textproduct: Grand Forks

KEY MESSAGES

- Several light snow chances with below average temperatures through the weekend.

- A stronger system arrives on Tuesday, with a 60% chance of at least advisory level impacts.

..Tuesday Clipper System

By late Monday, another area of low pressure will develop in the lee of the Canadian Rockies in Alberta. This wave looks to be the strongest in the parade of shortwaves. An interesting thing to note this far out is the lack of spread in modeled scenarios. Take the 12z GEFS for example. Every member develops an area of surface low pressure in Alberta, tracking it southeastward towards our FA by sometime during the day on Tuesday. The only real differences are how fast the clipper is, which will impact the exact timing of when precipitation starts/ends, along with how far north the low tracks. For being 4 days out, it is pretty remarkable that the differences in the systems track from ensembles members is on the order of counties, not half of states which seems to be more typical at this timeframe.

It is important to stress, however, that even though the general evolution of this system seems fairly certain, the small differences that remain will play a major role in determining the degree and type of impacts at any one location, such as in your own backyard. The strong warm air advection ahead of this system will likely crust at least some of the snowpack across the southern FA, limiting its blowability and increasing reliance on new snowfall to reduce visibility. Warm temperatures at the surface and aloft will likely complicate precipitation type as well for some locations, and impact snow to liquid ratios elsewhere. Snowfall ratios will likely not be consistent throughout the event either, as colder air works in on the backside. Add on top that conceptually, systems such as this one usually have the heaviest snow (associated with warm air advection and frontogensis) displaced to the north of where the strongest winds (associated with the largest surge of cold air advection behind the southward draped cold front) occur. EFI highlights this difference well, with both snow and wind showing a shift of tails, but in drastically different areas. Therefore, at this time it is too early to pinpoint where which exact type of impacts will occur. This system will be one to closely monitor over the weekend into early next week.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1131 AM CST Fri Dec 5 2025

MVFR will persist for nearly the entire TAF period, at most TAF sites. The current MVFR deck overhead will take all afternoon to work its way through all terminals. There have also been a few random flurries, mostly in the north, so added a PROB30 to KTVF, where visibility has been brought down to 5SM from time to time over the past couple of hours. As we go into the overnight period, there may be a slight break where we go VFR, however timing of this is highly uncertain/variable. In addition, with another system approaching from the west, it may be hard for ceilings to rise much before lowering again. Therefore, opted to keep MVFR ceilings going throughout the entire TAF period at KDVL, KGFK, KFAR and KTVF, knowing that there may be an hour or two of VFR embedded within that is too difficult to time out at this time. Outside of ceilings, winds will pick up a bit this afternoon out of the northwest, shifting to the northeast by the end of the TAF period.

FGF WATCHES/WARNINGS/ADVISORIES

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