textproduct: Bismarck

KEY MESSAGES

- Frigid low temperatures tonight, thus Freeze Warnings and Frost Advisories are in effect through early Sunday morning.

- Daily windy conditions and low humidity values through the upcoming work week may lead to daily critical fire weather conditions for parts of the area.

UPDATE

Issued at 951 PM CDT Sat May 9 2026

The forecast for tonight remains on track. We continue with a very dry northwest flow. Lows tonight will again dip down into the 20s.

UPDATE Issued at 852 PM CDT Sat May 9 2026

Quick update to expire Red Flag warning.

UPDATE Issued at 717 PM CDT Sat May 9 2026

Elevated fire weather concerns remain northwest where the Red Flag warning is in effect. No changes to headlines at this time.

Otherwise, a mostly clear sky as sfc high pressure builds south into the region this evening.

DISCUSSION

Issued at 156 PM CDT Sat May 9 2026

Current surface analysis places low over southeast Ontario with high settling through Saskatchewan into eastern Montana. Upper level analysis places low over northern Ontario, with ridge over the western CONUS. Slightly cyclonic north-northwesterly flow remains over our area resulting in some cloud development over our eastern areas. Otherwise, dry conditions continue with temperatures about 5 to 10 degrees below average.

For the rest of today into tonight, dry conditions remain resulting in humidity values dipping into the mid teens to mid 20s over most of the area, with the overlap of the higher winds with the lowest humidity values remaining over parts of northwest/north central North Dakota where a Red Flag Warning remains in place. See fire weather discussion below for more details. As we get into tonight winds will diminish as aforementioned surface high pushes over. With the dry atmosphere in places, mainly clear skies, and light winds, expect temperatures to drop below NBM guidance. Most locations should dip into the mid 20s to lower 30s, but some clouds loitering over the southwest may keep that area a bit warmer. Therefore, have issued a Freeze Warning for all areas except parts of the southwest where a Frost Advisory is in place.

On Sunday, high pressure meanders to the east keeping winds generally light over the area. Temperatures warm a bit behind the high as upper ridge nudges into the northern plains. Therefore, highs will push above average over the west, but still may stay a bit on the cooler side over our eastern locations. Surface trough deepens to the lee of the Canadian/Northern Rockies overnight as surface high pushes east. This will allow southerly winds to start increasing overnight.

Monday will see aforementioned lee side trough close off and move easterly through the southern prairie provinces, as a potent short wave trough busts through the ridge into the northern plains. Southerly winds will be on the increase bringing a very warm day to parts of the area, with highs in the 80s over our west. Surface trough followed by a cold front slide through with the passing low, with winds shifting west then northwest and remaining gusty. This will combine with a dry lower atmosphere to cause another day of fire weather problems, especially over the west (again see fire discussion below). To the east, humidity may be a bit higher depending on timing of the aforementioned system. Guidance is suggesting an area of instability developing. Although this may only be CAPE values of 200-500 J/kg, quite high forecast deep layer shear (50-60 kts effective bulk) is noted, thus the potential for a damaging wind threat. Therefore have painted in low thunderstorm chances in the afternoon/evening hours over parts of our east.

On Tuesday highlight will be the potential for higher winds over eastern portions of our area in the wake of the aforementioned cold front. With that said, the airmass behind the cold front will actually be quite mild, so expect highs to push into the upper 60s to mid 70s.

Warm and dry conditions continue through at least mid-week. Towards the end of the week a few disturbances might move through, but guidance remains lean with producing precipitation with this. Temperatures remain mild, with even the NBM 25th percentile of temperature spreads remain notably above average through Saturday.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 717 PM CDT Sat May 9 2026

VFR conditions will prevail through the forecast period.

BIS WATCHES/WARNINGS/ADVISORIES

Freeze Warning from 1 AM CDT /midnight MDT/ to 9 AM CDT /8 AM MDT/ Sunday for NDZ001>005-009-010-012-013-017>020-022-023-025- 033-035>037-046>048-050-051-055>060. Frost Advisory from 1 AM CDT /midnight MDT/ to 9 AM CDT /8 AM MDT/ Sunday for NDZ031-032-040>044-061-062.