Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/26/20

Area Forecast Discussion
National Weather Service Grand Forks ND
917 PM CST Fri Dec 25 2020 .UPDATE... Issued at 916 PM CST Fri Dec 25 2020 Seeing some patchy ground fog forming around Fargo to Thief River Falls. Conditions over the region highly variable. Some spots are calm and temps have dropped to around 10 degrees. Other locations mainly west of the RRV have a light west wind and not as cold. Then Warroad to Bemidji area in clouds and likely stay in them as upstream cloud cover extends well north. Updated to expand patchy fog mention to most areas, except far east, into Sun AM. UPDATE Issued at 604 PM CST Fri Dec 25 2020 A mild day west of the Red River and this evening continued mild with a light NW wind and some high clouds. Band of stratocu that dropped out of E Manitoba and Ontario is moving south mainly affecting Baudette but finger of low clods moving thru Bemidji to near Detroit Lakes. This band is moving southeast pretty quickly with clearing behind it. But upstream stratocu in E Manitoba likely will keep immediate Lake of the Woods area cloudy tonight. Rest of the area, the degree of cloud cover and especially what type is uncertain. Many of the short term models develop low clouds in an area of high pressure which will be Minot to Jamestown region late tonight. Some fog in this zone as well is possible. Uncertain as to extent of this in our fcst area, though higher chances in DVL region to Valley City and this is where prev shift has some patchy fog overnight. Low temperatures as well are a bit tricky as dew pts at 00z in the 15-25 degree range E ND but with high moving in and winds going light radiational cooling enough to lower temp and dew pt...though HRRR sfc temps have more teens vs single digits in E ND. && .SHORT TERM...(This afternoon through Sunday) Issued at 330 PM CST Fri Dec 25 2020 Main short term focus is on the clipper this weekend that could bring light accumulations and slick travel conditions to our region. This afternoon-Tonight: Quiet and relative mild conditions are in place with above freezing temperatures across much of eastern ND this afternoon and mostly sunny skies. There will be an increasing trend in cloud cover (high from the west and low from the east) this evening. Overnight temperatures should be near seasonal averages in the single digits above zero. As low level moisture increases low clouds and even some patchy fog may develop by Saturday morning. Saturday-Sunday: The clipper moves across our region Saturday night into Sunday followed by a stronger cold front Sunday night. There is good consensus that light snow will progress across most of our forecast area west to east, with around 1" or less likely based on model consensus. Good synoptic forcing is advertised, but mesoscale forcing will tend to be more disorganized, with progressive pockets of elevated frontogenesis shown by NAM/GFS. So, while localized higher amounts are possible as indicated by HREF/and some outliers confidence isn`t as high in where 2" or greater amounts may actually set up. Winds during the event should generally remain 5-15 mph, but as the cold front moves in, northerly gusts 20-30 mph may lead to patchy drifting/blowing of any snow that has fallen Sunday afternoon. Most likely impacts will be slick travel conditions with some visibility restrictions mainly due to the snowfall itself. .LONG TERM...(Sunday night through Friday) Issued at 330 PM CST Fri Dec 25 2020 Overview... A potentially impactful winter weather system will be possible Tuesday into Wednesday, but exact details are still variable at this time. Otherwise, the majority of the long term period is expected to remain quiet with generally below normal, but still seasonable, temperatures. Northwesterly flow aloft looks to continue to dominate the upper level pattern. While this pattern is typically conducive to periodic, transient shortwaves, ridging over the Pacific Northwest will keep the majority of these waves to the north of the international border. The Tuesday/Wednesday system, however, will be driven by an upper level trough progressing through the Plains. Sunday night and Monday... Some lingering light snow may be possible across west central Minnesota but should taper off moving into the overnight hours. A brisk northerly wind will aid in dropping low temperature by Monday morning into the negative single digits to negative teens across the forecast area. Below normal temperatures are expected to persist into Monday with highs in the single digits to mid teens. Tuesday through Thursday... The quiet weather pattern may potentially be disrupted by the aforementioned upper level trough. Ensemble guidance is in relatively good agreement on the timing of the incoming system, but there are still significant discrepancies from member to member with respect to the location of this potential system. GEFS and ECMWF ensembles are depicting a negatively tilted system that would increase snow potential over our forecast area as a result of the placement of the deformation zone. In contrast, CMC ensemble members are showing indications of a relatively vertically stacked system which would keep the system further to the south of our forecast area. This variance between models and ensemble members alike adds to the uncertainty of the location and intensity of this system which in turn factors heavily into the potential impacts from this system. All of that being said, current consensus is leaning toward the best chance for measurable snow for areas south of highway 2. Confidence is still low however and this system will continue to be monitored moving forward into next week. Prior to this system, high temperatures on Tuesday are expected to remain near normal for much of the forecast area. Following the passage of this system, high pressure looks to settle in and slightly below normal temperatures return to the area and should persist through the midweek period. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 604 PM CST Fri Dec 25 2020 Uncertainity is present in regards to develop of lower ceilings (MVFR and psbl IFR) late tonight/Sat AM. DVL seems most likely vs GFK/FAR/TVF. High pressure will be in the Minot-Jamestown area by 12z and with it light winds and potential for some fog/low cloud formation. Bemidji area too could be affected by lower band moving thru at 00z but upstream clouds in eastern Manitoba may affect BJI area overnight/Sat AM. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. $$ UPDATE...Riddle SHORT TERM...DJR LONG TERM...Rick AVIATION...Riddle