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 628 PM CDT Mon Aug 24 2026

Severe thunderstorm watch #625 has been issued for much of eastern North Dakota and northwestern MN. Deep convection has initiated on a cold front across central ND. Further north, satellite shows little cumulus development in our far western FA and adjacent portions of Manitoba, so we likely still have an hour or two until storms even initiate. Long, straight hodographs with effective shear of up to 50 knots will promote splitting supercells, with hail being the predominate threat. Current thinking is that the cluster of supercells north of Jamestown will continue to track east/southeastward towards southeastern ND with time. Additional storms will develop in an hour or two across southern Manitoba and northeastern ND. This area of convection will also eventually track east/southeast this evening into early tonight, impacting northern portions of watch #625. The watch is in effect until 1 AM CDT.

..Scattered Severe Storms This Evening and Overnight

Instability is slowly building this afternoon as warmer temps and higher moisture levels work into the area. Dew points have increased into the lower to middle 60s in most areas, with SBCAPE values generally in the 1500 to 2000 J/Kg range early this afternoon. Model soundings show the potential for 2500 to 3000 J/Kg by early evening. Mid level shear is present, but unidirectional above 700 mb, leading to straight hodographs and a continued support for splitting supercells. It is worth noting, however, that given the tendency to split, these supercells are also likely to interact and eventually form clusters. The primary hazard during the afternoon and early evening will be large hail to the size of golf balls, with a low chance for an isolated tornado. Due to relatively weak low level shear, tornado risk will be dependent on longer lived supercells that avoid interaction with nearby cells. With DCAPE in the 1100 to 1400 J/Kg range, damaging wind gusts to 70 mph are supported late this afternoon through mid evening.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 628 PM CDT Mon Aug 24 2026

Quite complicated set of TAFs, with thunderstorms rolling across all terminals from west to east this evening into tonight. Periods of MVFR visibility are likely under the strongest thunderstorms. Behind these thunderstorms, winds will shift to the west and eventually northwest. It will become gusty during the late morning and afternoon hours of Tuesday. At KGFK, KDVL and KFAR, gusts may flirt with 30 knots for a couple of hours in the afternoon. However, the probability they prevail at this magnitude is low at this time, therefore wind gusts in the 24 to 28 knot range. Clouds bases tomorrow morning and afternoon may briefly fall below 5,000 ft AGL, but at this time any ceilings that form look to remain VFR.

FGF WATCHES/WARNINGS/ADVISORIES

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