Bismarck forecast discussion

Update

Issued at 654 PM CDT Thu Oct 22 2026

The forecast remains in good shape. Current conditions and trends were blended in for this update.

Discussion

Issued at 200 PM CDT Thu Oct 22 2026

Broad upper level ridging continues to promote warm and dry weather over the northern Plains this afternoon, with mostly clear to partly cloudy skies and light (around 10-15 MPH) south to southeast winds expected through the afternoon. With the ensemble consistently underperforming with high temperatures this week we have nudged temperatures a 1 to 3 degrees higher this afternoon utilizing a 1:1 blend of NBM:NBM90, resulting in forecast highs broadly in the 70s this afternoon. Have opted to leave forecast low temperatures in the mid 40s to mid 50s as increasing cloud cover this evening and overnight will prevent the low temperature crash we've seen earlier this week. A few climate sites are set to break their daily record high min, including BIS, DIK, JMS, and XWA.

Conditions on Friday will then be characterized by an upper level trough lifting across the Rockies and eventually closing off over the southern Canadian Prairies through the early weekend. With flow over North Dakota turning southerly as the trough approaches, Friday is expected to the warmest day of the week with highs from the lower 70s to lower 80s. During the daytime lee cyclogenesis is expected to spit out a center of low pressure over southern Montana, which is then to slowly be lifted into the forecast area through the evening and overnight into Saturday. The passage of this low and its attendant cold front is expected to promote chances (20 to 50 percent) for rain over portions of the west. With the warmer weather we have been monitoring the potential for isolated thunderstorms accompanying these showers early Friday evening, but with surface winds turning southwesterly and advecting drier air across the west Friday afternoon the chances remain very low (less than 10 percent).

The main forecast challenge for Friday and Saturday will be the potential for strong winds across much of western and central North Dakota. Increasing low level lapse rates and an initial push of CAA will allow gusty south to southwest winds (sustained 20 to 25 MPH gusting up to 35 MPH) to mix down from a develop 850mb over portions of the west. Later Friday night through Saturday morning, stronger CAA and greater pressure rises is then expected to promote strong northwesterly winds sustained around 25 to 30 MPH and gusting as high as 45 MPH across the area. Have continued Portions of the forecast area are expected to approach Wind Advisory criteria during this period, though confidence is too low for headlines at this time.

Otherwise for Saturday and beyond, cooler conditions with highs broadly in the 40s and 50s are expected behind the cold front. Looking ahead, there's decent ensemble agreement on swinging another closed low out of the south across western and central North Dakota early Monday through Tuesday, and again Wednesday through early Thursday. The NBM advertises near daily low to medium chances for PoPs through this period, with enough variation in storm track between ensemble members to limit confidence at this time.

Aviation /00Z Tafs Through 00Z Saturday/

Issued at 654 PM CDT Thu Oct 22 2026

VFR conditions are expected through the forecast period. Some very light rain showers or sprinkles could move across parts of the state from south to north on Friday, with no impacts to aviation. Winds will remain southerly to easterly around 5-10 kts through tonight, then become more uniformly south-southeast on Friday and increase to 15-20 kts, with afternoon gusts to 25-30 kts. Low level wind shear could impact parts of south central North Dakota later this evening and tonight, including at KBIS and KJMS.

Bis Watches/Warnings/Advisories

None.

UPDATE...Hollan DISCUSSION...Adam AVIATION...Hollan