textproduct: Bismarck

KEY MESSAGES

- Well above average temperatures and mostly dry conditions continue through Wednesday.

- Active weather pattern Wednesday night through the end of the week, with medium to high precipitation chances and a strong cooling trend.

- Strong west to northwest winds are likely Thursday and Friday.

UPDATE

Issued at 621 AM CDT Tue Apr 21 2026

The forecast remains on track.

DISCUSSION

Issued at 427 AM CDT Tue Apr 21 2026

Overall quiet weather is on tap for today. Breezy southerly winds are likely to develop later this morning and into the afternoon as a tighter pressure gradient between surface high to the east and surface low pressure to the west slides through. This will also bring warmer air into the state, especially western ND where highs are progged to reach the low 80s.

For Wednesday, windy conditions out of the south to southeast are expected to develop as low pressure off to the west deepens and slides towards western ND resulting in the pressure gradient tightening even more. Simultaneously, thermal ridge will slide across the Northern Plains. Combined, these will aid in producing the warmest day of the week with current highs forecast to range from the mid 70s north to the mid 80s south. Deterministic models are coming into agreement that this low will track eastward across North Dakota or southern Canada Wednesday night through Thursday night, after which it may stall over southern Manitoba/western Ontario and potentially retrograde to some degree.

In regard to severe weather potential, machine learning models continue to peg low probabilities for severe weather later Wednesday afternoon and evening, while SPC bring a Marginal Risk just south of the ND/SD border. The best Gulf moisture advection seems to cut off south of the forecast area during the daytime hours. Moister air may advect into the eastern half of the state, but this seems more likely to occur Wednesday night into Thursday morning. Just not real favorable timing for severe weather this time of year. Plus modeled shear seems pretty marginal at this point as well. Overall, while there is a greater than zero chance that an isolated strong to severe storm could occur, concur with SPC that they are more likely to remain south Wednesday, and well off to the southeast on Thursday where much stronger gulf moisture advection is expected.

With that said, precipitation chances remain in the forecast across most of the state Wednesday evening through Thursday night, and potentially lingering through Friday. Initially, this should all be showers and thunderstorms Wednesday evening before becoming all rain overnight and through the day Thursday. Snow will likely mix in on the back side. NBM probabilities of at least an inch of snow remain high over most of western North Dakota that is also north of I94. At this time, medium probabilities of at least half an inch of precipitation in any form remains focused on the far northwest as dry slotting is favored to prevail over most of the forecast area, most of the time.

The biggest impact for much of the area with this system will likely be in regard to strong winds Thursday, and to a lesser degree, Friday. Overall, the EFI isn't too excited about winds over the forecast area being anomalously strong. However, with most of the forecast area seeing EFI values between .7 and .8, advisory level winds are favored at this time, especially in western ND where the highest values reside. One thing that seems more certain is much cooler temperatures behind this low pressure system. Current NBM highs are forecast in the 30s and 40s across most of the forecast area Friday through this weekend, while lows drop into the 20s and low 30s. Overall confidence in the temperatures forecast is relatively high considering NBM 25th/75th percentile spreads that are generally less than 10 degrees.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 621 AM CDT Tue Apr 21 2026

VFR ceilings and visibility are expected through the period. Current light winds will become southerly and breezy later this morning and during the afternoon hours. Winds will then become light and occasionally variable for most of the state tonight.

BIS WATCHES/WARNINGS/ADVISORIES

None.