textproduct: Bismarck

KEY MESSAGES

- Near to below freezing temperatures return to the northwest tonight. The highest probabilities for low temperatures below freezing temperatures are Monday and Tuesday nights.

- High chances (60 to 80 percent) for showers and a few thunderstorms Saturday night through Monday. The highest chances are during the day Sunday. There is a chance of Isolated severe weather in the southern James River Valley.

UPDATE

Issued at 920 PM CDT Fri May 15 2026

Winds have greatly diminish over the past hour or so, with many locations across western and central North Dakota having dropped to around 15 to 20 MPH, gusting up to 30 MPH. A few sites remain a bit stronger, though these sites will also follow the weakening trend through the remainder of the evening and overnight. Thus, Wind Advisory across western and central North Dakota has been allowed to expire on time. With the decreasing winds, and with the increasing relative humidities across the forecast area, fire weather conditions have improved greatly. The Red Flag Warning has also been allowed to expire. Currently, isolated weak radar returns linger over portions of the northwest and north central, mainly along a cold front dropping in out of Canada. These, too, have greatly diminished this evening, with little to no additional rainfall or thunder expected. Otherwise, patchy dust will remain possible through the evening as winds continue to relax.

UPDATE Issued at 700 PM CDT Fri May 15 2026

Strong winds persist across much of western and central North Dakota at the time of this early evening update. While we have likely already started to settle down from peak mixing, observations across portions of the north and central still remain well above advisory criteria, with speeds up to around 35 MPH and gusts up to 55 MPH, while the southwest is marginally at criteria. Notably, we have had a few isolated observations of gusts as high as 60 MPH where showers and a thunderstorm or two has developed. Occasional visibility reductions have also been observed in the north central, though a tour of NDDOT and NDAWN cameras indicate that these have been fairly brief in duration and limited in spatial extent, especially compared to yesterday. With this update have opted to extend portions of Wind Advisory across west and north another few hours. Winds are expected to rapidly diminish over the next few hours as the NBL is reestablished. Showers and isolated storms may also persist into the early evening, especially along a cold front slowly moving out of the southern Canadian Prairies, though these too should rapidly diminish with the loss of peak heating. Otherwise, with this update, have tweaked sky cover in accordance with satellite trends.

DISCUSSION

Issued at 251 PM CDT Fri May 15 2026

An upper level low continues to spin across Manitoba. Windy conditions continue across the state this afternoon as strong winds aloft mix down to the surface. Winds are forecast to diminish this evening across the area. The strongest winds are across the northern half of the state. These stronger winds have kicked up dust across southern Manitoba and portions of Northern North Dakota. There have been some slight visibility reductions observed in the Rugby Rolla area. Windy and dry conditions have lead to critical fire weather conditions across the state, (read the fire weather discussion for more information). High temperatures this afternoon have warmed into the 70s to lower 80s across the state. Surface high pressure is forecast to move across southern Saskatchewan tonight helping reduce winds. Surface high pressure will also cause temperatures to drop down into the mid 30s to the mid 40s tonight which could lead to areas of frost across the northwest Therefore, a Frost Advisory has been issued for portions of the northwest.

Tomorrow, temperatures will cool a few degrees in the north while the the south will remain in the mid 70s. The warmer temperatures across the south are from a subtle upper level ridge that will increase heights and traverse across the region tomorrow. Saturday a broad trough is forecast to dig across Western CONUS. This will place the Northern Plains in southwesterly flow aloft. A shortwave trough is forecast to move through the region Saturday night into Sunday. There is a chance for some stronger storms clipping the James River Valley early Sunday. Isolated severe storms should not be ruled out Sunday across the southern James River Valley. This upper level system will bring widespread rain across the state with the southeast seeing the highest amounts. A secondary trough is forecast to move through the region bring in some more precipitation through Tuesday morning. There is a high chance of widespread 0.25 of an inch of rain across much of the state. We will see how this play out as the high resolution model data starts to come in.

This wetter pattern will also bring cooler temperatures to North Dakota. There maybe even a chance of snow Monday night. Highs will drop down into the upper 40s to 50s Sunday through Tuesday with even the possibility of freezing conditions Tuesday and Wednesday mornings. Temperatures could rebound by the middle of the week as another subtle ridge moves across the region. The extended ensemble guidance does have a more active pattern by the end of the weekend into early next week.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 920 PM CDT Fri May 15 2026

VFR ceilings and visibility are expected at all terminals throughout the 00Z TAF period. Isolated showers and thunderstorms will be possible across the north through the evening, though confidence at impacts at any given TAF site are low. Have opted to keep a TEMPO -RA at KXWA based off of upstream obs, though these showers may struggle to persist over the next few hours. Periods of blowing dust may briefly impact visibility over portions of the north through the early evening, though these impacts have been limited in both time and area so far. Confidence in visibility impacts at any give terminals is low. Strong west winds at at the start of the TAF period are expected to rapidly diminish through the early to mid evening, becoming light overnight through Saturday morning. Winds are expected to strengthen and reorganize out of the southeast through the day Saturday.

BIS WATCHES/WARNINGS/ADVISORIES

Frost Advisory from 1 AM to 9 AM CDT Saturday for NDZ001>003- 009-010-055.