ESCANABA — With a string of thunderstorms and unusually warm weather hitting the area over the last few weeks, some may be wondering exactly what risk tornadoes, high winds and other natural disasters pose to Delta County.

According to the Federal Emergency Management Agency, commonly known by the acronym FEMA, the U.P. as a whole is a very low risk area for natural disasters, with Keweenaw County having the lowest recorded risk index score (0.1) and Marquette County having the highest at (38.02). Delta County comes in third with a risk index of 7.83, just behind Dickinson’s 8.53.

The index values are calculated using a series of formulas that first evaluate expected annual losses from 18 natural disaster types based on their exposure, annualized frequency, and historic losses. That value is then multiplied by the community risk factor, a separate metric based on social vulnerability — the susceptibility of social groups to the adverse impacts of natural hazards, including disproportionate death, injury, loss, or disruption of livelihood — divided by community resilience — the ability of a community to prepare for anticipated natural hazards, adapt to changing conditions, and withstand and recover rapidly from disruptions.

Perhaps unfairly, areas with fewer buildings, lower population or less agriculture will skew towards a lower risk index value because the expected annual loss is based on those three metrics. That inherently makes low population areas like the Keweenaw less risky than higher population areas like Marquette. It’s also why the highest risk index areas in Michigan are Wayne and Oakland counties and the greater Detroit-metro area.

Still, the data from FEMA paints a picture of what the risks are in each county. As would likely be expected, cold waves are the number one risk across the Upper Peninsula. The risk index scores for Marquette, Dickinson and Delta Counties are 94.15, 87.15, and 84.25, respectfully, placing all three counties in the “relatively high risk” category and suggesting that cold waves are one of the largest treats to property, life and agriculture.

In Delta County, the expected annual loss related to cold waves is $447,142. Most of that loss is related to “population equivalence,” FEMA’s calculation that translates injuries or deaths into economic loss. For cold waves, each fatality or ten injuries is treated as $11.6 million in economic loss, meaning it is expected than about two and a half people will be injured by cold waves significantly enough to cause economic disruption every year in Delta County.

Perhaps the most surprising part of FEMA’s data for Delta County is the number two hazard for expected annual loss: tornadoes, which FEMA estimates could cost the county $257,495 annually.

Over the past few years, a significant amount of buzz has been generated in the weather tracking community about changes in where tornadoes are forming. According to the National Weather Service, both tornado reports and tornado environments indicate an increasing tornado trend in portions of Mississippi, Alabama, Arkansas, Missouri, Illinois, Indiana, Tennessee, and Kentucky.

However, that shift to the east of “Tornado Alley” and the Great Plains may not be the reason FEMA is concerned with tornadoes in Delta County. According to data from the National Oceanic and Atmospheric Administration (NOAA), at least 10 tornadoes have hit Delta County since records began in 1950. Most of these tornadoes are small, weak, and only travel a mile or less on the ground. The notable exception was an F3 tornado that ripped a 71-mile long path through Schoolcraft, Delta, Menominee and Dickinson County on July 11, 1987.

The FEMA calculations are based tornados from a 70 year period from Jan. 1, 1950 to Dec. 31, 2019, but not all tornados are included in the metric. all tornadoes in the 70 year period are included for F2 to F5 — or EF2 to EF5, if using the newer Enhanced Fujita scale implemented to replace the Fujita Scale in 2007. Weaker tornadoes are only included in the data from Jan. 1, 1986 to Dec. 31, 2019. Those weaker tornadoes are more frequent than their higher-powered counterparts, with the most recent in Delta County being an EF1 tornado recorded on Aug. 31, 2020.

The next most significant expected annual loss is strong winds, which are scored as a higher risk for the county than tornadoes despite being less impactful financially. FEMA expects the annual loss value to be $186,282.

Also scored as a higher risk than tornadoes but with less financial impact is riverine flooding. Flooding rivers have an estimated annual loss value of $122,751, despite having a risk index score of 29.1 — less than the risk score of 35.4 for strong winds, but more than the 25.3 for tornadoes.

While Delta County has a number of rivers, flooding is relatively rare, occurring at a rate of less than once a year on average according to FEMA. However, like tornadoes, the amount of damage caused by flooding rivers is measured over a multi-year period — in this case, 24 years — to develop the estimated annual loss from floods.

Winter weather as a whole — excluding ice storms — comes in as the second highest rated risk for the county based on the risk index, at a score of 70.8, but winter weather is well below in cold waves in terms of expected annual loss. According to FEMA, the expected annual loss related to winter weather is $111,790. Ice storms come in much lower at only $908 in expected annual loss with a risk index score of 3.1.

Other hazards include lightning ($105,896 estimated annual loss; 55.6 risk index), landslides ($21,900; 38.8), hail ($13