textproduct: Bismarck

KEY MESSAGES

- Showers continue this evening across much of central North Dakota. Isolated thunderstorms early this evening could produce heavy downpours mainly in the north central.

- Patchy fog possible across the west and portions of central tonight into Saturday morning.

- Temperatures warm to well above normal for the first half of next week, with highs mostly in the 80s to lower 90s. Tuesday and Wednesday could be windy.

- Other than a few isolated showers or thunderstorms on Saturday, the holiday weekend is expected to be dry.

UPDATE

Issued at 646 PM CDT Fri May 22 2026

Widespread showers continue across much of central and eastern North Dakota, though have mostly ended over western North Dakota. A few heavier and more isolated showers have developed mainly in the north central west of the main precipitation shield. While there were a few strikes of lightning earlier, these have generally remained thunder free so far. Still, a few of these showers could develop into thunderstorms and produce brief heavy downpours over the next couple hours. Showers will gradually end from southwest to northeast through the night tonight.

DISCUSSION

Issued at 210 PM CDT Fri May 22 2026

Aloft, a positively tilted trough axis is draped between two low centers, one over southern Saskatchewan and one over eastern North Dakota. At the surface, a stacked low pressure system is lofting across western and central North Dakota this afternoon. Widespread showers associated with the broad precpitation shield extending off this low is found across portions of western and much of central North Dakota. CAMs continue to advertise the development of thunderstorms along an inverted surface trough extended across the north central later this afternoon, with model MUCAPE values generally around 500 - 750 J/KG. While the potential for server weather remains very low, the potential for redeveloping storms as the whole system lifts further north invites the potential for locally heavy rainfall. In general, additional rainfall totals of around 0.25" to 0.50" is forecast through the afternoon and evening, a period through which precpitation is expected to diminish from southwest to northeast as the inciting low pressure system moves off into southern Canada. Otherwise for today, cooler highs broadly in the 50s are anticipated with the prevalent cloud cover, though some portions along the ND/SD border could approach the lower 60s by the mid afternoon. Overnight low are forecast to drop mainly into the upper 30s to lower 40s, though diminishing cloud cover across the west late tonight into early Saturday could allow some areas in the southwest to drop into the lower to mid 30s. Notably, with the fresh precpitation and light winds expected overnight, patchy fog may develop Saturday morning behind the retreating edge of the cloud deck as it moves off to the east.

Cyclonic flow is expected over the northern Plains on Saturday as the merger between the two upper level lows stalls over the southern Canadian Prairies through the early weekend. With such a pattern, near daily low chances chances for isolated showers or thunderstorms will be possible, mainly in the afternoon and evening hours. Otherwise, mainly dry conditions are expected on Saturday. With the eventual displacement of the merged lows further off to the northeast, and with an building ridge moving in across the Great Plains this weekend, North Dakota is expected to fall into a a warming trend through the first half of the coming week. With this, highs mainly from the 60s and 70s on Saturday are expected to rise up into the the 80s and lower 90s by Monday and Tuesday. Mainly dry conditions can similarly be expected throughout this period, though isolated showers or storms are not impossible Sunday afternoon as flow turns zonal ahead of the building ridge. Amplification of the building ridge is then expected by late Tuesday into Wednesday, as a robust Pacific trough/closed low is progged to make landfall in the western CONUS. The ensemble seems to have fairly decent agreement in at least some displacement of the ridge further to the east by the incoming trough. Cluster analysis reveals that the ensemble is split between two broad scenarios depending on how far east the ridge is displaced. In the first scenario, an open wave nudges the ridge slightly to the east, allowing for low chances (10 to 30 percent) for precpitation across the west some time Wednesday through the end of the workweek. Scenario 2 advertises a more robust closed low bumping the ridge much further eastward, allowing for similarly low chances for precpitation across much of the west and portions of central North Dakota. In either scenario, overall rain totals are anticipated to be light at this time, with only a low chance (30 percent) for portions of the west to exceed 0.25" through this period. Notably, the CSU machine learning algorithm does paint low chances for severe hazards on day 5(Wednesday through Thursday), so we'll need to watch this period over the next few days.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 646 PM CDT Fri May 22 2026

Widespread showers continue across much of central North Dakota often resulting in MVFR/IFR visibility while raining. A few more isolated showers in the north central could produce occasional lightning strikes, as well as heavier downpours over the next couple hours. All in all, rain will gradually end from southwest to northeast through the night tonight. MVFR/IFR ceilings are also present across most locations east of Highway 85. These will persist through much of the night, though improve from west to east as skies clear. Fog development is also possible across western and parts of central North Dakota, especially in areas where skies do in fact clear off overnight.

BIS WATCHES/WARNINGS/ADVISORIES

None.