textproduct: Bismarck

KEY MESSAGES

- Chance of a shower or thunderstorm northwest late tonight into early Tuesday. - Above normal temperatures and another round of scattered to numerous severe thunderstorms Tuesday.

- Temperatures trending cooler after Tuesday, along with near daily chances for showers and thunderstorms through the remainder of the week.

UPDATE

Issued at 952 PM CDT Mon Jun 8 2026

For late evening update main change was to note thunderstorm chances in all precipitation around/after sunrise over the northwest given the expected instability. Otherwise, going forecast is in good shape.

UPDATE Issued at 705 PM CDT Mon Jun 8 2026

A little line of light reflectivity on radar is noted from southwest of Bismarck stretching northeast towards Fessenden. So far only a few drops have been reported, and do not expect much more than that to occur.

DISCUSSION

Issued at 333 PM CDT Mon Jun 8 2026

Currently, southwest flow remains aloft with an area of surface high pressure drifting east across the Dakotas. Westerly winds with a few gusts up to around 25 mph at times, with temperatures in the mid 60s to lower 70s early this afternoon. Some mid level convective clouds drifting northeast across the local area, with some light radar returns also showing up. Nothing reaching the ground with these cloud bases well over 10K Ft AGL.

WAA and southwest flow aloft increases tonight into Tuesday, as a subtle mid level S/WV ridge moves into the area ahead of another potent mid level trough developing into the Northern Intermountain West. A lead S/WV impulse ejecting out of the trough tonight will bring a chance for showers and thunderstorms to mainly northwestern North Dakota. Southerly return flow ramps up later tonight and into the day Tuesday as a sfc trough deepens over eastern MT and increases the pressure gradient. Gusty south-southeasterly winds expected during the day Tuesday, but are expected to remain below wind adv thresholds with latest BUFKIT soundings showing mainly 30- 35 kts within the mixed layer. This flow regime will push a warm front northward into/across the state, with temperatures tomorrow in the low/mid 90s well behind the warm FROPA south and cooler in the upper 70s to mid 80s north. Low level moisture increases as well, with widespread surface dewpoint temperatures well into the 60s again east of the sfc trough.

The warm and moist airmass mentioned above will yield moderate to high instability, with a corridor of MUCAPE in excess of 5K J/kg over central ND, with 0-6km shear increasing in the afternoon ahead of the aforementioned trough developing into the Rockies. Steepening mid level lapse rates as well as the mid level trough approaches. CAMs and ensembles favor convection initiating over western ND in the afternoon as the sfc trough advances east, when and where large hail and damaging winds are expected to be the main hazards. We then expect these storms to increase in strength as they develop east into a more favorable environment of higher low level moisture and also better low level wind shear, with all severe weather hazards possible (very large hail, damaging winds, and a few tornadoes). With time, storms will again (as they did Sunday evening) evolve into linear modes resulting in damaging winds becoming the main threat. SPC has maintained the Slight/Enhanced Risk (2/3 of 5) for much of the area Tuesday aft and evening. With storms developing farther east vs on Sunday, we expect storms to be east of central ND by late evening.

The mid level trough will slow down Tuesday night, then slowly moves east across the Northern Plains Wednesday before closing off to our northeast on Thursday. This will maintain high chance to likely showers and a few thunderstorms Wednesday into parts of Thursday, along with much cooler temperatures (cooling down into the 60s to lower 70s Thu).

Thereafter, we will be in a north-northwest flow aloft maintaining cooler temperatures and near daily chances for showers and isolated thunderstorms through this coming weekend.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 952 PM CDT Mon Jun 8 2026

VFR conditions are expected over most locations through mid-day Tuesday. The only exception may be over northwest North Dakota very late tonight into Tuesday morning where a few showers and light thunderstorms may develop. Visibility restriction should only be limited to MVFR, possibly very brief IFR in a heavier shower. Tuesday afternoon thunderstorms are expected to develop, mainly after 20Z. Severe weather is expected, with large hail, damaging wind gusts, and possibly a few tornadoes. The storms will eventually form a line which will push east during the evening, with conditions becoming mainly VFR in its wake.

BIS WATCHES/WARNINGS/ADVISORIES

None.