textproduct: Grand Forks

KEY MESSAGES

- There is a level 2 out of 5 risk for severe thunderstorms this afternoon into the overnight. Hail to the size of golf balls and wind gusting to 70 mph will be the main threats.

UPDATE

Issued at 419 AM CDT Mon Aug 24 2026

A line of slow moving thunderstorms developed within the region of 925-850MB WAA and a 25-30kt low level jet where there was an axis of elevated mid level convergence. A weaker frontal zone/outflow is moving in from the west (near Minot) with the main upper wave still well over to the northwest along with it's associated front. There was training with high rain rates within this line that may have been enough to support flooding of low lying/poor drainage areas withing parts of northwest Benson County. This mornings activity is already showing signs of weakening as it moves off the axis of better instability to our west, and as the LLJ is continuing to weaken. This trend should continue, though some remnant showers/weak thunderstorms may continue to move east into the northern RRV during the morning hours.

The main focus for severe chances today will continue to be the cold front expected to arrive this afternoon and push east through the evening/overnight hours as the main mid/upper waves passes to the north. Morning convective activity/cloud cover could initially play a complicating role in earlier initiation and if there isn't enough clearing activity may tend to be more elevated (lowering the ceiling on severe impacts). Considering the advertised effective shear with generally straight hodographs orientated W-E with the frontal zone. This would support the potential for splitting supercells at least early on during the evening (late afternoon/evening) before any activity clusters up and potentially turns into one or several MCS's. 0-3km shear does increase to 30kt behind the front later this evening as a NW orientated LLJ develops, but ahead of and along the front low level shear is weaker (25kt or less), so the wind threat may remain dependent on RFD surges or cold pool development. The more elevated the activity becomes though the less likely wind will be a factor, and the more hail would become the main threat.

There may be just enough effective SRH near the frontal zone to support a low tornado risk early in the evening, with right split supercells (very subtle right curvature on some hodographs), and some AI systems are highlighting this risk. Just like with the wind threat today, any tornado risk will be highly dependent on the nature of the storms and if they remain surface based (hard to say at this point).

UPDATE Issued at 1146 PM CDT Sun Aug 23 2026

Northern end of some convection has been tracking through the Devils Lake basin for the last couple of hours, with the main impacts being some rain up to 4 tenths of an inch so far and some lightning. Heavier cells tracking southeastward through Wells and Foster counties, but on a weakening trend as they move into less unstable air. Most of the CAMs have the complex weakening as it moves towards the Red River later tonight, although a few models break out some stronger convection again on the northwest side. Given cell currently tracking into northwestern ND from MT, will keep a close eye on the activity.

..Isolated Severe Thunderstorms Late Monday

Severe thunderstorm coverage on Monday afternoon and evening will depend heavily on the timing of an approaching cold front. Warm air advection will be strong through much of the day across eastern North Dakota and west central Minnesota; however, with remnant shower activity on Monday morning potentially lingering, this could shorten the window of potential severe weather late Monday. Looking at CAMs, there are several potential scenarios, ranging from potential splitting supercells, to elevated clusters. Model soundings are consistent with nearly straight hodographs as the front approaches, which continue to support splitting supercells and hybrid clusters. As such, a high end scenario supports supercells developing west of the Red River during the late afternoon, with hazards including wind gusts to 75 mph and large hail to the size of golf balls. A more likely scenario would be that we have lingering convective inhibition later into the afternoon, thus delaying convection until later in the evening. This would still support wind gusts up to 70 mph, but would transition into mainly an elevated hail scenario that extends into the early overnight hours. With this later scenario, we could see isolated severe thunderstorms lingering into Tuesday morning across parts of northwest Minnesota.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 635 AM CDT Mon Aug 24 2026

A cluster of showers and thunderstorms is moving across northeast ND to the east, with the main area of thunderstorms tracking to the southeast and weakening. Confidence in thunderstorm activity moving into the vicinity of KFAR/KGFK is lower than actual shower chances this morning based on current radar/lightning obs in relation to where more unstable air is in place. After the activity this morning transitions east and breaks up, showers and thunderstorms should redevelop along a frontal zone late this afternoon and evening and then track east. Coverage of thunderstorms again will be more uncertain than showers at TAF sites, with highest coverage more likely in MN depending on how thunderstorms develop/track. Winds should shift from the southeast to southwest then west as the main cold front passes through the region.

FGF WATCHES/WARNINGS/ADVISORIES

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