textproduct: Bismarck

KEY MESSAGES

- Critical fire weather conditions expected again today across central North Dakota, including the James River Valley.

- Strong winds expected across central and eastern North Dakota this morning through the afternoon.

- Windy conditions and low humidity values through the rest of the upcoming week may lead to daily critical fire weather conditions.

UPDATE

Issued at 956 AM CDT Tue May 12 2026

Winds continue to pick across the central half of the state and the eastern half of the state. Clear skies and warming temperatures will allow stronger winds to mix down to the surface this afternoon. No major updates are needed at this time as the forecast remains on track.

UPDATE Issued at 629 AM CDT Tue May 12 2026

The forecast remains on track.

DISCUSSION

Issued at 456 AM CDT Tue May 12 2026

Windy and mostly dry conditions remain the story through the remainder of the week. For today, surface low pressure currently centered over Minnesota will gradually slide eastward into the Great Lakes Region. Simultaneously, surface high pressure currently over Montana will gradually nudge into the Dakotas. This will result in a tighter pressure gradient over the eastern half of the state today that should gradually loosen from west to east. However, a trailing strong LLJ remains over much of the state. These winds should mix down to the surface fairly easily this morning resulting in very windy conditions this morning and afternoon, especially for locations east of Hwy 83. Depending on how quickly the gradient loosens and strong lower level winds move off to the east will impact just how windy and for how persistent winds will be today. Either way, winds will rapidly diminish and become light and variable this evening. All in all, the ongoing Wind Advisory looks good at this time.

Current NBM lows for tonight mostly range from 40 to 45 degrees. However, with a good radiational cooling set-up, wouldn't be surprised if temperatures don't wind up cooler than forecast, especially in our traditionally colder spots. Depending on how cold things get, frost development isn't entirely out of the question.

Come Wednesday, high pressure over the state will shift eastward as the next surface low passes from west to east across southern Canada. This will tighten the pressure gradient in western ND on Wednesday, which is favored to produce windy conditions mainly west of Highway 83 during the day that will then expand eastward through the overnight hours. Very windy conditions are then favored Thursday, especially in the northwest as an enhanced EFI signal is starting to appear. An axis of increased dewpoints looks to accompany the associated surface trough as it moves through Wednesday night/Thursday. This, along with a mid- level shortwave could produce isolated to scattered showers and a few thunderstorms, although widespread wetting rains look unlikely.

Even windier conditions are then possible Friday, especially north of I94 where a further enhanced EFI signal shows higher confidence in a stronger wind event. That said, current run shows a shift of tails between 0 and 1 for most of the enhanced signal. This doesn't particularly favor an anomalous event, but doesn't rule one out either. Beyond Friday, winds remain breezy to windy, though more widespread precipitation chances return. Especially Saturday night where 45 to 55 percent precipitation chances are present across the entire state.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 629 AM CDT Tue May 12 2026

VFR ceilings and visibility are generally expected through the period. However, another windy day is on tap today, especially east of Highway 83. This may result in patchy blowing dust that could at least temporarily reduce visibility and possibly result in the ASOS/AWOS network producing brief false ceilings. Should patchy blowing dust develop, the terminal most likely impacted would be KJMS, though confidence in this occurring at the terminal is low. Winds will rapidly diminish this evening, becoming light and variable.

FIRE WEATHER

Issued at 456 AM CDT Tue May 12 2026

Winds are expected to ramp up again this morning, especially for the eastern half of the state. As surface low pressure and trailing low-level jet moves off to the east, winds should gradually diminish from west to east this afternoon. However, minimum relative humidity values are still expected to range from 15 to 25 percent. It seems like winds should diminish quick enough in western North Dakota to prevent critical fire weather conditions from developing, but still advertising near critical fire weather conditions should winds persist a little longer. Based on these factors, the current Red Flag Warning looks good as-is.

Encroaching high pressure will result in winds quickly becoming light and variable across the entire state this evening as any residual mixing is lost. For Wednesday, the next surface low pressure will begin passing from west to east across southern Canada. This will tighten the pressure gradient resulting in another windy day in western North Dakota on Wednesday while very dry conditions persist. As the low continues propagating eastward, these windy conditions will further expand eastward Wednesday night through Thursday, and then likely persisting through Friday. Critical fire weather conditions are possible each day. Isolated to scattered showers, and possibly a few thunderstorms, may pass through mainly Thursday through Thursday evening. However, widespread wetting rains seems unlikely.

Towards this weekend, cooler temperatures resulting in at least somewhat higher RH values, as well as more widespread precipitation chances, begin to enter the picture. The highest probability for wetting rains are currently Saturday night through Sunday. During this timeframe, most of western through central North Dakota has a 20 to 40 percent chance of seeing a wetting rain.

BIS WATCHES/WARNINGS/ADVISORIES

Red Flag Warning until 9 PM CDT this evening for NDZ003>005- 011>013-021>023-025-035>037-046>048-050-051. Wind Advisory until 7 PM CDT this evening for NDZ005-012-013- 022-023-025-035>037-046>048-050-051.