textproduct: Bismarck

KEY MESSAGES

- Low to medium chances for showers and isolated thunderstorms across western and north central North Dakota late this afternoon through the evening, then medium to high chances across the western half of the state Thursday through Friday.

- Temperatures remain closer to normal through Friday, then warm to well above normal by the end of the holiday weekend.

UPDATE

Issued at 535 PM CDT Wed May 20 2026

Updated pops based on latest radar. Showers have spread into central ND and have pulled slight chance pops farther east. There is some occasional lightning, so for this afternoon and evening utilized coverage terms for shower and thunderstorm activity. Williston picked up just over a quarter inch of rain and gust to around 35 mph. Updated text products will be transmitted shortly.

DISCUSSION

Issued at 208 PM CDT Wed May 20 2026

High temperatures are forecast to warm into the 60s and 70s this afternoon. Surface high pressure has shifted off to the southeast over Minnesota as surface low pressure moves into eastern Montana. This has lead to breezy to windy conditions across the central and eastern half of the state due to a tighter north south orientated pressure gradient. An upper level low is forecast to move into southern Saskatchewan tonight. This low has brought two upper level waves to the region. Water vapor imagery shows the first wave which is moving across the north central into the northeast while the second wave is forecast to move through eastern Montana into the west this afternoon and evening. Majority of the precipitation will remain scattered to isolated across the west from the second wave.

The aforementioned upper level low is forecast to stall out over southern Saskatchewan Thursday and Friday. Hi-Res models are showing a band of precipitation that will traverse west to east Thursday into Friday. However, the HREF has this banded precipitation stalling across the west maybe barely making it to the HWY 83 corridor. Storm total qpf on the HREF is up to around an 1.5 inches in some areas with locally higher amounts possible this is supported by decent rainfall rates and residence time of banded precipitation. This mean central and eastern North Dakota will likely miss out on the majority of rain the next two days. This cooler pattern will keep temperatures in the 60s to 70s Thursday and Friday until warming up by the weekend. Saturday morning there is a chance of some patchy frost in the southwest. The NBM 25th begins to push the high temperatures into the upper 70s to lower 80s and the 75th percentile has the lower 90s by early next week. There is fairly high confidence for warm weather to start off next week. The pattern could shift again by the end of next week as an upper level troughing could return to Western CONUS.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 535 PM CDT Wed May 20 2026

A slow moving cold front will move from eastern Montana into western ND tonight and remain over western ND Thursday morning and only possibly push into western portions of central ND by the end of the 00Z TAF period. Scattered showers and thunderstorms over western and central ND this evening are expected to dissipate around mid to late evening. On Thursday afternoon shower and thunderstorm activity will develop again over western ND and remain mostly over western ND, right along the stationary or slow moving cold front. Through the period winds will remain breezy to windy at times from the south to southeast over central ND, ahead of the front. Over western ND, southwest flow this afternoon will become light tonight and then turn northerly on Thursday as the cold front moves east. Generally VFR conditions are expected through the period. However, occasional MVFR visibilities are possible, along with gusty and erratic winds with any heavier shower or isolated thunderstorm activity.

BIS WATCHES/WARNINGS/ADVISORIES

None.