textproduct: Grand Forks

KEY MESSAGES

- No significant weather related hazards thru the end of the week.

..Synopsis

SW flow ahead of a larger mid level trough is in place across the Northern Plains, with a PV height anomaly associated with a mid level shortwave ejecting into eastern ND within this flow. Higher level clouds in SD to the south of this PV anomaly could be the next area of forcing that could trigger initiation along the frontal zone in the 22-00Z period. The frontal zone is currently in place from Lake of the Woods to just south of Grand Forks and just west of Fargo and is starting to show signs of moving east-southeast on radar/satellite ahead of this mid level wave. Good forcing for ascent and at least elevated instability will continue to support showers and thunderstorms (some severe) into the evening before dry/stable air arrives later this evening/overnight.

The larger scale trough/upper low becomes a more dominate feature for our region through the week as it stalls and deepens over the Hudson Bay region and flattens the larger scale ridging to the south. This results in either weaker NW flow or westerly flow and the stronger storm track mainly remaining in Canada. However, flow will at least periodically allow for some influence of waves rounding the mid/upper low and periodic shower/thunderstorm chances. The signal for PoPs is generally washed out by the variability of these features in Canada, and machine learning is not highlighting a specific period for impacts.

After cooler than average temperatures Tuesday, this pattern will generally support temperatures in seasonal ranges for most days into the weekend (+/- 1 standard deviation of normal), and a break from the much hotter temperatures in the 90+ range.

...Severe Thunderstorm Risk Today..

Very high effective shear will be in place with values already in the 50-70kt range across our CWA. As deeper layer shear vectors will tend to be parallel or near parallel to the frontal zone there should be a tendency for clustering of thunderstorm activity that develops later this afternoon/evening. Severe mode and coverage will ultimately come down to timing of initiation and continued destabilization along/ahead of the frontal zone before sunset. Shear profiles support supercell development, however discrete mode may be hard to come by outside of the early part of initiation. Tornado threat will require surface based parcels which for now appear hard to come by, however with clearing that is just starting to occur in southeast ND/west central MN ahead of the front cap erosion could continue and create a window for this threat early in the event with right movers that do develop. More likely scenarios favor elevated cells and at least a window for transient elevated supercell threat which would primarily favor large hail as a threat. Whether clusters can grow upscale with strong enough cold pools in this shear profiles. Line normal vectors are going to tend to be towards the northeast (though the critical angle will be a bit higher due to the strong shear environment).

Backward propagation or training potential along the frontal zone raises the potential for localized heavy rain threat particularly with PWATs exceeding 1.5" along the front. As the front should be progressing quickly eastward there shouldn't be more than 1-3hr of this type of training, but this could be enough with higher rats for localized flash flood potential if this happens over a town/urban area where there is poor drainage.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1216 PM CDT Tue Aug 4 2026

VFR conditions with some cumulus clouds forming this afternoon, but think that coverage will be scattered and if any ceilings do form they will be over 3000 ft. Cumulus will dissipate after sunset, and our winds that are gusting up around 20 kts in some spots from the northwest will also decrease down below 8 kts. Winds will pick up again out of the southwest by tomorrow morning, with a few spots gusting above 20 kts again.

FGF WATCHES/WARNINGS/ADVISORIES

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