textproduct: Grand Forks

KEY MESSAGES

- There is a level 1 out of 5 risk for severe thunderstorms Tuesday afternoon into early evening. The main hazards will be hail up to the size of ping pong balls, gusty winds to 60 mph, and perhaps a few brief, weak tornadoes.

- Growing signal for potentially strong to severe storms late this weekend into early next week.

..Weekend into early next week severe potential

The chance for synoptic ingredients typical for producing severe storms in our region continues to increase this weekend into early next week. However, more refined and important details that would dictate coverage and severity of storms remains uncertain due to this period toward the end of the predictability horizon.

Synoptic ingredients include a preceding period for moisture and instability returning into our area ahead of a synoptic upper trough and attendant mid level jet max ejecting into the Northern Plains and Upper Midwest.

Several AI guidance also reveal this signal of severe potential as well. This includes some more robust signals on Sunday and Monday that keep widespread and/or significant severe potential on the table. Backing these signals is the speed at which the upper jet max traverses through our region, the orientation of this jet into the geometry of the warm sector (although this aspect is still somewhat in question), as well as the degree of instability (possibly very unstable air mass).

In general our local window of potential severe storms with this period starts as early as late Saturday/early Sunday, and potentially extending through Monday/Tuesday.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 640 PM CDT Mon Jun 22 2026

Aviation impacts are forecasted, coming in waves over the next 24 hours. First, a band of rain (and embedded thunder) will push from west to east late tonight through Tuesday morning, eventually impacting all terminals. At this time, kept out any mention of -TSRA from the TAF as its coverage is uncertain. However, as we get closer there may be a need to include -TSRA as a TEMPO for a few of the terminals. MVFR ceilings will accompany this wave of rain, with a low chance for a few pockets of IFR as well. If predictability increases in IFR, this too could be included in a TEMPO. Rain will push eastward by midday, leaving all terminals except KBJI dry. Additional shower and thunderstorm development is forecasted to occur Tuesday afternoon. This spotty activity may eventually require the addition of a PROB30 into the TAF, highlighting the mid to late afternoon period in particular. Guidance shows cloud cover breaking up a bit into the afternoon hours at most terminals. Clouds bases will bounce on the edge of MVFR/VFR, and there is uncertainty in if a persistent ceiling actually develops. Therefore, kept SCT into the afternoon at most terminals.

FGF WATCHES/WARNINGS/ADVISORIES

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