textproduct: Bismarck

KEY MESSAGES

- Strong winds are expected beginning in western North Dakota late Wednesday, and across all of western and central North Dakota Wednesday night, and especially Thursday and Friday.

- Critical fire weather conditions are expected in western North Dakota Wednesday, and there is a high chance of critical fire weather conditions across all of western and central North Dakota Thursday through Friday.

- A low chance (15-25%) for showers and thunderstorms across the east Thursday, and a chance (40-60%) of rain this weekend.

UPDATE

Issued at 941 PM CDT Tue May 12 2026

Winds have rapidly diminished as expected, so the Red Flag Warning was allowed to expire. As of 0230z, surface high pressure extends from western ND into central SD and north central NEB, and is expected to shift southeast overnight. The forecast for a cool and mostly clear night with light winds is on track, with no significant changes needed with this update.

UPDATE Issued at 655 PM CDT Tue May 12 2026

We will allow the remainder of the Wind Advisory to expire as planned with observed decreasing trends in winds area-wide. We expect winds to quickly become light with sunset as the boundary layer rapidly decouples. Surface high pressure will move across the region tonight, leading to an effective radiational cooling environment with light winds and a mostly clear sky. We reduced forecast lows into the upper 30s F over more of southwestern and parts of central ND with this update, though did not lower them enough to introduce frost to the forecast since light return- flow and related weak low-level warm air advection may develop before sunrise as the surface high shifts southeast of the local area. Nonetheless, there remains a low chance of frost in low- lying areas tonight.

Otherwise, we will allow the Red Flag Warning in central ND and the James River Valley to continue until closer to its scheduled expiration, as some observations are still meeting criteria as of this writing.

UPDATE Issued at 541 PM CDT Tue May 12 2026

Quick update to cancel the western row of counties from the Wind Advisory, as wind speeds and gusts have decreased to magnitudes comfortably below advisory criteria in that area as the surface pressure gradient and winds aloft relax. We anticipate allowing the rest of the Wind Advisory to expire as scheduled at 7 pm CDT.

DISCUSSION

Issued at 342 PM CDT Tue May 12 2026

There is an upper level low located over the Great Lakes with an upper level ridge over the west. This has placed the Northern Plains in the in northwesterly flow. The surface pressure gradient is in a northwest to southeast orientation thus resulting in windy northwest winds. There are 40 kt winds at 850 mb aloft which have mixed down to the surface resulting in windy conditions across the eastern half of the state. This has led to windy conditions and dry conditions this afternoon (see the fire weather discussion for more information.) Temperatures this afternoon have warmed into the 70s. Surface high pressure is forecast to move into the region tonight bringing in calm winds. Surface high pressure could bring cooler overnight lows across the region. There is a low chance of frost as lows could drop down into the mid 30s, but this is less likely.

Tomorrow, another upper level low is forecast to dig across the Pacific Northwest. This will lead to surface low pressure over eastern Montana and surface high pressure out over Minnesota. Thus, leading to a tight north south orientated pressure gradient producing windy southeasterly winds. Winds are forecast to be around 20 to 30 mph by the afternoon into the overnight hours. High temperatures tomorrow are forecast to warm in to the upper 70s to upper 80s out west. Dry and windy conditions will lead to more critical fire weather out west.

The aforementioned upper low over the Pacific northwest will deepen east of the Northern Rockies moving out over the Northern Plains Thursday into Friday. There is a low chance for thunderstorms across the eastern half of the state, but the majority of western and central North Dakota looks to be in the dry slot of the upper low. This upper level low is forecast to bring high winds across much of the northern half of the state Thursday and across much of the state Friday. A 60 to 65 kt 700 mb jet streak is forecast to line up across northern North Dakota Thursday afternoon into early Friday supporting high winds. Dry conditions will continue, and with high winds will lead to critical fire weather concerns until the weekend. Temperatures will remain in the 70s and 80s until the weekend.

Surface high pressure is forecast to move across the region Friday night, thus leading to clearing skies and a colder airmass. This could bring back chances for frost across the north for Saturday morning. A subtle ridge is forecast to move off to our east resulting in southwesterly flow Saturday into Sunday. A trough will move through the region bringing in a chance for some rain this weekend, which will bring a subtle reprieve from the dry and windy conditions. The pattern remains to look active in the extended.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 941 PM CDT Tue May 12 2026

VFR conditions will prevail across western and central ND for the duration of the 00z TAF cycle. Light winds will occur overnight as surface high pressure crosses the region. Winds will turn southeast on Wednesday and will increase in the afternoon, especially in western ND. We expect southeast winds gusting from 25 to 35 kt at KXWA and KDIK beginning Wednesday afternoon. This will be the beginning of a long-duration strong wind event that will impact all of western and central ND beginning Wednesday night, and peaking in intensity Thursday and Friday.

FIRE WEATHER

Issued at 941 PM CDT Tue May 12 2026

Southeast winds Wednesday are forecast to be around 20 to 30 mph by the afternoon out west, increasing across the central and James River Valley Wednesday night. Minimum relative humidity is forecast to drop down to around 15 percent out west. Thus, the west and portions of the south central will see another round of critical fire weather conditions Wednesday. Overnight recoveries are forecast to be poor Wednesday night, helping further the critical fire weather conditions.

Critical fire weather conditions will return again Thursday and Friday across the whole region. Another dry system will move through the region Thursday and Friday bringing in high winds across the state. There is also a low chance for thunderstorms Thursday afternoon. Strong westerly winds could approach 40 mph sustained with gusts up 60 mph possible. The minimum relative humidity is forecast to drop down around 15 to 25 percent. Any fires that ignite will spread rapidly and become difficult to control or suppress.

Rain chances return to the region Saturday night into Sunday bringing in some temporary relief.

BIS WATCHES/WARNINGS/ADVISORIES

Red Flag Warning from 11 AM CDT /10 AM MDT/ to 10 PM CDT /9 PM MDT/ Wednesday for NDZ001-002-009-010-017-018-031>033-040>045.