The top map shows severe weather reports for Wed. and Wed. night. There were 136 severe wind reports, 15 reports of large hail and one tornado in Utah, though I saw a pic. of a tornado in Wisconsin and that will likely be surveyed. The fastest measured wind gust was 78 mph at Weston Wisconsin, but there were many areas that had 50-60 mph gusts and wind damage, which was mostly downed trees and wires. There were a few spots with structural damage, including a portion of the roof of a Family Dollar store coming off at Osseo WI.
As of early Thu. PM, there were still 47,449 customers without power in Wisconsin (it was up over 80,000 last night), 13,453 in Illinois and 11,305 in Michigan. The Michigan total included 624 customers in Allegan Co., 324 in Kalamazoo County and 220 in St. Joseph County.
Wind damage (mostly downed trees, wires and limbs) was reported at S. Haven, Beechwood, Otsego, Allegan, Cooper Twp., Parchment and Vicksburg. Peak wind gusts: Macatawa 61 mph, Wayland 51 mph, Port Sheldon 47 mph, S. Haven Beach 46 mph, Battle Creek 45 mph. The Severe T-Storm Watch that SPC (with the help of the G.R. NWS) around 2 am was right on – with the watch including Allegan and Kalamazoo Counties, but not Kent Co.
Most rainfall reports were relatively light. We did get a report of 1.12″ in Saugautck. Holland (arpt.) had 0.43″, Kalamazoo 0.21″, Grand Rapids (arpt.) 0.08″ and Battle Creek just 0.05″.
Interesting note…there was a seiche (meteotsunami) on Lake Michigan last night. As the strong northwest winds pushed out from the thunderstorms they pushed the water on Lake Michigan, causing it to “pile up” at the south end of the lake. The water level rose up to 2.5 FEET. The water than retreated as the strong winds ended. That’s why it can be dangerous to head back in the water or go out on the piers after a windstorm – the water levels can go up and down, creating dangerous rip and structural currents.
The storms last night, while not nearly as strong, took a similar path to the“More Trees Down Derecho” of July 14-15, 1980. That derecho produced a 112 mph gust at Eau Claire, Wisconsin (then the anemometer used to measure the wind blew away) and 103 mph at Benton Harbor, Michigan. Power was knocked out for 10 days in parts of Southern Lower Michigan. The TV stations and 7 of the 8 radio stations in Eau Claire WI were knocked off the air by the storm. Here’s a list of the circumstances of the deaths and injuries with that storm:
This derecho in 1980 was strong enough to overturn mobile homes.
Some generic tips on what to do before the storm hits:
Stay away from windows, esp. on the west and sides of buildings – windows can break and the glass flies in. Make sure people who are camping know of the threat. Limbs and trees can fall on tents and RVs.
If you can, don’t park your vehicle under a tree(s) tonight. Keep your garage door closed. Pick up your yard this evening – so that things like toys and your garbage bin don’t blow away. Take down hanging baskets and bird feeders that may get blown down in the storm.
Trampolines can get picked up and tossed about by the winds. Turn then upside down if you can. With the threat of power outages, make you have your phone charged and keep a flashlight handy if the power goes out. Pets are often scared of the lightning, thunder and wind. Try to find a safe and relatively quiet place for them. Watch for downed power lines. Most down lines are not live, but a few are and they can be deadly.
Try not to travel at night during the storm (strong wind, low visibility, flying debris) or after the storm (downed trees, wires and limbs on the roads that might be hard to see in the dark.
Try to minimize travel during and after the storm. There will likely be trees, limbs and wires down across roads. During the Iowa Derecho of August 10, 2020 – there were more injuries AFTER the storm than DURING the storm…with people falling, stepping on debris and having accidents cleaning up.
Also – beware of a seiche on Lake Michigan. Strong winds can push the surface water toward the Michigan shore. Watch for the water level to rise – perhaps 1-3 feet if it’s a strong derecho ) – then retreat significantly as the water “sloshes” back toward Wisconsin…that sloshing back and forth could last for hours, creating dangerous rip currents and structural currents later tonight into tomorrow AM. A seiche is sometimes called a meteotsunami. METEOTSUNAMIS ARE GENERATED FROM FAST MOVING SQUALL LINES THAT SWEEP OVER THE LAKE. RAPID WATER LEVEL FLUCTUATIONS CAN BE EXPECTED WITH METEOTSUNAMIS. PEOPLE WITH INTERESTS ALONG THE LAKE MICHIGAN SHORE AND IN HARBORS DIRECTLY ADJACENT TO THE LAKE SHOULD BE AWARE THAT THAT THESE RAPID WATER LEVEL FLUCTUATIONS ARE POSSIBLE TONIGHT AND INTO THE MORNING HOURS OF THURSDAY.”
The map was the Severe Weather Outlook Area from the Storm Prediction Center for the storms Weds. night. Compare this to the top map of storm reports. Their forecast was a little too far northeast. We didn’t get the severe weather in Grand Rapids, but they did in NE Illinois. The storms tracked more SSE (or even south) than SE.
From the La Crosse WI NWS: “ONCE THE STORMS START, THEY WILL ESCALATE VERY QUICKLY…ZERO TO SEVERE IN 1/2 HOUR?” And that’s what they did.
This is the Severe Weather Threat Map for this jPM/night (Thu.) The storms will be across IL/IN/OH. Wind damage is still the greatest threat.
Lake Michigan water temps. (and probably inland lakes as well) are about as warm as they are going to be all summer. A north wind will likely mix in cooler water starting on Thursday night and we may see significantly cooler water early next week. So, if you like warm water at Lake Michigan – head there now and take a dip.
Current water temps: Muskegon 77, Holland 74, S. Haven 75.
The average wind speed from midnight to 5 pm in G.R. was just 2.8 mph – the calm before the storms.
Also: In the last 24 hours, Death Valley, California (Furnace Creek), has had more rain (0.74″) than Portland (OR), San Diego, Los Angeles, Honolulu, San Francisco, Spokane, and Denver have COMBINED for all of July. Death Valley has also had more rain this month thru 7/28 than Holland MI (0.70″).