textproduct: Grand Forks

KEY MESSAGES

- Scattered storms overnight and again Wednesday evening will bring strong to severe storms to southeast North Dakota.

- Multiple rain chances with a 50% chance for a cumulative half inch through early next week for most areas across the region.

..Synopsis

Currently a very elongated ridge exists across the southern CONUS with zonal to WNW mid level flow in the northern CONUS. As we progress through the week, ridging over the four corners into Texas panhandle will amplify. At the same time PNW troughing begins to turn flow more zonal over us as the ridge gets pushed east. By Thursday SW flow looks to dominate the western CONUS bringing pacific moisture over the Rockies with embedded shortwaves. Certainly still differences remaining among clusters but the potential for a wet late week/weekend continues to increase. Current guidance is now favoring western areas (eastern North Dakota) over eastern areas (northwest Minnesota) with a 60% chance for over half an inch in the next seven days vs only 40% chance out east. As much of this rain looks to be more convective and thunderstorm driven vs a slow soaking rain totals will likley vary greatly over short distances.

- Severe threat today

This morning MUCAPE of 1000-2000 j/kg atop a nearly stationary surface boundary led to the formation of a lone supercell that tracked from north of Jamestown towards Fort Ransom dropping up to baseball sized hail along the way. Overall this was mostly a surprise and not in the forecast given the skinny CAPE, however the very favorable straight hodos and eff shear of around 50kts at least helped explain it a little. Looking ahead to this evening CAMS largely maintain the instability across the area but fail to convect despite an overall capable environment should a forcing mechanism exist. The chance for a storm this evening is likely less than 10% but if one goes, something similar to this morning is certainly possible. By the overnight there is higher confidence in storms forming west of Bismarck and moving east reaching the James/Sheyenne river valleys around 4-5am. Storms still look to be elevated and a primary hail threat, but cant 100% rule out damaging winds. This threat would persist into the mid morning hours mainly for southeast North Dakota and perhaps west central Minnesota is storms made it that far east.

- Severe threat Wednesday

A more pronounced shortwave will roll across the Dakotas Wednesday evening bringing forcing for widespread convection. thunderstorms may occasionally have large hail and gusty winds but overall this looks to be more of a general thunderstorm/widespread rain event for eastern North Dakota. Amounts will generally will be a quarter to half inch but isolated totals in excess of 1" are possible.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1240 PM CDT Tue Aug 11 2026

VFR skies today with some smoke aloft and scattered CU this afternoon around 5kft if they form but over the boundary layer is relatively dry and mixed keeping most areas cloud free. winds light and variable through the entire period with many areas going calm for long stretches. Winds under 10kts for all sites through tomorrow afternoon.

FGF WATCHES/WARNINGS/ADVISORIES

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