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2024 Hennepin County All -Jurisdiction Hazard Mitigation Plan <br />Volume 2 — Hazard Inventory <br />8 years inside the 494-694 loop. It should also be noted that blizzard conditions can occur without large <br />snowfall accumulations. These "ground blizzard" situations are most common in rural Minnesota, but can <br />occur in open areas of Hennepin County, west of the 1-494 corridor, and especially west of MN highway <br />101. <br />Calendar -day . <br />.. <br />.. <br />2-day snowfall.. <br />3-day snowfall•: <br />5-day snowfall•: <br />total <br />November 1991 <br />(nearMonthly <br />. Lake . <br />994 <br />Snowstorm total <br />47" (near FInland, Lake County <br />01/06-08/1995 <br />Monthly total <br />.. (Collegeville) <br />• • <br />4.3.11.3. Spectrum of Consequences B211b <br />Outdoorlife safetyhazards: Severe winter storms and blizzards are often accompanied by falling <br />temperatures and dangerous wind chills. Persons caught outside unprepared can face <br />disorientation, frostbite, hypothermia, and death. A quarter of winter storm casualties occur <br />among those caught outside in the storm. <br />Poweroutoges/utilities: Heavy snow can cause power outages from direct loading on electrical <br />wires, and more commonly from indirect sources, for example when tree limbs become <br />overloaded with snow and fall onto wires. Heavy, wet snow can cause widespread power outages, <br />and strong winds exacerbate this impact. The duration of service outages is typically related to <br />the complexity and magnitude of the outage pattern, along with the ability of crews to get to <br />repair sites. Thus, high -volume, heavy, wet, wind -driven snow events are associated with higher <br />outage numbers and longer service delays. <br />Structural failure: Heavy snow will can cause roof collapse, not just at residences, but at larger <br />commercial facilities as well. Large roof spans lacking consistent support are especially vulnerable. <br />The former Hubert H Humphrey Metrodome Stadium in Minneapolis failed three separate times <br />from excessive snow loads causing the Teflon canopy to tear. <br />Transportation: By far the greatest and most common impacts from winter storms in Hennepin <br />County are to the transportation infrastructure, but there is no strict threshold above which heavy <br />snow is guaranteed to produce a particular impact. Stranded vehicles and snow removal costs <br />increase with greater accumulations, but accidents and spinouts are often a function of prior road <br />conditions, driver preparedness and awareness, and the consistency of the accumulating snow. <br />For instance, from January 31- February 2, 2004, a well -forecast series of winter storms produced <br />widespread 8-11" snowfall totals across the Twin Cities, but a relatively small impact, owing to <br />preparedness, and the generally fluffy nature of the snow. By contrast, a much smaller event on <br />March 8 that same year, produced only 1-3 inches, but did so unexpectedly and within a 2-hour <br />window. This "surprise" event caused hundreds of spinouts and accidents and forced the closure <br />171 <br />