textproduct: Bismarck

KEY MESSAGES

- Highs in the 70s and 80s today, warming into the 80s and low 90s for the weekend.

- Isolated to scattered severe thunderstorms are possible over western North Dakota Saturday night.

- Isolated to scattered over much of western and central North Dakota Sunday evening.

- A more active severe weather pattern looks to continue next week.

DISCUSSION

Issued at 228 AM CDT Fri Jun 5 2026

A broad quasi-zonal flow containing a number of weak impulses is tracking across eastern Montana and North Dakota early this morning. There is enough weak elevated instability and skinny Cape that an occasional showers or thunderstorms will pop up. Models are having a hard time capturing this whack-a-mole convection early this morning. Will do a late re-evaluation of the radar before sending out the main forecast package and may end up going with some broad brush low pops instead of playing catchup every hour. Eventually this weak non-severe convection will push through the west this morning and exit the eastern portion of the CWA by later this afternoon as shortwave ridging moves into the west ahead of a digging upper level trough over the eastern Pacific. Highs today are expected to range from the mid 70s to mid 80s.

We are expecting a quiet night tonight and a hot and increasingly breezy and humid Saturday, especially west. The possible exception late tonight may be convection over eastern Montana that could clip the far northwest early Saturday morning. Daytime highs Saturday are forecast to climb into the upper 80s to mid 90s. During this time the eastern Pacific upper low moves onto the Pacific Northwest shore early Saturday, to eastern Washington State Saturday evening and then into the Southern Canadian Rockies Saturday night. Cyclogenesis will occur in the lee of the northern Rockies with a surface low emerging into the northern High Plains Saturday afternoon, and pushing into the Mondak region Saturday night.

Convection is expected in the late afternoon/evening over eastern Montana within a moderately unstable airmass and increasing vertical shear. As convection propagates farther east and into North Dakota it will approach an increasingly moist and unstable atmosphere, with an increasing strong low level jet, but also one that will be experiencing increasing Cin with the loss of daytime heating. Will message ping pong ball sized hail and 60 mph winds at this time. Could see these hazards increase, but there are some limiting factors in play. Mainly the Cin, which is also a timing factor. The later the convection moves in, the more Cin to overcome. With the strong llj and increasing shear this could definitely happen, but some of the forecast soundings that go out that far, show max instability and min Cin early in the evening, but with Cin then increasing with decreasing instability aloft. Think there's enough time to adjust hazards as needed.

Sunday will bring another day of severe storm potential. Hot and humid conditions are expected with a very unstable airmass developing over central ND. The NAM is currently depicting CAPE value in excess of 5000 J/Kg over central ND at 00Z Monday. A cold front will also be progressing east across the forecast area. There are still a lot of uncertainties. First, there will be strong capping over central ND but as the front impinges upon the very unstable air, will there be enough forcing for ascent to initiate convection. If so, a quickly developing supercell would be possible with the potential for very large hail. Shear is not overly strong ahead of the front, but more perpendicular to it. A tornado would also be possible but high LCL's may limit this potential. If convection does not develop ahead of the front, then just behind the front we see strong bulk shear that is more parallel to it. thus the threat for hail would lessen with an increasing wind threat with upscale growth into a linear convective system. Definitely something we will continue to monitor.

As we head into next week it looks like we may see a break behind this exiting upper low on Monday with cooler and drier overtaking the area. Then we're right back under the gun as we see a broad southwest upper flow develop ahead of another upper low over the Pacific Northwest.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1220 AM CDT Fri Jun 5 2026

VFR conditions are expected through the 06Z TAF period. With that said, can not rule out some patchy morning for or a brief period of MVFR morning ceilings. Way to uncertain though to mention at any one TAF site attim. Generally light and variable flow overnight and through mid morning Friday, then mainly a westerly flow 5-15knots through Friday afternoon before winds drop off and shift southeast aft 01 UTC Saturday.

BIS WATCHES/WARNINGS/ADVISORIES

None.