092 FXUS63 KFGF 250955 AFDFGF Area Forecast Discussion National Weather Service Grand Forks ND 355 AM CST Wed Dec 25 2019 .SHORT TERM...(Today through Thursday) Issued at 355 AM CST Wed Dec 25 2019 Wintry travel impacts the main concern today into tonight. Guidance is in good agreement with the synoptic pattern. Main issues will be attempting to get a handle on current impacts and then how to handle expected impacts. Currently, upper level system observed on water vapor imagery exiting the Texas Panhandle will propagate northward through the day. The region is currently in the warm sector with low clouds and fog/drizzle. Current observations indicate that the visibility due to the fog/drizzle is mostly above 1/4sm, so dense fog advisory is not required. However, there is scattered ice being reported on some roadways due to the fog/drizzle (freezing drizzle). One report from media indicated there is drizzle, but it is barely noticeable. Any freezing drizzle can be impactful, but thinking impacts are still more isolated than widespread, and will continue to message via the Special Weather Statement. Forcing is very weak right now as well. Guidance and current observations (radar) indicate two main forcing mechanisms to affect the forecast area. The first is stronger warm air advection ahead of the upper level system, with radar returns already observed across Nebraska. As this weak forcing enters the southern FA (timed to be mid-late morning), forecast sounding support freezing drizzle (no ice nuclei with sfc temps below freezing). Not sure how far north this forcing may get before weakening, and will issue a winter weather advisory for southeast North Dakota and adjacent portions of Minnesota for this more impactful freezing drizzle potential. The second forcing mechanism will be deformation as the mid-level low propagates through the region. As this forcing develops this evening, expect freezing drizzle becoming mainly snow. Given the potential for ice and then 1-3 inches of snow, will expand winter weather advisory into much of the Valley and Minnesota early this evening. Potential for greater than 3 inches of snow appears very low given this is a fairly transient system and banding potential is low (lack of Fgen). Snow tapers off on Thursday. .LONG TERM...(Thursday night through Tuesday) Issued at 355 AM CST Wed Dec 25 2019 00Z Fri - 12Z Sat Upper level trough over BC will move across southern Canada Thu night/Fri morning. Low level return flow will commence Fri. Another weak cold front will move out of Canada Fri night. Little or no precipitation is expected this period as well as no impacts at this time. Sat - Tue Long wave trough over the southwest US will shift east into the eastern US through the period. A broad flat long wave ridge will build into the western US. The concern for this period will be an upper level system will move across the Northern Plains Sat night into Sun. The ECMWF was trending slower while the GFS has remained relatively persistent over the last couple model runs. The ECMWF ensemble mean and GEFS were similar on Sat with a system affected area mainly south of our area. However north winds will increase Sat night into Mon. Potential impact could create drifting snow could ice up area roads Sat night into Mon. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 355 AM CST Wed Dec 25 2019 All sites IFR and will remain this way through the TAF period. Mist or freezing drizzle conditions expected to continue to worsen through the morning as well, becoming more likely and/or intense toward this evening. All aviators should check the latest icing products at aviationweather.gov as moderate-severe icing is possible with tomorrow evening's expected mixed precip event. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...Winter Weather Advisory from 10 AM this morning to noon CST Thursday for NDZ039-049-052-053. Winter Weather Advisory from 6 PM this evening to noon CST Thursday for NDZ027-030. MN...Winter Weather Advisory from 10 AM this morning to noon CST Thursday for MNZ003-027-029-030-040. Winter Weather Advisory from 6 PM this evening to noon CST Thursday for MNZ001-002-005>009-013>017-022>024-028-031-032. && $$ SHORT TERM...TG LONG TERM...JH AVIATION...Speicher/TG