textproduct: Grand Forks

KEY MESSAGES

- Scattered showers and isolated thunderstorms are forecast early this morning mainly in the southern Red River Valley. Scattered thunderstorms are expected tonight across much of the region, with lightning the main threat.

- Several periods of showers and thunderstorms are expected Monday through Friday, with better chances for wetting rainfall over more of the region.

- There is a level 2 out of 5 risk for severe thunderstorms late Tuesday afternoon through Tuesday evening over the Devils Lake Basin. There are low chances for severe thunderstorms Wednesday into Thursday.

UPDATE

Issued at 343 AM CDT Sun May 31 2026

Several clusters of showers and a slow moving line of thunderstorms hover south central ND and eastern SD ave been pivoting northward, but weakening as they have approached southeast ND due to much more stable/drier air aloft in place locally. Eventually some of this activity should spread north this morning (weakening). Actual lightning coverage will be lower and intensity of rainfall much less than current activity to our southwest.

Looking ahead to tonight, there is still a much stronger signal for increasing shower/thunderstorm coverage as the trough axis to the west moves eastward shifting the better moisture axis into our region as a negatively tilted shortwave rotates into our region. Elevated/skinny CAPE profiles generally 500 J/KG and weak shear (15kt or less) will tend to limit updraft strength, however lighting coverage would be increased compared to the last few days. The coverage of rainfall is higher with this round, but the signal for 0.1-0.25" totals is much more localized in CAMs with those totals more likely tied to convective activity.

Looking ahead to Tuesday, the axis of better instability that has remained well west and southwest of our region, should be better aligned with central and eastern ND as another shortwave rotates around the larger mid/upper low. A combination of increased instability and increased shear supports at least some severe threat, with hodographs supporting supercell structures during the earlier part of the event to the west eventually merging into lines or clusters as they progress into the Devils Lake Basin and northeast ND Tuesday evening. As a result, impacts will be a bit harder to judge as earlier initiation farther east would support higher impacts, but current timing favors lower end severe impacts at this time (some thing to monitor).

Wednesday and Thursday continue to be highlighted by machine learning systems for severe potential, however the actual risk/probability of severe occurrence will be tied to the evolution of the mid level low, associated waves rotating around it, and surface features which are all carrying higher spread and lower predictability at this time.

UPDATE Issued at 1116 PM CDT Sat May 30 2026

Regional radar reveals some lingering pockets of light rain, mainly within North Dakota. Dry air in the lower levels still is helping most rain evaporate before reaching the ground, although some higher returns have resulted in light rain/sprinkles thus far this afternoon/early evening.

A complex of thunderstorms in South Dakota is forecast to push into portions of central North Dakota and eastern South Dakota. However, instability and forcing feeding this convection is expected to sharply diminish as it pushes into southeast North Dakota Sunday morning. This leads to the expectation of light rain showers without lightning.

There is an additional chance for showers and general thunderstorms Sunday late afternoon into evening. This activity is not expected to be strong/severe, with main hazard being low lightning activity.

Issued a Special Weather Statement for portions of north-central Minnesota (namely Lake of the Woods and northern Beltrami counties) due to the forecast of low relative humidity values around 20 percent concurrent with southeast winds 10-15 mph. Despite recent green-up of vegetation, latest reports on fuels reveal variable susceptibility to fuels conducive for rapid spread of fires.

..Showers and Thunderstorms Today Through Next Week

Today: There is very little in the way of instability for thunderstorm development. Areas with higher MUCAPE are situated too far under the ridge to have access to any meaningful lift. The best chance for isolated development will be in northeast North Dakota and the northern Red River Valley, where low level lapse rates are a bit higher.

Sunday: Western flank of the upper ridge remains in place just west of the CWA. Isolated thunderstorm development could occur in southeast North Dakota and the southern Red River Valley, mainly during the late afternoon. Mid level lapse rates could support small hail; however, lightning will be the main risk.

Monday-Friday: Upper ridging gradually weakens through the week, with upper flow turning nearly zonal by mid week. Shortwave activity will allow for a mention of thunderstorms nearly each day, with the possibility for strong storms by Tuesday. ML products show a 5-15 percent chance for strong storms Tuesday and Wednesday. It is worth noting, however, that shortwave timing is uncertain due to current ensemble spread.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 1116 PM CDT Sat May 30 2026

Overall, VFR conditions are forecast through the TAF period with the exception of MVFR to perhaps IFR ceilings in portions of North Dakota Sunday morning. This includes KDVL where MVFR ceilings are in the forecast after 15Z. There is also a 20% chance for thunderstorms after 00Z Sunday afternoon/evening, although confidence was not high enough to include in the TAFs at this time. Additional chances for weak thunderstorms exists just beyond the TAF period through Sunday overnight. Winds will generally be out of the southeast 10-15kt, with the exception of gustier winds 25kt in eastern ND, including KDVL, between 10Z-20Z.

FGF WATCHES/WARNINGS/ADVISORIES

ND...None. MN...None.