textproduct: Bismarck

KEY MESSAGES

- Low to medium shower/thunderstorm chances return Friday morning and will continue through the weekend and into early next week.

- Isolated severe thunderstorms are possible across much of North Dakota Friday and Saturday.

- Near to slightly above average temperatures to continue through early next week.

UPDATE

Issued at 1242 AM CDT Fri Aug 28 2026

Continue to monitor the progression of thunderstorms upstream in Montana. Overall storms are fairly unorganized, with lightning currently the main threat. As this activity moves eastward toward ND, MUCAPE and shear will increase in the west. However, weak lift combined with a weakening low level jet make the chances for stronger thunderstorms uncertain for early Friday morning. There still could be some isolated to scattered shower and thunderstorm activity if the activity in MT can hold together. For now left the forecast as is and will continue to monitor.

UPDATE Issued at 930 PM CDT Thu Aug 27 2026

Quiet weather continues across western and central North Dakota at the time of this mid to late evening update. Upstream in Montana, showers and some scattered thunderstorms continue to develop along a weak warm front. These showers and storms have so far struggled to survive moving off this front and toward our forecast area, but overall chances for both will gradually increase tonight through Friday morning from west to east as this warm front is lifted across northern Plains by low center in southern Canada. With this update, have blended the latest short-term guidance into the forecast, which captures somewhat higher coverage across western and north central North Dakota Friday morning than previously advertised.

UPDATE Issued at 625 PM CDT Thu Aug 27 2026

With quiet weather found across all of western and central North Dakota at the time of this early evening update, no major adjustments to the forecast were performed.

DISCUSSION

Issued at 225 PM CDT Thu Aug 27 2026

Current surface analysis places high pressure in the eastern two-thirds of the state. There also sits a low pressure in central Montana. Aloft a shortwave ridge axis is centered over Montana and moving eastward. Over Washington State a trough and low pressure is digging into the CONUS. Tonight the aforementioned ridge axis will slide into western North Dakota, switching the flow to our active southwest pattern. Isolated showers and thunderstorms are possible tonight across the west and north.

Friday and Saturday under the active southwest flow pattern, severe weather is once again possible. Friday the surface low will move into southern South Dakota along a stationary front that stretches into Canada. With ample surface heating into the upper 80s and dew points in the mid 60s, models predict plenty of MUCAPE in western and central North Dakota, about 1000 to 2000 J/kg. Shear looks to be plenty around 40kts. The marginal level 1 risk is across most of western and central North Dakota. If severe storms organize ping pong size hail could occur and 60mph winds. Saturday the exact same area is under the gun with the marginal stretching across the same area. Global models agree that there will be significantly less MUCAPE, around 1000 J/kg or less, and 40 to 50 kts of shear. So the risk on Saturday is much lower.

There will be chances for storms all weekend as that active southwest flow continues. Sunday the low pressure from Washington slides into eastern Montana, creating strong diffluent flow across the state. This could cause severe storms, but SPC does not have a day 4 highlight yet, and models do not agree on the CAPE profile. Some have plenty of CAPE, others don't. For the rest of the forecast period mainly the southwest flow will stick around, leading to near daily chances for showers and thunderstorms. Temperatures will be near normal in the 80s.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1242 AM CDT Fri Aug 28 2026

Overall VFR conditions expected through the forecast period. There are two round of showers and thunderstorms possible through the forecast period. The first being early Friday into early Friday afternoon from west to east. Added in PROB30 groups for most sites to account for this. The second being Friday evening which only had enough confidence for PROB30 groups in western and some central sites. Any thunderstorm could bring brief MVFR conditions. An isolated severe storm is also possible Friday through Friday evening. Otherwise look for a steady southerly wind from 10 to 20 knots with a few higher gusts for most sites through Friday, diminishing Friday evening.

BIS WATCHES/WARNINGS/ADVISORIES

None.