


Area Forecast Discussion
Issued by NWS Grand Forks, ND
Issued by NWS Grand Forks, ND
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161 FXUS63 KFGF 110946 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 446 AM CDT Fri Jul 11 2025 .KEY MESSAGES... - There is a level 1 out of 5 risk for severe thunderstorms this afternoon for portions of southeast North Dakota into northwest and west- central Minnesota. Main hazards will be gusty winds to 60 mph and hail to the size of ping pong balls. - Wildfire smoke will degrade air quality behind a cold front today, potentially into the weekend. && .DISCUSSION... Issued at 404 AM CDT Fri Jul 11 2025 ...Synopsis... Well developed upper/mid level trough is easily viewable on water vapor imagery migrating through MT and southern SK early this morning. This will provide upper forcing for ascent for showers and thunderstorms along/near a cold front working its way east across ND, eventually into MN this afternoon. Some thunderstorms this afternoon may be severe (more details below). Behind the cold front, smoke from Canadian wildfires is being observed, and will degrade air quality through at least today (more details below). As the upper/mid trough pushes east into the Upper Midwest and western Great Lakes, drier air behind the cold front filters into the region, although there may be some scattered showers and/or weak thunderstorms near northwest Minnesota Saturday afternoon. Northwest flow aloft briefly sets up around Sunday, along with increased shear. Meager instability and lack of more organized forcing will preclude messaging of potential strong to severe storms Sunday afternoon, although if either increases (either from better moisture return and/or added moisture from evapotranspiration; subtle impulse aloft to increase forcing), then this chance increase. Into next week, most ensembles favor low amplitude upper ridging into the Northern Plains and Upper Midwest between Monday and Tuesday, offering a chance for warming trend with increasing low level moisture. This comes ahead of upper troughing extending out of central Canada into the Northern Plains and Upper Midwest mid to late next week. This increases chance for showers and thunderstorms. There is a signal within ensemble guidance that hints at potential heavy rainfall via increased EFI values/probabilities within ECMWF ensemble suite. Increased instabilty and forcing/kinematics from this trough also increases the chance for potentially strong to severe thunderstorms. This is backed up by AI tools like FengWu AI-NWP forecast, namely on Monday into Tuesday. Behind this trough, most ensemble guidance shows a much drier and cooler air mass moving into the region by late next week. ...Severe storm potential this afternoon... Latest high resolution guidance strongly suggests thunderstorms to develop along/near a cold front this afternoon within portions of southeast ND into northwest and west-central MN. While shear is quite meager within the vicinity of thunderstorms, rich moisture and increasing daytime temperatures beneath cooling air mass aloft will aid in moderate to strong instability. Given the lack of overall shear, quick upscale growth of thunderstorms are anticipated, aided by forward momentum of the cold front itself. While shear will be low, there may be enough of an extension of increased flow aloft from the incoming trough to help transfer toward the surface of eventual MCS, also aided by cold pool organization. Thus, gusts to 60 mph will be possible from this activity. There will still be a short timeframe where thunderstorms initially in their semi-discrete mode shortly after initial development will be capable of hail to the size of ping pong balls given the instability that will be in place. ...Degraded air quality today, potentially into this weekend... Surface observations behind the cold front early this morning show wildfire smoke reducing visibility less than 2 miles and AQI values into the "unhealthy" category. This lends confidence that smoke will infiltrate the area behind the cold front at least through today. Guidance also offers another round of near surface smoke behind another cold front around Sunday. It is unclear to the degree in which this may degrade air quality. && .AVIATION /06Z TAFS THROUGH 06Z SATURDAY/... Issued at 1144 PM CDT Thu Jul 10 2025 Isolated thunderstorms continue through the overnight, with the best chances closer to the US/Canada border, and probabilities too low to include at TAF sites. Better chance for showers, but still lower coverage of thunderstorms arrive the main upper level system moves through the region Friday morning in ND and across northwest MN Friday afternoon. Winds shift to the west- northwest and increase behind this front during the daytime period Friday. Wildfire smoke from Canada is arriving behind this front, with MVFR visibilities reported upstream, along with a few locations briefly dropping to IFR. This axis of smoke should move northwest to southeast across the region through Friday morning and eventually across MN during the afternoon. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ DISCUSSION...CJ AVIATION...DJR