FXUS63 KFGF 201117 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 617 AM CDT Wed May 20 2026 .KEY MESSAGES... - Freeze Warning for all areas tonight except west central Minnesota (Frost Advisory) with temperatures widely falling to the low 30s and upper 20s. && .UPDATE... Issued at 950 PM CDT Tue May 19 2026 Some guidance is beginning to hint at fog potential along the the eastern edge of the valley tonight once winds go calm with soundings ranging from a 3-5 degree dewpoint spread to a full on low level inversion and ground fog. Unsure whether clear skies prevail with the calm winds or if patchy ground fog develops but even with a worst case scenario would expect isolated pockets as low as a 1/4 to 1/2 mile with more widespread 1-2 mile vis from Fergus Falls north to Hallock and Crookston. Would say that is about a 30% chance. && .DISCUSSION... Issued at 212 PM CDT Tue May 19 2026 ...Synopsis... Upper trough axis currently over the Red River Valley will pull east into the western Great Lakes tonight. The high pressure centered over the western Plains currently will shift into the upper midwest tonight. Another trough will be digging into the Rockies tomorrow night into Thursday, so westerly flow will quickly shift back to southwesterly. The upper trough to our west splits into a northern and southern branch, and ensemble members vary a bit on how exactly they handle it as it moves east. Most solutions do push the trough east over the weekend, with ridging building into the Plains by Memorial Day. Details such as precipitation timing and placement with the trough are low confidence, but there seems to be good agreement on below average temperatures becoming near to above average by the end of the period. ...Frost and freeze headlines... Clouds should clear out as the upper trough moves east, and with high pressure overhead, winds will become light and variable overnight. There will be a good setup for radiational cooling, and dew points currently in the low 30s over southern Manitoba should be down in our area by tonight. Temps should drop to near or below the freezing mark in most locations, with a 60 to 90 percent chance of 32 or lower for much of eastern ND into northwestern MN. Probabilities of less than 32 are much lower for some reason in west central MN from Elbow Lake up to Detroit Lakes, with chances 20 percent or less.Kept Grant, Otter Tail, and western Becker as frost advisory but have the rest of the CWA in a Freeze Warning. && .AVIATION /12Z TAFS THROUGH 12Z THURSDAY/... Issued at 615 AM CDT Wed May 20 2026 Shallow fog this morning will improve fairly quickly and within the next 2 hours, giving way to VFR conditions. Winds will initially be light and variable this morning but will increase from the south towards the afternoon hours. Once this occurs, winds will remain elevated through the end of the TAF period, with the highest speeds generally in eastern North Dakota, decreasing as you head further east. No other aviation impacts are expected at this time. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...Freeze Warning until 9 AM CDT this morning for NDZ006>008- 014>016-024-026>030-038-039-049-052>054. MN...Freeze Warning until 9 AM CDT this morning for MNZ001>009- 013>017-022>024-028-029-032. Frost Advisory until 9 AM CDT this morning for MNZ027-030-031- 040. && $$ UPDATE...TT DISCUSSION...JR AVIATION...Perroux