textproduct: Grand Forks

KEY MESSAGES

- Thunderstorm chances Tonight through Sunday Night. Isolated Severe storms possible.

UPDATE

Issued at 545 AM CDT Fri Aug 28 2026

The return of southwest flow aloft has commenced as an upper low is moving southward along the British Columbia coast from southeast Alaska. This main upper low will eject into the Canadian prairies Sunday and a cold front will move east south of this system thru the area Sunday night. This is when severe storm chances will be higher. Until then will have shower and t-storm chances increase late today into tonight, then another wave late Saturday afternoon and Saturday night. Isolated severe possible with each of these waves, mainly though focused in south central ND.

DISCUSSION

Issued at 228 PM CDT Thu Aug 27 2026

High pressure over the region will start to shift east tonight as ridge axis currently over the Northern Rockies starts to move slowly into the Plains. Most of the model solutions have a weak shortwave coming through the top of the ridge into the Plains late Friday. A few of of the models have a narrow band of 2000 J/kg of CAPE and 40 kts of deep layer bulk shear nosing into our far southwestern counties Friday evening. On the other hand, HREF updraft helicities are fairly unimpressive, and NBM box and whisker plots for southeastern ND range from nothing up to 1500 J/kg. The machine learning has some low chances for severe brushing our southwestern corner Friday, but have higher probabilities for Saturday and Sunday when flow aloft turns more zonal to southwesterly. Instability is a little more uncertain over the weekend depending on where a frontal boundary ends up, with most solutions having the best CAPE values well to the southwest when the good forcing arrives late Sunday. All this to say, there are some chances for severe over the weekend, but not high enough to start messaging specifics at this point.

Near zonal to southwesterly flow aloft continues into next week. Temps look to be above average with several chances for precipitation as weak shortwaves come through. Timing and intensity of any storms still uncertain with such weak forcing and unknown instability.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 704 AM CDT Fri Aug 28 2026

Unsettled next few days ahead. Today will start off quiet with light wind then southeast winds do pick up this afternoon and evening RRV and west, mostly into the 10-15 kt sustained range with some gusts 20 kts. Increasing clouds today...thinner cirrus east then thicker mid clouds spreading into DVL basin this afternoon and evening. Will watch the activity in western/central ND northwest of Bismarck to see how far east it can get today before diminishing. Thought chance was high enough for a shower into Devils Lake TAF site early to mid afternoon. Scattered showers and possible t-storms tonight, but this is when trying to pin down timing at any one site is quite difficult and best to wait on the next set of TAFs to fine tune timing.

FGF WATCHES/WARNINGS/ADVISORIES

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