Winter Weather and Heavy Freezing Spray Warnings for Michigan, Minnesota and Wisconsin

Urgent weather warnings are in effect for Minnesota today due to heavy freezing spray.

According to the National Weather Service (NWS), areas such as the Black River, Ontonagon, Portage Canal, Eagle River and Manitou Island, Minnesota, are being hit by "heavy freezing spray at a rate of two centimeters per hour (cm per hour). Saxon Harbor, Port Wing, Sand Island and Bayfield, Wisconsin, are also affected.

The warning is in effect until 10:00 a.m. CST tomorrow, with heavy freezing expected to start from 6:00 p.m. CST today.

According to NWS, a warning heavy freezing spray is for an "accumulation of freezing water droplets on a vessel at a rate of two cm per hour or greater." It is caused by a combination of cold water, wind, cold air temperature, and vessel movement. Operating a water vessel in heavy freezing spray is hazardous, as the spray may render mechanical and electronic components inoperative. Rapid ice accretion on decks and superstructures may result in a catastrophic loss of stability, according to NWS.

According to the warning issued yesterday at 10:04 p.m. CST last night, mariners need to prepare for a dangerous accumulation of ice on their vessels. If possible, it is recommended that they remain in port, avoid the warning area or conduct mitigation.

Areas that mariners need to avoid are:

  • Lake Superior west of a line from Saxon Harbor, Wisconsin, to Grand Portage Minnesota, beyond five nautical mile
  • Lake Superior from Saxon Harbor, Wisconsin, to Upper Entrance to Portage Canal Minessota, five nautical mile offshore to the U.S. / Canadian border including Isle Royale National Park
  • Lake Superior from Upper Entrance to Portage Canal to Manitou Island Minessota, five nautical mile offshore to the U.S. / Canadian border
  • Lake Superior West of Line from Manitou Island to Marquette Minessota, Beyond five nautical mile from shore
  • Lake Superior East of a line from Manitou Island to Marquette, Minessota, and West of a line from Grand Marais Michigan, to the U.S. / Canadian border beyond five nautical mile from shore
  • Lake Superior from Grand Marais to Whitefish Point, Michigan, five nautical mile offshore to the U.S. / Canadian border
Tuesday Weather Forecast 1 2019
Weather forecast for 12 Z Time, Tuesday, December 10, 2019 NOAA

The warning for the area also says that northwest winds of 15 to 20 knots with gusts up to 30 knots and waves six to nine feet are expected. The offshore waters forecast by NWS Fairbanks, Arkansas, for the U.S. Arctic waters says that waves may be twice as high due to combined wind wave and swell height. The forecast covers the early hours of this morning, with gale warnings in effect.

The weekly forecast from the NWS says that eastern U.S. and Gulf Coast will experience a strong cold front from tomorrow. "Widespread rain is expected ahead of the front Monday night and into Tuesday, with temperatures briefly above average for Tuesday for the East Coast," the forecast explains. The arrival of an arctic airmass in the Great Lakes region will support eventual snowy weather from the central Appalachians to New England before the end of tomorrow.

Western U.S. will experience unsettled weather patterns from today, with light showers and mountain snow, according to NWS. Stronger storms will lurk offshore, with the heaviest precipitation affecting southern Oregon and northern California.

For eastern Montana to northern Michigan, temperatures are expected to reach subzero lows with single digit heights.

Winter Weather and Heavy Freezing Spray Warnings for Michigan, Minnesota and Wisconsin | U.S.