Area Forecast Discussion

KEY MESSAGES

- Near critical fire weather will return on Monday and again on Wednesday with much warmer temperatures and breezy conditions. Wednesday may see near record high temperatures.

- Limited precipitation chances will continue through Wednesday.

- Shower and thunderstorm chances return Wednesday night into Thursday night. Some hints that much of the area could be split by strong upper level forcing to the northwest and deeper instability south and east, keeping our precipitation more isolated to scattered. - While Monday through Thursday will see above normal temperatures, possibly approaching record highs Wednesday, below normal temperatures are expected Friday into next weekend.

DISCUSSION

Issued at 100 PM CDT Sun Apr 19 2026

Cool high pressure shifts east tonight bringing southerly flow back to the area. Lows will mainly be from the upper 20s to lower 30s.

Southerly flow increases on Monday with gusts around 25 to 30 mph likely through the day. With fairly dry conditions expected once again, this creates elevated to near critical fire weather. Afternoon relative humidity should vary from the teens in central SD where winds will be a little lower during the lowest relative humidity with 20 to 25 percent over eastern SD into southwest MN. Will have a fire weather watch out for southwest MN and into Brookings county. If confidence increases enough in higher winds to the southwest of this watch, a watch/warning may be needed there as well. There has been a trend for slightly stronger winds and lower humidities each day for the past few days, so something to take into account.

A weak wave and associated weak cold front at the surface will move through Monday night, bringing weaker northerly and easterly flow into the area for Tuesday. This will bring warm and dry conditions to the area, but with winds mainly below 15 mph the fire weather threat Tuesday will remain muted.

Strong southerly flow returns on Wednesday, gusts 35 to 40 mph, with temperatures sky rocketing into the 80s and 90s. While afternoon relative humidity will be marginal for fire weather, the potential for very strong winds will lead to near critical fire weather conditions.

Low pressure moves onto the Western High Plains late Wednesday night and moves north and deepens over south central SD. This spreads instability into the area Wednesday night but the deeper westerly flow that develops Thursday quickly pushes this deeper instability to the east by mid day Thursday. There may be a small moment on Thursday afternoon near and east of a Marshall to Correctionville line where a thunderstorm could pop, but confidence pretty low. Otherwise colder air will move in Thursday afternoon and evening and like bring some pretty strong winds Thursday night.

Friday through Sunday will see this large low pressure over southern Canada keep generally dry conditions and below normal temperatures in place. Lows in the 30s and highs in the 50s.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1207 PM CDT Sun Apr 19 2026

VFR through the period. Gusty southerly winds return later tonight into Monday with gusts of 25 to 35 mph likely by Monday morning, especially near and west of I-29.

FSD WATCHES / WARNINGS / ADVISORIES

SD...Fire Weather Watch from Monday morning through Monday evening for SDZ040. MN...Fire Weather Watch from Monday morning through Monday evening for MNZ071-072-080-081-089-090-097. IA...None. NE...None.