textproduct: Bismarck

KEY MESSAGES

- A brief period of near critical fire weather conditions may be found in the far southwest this afternoon into the early evening hours.

- Low to medium chances for rain through this evening from north to south during passage of a cold front. Some light snow mixed in possible in the north.

- Notably cooler temperatures Sunday, then a warming trend into mid-week.

DISCUSSION

Issued at 250 PM CDT Sat Mar 21 2026

Warm temperatures in the south have lead to some low RH values. Increasing winds are expected ahead of a cold front passage in these areas, which may still bring increased to near critical fire weather conditions this afternoon into this evening, especially in the southwest. Uncertainty remains on how long of a period these conditions will last as the mentioned cold front will cool temperatures and bring increased RH values when the stronger winds move through. For now kept with near critical fire weather conditions wording in the southwest. Meanwhile, along this front are lower clouds, cooler conditions, and increased northerly winds. Precipitation is slow to develop so far with some light radar returns in the northwest, and brief reports of drizzle and mist during initial passage of the front. Dry air in place may limited shower potential, although still maintained low to medium PoPs through this evening for the passage of this front. Mainly rain is expected, although areas north of Highway 2 could see some snow mix in at times. Precipitation chances diminish this evening, with cooler overnight lows in the 20s and diminishing winds expected for tonight. A surface high enters the state late tonight which will bring light and variable winds and high RH values. This could provide for some patchy fog, although confidence was not high enough to include at this time. Surface high moves eastward across the state on Sunday with northwest flow aloft. Cooler temperatures are forecast with highs in the 30s north to 40s and lower 50s south. Breezy winds may be found in the far southwest, although most areas will see less wind than today. Weak waves in the northwest flow aloft, combined with some steep mid level lapse rates, could bring a few rain or snow showers Sunday afternoon. Seasonable temperatures with dry conditions and light winds are then expected for Sunday night. This could lead to some patchy fog across the area, although confidence was not high enough to include at this time.

Zonal to northwest flow aloft looks to be found to start the work week. This is forecast to bring mild and mainly dry conditions through Tuesday. Ensembles still showing a northern rockies surface low could move across the region sometime Wednesday along with a trailing cold front. Ahead of this front would likely be more well above normal temperatures in the 50s and 60s, with lowering RH values in the 20s and 30s, and increased winds. Perhaps increased to near critical fire weather conditions return as a result. Chances for rain and snow could then return as a cold front moves through sometime Wednesday through Wednesday night. Chances for accumulating snow are low in the NBM right now, with near 20 percent chances in the north. Cooler more seasonable temperatures are then forecast behind this system to end the week. Lingering northwest flow could also bring some breezy winds at times. Right now chances for precipitation late in the week are low, pending any weak waves in the mentioned northwest flow.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 105 PM CDT Sat Mar 21 2026

A cold front moving from north to south will bring lower clouds and a chance rain or perhaps brief snow showers today through this evening. Ceilings could be MVFR to IFR during passage of this front today through this evening. Most sites have a chance of rain during passage of this front today, however, confidence was only high enough to use PROB30 groups. Tonight, chances for rain and snow will diminish this evening with MVFR to some IFR ceilings remaining through the night. MVFR ceilings could then remain into Sunday morning. Breezy northerly wind expected through tonight, becoming light and variable Sunday morning.

BIS WATCHES/WARNINGS/ADVISORIES

None.