textproduct: Bismarck

KEY MESSAGES

- Critical fire weather conditions today across western through most of central ND, including the James River Valley.

- Areas of frost early this morning over much of the James River Valley.

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

UPDATE

Issued at 636 AM CDT Mon May 11 2026

The forecast remains on track.

DISCUSSION

Issued at 502 AM CDT Mon May 11 2026

The forecast challenge for the week remains mostly dry and frequently windy conditions. The overall biggest impacts will be in regard to fire weather. Those are primarily discussed in the Fire Weather section below.

Currently, surface high pressure sits over Minnesota and the western Great Lakes Region, while a surface low is along the southern Alberta/Saskatchewan border. This low will gradually slide across the International border through the day today. A tightening pressure gradient will help produce gusty southerly winds, especially east of Highway 83 this morning. These winds are currently forecast from 25 to 35 mph with gusts up to 45 mph. As the low slides eastward, associated cold frontal boundary will cause winds to switch to a northwesterly component from west to east across the state this afternoon and evening. There remains the potential for isolated showers and thunderstorms late this afternoon and early evening, especially for northern North Dakota. With inverted V type soundings, any showers and thunderstorms could produce further enhanced and erratic wind gusts.

With the exception of the far northwest, the strongest pressure rises and CAA remain favored for after sunset. In the far northwest, this could result in very windy conditions this afternoon similar to those east of Highway 83 in the morning and early afternoon. However, this unfavorable timing may help limit peak winds overall. Still, there remains the possibility that winds are somewhat underforecast for at least a few hours overnight.

For Tuesday, a strong LLJ is progged to remain in place during the morning over the eastern half of the state before gradually moving off further to the east. In addition, surface high pressure will begin to nudge its way in resulting in a loosening pressure gradient. Nevertheless, with sunny skies, it should be a good mixing day. Therefore, do expect there will be windy conditions yet again, especially in the eastern half of the state. Still, it remains possible that the NBM 5.0 could be a little overdone, especially in regard to sustained winds. Either way, winds should rapidly become light and variable with the loss of diurnal heating in the evening.

The next surface low will then approach from the lee of the northern Rockies starting Wednesday, and pass across southern Canada or North Dakota to finish out the workweek. This will produce another round of windy conditions, mostly in the west on Wednesday, then statewide Thursday and possibly Friday depending on the speed and track of this low. Low precipitation chances begin to return towards the end of the workweek with 20 to 40 percent shower and possibly thunderstorm chances statewide Saturday afternoon through Sunday.

Lows should remain above freezing (40s and sometimes 50s) through the remainder of the week. Highs today are expected to range from the upper 60s in northeastern North Dakota to the mid 80s west. Following the aforementioned cold frontal boundary, highs Tuesday will be from the mid 60s to mid 70s. A warming trend is then progged Wednesday and Thursday with highs Thursday mostly in the 80s. A slight cooling trend is then favored this weekend.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 636 AM CDT Mon May 11 2026

Southerly winds will rapidly increase this morning, especially in the eastern half of North Dakota. However, until then there are likely pockets of LLWS, mainly in central North Dakota, where winds remain light and with more of a southeasterly component. Any LLWS will diminish as winds pick up over the next couple hours. Otherwise, a cold frontal boundary will pass through from west to east this afternoon and evening resulting in a shift to northwesterly winds. There may be a bit of a lull in wind speed ahead of the frontal passage. However, very windy conditions are expected behind the front, especially in northwestern North Dakota this afternoon and evening. Isolated showers, along with a few thunderstorms, are possible mainly during the afternoon and early evening hours. Confidence in where they develop and at what particular time remains low. Enhanced and erratic winds are possible with any showers or thunderstorms that develop. Other than during any potential precipitation, VFR ceilings and visibility are expected through the period.

FIRE WEATHER

Issued at 502 AM CDT Mon May 11 2026

Surface low moving from west to east across south central Canada will tighten the pressure gradient and produce increasingly strong southerly winds this morning. These winds will be strongest for locations east of Highway 83 that are also along and south of Highway 2. In addition to strong southerly winds, marginally higher dewpoints in the 30s to low 40s will advect into much of the state this morning and early afternoon. An associated cold frontal boundary will then pass from west to east across the state this afternoon and evening, which will quickly lessen dewpoints yet again. When all is said and done, there will be a sharp gradient in minimum relative humidity this afternoon with much drier conditions west versus east. In addition to relatively brief increased dewpoints, there will likely be somewhat of a lull in winds ahead of the frontal boundary, followed by a strengthening behind it. This will produce gusty northwesterly winds across western North Dakota in the afternoon, especially in the far northwest. The strongest winds during both time periods and geographical locations will be from around 25 to 35 mph with gusts up to 45 mph.

Strong winds combined with these low humidity values will result in critical fire weather conditions today for most of western through central North Dakota, including the James River Valley. Of note, one additional concern for this afternoon and early evening is the potential for isolated showers and a few thunderstorms. While any precipitation is not expected to be widespread, inverted V soundings suggest enhanced erratic winds are possible with any shower or thunderstorm activity that does occur.

Winds will become light across most of the western half of the state tonight, though remain breezy to windy in the eastern half. That said, higher pressure rises and strong CAA could maintain a bit stronger winds than currently forecast. At least for a few more hours. Another windy day is then expected Tuesday with strong northwesterly winds, especially east of Highway 83 where winds may once again range from around 25 to 35 mph with gusts up to 45 mph. Locations further west should remain moderately lighter, albeit still breezy at around 15 to 20 mph. The one thing that does lower confidence in winds reaching their maximum potential on Tuesday is a loosening pressure gradient, and a strong LLJ that may move off to the east by the afternoon. Still, a good mixing day favors windy conditions that when combined with continued dry conditions, will likely be enough to result in critical fire weather conditions once again for much of central North Dakota, and possibly western North Dakota as well.

Beyond Tuesday, low minimum relative humidity values will occur daily through the remainder of the workweek. Meanwhile, breezy to windy conditions are expected again Wednesday afternoon, especially in the west, while windy conditions are favored across most of the state Thursday. Things become more uncertain towards the weekend, though precipitation chances do increase with widespread 20 to 40 percent chances currently in the forecast Saturday night through Sunday.

BIS WATCHES/WARNINGS/ADVISORIES

Red Flag Warning from 11 AM CDT /10 AM MDT/ this morning to 10 PM CDT /9 PM MDT/ this evening for NDZ001>004-009>013-017>023- 025-031>037-040>048-050-051. Frost Advisory until 9 AM CDT this morning for NDZ025-037-048- 051.