textproduct: Bismarck

KEY MESSAGES

- Isolated showers over portions of south central North Dakota overnight through mid Wednesday morning. - Dry and warmer on Wednesday, with highs in the mid 60s to mid 70s.

- Wide range in temperatures from northwest to southeast Thursday as a cold front pushes into the state.

- Turning much colder with periods of rain and snow Thursday night through Friday, with medium to high chances for light accumulations of snow.

- Well below normal temperatures Friday through Saturday, followed by a gradual warm-up into early next week.

UPDATE

Issued at 1245 AM CDT Wed Apr 15 2026

Scattered weak radar returns continue to move across south central North Dakota at the time of this mid night update. Very light rainfall was observed at the office as they passed over the Bismarck area, so at least some of this precpitation is reaching the ground. With this update, have opted to propagate PoPs across south central North Dakota through the early to mid morning, at which time the inciting surface trough should begin to exit to the east across the James River Valley. Otherwise no major adjustments to the forecast were performed with this update, as it remains broadly on track.

UPDATE Issued at 1047 PM CDT Tue Apr 14 2026

Intensity and coverage of shower activity has decreased late this evening, but the areal footprint of isolated showers has actually expanded into northwest North Dakota, reaching all the way to the Canadian border. The broader area of isolated showers lies in a weak surface trough that is directly under a 500 mb shortwave. Aside from south central North Dakota, which is closer to the base of the upper trough, model guidance is inconsistent with development and maintenance of isolated showers through the night. Will continue to update the forecast with observed trends as needed, but do not anticipate more than a hundredth of an inch of rain at most at any given location.

UPDATE Issued at 705 PM CDT Tue Apr 14 2026

Scattered showers have developed over southwest North Dakota, with a steady increasing trend in coverage since late afternoon. At 6 PM MDT, the most concentrated shower activity was located at the northern end of a 500 mb shortwave from around Beach to Killdeer, and along a surface trough from around Richardton to Hettinger. The northern showers have access to higher MLCAPE on the order of 500 J/kg, and very infrequent lightning is being detected with these. This activity is mostly expected to dissipate after sunset, but the base of the 500 mb shortwave could prolong shower activity along the South Dakota border into the overnight hours.

DISCUSSION

Issued at 345 PM CDT Tue Apr 14 2026

A digging western U.S trough will bring a chance of rain and snow followed by much colder temperatures late in the workweek and into the weekend.

Currently, stratus has cleared in the west and continues to erode over central and eastern ND. Afternoon CU has developed over portions of western ND however. For the rest of this afternoon and tonight, there remains a low probability of an isolated shower due to the combination of daytime heating and forcing from an approaching shortwave currently over northeast Wyoming. Forecast soundings show a shallow and narrow region of instability so thunder is not anticipated and any weak shower activity that does develop will likely produce little if any qpf reaching the ground.

Quasi-zonal upper level flow continues through the day Wednesday before backing to the southwest in response to the upper level trough dropping into the Pacific Northwest. Wednesday should be an very pleasant day with highs in the mid 60s to mid 70s with not a lot of wind by North Dakota standards.

The upper trough tracks into the northern Rockies Wednesday night bringing the initial chances for precipitation to northwest ND late Wednesday night.

Thursday through Friday...The upper trough moves into the Northern High Plains Thursday, then traverses the forecast area Thursday nigh through Friday. At the surface a surface low develops over the Mondak region and is situated along the ND/SD border at 12Z Thursday. The low pushes east during the day with an elongated surface low from northern Minnesota into northeast Colorado by 00Z Friday. This will produce a very tight temperature gradient from northwest to southeast Thursday. Highs are expected to range from the lower 40s far north to the mid 70s far southeast. Winds will also be picking up during the day from northwest to southeast as the surface trough pushes east. There are some (mainly) chance pops in the west and far north Thursday but only the far northwest looks to be the most likely area to see more than a trace, maybe a few hundredths of an inch of rain. The best precipitation chances will occur Thursday night through Friday as the upper level trough moves through the forecast area.

A cluster analysis shows that there's a 60/40 split between a more compact wave moving through the forecast area versus a split wave with better energy north and south of the forecast area. It looks cold enough that both solutions will bring snow. It also looks like the forcing and moisture available are limited enough that qpf is pretty light with a broad swath of 0.10 to 0.15 from southwest ND into north central to northeast ND. The more compact wave would yield a more widespread swath of QPF, but overall the differing impacts between the two solutions looks to be minimal. Our latest NBM guidance is depicting a medium probability for an inch of snow extending from southwest into northwest and north central ND, with low to very low probabilities elsewhere. This is the 24 hour probability ending at 18Z Friday. Two inch probabilities then taper to low for this same area. Probabilities for at least a hundredth of an inch of snow are medium to high across all of western and central ND, so most will likely see a little light snow with this system.

It will breezy to windy as the rain changes to snow and temperatures will drop well below freezing over much of western and north central ND, so even though snow accumulations are not expected to amount to much, there could be some minor impacts to travel Thursday night into Friday morning where we do see the combination of snow and winds with freezing surfaces.

Once the snow ends on Friday the rest of the weekend into early next week looks to remain dry as upper level ridging builds over the region. It will be cold again Friday night into Saturday morning with Saturday morning lows possibly into the teens over parts of the west and north and highs in the mid 30s to mid 40s. We do begin a gradual warm-up Saturday through early next week with highs climbing back into the 60s and lower 70s by Monday and Tuesday.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1230 AM CDT Wed Apr 15 2026

VFR ceilings and visibility is generally expected at all terminals throughout the 06Z TAF period. Isolated rain showers moving across south central North Dakota this morning are expected to have limited impact at any given terminal as precpitation must fall through a significantly dry layer near the surface. Otherwise, a brief period of LLWS is possible in the northwest in the late to mid morning, though confidence is too low to include mentions at KXWA at this time. Winds around 5 to 10 knots will generally remain out of the south overnight, before turning to the west southwest and strengthening to around 10 to 15 knots through the late morning and afternoon. A few isolated wind gusts up to 15 to 20 knots will be possible in the afternoon, mainly across the north.

BIS WATCHES/WARNINGS/ADVISORIES

None.