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NWS preliminary survey shows damage from EF0, EF1 tornadoes

Posted at 7:39 PM, Aug 21, 2016
and last updated 2016-08-21 22:53:58-04

WEST MICHIGAN — Preliminary surveying from the National Weather Service has found EF1 tornado damage in Allegan, Ottawa and Van Buren counties and EF0 damage in Kent County from Saturday's storms.

A complete investigation with final ratings are still to be determined.

After tornadoes ripped through several portions of southwest lower Michigan on Saturday, the National Weather Service has the difficult task of surveying all of the damage in each location with a fine tooth comb. What they're looking for is something very few of us can find and recognize: a twisting, turning motion, damage and destruction in similar directions, or something else that will tell them exactly what kind of weather tore through our area.

While one survey was already completed in northern Ionia County and southern Montcalm County Saturday evening, that storm was classified as an EF1 tornado with maximum 90 mph winds. The path was eight miles long and about 100 yards wide. By EF1 standards, low on the scale that goes all the way to 110 mph winds.

Two NWS storm damage survey teams were out on Sunday taking photos, talking to witnesses, and trying to piece together whether one long-lived long track tornado, or a combination of several tornadoes cut a swath of extensive damage across a four county area beginning in Van Buren County around Bangor, then travelling north/east through Allegan County, extreme southeast Ottawa County, and southwest Kent County...including the south side of Grand Rapids proper in Wyoming.

Here's what we know so far according to the Grand Rapids National Weather Service:

"Investigation of Saturday`s tornadoes from Van Buren to Kent County will continue on Monday. Survey teams have confirmed tornado damage did occur in Van Buren, Allegan, Ottawa, and Kent Counties. However, surveys need to be completed before more detailed information can be provided. There is preliminary evidence of EF-1 damage in Van Buren, Allegan, and Ottawa Counties, and EF-0 damage in Kent County. Survey teams will provide additional information Monday.

We do know that a brief EF0 tornado touched down in Kent County near Perkins Avenue northeast between Leonard Street northeast and Knapp Street northeast. Tree damage and some property damage from fallen trees occurred as a result. The time was estimated at around 2:50 P.M. Peak winds were estimated between 70 and 80 mph. The path width was approximately 25 to 50 yards. Path length was about .75 mile long. Our preliminary report also indicates this tornado was on the ground for about two minutes."

The task is daunting and overwhelming to say the least with several miles that need to be surveyed, examining tree damage (broken/sheared/uprooted), the size of those trees, and any structural damage to houses. In fact, in the early days of classifying wind damage, the Fujita scale developed by famed scientist/meteorologist Theodore Fujita, classified tornadoes and wind speed by the damage they did. F0, F1, F2, F3, F4, and F5. That scale became somewhat outdated and obsolete in recent years not taking in to account the newer building codes and the newer materials and more structurally sound construction of todays times. So an "enhanced Fujita" scale was developed and that is what we adhere to now.

Any wind damage, whether by tornado, straight line winds, microburst, etc., is classified with this newer EF scale. EF0 damage is 65 to 85 mph winds. EF1 damage is 86 to 110 mph winds. EF2 111 to 135 mph winds. EF3 136 to 165 mph, EF4 166 to 200 mph, and EF5 is over 200 mph winds. These winds are estimated not measured. Click here for more on the Fujita scale.

It is likely with some of the tree and structural damage that this one tornado, or multiple tornadoes did from Van Buren to Kent County, it will be mainly EF1 damage. It will be the job of the NWS to determine where and when the tornadoes hit (calibrated/corresponding to radar data/time), what type of damage on the EF scale they did, or if it lifted in certain places and became more straight line wind damage.

It's worth noting that some of the uprooted trees, not the ones sheared off, may have been the result of previously saturated soil from very heavy rains earlier in the week. It's the tree trunks, branches, and limbs, as well as any structural damage, and the direction in which they are laying that will be the tell tale sign of either an actual tornado or straight line wind.

It goes without saying that we as a community are very fortunate that there were no fatalities or injuries reported amidst all the devastation and destruction. For a damage path that reportedly spanned several miles and four counties, that was indeed amazing! Property can be replaced, but the value of human life and safety are immeasurable. Meteorologists do what they do to save lives and help prevent injuries. The fact that we clearly saw and tracked rotation with these cells and had a substantial lead time before they hit highly populated areas is a true testament to our current technology. While we can't catch everything and our current NWS Doppler radar is far from perfect, it's the best we have in 2016.

Get the complete West Michigan forecast at www.fox17online.com/weather.