. The initial wave will move in early Saturday and aid in tightening the surface pressure gradient and bringing winds of 20 to 40 mph to the area. The strongest winds should be east of the James River. Temperatures will climb well into the 70s and lower 80s near and west of I-29 while 70 to 75 will be most common east of I-29. Lapse rates aloft should support some higher mid level cloudiness and a very small chance for a few sprinkles, but the overall effects should be minimal with the better chances north of I-90. Saturday night into Sunday will see these elevated lapse rates increase a bit and become a touch more supportive of rain showers or maybe an isolated lightning strike. There is a fairly substantial dry sub cloud layer to fight through, but if anything can get going some stronger winds gusts will be possible with these showers. Rainfall amounts should mostly be a tenth of an inch or less. Overnight lows into Sunday morning will be mild in the upper 40s to lower 50s with highs Sunday cooler than Saturday, but still from 65 to 75 with the warmer readings in northwest IA. Cold advection continues Sunday night into Monday with strong northwest winds expected to continue. Low level moisture at the top of the mixed layer along with some weak instability could lead to some shallow light rain or light snow showers. Amounts will be minimal. Lows generally in the 30s with highs in the 50s, although temperatures could trend down a touch given the expected cloud cover and low level thermal field. Northwest flow aloft will keep cooler conditions in place on Tuesday but a more west northwest flow aloft may deliver some milder (highs 60s to 70s) and mainly dry conditions Wednesday and Thursday. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1030 PM CDT Thu Apr 10 2025 Conditions will mainly be VFR through the period, though with light winds overnight there is some potential for patchy fog formation. Latest hi res models would indicate slightly better probabilities (30-50%) through east central SD and southwestern MN. With lower probabilities elsewhere, did not include in the TAFs at this time. Winds will remain light through Friday afternoon, then begin to increase out of the southeast on Friday evening. && .FIRE WEATHER... Issued at 218 PM CDT Thu Apr 10 2025 Dangerous fire weather conditions will quickly improve near and just after sunset as northwest winds diminish. Friday will see quieter fire weather conditions as surface high pressure drifts east and lighter winds are expected. Central SD will see high to possibly very high fire danger as southerly winds gust to 15 to 20 mph along with relative humidities below 30 percent. Strong southerly flow with gusts to 30 to 40 mph possible, nearly fully cured fuels and a marginally dry air mass will lead to elevated and possible critical fire weather conditions on Saturday. A cool front will swing through Saturday night and bring strong northwest flow into the area on Sunday, leading to another day with elevated fire weather concerns. With only minor precipitation chances through next week, fire weather concerns will linger, especially mid to late week if temperatures warm into the 60s and 70s as expected. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. IA...None. NE...None. && $$ DISCUSSION...08 AVIATION...JM FIRE WEATHER...08