When the weather hazards transition for the season from threats associated with severe thunderstorms to the threats associated with heavy snow, ice, and the flooding conditions that can result from runoff or ice jams, the Winter Weather Outlook will replace the Thunderstorm Outlook in the upper right hand corner of the blog. This widget will change modes depending on whether or not Michigan faces threats from primarily heavy snow vs. threats from freezing rain.
---Snow Template Legend---
Blog Forecasts:
• Snow Flurries Possible: Little to no accumulation would be expected in these regions, though flurries through the air would be expected. Conditions hinder visibility, especially during the night time hours, but otherwise a light dusting caused by a weak system or light lake effect snow showers.
• 1-3" Accumulation Possible: The typical disturbance caused by an Alberta Clipper or moderate lake effect snow showers. Light accumulation added to what - if any - is already on the ground. Usually powder. Roads could become slippery during the overnight hours.
• 3"+ Accumulation Possible: A stronger winter storm and/or blizzard could impact the area within the coming week. Preparations should be made for an event which could significantly impact travel during the forecast period.
National Weather Service Alerts:
• Winter Weather Advisory: Significant winter weather is expected or occurring. Criteria varies for state to state, but as far as Michigan is concerned, this would typically mean 3-6" of moderately heavy snow expected within a 24 hour period when used in the snow template. Travel during a winter weather advisory is typically treacherous and slow.
• Winter Storm Watch: Very significant winter weather is expected within 48-36 hours of the issuing of a watch. For Michigan, this typically means 4"+ of snow is expected within a 24 hour period. As model data progresses, areas under a watch will typically either be changed over to a winter weather advisory or upgraded to a warning.
• Winter Storm Warning: Severe winter weather is expected within 24 hours of issuance. For Michigan, this typically means 6"+ of heavy snow expected within a 24 hour period, or slightly lesser amounts combined with significant blowing and drifting (usually winds in excess of 25mph). During a winter storm warning, travel can be especially dangerous and should be avoided if possible.
• Blizzard Watch: A winter storm watch with the added fun of winds potentially exceeding 35mph, which in combination with ~5"+ of heavy snow meets blizzard criteria. These watches are frequently upgraded to blizzard or winter storm warnings and should be taken very seriously when issued. Typically issued 48 hours in advance of a very powerful storm in order to allow people adequate time to prepare for being snowed in.
• Blizzard Warning: As bad as it gets. Extremely severe winter weather is expected within 24 hours of issuance. For Michigan, this means significant amounts of heavy snow within a 24 hour period in combination with winds in excess of 35 miles per hour. Visibility will be near zero in addition to snow totals which can easily exceed a foot or more combined with significant blowing and drifting.
DO NOT TRAVEL if a Blizzard Warning is in effect except in an emergency situation, and be certain to take a
winter survival kit with you if you must. Becoming stranded during a Blizzard Warning is very likely, as many roads will become impassible. Emergency crews will likely be unable to reach residents during such conditions, so adequate preparation for potential days of isolation should be made.
---Ice Template Legend---
Blog Forecasts:
• Rain Possible: Primarily liquid precipitation is expected with little to no freezing transition. This will occur when counties are in the path of the warm sector of a storm system where temperatures remain above freezing.
• Sleet Possible: Frozen ice pellets or icy slush - typically seen during our "wintry mix" days. Slush can make for miserable travel and especially slippery roads, as well as difficult walking for those sensitive to the often stinging cold droplets. Windshields tend to ice over more during this condition than any other.
• Freezing Rain Possible: Rain which initially falls clear but quickly freezes as soon as it adheres to a surface. A particularly nasty situation, as roads and bridges almost always become iced over quickly, and tree branches and power lines may become coated in extreme situations, leading to increasing weight, which can cause power outages and structural damage.
National Weather Service Alerts:
• Winter Weather Advisory: When a winter weather advisory is issued for sleet or freezing rain, it often means conditions will cause travel conditions to deteriorate enough to be dangerous. Visibility may be inhibited, and roads will likely be slick and treacherous.
• Winter Storm Watch: Typically issued 36-48 hours in advance of a potential ice storm or mix of significant snowfall with freezing rain.
• Freezing Rain Advisory: Significant freezing rain is expected or occurring. Travel conditions will likely be very dangerous, especially at high speeds, as roads and bridges will be covered with ice. Extreme caution is advised when traveling in such conditions.
• Winter Storm Warning: When issued for a snow/ice event, typically includes 3"-4"+ of snow in combination with 0.2"+ of ice. Severe conditions will make for extremely dangerous travel, which should be avoided if at all possible. Usually issued within 24 hours of a snow/ice event.
• Ice Storm Warning: Usually issued within 24 hours of what is typically an extreme freezing rain event. 0.25-0.5"+ of ice coating will likely cause significant structural damage and power outages. Travel conditions will slick and dangerous, and travel is not advised. It is recommended to stock up on adequate supplies of non-perishable food items and water if such a warning is issued, as damage to electrical infrastructure and difficult travel conditions can lead to extended periods of isolation.
