The line of severe thunderstorms that moved through Pine County, Minnesota, and northwest Wisconsin, produced widespread, non-tornadic wind damage. Such winds are also often referred to as "straight-line winds" or "downburst winds". The damage included some areas of very intense forest blowdown. The National Weather Service in Duluth conducted a storm damage assessment the following day in parts of Pine, Burnett, Washburn, and Douglas Counties. This assessment was aided by aerial flyovers of the damage by the Burnett County Sheriff's Department. Both the ground and air assessments concluded that the damage across the area was caused by widespread, non-tornadic, straight line wind gusts in excess of 60 mph, with smaller pockets of intense winds in excess of 100 mph .
Damage Map
Based on a combination of information from aerial and ground surveys, as well as spotter reports, we have created a map of the swaths of the most intense wind damage associated with these thunderstorms. Generally, these areas were a few miles wide and consisted of "straight-line" or diverging damage patterns.
Over the entire area pictured on the map there was at least sporadic tree damage, and wind gusts were likely into the 50 to 60 mph range at most spots. In the first level of shading, damage was observed to be more concentrated, and these were areas where many trees were damaged or blown over. Winds in those areas were likely closer to 70-80 mph. In the second level of shading, there was a combination of more intense tree damage and damage to a few structures. Winds were likely between 80 and 100 mph in those spots. And in the darkest level of shading, corridors of severe forest blowdown existed. Winds in those spots likely exceeded 100 mph.
The EF-2 tornado track near Solon Springs is also plotted in red.
Keep in mind that there will be some areas that aren't shaded that may have experienced much smaller areas of significant wind damage. However, in general, the shaded areas in the map represent the areas where the greatest concentration of damage existed.
Aerial Photographs
Often times when meteorologists are assessing storm damage, aerial photographs can be extremely valuable in determining the extent and cause of the damage. This is especially true in parts of northeast Minnesota and northwest Wisconsin where large tracts of forest can limit the area of a ground survey. In this particular case, the aerial photographs revealed widespread wind damage. Non-tornadic damage will involve the vast majority of trees or objects being blown in a similar direction. Special thanks go to the Burnett County Sheriff's Department for conducting the flyover of the damage, and providing these images to National Weather Service meteorologists.
First, here are some annotated versions of the aerial photographs showing approximate damage vectors (the direction trees and objects were blown).
Here are some unedited versions of aerial photographs from around the Burnett County area. Photos were taken by Stacy Hopke of the Burnett County Sheriff's Department.
Ground Survey Photographs
National Weather Service meteorologists also conducted a ground survey. Here are some pictures from that survey.
Historical Forest Blowndown Events
Areas of northeast Minnesota and northwest Wisconsin are susceptible to forest blowdown events from time to time, some more severe than others. One can pretty easily compare the damage photos from Burnett County on July 1, 2011 to photographs from several other major forest blowdowns in the area. In all those events, broad swaths of trees were removed from the existing forest. However, in this particular case, the forest damage was not as widespread across the area as the examples provided below.
Left in the storm's path are hundreds of property owners removing dead tree from roof tops, driveways, yard and lake shore areas. Consider the following tips:
MANAGE YOUR FIRE HAZARD
The 2012 spring's fire season is coming soon, so be sure to think about the fire-fuel downed trees will create next spring. Focus on cleaning up dead trees and branches close to your home and driveway, removing the fuels that will create a fire hazard near your buildings first and foremost. If you burn, be sure (e.g. leaves, brush and pine needles) you obtain an annual burning permit and check each day for burn restrictions. Burning when the ground is snow-covered is by far the safest option. Covering brush piles with a tarp will keep them dry prior to burning when the ground is snow covered and on a day when calm winds won't blow smoke over a busy road or into your neighbor's house. Keep brush piles a safe distance from buildings, sheds and over head utility lines. For those of you owning larger property with extensive damage you can find helpful information at http://dnr.wi.gov/forestry/stormrecovery/
LEAVE DOWNED TREES FOR FISH WILDLIFE
Downy woodpeckers, wood ducks, chickadees, flying squirrels and a host of other wildlife species use tree cavities in dead or dying trees. Consider leaving a few dead trees(those that don't pose a hazard) and enjoy watching the wildlife that will move in. Dead and downed trees in lakes are important habitat features for fish and wildlife. They are used by many different species for hiding, feeding, roosting and basking in the sun.
REPLANT TREES
Consider replacing lost trees with seedling trees. The Burnett County Land and Water Conservation Department offers a variety of native "bare root" trees for sale each spring. The Town of Jackson in conjunction with S&S Tree Service will also be selling these kind of trees in the spring. Watch this website as well as the Town of Jackson website for information on this event. The variety of trees offered may be red pine, red oak, red maple and white pine. Because they are bare roots they need to be picked up and planted in a timely manner. For Burnett County you can contact Ann Lane at 715-349-2186 if you would like a tree order form. The trees are three year old transplants and are 10-16 inches tall. You can also print the order form for yourself by going to www.burnettcounty.com/treesale.
Local nurseries typically offer bare root tree early in the year for a few days and then offer a variety of pottedd seedling and sapling trees throughout the growing season.
PLANT SHRUBS
Shrubs are typically more resistant to wind damage than large trees, thye provide great wildlife habitat and provide attractive fall colors.
Schedule a shoreland site visit. In addition to helping guide your tree and shrub planting needs you can expert advice on controlling erosion on your property and receive a free no-strings attached shoreland planting tailored to fit your property and your needs while protecting our beautiful lake and providing wildlife habitat. Contact Ann at Burnett County Land and Water Conservation Department to schedule a FREE visit with a shoreland restoration expert at 715-349-2186 or email her at alane@burnettcounty.org.
