textproduct: Bismarck

KEY MESSAGES

- Chances for showers and thunderstorms increase into this weekend, with strong to severe storms possible.

- Temperatures remain at or slightly below normal through Friday, then will be closer to normal this weekend.

- Temperatures trend much warmer next week, with low to medium chances for daily showers and thunderstorms.

DISCUSSION

Issued at 235 PM CDT Thu Jun 25 2026

Currently a very slight ridge is over central North Dakota, upstream there is a shortwave moving east through Montana. On the positive vorticity side of the shortwave, an area of showers and thunderstorms extends down through Wyoming. At the surface a high pressure sits just north of the state in Canada. Diurnally driven cumulus clouds have formed and are moving clockwise around the high across the Dakotas. In the Pacific Northwest is big low is starting to push down into Washington state.

Tonight this shortwave will push east across eastern Montana, leading to rain showers overnight and through the morning across the southwest and central. As that big low digs into Washington, strong southwest flow will setup across the Rockies and Northern Plains by Friday morning. A surface low will then form Friday afternoon as air stretches and spins off the northern Rockies. This low will create breezy winds Friday in the northwest and central as the pressure gradient tightens. Saturday will also be very breezy in the central and east from the low pressure being in the state. The surface flow, and the low level jet will carry warmer moist air up from the Gulf Friday through the weekend. This will also lead to temperatures leaning more towards normal.

For the severe storms, there is potential Friday through Sunday as the strong southwest flow continues over the western CONUS. Friday there is a level 1 of 5 risk in the far southwest, near the surface low in northeast Wyoming. There is only around 500 J/kg of CAPE, but about 50 kts of shear. So there could be an isolated storm that produces one inch hail. Saturday is the main show as the surface low moves into southwest North Dakota. Most of western and central North Dakota is in a level 2 of 5 risk. All hazards are possible as there will be 1500 to 3000 J/kg of CAPE and 35 to 50kts of shear (depending on the model). The low pressure center in the state also brings in plenty of low level helicity that could produce a tornado. The limiting factor in the large hail and tornado threat is storm mode. Right away the shear vector is perpendicular to the north south front/surface trough located in western ND, but into the evening it becomes more parallel. The CAMs reflect this too, showing one or two discrete cells then a MCS forming in western North Dakota. Another possible limiting factor is there looks to be showers and maybe thunderstorms Friday night, does the atmosphere recover by the afternoon? Timing of the severe storms looks in be in the afternoon through the evening. Sunday looks to be a very similar setup just a few counties to the east.

Looking at next week, an upper level high develops over the Southeast CONUS, leading to the southwest flow continuing up here. Near daily chances for showers and thunderstorms are forecast. Some could be stronger. A big story for next week is the big warmup in temperatures as the low level jet pivots southwest, bringing the even warmer desert air north. Expect widespread highs into the mid 90s by The Fourth of July.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1234 PM CDT Thu Jun 25 2026

VFR with diurnal cumulus clouds this afternoon. Overnight rain showers will move from the southwest to the northeast. PROB30s were used for terminals on the edge of those showers. Some MVFR CIGs may be found with these Friday morning. Winds will increase from the southeast Friday.

BIS WATCHES/WARNINGS/ADVISORIES

None.