The continued mild pattern across Upper Michigan over the past week will come to a quick end tonight as a strong cold front pushes through the region, bringing along an arctic air mass. Strong winds, much colder temperatures, and moderate lake effect snow are expected for tonight and Friday. Those locations exposed to northwest winds (the Keweenaw Peninsula and Alger/Luce counties) will see the biggest impacts. Below are the highlights of the system to help you plan your Thanksgiving travels.
1) Winter Storm Warning west and north central for strong winds and moderate snow off Lake Superior. A Winter Weather Advisory is in effect elsewhere...except for south central (Dickinson and Menominee Counties).
- Late tonight through Friday night: http://www.crh.noaa.gov/mqt/?n=winter_monitor
2)Timing of initial cold frontal passage
Central: This Evening
East: Late tonight
Winds will quickly turn to the west at 10-20 mph as the front passes (as has already been observed across western portions of Upper Michigan). However, winds are then expected to be northwesterly at 15-25 mph overnight through the day on Friday. Gusts over 45 mph will be possible for the Keweenaw Peninsula and along Lake Superior east of Marquette.
4) Lake Effect snow
Arctic air flowing over Lake Superior waters that are still in the mid 40s will lead to unstable conditions and promote Lake Effect Snow (LES) for areas prone to LES with northwest winds. Though a band of snow is possible along the front for the east on Friday, much of the precipitation with this system will be in the form of LES showers tonight through Friday. 8 to 12 inches of snow is possible across the western shoreline of Lake Superior (including the Keweenaw Peninsula between tonight and Saturday morning), as well as over the higher terrain of the Huron Mountains. 8 to 12 inches is also possible in portions of Alger County, lingering through Saturday afternoon. 4 to 7 inches could be expected elsewhere near Lake Superior. The strong winds combined with snow (falling, and on the ground) could reduce visibilities at times.
5) Much colder temperatures
Warm temperatures in the 50s earlier today will quickly drop to the mid 20s for the west half and mid 30s for the east half by early Friday morning. Temperatures on Friday will then continue to fall throughout the day, with all of Upper Michigan below freezing by Friday evening. With the expected strong winds, wind chills will drop into the lower teens by Friday, and into the single digits above zero for the west half on Friday night.
Regional Overview of Snowfall Totals
This map is a regional view of expected snowfall totals through Saturday afternoon. For those traveling, check with the local forecast for updated travel conditions. For roads within the highest snow totaling areas, expect them to become snow covered and slick, with blowing snow and white out conditions possible. Take extreme caution and be safe!