textproduct: Bismarck

KEY MESSAGES

- Cooler temperatures Saturday, but still near-critical fire weather conditions across most of western and central North Dakota.

- Near to sub-freezing low temperatures are possible across northern North Dakota tonight into Saturday morning and most of the state Saturday night into Sunday morning.

- Warm and windy weather next week could lead to daily critical fire weather conditions, especially in western North Dakota.

UPDATE

Issued at 100 AM CDT Sat May 9 2026

05Z surface analysis shows the southward advancing cold front along the ND/SD border. Trailing this front is an area of light rain showers that is being supported by mid level frontogenesis. The risk for lightning and higher-end wind gusts appears to have ended. The band of light rain will continue to sag southward overnight, exiting the state by sunrise Saturday morning.

Current headlines remain on track. The Red Flag Warning was allowed to expire on time at 10 PM CDT, and a Frost Advisory remains in effect across the northern half of the state. Already seeing temperatures falling into the mid 30s along the Canadian border, with weak but persistent cold air advection forecast to continue through the night under a clear sky that could be temporarily interrupted by a batch of mid level clouds for an hour or two.

UPDATE Issued at 726 PM CDT Fri May 8 2026

An embedded mid level wave and associated sfc trough continues to result in an area of showers and isold thunderstorms moving south-southeast across the Northern Plains this evening. Modifications to the forecast were overall minor as most weather elements were on track.

DISCUSSION

Issued at 238 PM CDT Fri May 8 2026

Near critical to critical fire weather conditions will remain this afternoon and evening across much of North Dakota as windy northwest winds combined with low RH values remains. A Red Flag Warning remains in effect for these conditions through this evening, see the Fire Weather Discussion below for more details. Cold front will push south across the state this evening bringing some shower and thunderstorm activity, currently being noted in central Canada. Instability overall looks limited, although given the dry air in place leading to inverted-v soundings, some strong wind gusts will be possible through this evening with any shower or thunderstorm. This front could also bring some slightly increased northerly winds during passage this evening. Gusty winds and shower activity diminishes tonight, with some clearing skies in the north. Colder air behind the mentioned cold front will bring lows in the 30s tonight. Given today has been declared the start of the growing season, this means frost is likely. Thus issued a Frost Advisory tonight into Saturday morning for areas mainly along and north of Highway 200. Areas south of this could see isolated frost temperatures yet not widespread enough for a highlight.

Mainly dry conditions and seasonable to slightly below normal temperatures are then expected for this weekend. Surface high will gradually push into the state Saturday. Before doing so increased northwest winds will be found across much of the area, along with slightly cooler temperatures. Dry conditions will lead to low RH values in the 20s to mid 30s Saturday afternoon. Currently the more elevated winds tomorrow do not align up with the lower RH values, although slightly dryer air or slightly more wind could increase the fire weather danger. Thus will continue near critical fire weather conditions wording for Saturday. Surface high settles in Saturday night into Sunday morning bringing clearing skies and light winds. This will also help cool temperatures slightly with lows forecast in the upper 20s to the 30s. More frost/freeze products will likely be needed as a result, although determining where each is needed still remains uncertain. Overall those with sensitive vegetation should keep a close eye on the forecast Saturday night. Slightly warmer temperatures, light winds, and continued dry conditions will then be found for Sunday. Afternoon RH values will remain low, although light winds will limit any fire weather danger threat. A shift to southerly winds Sunday night will keep mild overnight lows, limiting frost potential except in some western portions.

Near critical to critical fire weather conditions look to return near daily early to mid next week. Surface low combined with a clipper system will impact the state on Monday. Ahead of this low will be a windy and warm southerly wind, becoming a windy northwest wind sometime later Monday with passage of a cold front. Depending on the track of the mentioned low this could bring critical fire weather conditions along with chances for showers and thunderstorms. Some increased instability could bring a slight increase to more organized storms Monday, although with dry air in place the main threat would be strong winds with these potential stronger storms. A post frontal day is then forecast for Tuesday. Even with slightly cooler air temperatures are still forecast to be above normal. Strong northwest winds could also be found in the eastern half of the state Tuesday, with the ECMWF EFI values slightly elevated indicating perhaps some advisory level winds. Low RH values combined with these strong winds could again bring near critical to critical fire weather conditions. The uncertainty with Tuesday being if the lower RH values line up with the strongest winds, which right now they are not quite aligned. This will have to be monitored closely though. Another weak surface low could then repeat this pattern Wednesday and Thursday with warm temperatures and windy southerly flow on Wednesday, becoming a windy yet still warm westerly flow on Thursday. Chances for precipitation with this second low look minimal right now. This dry low could continue the near critical to critical fire weather conditions. With above normal temperatures forecast for much of the week next week, the chances for frost and freeze products are low.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 100 AM CDT Sat May 9 2026

A band of light rain showers with gusty winds across southern North Dakota will continue to push south through the night. VFR conditions are expected through the forecast period. Lighter northerly winds are expected later tonight into Saturday morning, then becoming northwest and increasing to around 15 kts with gusts to 25 kts Saturday afternoon.

FIRE WEATHER

Issued at 100 AM CDT Sat May 9 2026

Near critical fire weather conditions could remain through this weekend as low humidity values in the 20s to lower 30s are found. North northwest winds 10 to 20 mph will be found on Saturday, with the higher winds forecast in the north and east. These will be the areas of greater fire weather concerns, although currently fall shower of critical fire weather criteria. Low humidity values remain on Sunday, although lights winds are also forecast.

After Sunday, a long stretch of enhanced fire weather concerns enters the forecast next week as temperatures are favored to be well above normal. Confidence is increasing that much of western North Dakota will experience critical fire weather conditions on Monday, with gusty southerly winds early in the day shifting to the northwest and becoming strong in the afternoon as humidity falls to near 20 percent. The risk for critical fire weather conditions more or less continues in western North Dakota through the work week, with daily gusty winds and minimum RH around 20 percent. Tuesday looks to be the least windy day in the west, but perhaps the windiest day for the eastern half of the state. A secondary area that shows up repeatedly in NBM guidance for critical fire weather next week is a portion of south central North Dakota bounded by Interstate 94, the James River, South Dakota, and Lake Oahe. Daily details for fire weather beyond the Monday/ Tuesday time frame remain uncertain, but there is undoubtedly increasing potential for a longer duration of high-impact fire weather, at least until fuels start to green up.

BIS WATCHES/WARNINGS/ADVISORIES

Frost Advisory until 9 AM CDT /8 AM MDT/ this morning for NDZ001>005-009-010-012-013-017>020-022-023-025-055>058.