textproduct: Grand Forks

KEY MESSAGES

- Blizzard conditions are expected in the Red River Valley and just to the east of the Red River Valley. Whiteout conditions with accumulating snow between 2 and 6 inches will make travel dangerous.

- Uncertainty remains in how far east the 2 inch snow line gets, which will determine if blizzard conditions arise west of the Red River Valley.

- East of the Blizzard Warning, accumulating snow is likely between 3 and 5 inches. There is a 10% chance to get 6 inches or more in some locations.

- Below average temperatures continue.

UPDATE

Issued at 1132 PM CST Sat Dec 27 2025

With the development of a snowband along the 700mb frontogenesis zone, confidence has increased in at least 2 inches of snowfall in the Red River Valley. With winds expected to increase tomorrow afternoon, blizzard conditions appear likely in the Red River Valley and to the counties adjacent to the east.

Lingering uncertainties exist for both the western portions and eastern portions of our area. There is the potential on the west end to upgrade to a blizzard warning, but this depends on if at least 2 inches of snow falls out there. Right now, that probability is about 50%, so there remains the chance for a Blizzard Warning out there. To the east, the main concern will be accumulating snowfall. The bulk of guidance seems to be honing in on the axis of heaviest snowfall occurring mainly within the Blizzard Warning, although close monitoring will be necessary to see if warning impacts arise within the eastern advisory area.

The Dense Fog Advisory has also been allowed to expire this evening due to improvements in visibility.

UPDATE Issued at 929 PM CST Sat Dec 27 2025

Quiet conditions continue this evening but snow is expected to enter the region within the next 4 hours. Fog will continue to diminish later this evening, so the Dense Fog Advisory should be allowed to expire by then. Expect conditions to begin to slowly diminish after midnight as we prepare for the upcoming winter system.

UPDATE Issued at 657 PM CST Sat Dec 27 2025

Fog conditions continue to improve spatially this evening, however 1/4SM observations continue to roll in. The Dense Fog Advisory remains in effect until midnight tonight.

Regarding the upcoming winter storm, the frontogenetic band of snow does appear to be taking shape in northwest South Dakota. Close monitoring will be necessary of this band to see what track it takes, as it will determine if we get higher snow totals on the western side of the Winter Storm Watch. Lingering uncertainties on where at least 2 inches of snow will fall continue, so no upgrades occurred on this update for the Winter Storm Watch. A Winter Weather Advisory was issued west of the watch as it is expected at least blowing snow and freezing drizzle will impact this region beginning just after midnight.

..Synopsis

Sunday's system can already be noted across Montana and southern Alberta in water vapor imagery with the baroclinic zone along the international border. As the low drops southeast through the Dakotas and into southern Minnesota by Monday morning strong northerly flow will develop at the surface with moderate FGEN along and east of the Red River Valley to the north of the low acting as an inverted trough shutting off precip to the west of wherever the FGEN sets up. With this there are a few scenarios but we boil it down into two primary ones down below. As the low moves southeast into Iowa on Monday the pressure gradient weakens and blowing snow comes to an end with cold conditions on the back side. Beyond the cold a few shortwaves amid the northwest flow could bring shots of light snow and blowing/drifting snow but more tranquil (and less foggy) weather expected.

- Ongoing Fog

Advection fog remains across the region albeit not contiguous for the most part as warm air traverses the saturated snowpack with a warm nose aloft and thick stratus preventing any good surface heating and thus keeping us in this December wintry soup. At least with it being below freezing its freezing fog so all the trees are nice and pretty (we'll ignore that its also making the roads icy per DOT reports)... gotta find a bright side I tell myself.

- Sunday/Monday Snow

Scenario 1) where the strongest FGEN lines up from Detroit Lakes to Roseau or east of there. Scenario 2) where it lines up slight east of there bringing heavier snowfall to the valley (greater than 2"). In both cases to the east of the FGEN expect 2-4" with locally higher totals approaching 6-7" (10% chance). However in the western case strong winds/gusts of 45mph or greater are likely to overlap with areas that see 2" leading to a 60% chance for blizzard conditions if snow is no longer falling and a 100% chance for blizzard conditions if snow remains falling during strong winds (even 1" over 6 hours would satisfy this falling snow criteria). As of now the eastern scenario where strong winds do not overlap with 2" of snow in the Valley seems to be the favored outcome by guidance but there has been a rapid shift from almost nothing to now a possible blizzard in the last 36 hours so not selling the house on what the current guidance shows as things remain fluid. So as a floor this feels like a solid advisory event between a widespread 1" (valley) to 3-5" in the MN northwoods with isolated to scattered blowing snow (dependent upon how much new snow falls in a given location). As a ceiling one could see this going as severe as a Blizzard in the RRV (2" of new snow in combination with wind gusts > 45mph) and a winter storm warning in the MN northwoods with 4-7" of new snow and scattered blowing snow in more open areas. As such with the wide uncertainty and potential ceiling have gone with a winter storm warning for the entire Red River Valley (blizzard potential) and the Minnesota northwoods (>6" of snow possible). West of the Red River Valley even at the ceiling this looks to be an advisory with up to 1-2" of new snow and patchy blowing snow. Timing Sunday morning (midnight to 6am) to Monday morning (6am)

- Monday

Other than the recovery from whatever this event ends up being there is high confidence in cold temps/wind chills. Widespread wind chills in the -20s for all with more northern areas still favored to fall into the -30s meeting cold weather advisory thresholds. Should be only for a short duration (6pm Sunday to noon Monday) but in combination with the winter storm could pose an extra level of impact to travelers that are unprepared. Highs through the period otherwise look seasonal if not slightly below average with all days failing to reach into the 20s (minus Tuesday which cold reach near freezing)

- Tuesday

A weak clipper looks to move through Tuesday night into Wednesday bringing a quick shot of light snow 1-2" (didnt look much at this with tomorrow's system the primary focus of this forecast period) and some patchy blowing snow likely Wednesday morning as temps fall behind the attendant cold front.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 1132 PM CST Sat Dec 27 2025

While fog will continue to improve, expect low end MVFR to high end IFR ceilings to persist for the TAF period. A winter system will approach from the west impacting all TAF sites, with increasing northwesterly winds, gusting up to 40 knots at GFK and FAR, with lower gusts outside these TAF sites. This will contribute to blowing snow and reduce visibility to at least 1/2SM at times, with predominant 1/4SM at GFK/FAR/TVF expected, although when this occurs is uncertain.

Blowing snow will continue to linger once falling snow ends, so do not expect significant improvements to visibility until just after the TAF period. Gusts should at least improve with sunset, so impacts from blowing snow should at least markedly diminish after 00z, but will still continue with elevated overnight winds.

FGF WATCHES/WARNINGS/ADVISORIES

ND...Blizzard Warning from 3 AM Sunday to 6 AM CST Monday for NDZ008-016-027-029-030-039-053. Winter Weather Advisory until 9 PM CST Sunday for NDZ006-007- 014-015-024-026-028-038-049-052-054. MN...Blizzard Warning from 3 AM Sunday to 6 AM CST Monday for MNZ001>004-007-029-030-040. Blizzard Warning from 9 AM Sunday to 6 AM CST Monday for MNZ005-008-013>015-022-027-028-031-032. Winter Weather Advisory from 9 AM Sunday to 3 AM CST Monday for MNZ006-009-016-017-023-024.