textproduct: Grand Forks

KEY MESSAGES

- Scattered thunderstorms mainly in southern North Dakota into parts of west central Minnesota today into tonight. Isolated severe with hail and wind hazards.

UPDATE

Issued at 447 AM CDT Wed Aug 12 2026

The thunderstorm cluster than went thru various stages of strength from small hail then from Valley City into Fargo wind. Strongest winds around 50-55 mph in this stretch with pockets of 60 mph. These storms have weakened dramatically are not now into MN lakes country. Balance of the upcoming day will see a chance for additional t-storms just about anytime in the southern parts of ND into west central MN as water vapor shows another area of deeper moisture in southern Montana into SW ND spreading east today. Then a break Thursday.

UPDATE Issued at 1154 PM CDT Tue Aug 11 2026

Strong to severe thunderstorms continue to slowly move east across central North Dakota tonight. Storms will gradually weaken as the night progresses, however, isolated severe storms could bring impacts into portions of eastern North Dakota after midnight. The primary hazard will be large hail.

UPDATE Issued at 634 PM CDT Tue Aug 11 2026

Severe thunderstorm watch will be in effect for Barnes, Ransom, and Sargent County through 1 AM CDT.

..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 /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1154 PM CDT Tue Aug 11 2026

VFR conditions prevail through the period at all TAF sites. Still monitoring for the possibility of thunderstorm activity during the early morning hours Wednesday, however, confidence in coverage remains quite low at this time. The most likely timing for potential storms would be 07Z through around 10Z, and would primarily be in the vicinity of KFAR. Winds are expected to remain light and variable overnight before increasing slightly heading into Wednesday morning.

FGF WATCHES/WARNINGS/ADVISORIES

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