textproduct: Grand Forks

KEY MESSAGES

- After a few showers and thunderstorms on Friday, temperatures will slowly warm to near 80 by late next week.

..Showers and Thunderstorms Friday

A wave propagating southeastward from Saskatchewan Thursday night quickly into Minnesota by Friday afternoon will be the trigger for shower and thunderstorm development beginning tonight. As the low swings through the FA late Friday morning into the afternoon, an airmass characterized by up to 1000 J/Kg of MUCAPE and 20 to 30 knots of effective shear will allow for showers and thunderstorms to blossom. The speed at which the low tracks through the FA will determine where the strongest thunderstorms initiate. A quicker low will whisk much of the instability eastward by afternoon, leaving all but our far southeastern counties with any chance for a stronger storm. A slower system would allow instability to remain over more of the region, and storms to develop further west, probably closer to the MN side of the Red River Valley. The best overlap in shear and instability in either scenario is in west central MN (Park Rapids, Detroit Lakes, Wadena, Fergus Falls areas). If a thunderstorm were to become strong to marginally severe, it would be in this region during the mid to late afternoon hours, with just sufficient speed shear for hail to be the primary threat. Therefore, the Storm Prediction Center has placed our far southeastern counties in a marginal, level 1 out of 5 risk for severe thunderstorms Friday afternoon.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1138 PM CDT Thu Jun 18 2026

An initial band of showers is working its way through central North Dakota and may impact all TAF sites as it progresses eastward. Having said that, precipitation should remain fairly short-lived initially and impacts to visibility should remain minimal. Lightning risk should also remain fairly limited and carries a low probability of terminal impacts. VFR conditions will prevail through the early morning hours as well even with falling ceilings.

As we approach 12z, more widespread showers are expected to develop across northwest Minnesota, again with a limited lightning risk. Further west, ceilings are likely to fall in eastern North Dakota, with the potential for MVFR ceilings to briefly impact DVL. Ceilings should quickly rise through the late morning hours so this period should be fairly brief should this arise. A break in precipitation occurs early tomorrow afternoon before additional showers are likely to develop. With stronger instability expected tomorrow afternoon, thunderstorms have a greater chance to impact all TAF sites, especially GFK and FAR. For this reason, PROB30 groups with TSRA will be added to the forecast for GFK/FAR. Showers/storms may linger through the early evening hours but the bulk of activity should shift eastward tomorrow evening. Stronger northwesterly winds will be left in its wake, generally sustained between 10-20 knots with occasional gusts to 25 knots, although frequency of gusts should remain limited as sunset approaches.

FGF WATCHES/WARNINGS/ADVISORIES

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