Grand Forks forecast discussion

Update

Issued at 128 AM CDT Fri Oct 16 2026

North winds remain gusty but speeds are well below advisory levels. North winds within the Red River valley at 06z were sustained 20-30 mph with gusts 35-40 at times. Cold advection a bit too weak to sustain higher values that are above the surface. So wind advisory for all areas dropped. Coord with WFO BIS.

Discussion

Issued at 246 PM CDT Thu Oct 15 2026

...Synopsis...

Widespread stratus is present across the area this afternoon, both head of and behind the surface cold front that is moving through the region. Satellite imagery suggests extensive upstream stratus will prevail through much of tonight, save for across the Devils Lake Basin where some late-night clearing is expected. Showers are developing in southern Manitoba and north central ND in cyclonic flow, and are expected to spread south- southeast through this evening, resulting in a high PoP/low QPF scenario as the primary middle- and upper-level shortwave trough axis crosses the region. In the wake of this wave, mean upper- level ridging is forecast to build into the region by this weekend and is forecast to remain in place through much of next week. Low-level warm air advection this weekend will result in above-normal temperatures beginning Saturday and continuing through the middle to latter parts of next week. The spread in ensemble guidance and NBM membership is small for most of this period, with high confidence in highs in the 60s across much of the area from Saturday through next Thursday. Guidance suggests that a weakening shortwave trough and cold front may move through late this weekend, with breezy south-southwest winds ahead of that on Saturday, and breezy northwest winds behind it on Sunday. A mainly dry forecast is also in place from Friday through the middle to late part of next week given the mean ridging, though a low to medium probability exists for flow aloft to turn southwest by the middle of next week, which may eventually predicate low rain chances by then.

...Strong Winds through Tonight...

Northwest winds gusting up to 35 to 45 mph this afternoon are forecast to turn northerly and increase further tonight, with gusts of 40 to 50 mph, particularly in the Red River valley. Surface low pressure is centered near Lake of the Woods as of early afternoon, with a trailing cold front southwestward into west central MN. The surface low and cold front are both forecast to continue moving east-southeast across the area by late afternoon. Initial low- and midlevel cold air advection and an increasing surface pressure gradient behind the front is contributing to gusty winds in eastern North Dakota, which may approach advisory criteria from the Devils Lake Basin southward toward Valley City before 00z. However, the initial push of cold air advection is not particularly long-lived, and surface pressure rises are lacking. Both of those aspects will change after 00z when the middle- and upper-level shortwave trough axis passes eastern ND, turning deep-layer flow to a northerly direction, with a secondary and stronger surge of cold air advection concurrent with increasing deep-layer subsidence. The low-level wind fields will also increase with 45-50 kt flow in the 925 to 850 mb layer and cold-air-advection-steepened lapse rates contributing to sufficient mixing and momentum transfer through much of that layer. We also anticipate a 5-7 mb/3 hour surface pressure rise bubble moving southward through eastern ND and far western MN. This scenario is expected to yield advisory-level north-northwest winds in those areas, maximized in the Red River Valley given the orientation of the flow. Point forecast soundings at both Grand Forks and Fargo suggest momentum transfer may be sufficient for 50 kt gusts, but the depth and temporal efficiency of the mixed layer was not sufficient for us to upgrade to a High Wind Warning. Having said that, there is a 30-50% chance of gusts reaching 60 mph in the Red River Valley tonight when the aforementioned ingredients align, particularly in the 02z to 07z time frame. Both time- lagged HRRR and 12z RRFS/REFS guidance support maximum gusts near 50 mph, consistent with some uncertainty in the depth of mixing.

There is also around a 50% probability that advisory-level gusts extend further into west central MN, e.g., portions of Otter Tail and Grant Counties. Time-lagged HRRR guidance supports that potential, but with some uncertainty in mixing nocturnally, we have not yet added them into the Wind Advisory.

Winds are forecast to rapidly diminish by Friday morning as a surface ridge axis begins to approach the area.

...Freezing Temperatures...

We have issued a Freeze Warning for portions of the area centered on the Devils Lake Basin tonight, where ensemble guidance and upstream observations provide high confidence in overnight lows in the upper 20s to lower 30s F. This is supported by expected low-level cold air advection, but may be offset by lingering clouds (stratus) and winds that may not diminish until close to sunset even in those areas. Across the remainder of eastern ND and northwest and west central MN, we believe the cloud cover and winds will tend to inhibit the efficiency of cooling. Taken at face value, the 50th percentile NBM guidance suggests temperatures around 32 in parts of the MN lakes country. In contrast, MOS-based guidance (which is not bias-corrected by recent background trends) favors the temperatures staying above freezing, consistent with the expectation of cloud cover and winds limiting full cooling potential.

Medium to high probabilities for freezing temperatures exist Friday night owing to the cool post-frontal air mass and expectation of a clear sky. The official forecast calls for low temperatures in the upper 20s to mid 30s F, lowest in parts of west central MN, which will be near a surface ridge axis the longest during the night.

Aviation /06Z Tafs Through 06Z Saturday/

Issued at 1151 PM CDT Thu Oct 15 2026

Winds, ceilings, and showers have evolved pretty much as expected. The main challenge for the remainder of the night will be how quickly winds diminish and how quickly ceilings lift and/or dissipate. Current satellite imagery indicates breaks in the cloud cover across portions of eastern North Dakota into Manitoba, although there are also areas of MVFR cigs across this area. General trend will be improving conditions, but timing will be more uncertain (anticipate the TAF forecast to unfold as written but not at the exact times). Light winds and clear sky on Friday.

Fgf Watches/Warnings/Advisories

ND...Freeze Warning until 9 AM CDT this morning for NDZ006-007-014- 015-054. MN...None.

UPDATE...Riddle DISCUSSION...FGF AVIATION...TG