169 FXUS63 KFGF 040343 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 943 PM CST Fri Dec 3 2021 .UPDATE... Issued at 940 PM CST Fri Dec 3 2021 Added slight chance of flurries over northern portions of Lake of the Woods as we have been getting some isolated reports of flurries at times this evening. Otherwise, clouds continue to move in from the west. Temperatures drop down to the teens in the north and lower 20s further south. No changes to winter storm messaging. See short term discussion. UPDATE Issued at 638 PM CST Fri Dec 3 2021 Increased cloud coverage in the SW forecast area as cloud deck is starting to move in slowly. Temperatures continue to fall overnight to the teens in the north and lower 20s further south. Increased clouds in the south will help keep temperatures from dropping quickly. No changes to winter storm messaging. See previous discussion. && .SHORT TERM...(This evening through Sunday night) Issued at 200 PM CST Fri Dec 3 2021 Headline continues to be the winter storm chances on Saturday through Sunday. The Winter Storm Watch has been expanded further south to include Barnes, Cass, and Clay counties due to increasing potential for blowing snow impacts on Sunday. There is high confidence (>90%) that a winter storm will impact the region starting tomorrow afternoon and lasting through Sunday night. For today and tonight, expect clear to partly cloudy skies to continue with temperatures in the 20s and 30s this afternoon. Overnight temperatures look to fall into the teens and 20s thanks to mostly clear skies. Looking ahead towards Saturday...there is high confidence (>90%) for a winter storm starting tomorrow afternoon and lasting through Sunday night. Snow is expected to start around mid to late afternoon in the south Red River Valley near the Dakota border thanks to 700mb frontogenesis induced by warm air advection, giving high confidence in the location and start of this event. This band is expected to trek northeastward before the primary synoptic forcing arrives. The heaviest snow is expected to arrive Saturday night as synoptic forcing arrives in association with the upper wave. Due to orientation of the snow (west to east) and the track of the system (east-southeast), snow is expected to be prolonged through the night, increasing snow totals. Where the axis of highest snowfall is will depend on the track of the upper low. Fluctuations in this track will shift the axis north or south, and ensembles are still struggling to get in solid agreement on its location. Regardless, the chances for at least 4 inches of snow are at least 60% for most of the CWA, especially north of US Highway 10. The highest chances for at least 6 inches of snow are currently north of highway 200, sitting between 60 and 80 percent. Again, while the highest confidence for at least 6 inches of snow is within the central Red River Valley and north, fluctuations in track will change where the highest snow totals are. Snow will continue to last overnight through Sunday morning, with some lingering deformation zone snow behind the upper wave. Increased PGF and mixing will allow for winds between 20 and 30 mph, potentially gusting up to the 40s. Where the higher snow totals are, blowing snow impacts appear likely. The degree of whiteout/blizzard conditions is very uncertain at this time, especially with the lingering deformation band snowfall behind the low. With falling snow, the chance for blizzard conditions increase if it is collocated with higher winds. At the very least, blowing snow impacts are likely, decreasing visibility in some spots. At this time, the chance for blizzard conditions anywhere is at most 30%. To recap, a widespread snowfall event is anticipated to take place tomorrow, starting sometime in the afternoon near the ND/SD border. Most of the heaviest snow is expected to fall Saturday night through Sunday morning, with the highest chances for the highest totals being in the central and northern Red River Valley. However, fluctuations in storm track will cause a shift in where the highest snow totals are. Blowing snow impacts appear likely on Sunday, although the spatial extent is still uncertain. Regardless, travel impacts are expected, starting tomorrow afternoon and lasting through Sunday evening. .LONG TERM...(Monday through Friday) Issued at 200 PM CST Fri Dec 3 2021 A cold period to start next week as northwesterly upper level flow persists. Sunday night into Monday will see the impacts from the latest system wane with the coldest air of the season filtering into the region with falling temps Sunday night into Tuesday morning. NW winds will create wind chills of 15 to 30 below Monday and Monday night. Winds will decrease Monday night with cold SFC high pressure bringing temps down into the single digits to teens below for lows Tuesday morning. Temperatures moderate by the middle of the week with a more zonal upper flow trying to develop with ensembles indicating a 20 to 30% chance for snow Thursday with upper trough passing across the northern plains. Temps will rebound into the 20s and possibly 30s for Wednesday and Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 519 PM CST Fri Dec 3 2021 VFR conditions continue for all sites, with a few clouds at 25kft. Winds slowly diminish from diurnal trends, with a change in direction tomorrow morning into the afternoon as a front moves across the area. Winds shift begins near DVL and works its way toward BJI by mid afternoon. Ceilings slowly drop to 10kft as a cloud deck moves in Saturday morning. Aviation impacts increase after the current TAF period as stronger system brings snow, blowing snow, and low ceilings Saturday evening into Sunday && .FGF WATCHES/WARNINGS/ADVISORIES... ND...Winter Storm Watch from Saturday evening through Sunday afternoon for NDZ006>008-014>016-024-026>030-038-039-054. MN...Winter Storm Watch from Saturday evening through Sunday afternoon for MNZ001>009-013>017-022>024-027-028. $$ UPDATE...Spender SHORT TERM...Perroux LONG TERM...JK AVIATION...Spender