textproduct: Bismarck

KEY MESSAGES

- A winter storm will impact the region today into Saturday. There are high chances for exceeding 6 inches of snow and low to medium chances for exceeding 12 inches across the southern half of the state.

- Gusty north to northwest winds could cause patchy blowing snow in south central and eastern North Dakota on Saturday.

- Dry and seasonably cool Saturday night through Monday night.

DISCUSSION

Issued at 444 AM CDT Fri Apr 3 2026

Well-advertised winter storm is getting underway early this morning. The responsible closed upper low was spinning over Wyoming at 4 AM CDT. The low is forecast to slowly spin eastward through South Dakota today and tonight, then into Minnesota on Saturday. Intense quasi-geostrophic forcing will develop a large area of snow over southwest and far south central North Dakota this morning, lifting northeastward to cover at least the southern half of the state by mid afternoon. The snow is then forecast to expand into northeast North Dakota this evening, followed by snow ending from west to east across the state late this evening through early Saturday afternoon.

The 00Z suite of guidance provided 1) a slight southward shift of the northern half of the snowfall footprint, 2) a tightening of the northern gradient of forecast snowfall, and 3) a slight decrease in maximum amounts and probabilities for exceeding +12 inches of snow. This does not greatly change the messaging, especially along and south of Interstate 94 and extending into the northern James River Valley where the Winter Storm Warning remains in great shape. But for areas to the north, it now appears that snow totals are more likely to verify closer to the 25th percentile of our snowfall forecast, if not lower. But we are still reluctant to make any changes to our headlines before the event is underway, especially with there still being non- zero chances for reaching warning and advisory criteria within each headline area, respectively.

High temperatures today will be limited to the lower and mid 30s, with northeasterly winds around 10 to 15 mph and perhaps a few gusts over 20 mph. Given the expected heavy and wet nature of the snow, blowing or even drifting snow should not be a concern through tonight. That could change for south central and eastern North Dakota on Saturday as winds turn to the northwest and increase to 20 to 25 mph with gusts to 35 mph. The increase in wind is not expected to occur until near or shortly after the end of falling snow, and our blowing snow model would suggest it will be very difficult for blowing snow on its own to significantly reduce visibility. We will continue to message patchy blowing snow on the chance that winds are stronger, temperatures are cooler, or the characteristic of the snow is drier than anticipated.

After the storm system departs on Saturday, we will transition to a northwest flow pattern through at least early next week. There are a couple of weaker shortwaves that could bring some light precipitation through the region Saturday night and Sunday, but the probability is too low to mention in the forecast at this time. The second of these waves is a clipper passing by to our northeast that should give us a slight warm up to highs in the 40s on Sunday, but with northwest winds around 20 to 30 mph. That clipper will usher a modified Arctic air mass into the region for Monday, with a ~1040 mb surface high quickly sliding from Saskatchewan to the Upper Mississippi River Valley. Forecast highs on Monday fall back into the 30s, and could be limited below freezing where a deep snowpack persists. A transient upper ridge is then forecast to quickly move through the region on Tuesday ahead of a potent shortwave digging into the Northern High Plains. This could ignite a quick and substantial warm up to highs in the 50s and 60s for western North Dakota on Tuesday, while central and eastern North Dakota remain stuck in the 40s and 30s, respectively. Cluster analysis reveals a high degree of uncertainty on the evolution of the shortwave after it exits British Columbia, resulting in a mid week forecast that features a large temperature spread and low chances for precipitation. The highest confidence aspect of the mid week forecast is for windy conditions, which is already showing up as a shift-of-tails (low probability for higher impacts) in the EFI product.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 444 AM CDT Fri Apr 3 2026

Snow will increase over southwest North Dakota this morning and spread eastward across the southern two thirds of the state through the day. The snow will be moderate to heavy at times, with prevailing IFR to LIFR visibility. KXWA and KMOT will be near the northern edge of lighter snowfall at times throughout the forecast period.

Mostly IFR ceilings this morning, but moreso MVFR in north central North Dakota. By this afternoon, expecting MVFR ceilings across the north and IFR across the south. Winds will gradually turn from easterly to northerly through the forecast period, sustained around 10-15 kts.

BIS WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory from 1 PM CDT /noon MDT/ this afternoon to 1 PM CDT /noon MDT/ Saturday for NDZ005-010>013- 017. Winter Storm Warning until 1 PM CDT /noon MDT/ Saturday for NDZ018>020-031>034-040>045. Winter Storm Warning until 4 PM CDT Saturday for NDZ021>023- 025-035>037-046>048-050-051.