textproduct: Bismarck

KEY MESSAGES

- Medium to high chances for showers through tonight.

- Mainly dry and warmer Tuesday and Wednesday.

- Wide range in temperatures from northwest to southeast Thursday as a cold front pushes into the state. - Significant cool down for the end of the week, with medium chances for rain and snow.

UPDATE

Issued at 1230 AM CDT Tue Apr 14 2026

Showers continue across portions of the forecast area at the time of this mid night update. While thunder has generally ended, a very short lived thunderstorm did develop in the north James River Valley in the past half hour. An interrogation of the SPC mesoanalysis page indicates that a bubble of weak instability was previously found over this area, though should continue to continue to exit to the northeast out of our area over the next hour or so. Will continue to monitor model trends, but not really expecting much if any more thunder at this point. Overall, the forecast remains on track.

UPDATE Issued at 1002 PM CDT Mon Apr 13 2026

At 930 PM CDT, the most concentrated and heaviest shower activity was located over central North Dakota, directly downstream of a 700 mb vort max. A few thunderstorms have been embedded in this activity at times, but no lightning has been observed in the last half hour. With SPC mesoanalysis showing only around 100 J/kg MUCAPE, the risk of thunderstorms appears to be winding down. Another arc of more persistent rain tied to a 500 mb low was pivoting over southwest North Dakota, and the broader area encompassing the two lies under the left exit region of a 300 mb level jet. The mid to upper level forcing will glide northeastward through the night, carrying the rain with it. Latest model guidance continues to show rain could mix with or change over to snow in the Turtle Mountains and Devils Lake Basin areas early Tuesday morning, with little to impacts expected within our forecast area.

UPDATE Issued at 702 PM CDT Mon Apr 13 2026

The risk for a severe thunderstorm in southwest North Dakota has greatly diminished as the stronger updrafts in northwest South Dakota have taken on a direct eastward trajectory. Most of south central North Dakota should also be in the clear from severe storms, but will still need to monitor the South Dakota convection as it could reach a kinematic environment that could spawn an elevated left-moving supercell later this evening. But that would be a reasonable worst-case scenario, low probability outcome. Isolated non-severe thunderstorms will remain possible across southwest and south central North Dakota through the evening.

The fog forecast for this evening into Tuesday morning could prove to be challenging. Dense fog had been plaguing parts of southwest North Dakota for several hours this afternoon, but is now finally starting to lift with the arrival of more persistent rainfall. HRRR/RAP guidance would indicate that fog could develop outside of rain showers across much of western and central North Dakota later tonight. Will leave a patchy fog mention over much of the area and refine later as needed.

DISCUSSION

Issued at 158 PM CDT Mon Apr 13 2026

Chances for showers and thunderstorms through tonight, with a low potential for a few strong to marginally severe storms far south late this afternoon and this evening. Drying out Tuesday, warm Wednesday, then a significant cooldown late in the workweek and into the weekend.

Latest satellite imagery and upper level analysis shows upper level circulation along the MT/ID border with additional shortwave energy lifting from WY into southeast MT. Showers and scattered thunderstorms have been on the increase over Northeast WY into southeast MT over the past hour or so. This has resulted in steep low and mid-level lapse rates over this area. Through the remainder of the afternoon as the shortwave propagates east northeast, expect this environment to work into the western Dakotas. SPC has issued a MCD for portions of northwest SD into southeast MT and northeast WY. The problem is, the farther north and east you go, the more stable the environment. We expect convection, some strong, will approach southwest ND this afternoon. The main question is how far can it progress into the forecast area, characterized by a more stable lower level environment, before dissipating. The main threats with the high based convection will be strong wind gusts to 60 mph. Better chances will remain south of the border, but an isolated strong to marginally severe storm can not be ruled out late this afternoon through the evening along the South Dakota border in the southwest and south central.

As we then go through the evening and overnight as the mid-upper level circulation tracks from far southwest ND through east central ND. This will support scattered to numerous showers and isolated thunderstorms tracking through the forecast area tonight. Late tonight, as the precipitation lifts into northeast ND, there it the potential for a bit of mixed precip around the Turtle Mountains. At this time the warm temperatures should inhibit any significant snow accumulation, but a little accumulation on grassy surfaces can not be ruled out.

For the most part warming Tuesday and Wednesday with mostly dry conditions. Our given NBM guidance gave us several hours of splotchy slight chance pops on Tuesday over western ND. There does appear to be a small potential for an afternoon shower or possible thunderstorm. we opted to include a broad brush slight chance pops over the west Tuesday afternoon. It's possible that as we go into the evening, we could see slight chances propagate into central ND. For now we will limit the slight chance pops to mainly along and west of the Highway 83 corridor, Tuesday afternoon.

Wednesday looks to be warm and mild. We could see afternoon humidities drop into the 20-25 percent range over southwest ND but winds look to be rather light out of the southwest Wednesday afternoon.

In the Tuesday-Wednesday timeframe an upper level low in the eastern Pacific drops south and moves onto the Pacific Northwest coast by Thursday. This will result in surface cyclogenesis in the lee of the northern and central Rockies and by Thursday the surface low ejects onto the Plains. At this time it looks like the energy in this upper trough splits with a piece tracking north of the forecast and another tracking well south of the area. Current temperature guidance on Thursday suggest a 30 degree or so difference in temperatures between the far north (mid to upper 40s) and the southern James River Valley (Mid to upper 70s). Should we reach the mid 70s across the south central on Thursday, we could see a period low humidities, possibly into the low to mid 20s in the far south central east into the southern JRV. Winds should not be an too strong during this timeframe.

As the upper level trough swings through the northern Plains we will see a period of precipitation, most likely rain initially, then changing to snow. With the split flow pattern there remains quite a bit of uncertainty as to how much qpf we see. Right now, the NBM 24 hour probability of a quarter inch of liquid from Thursday afternoon through Friday afternoon remains low across all of western and central ND. Whether that falls as rain, snow or a mix, impacts from qpf amounts look to be low. There will be a period of strong wind with this system, followed by much colder temperatures late in the workweek and into at least the first half of the weekend.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1230 AM CDT Tue Apr 14 2026

Variable ceilings can be found across western and central North Dakota to begin the 06Z TAF period. While low stratus generally continues to promote IFR to LIFR ceilings at most terminals, areas of showers moving across the area have promoted improvements to MVFR to even VFR ceilings on their onset at any given TAF site. As showers move off to the northeast overnight, a rapid return to lower ceilings can be anticipated, with some patchy fog possible. A general improvement of ceilings back to VFR conditions are is expected from west to east late this morning through early this afternoon.

Winds are expected to remain around 10 kts or less through much of the period, turning out of the east tonight to the west through this morning and afternoon, then out of the south through this evening and the end of the TAF period.

BIS WATCHES/WARNINGS/ADVISORIES

None.