More storms in metro Detroit forecast, plus important lesson about tornados

DETROIT – Before getting to the forecast, I want to emphasize a very important lesson we learned Wednesday afternoon.

As you've probably heard by now, sirens started going off around 2:10 p.m. Wednesday. There were no tornado warnings in effect. I learned about this when my phone started ringing, and I started getting tweets about it.

Shortly thereafter, some of you started posting photos of a funnel cloud on Storm Pins, as well as e-mailing and tweeting photos to me and, later, reports of a possible touchdown. Your communication was EXTREMELY helpful, as there was almost no indication on radar of a tornado, and Ben Bailey and I were scanning that storm with our radar velocity tool and saw no evidence of rotation.

How could this happen?

The radar beam at the location where the funnel cloud first formed is just over 1/2 mile wide. The weak funnel that developed was much, much smaller than that and, since the storm was not a rotating supercell, the funnel was way too small to be detected by the radar, although Ben and I did see a small hook echo develop, which prompted us to cut into programming and alert you to at least the possibility of a funnel cloud or tornado.

Late Wednesday afternoon, the National Weather Service confirmed an EF0 tornado with 75 mph wind briefly touched down on Place Road between 29 Mile and 30 Mile Roads in Lenox Township. The path length was estimated to be only a 1/4 mile long, with a path width of 100 yards. Several trailers were blown over, and the roof to a garage was torn off.

Wednesday was NOT a day conducive for severe weather. Something very localized to northern Macomb County caused enough wind shear to spin up this small tornado. While Doppler radar shows us rotation in storms long before most strong tornados touch down, small or weak tornados like we had Wednesday are almost impossible to detect, which leads us to a very important lesson: If you EVER see the type of dangerous weather that makes you think your life is in danger, immediately head to your place of safety and don't wait for the warning. Enough people called local law enforcement reporting a funnel cloud, so sirens were properly sounded on the basis of that information.

Again, I cannot express strongly enough how important your communication was. I had no idea that a funnel cloud, and then a tornado, had developed until you told me about it. If this situation ever repeats itself, make sure you take care of yourself first -- take cover immediately, and only then, if you can safely do it, tweet or e-mail me.

You can follow me on Twitter at @PaulGrossLocal4, and you can e-mail the Local4Casters at Local4Casters@ClickOnDetroit.com.

Alright, onto the forecast:

Any isolated evening showers and thunderstorms should end fairly steadily after sunset, leaving us partly cloudy for the balance of the night. Lows in the mid 60s. West wind at 4 to 7 mph.

Warm and humid on Thursday with afternoon thunderstorms once again possible. The best chance to see some storms and even a slight...albeit very uncertain...severe weather threat is basically south and west of a line from Detroit to Muskegon. Highs near 80 (perhaps into the 80s if we get more sunshine). Southwest wind at 5 to 10 mph.

We still have some shower and thunderstorm chances Thursday night. Lows in the upper 60s.

Warm and humid on Friday with afternoon thunderstorms possible once again. Highs in the low 80s.

Any Friday evening showers and thunderstorms should diminish within a few hours after sunset. Warm and humid with lows in the upper 60s.

The weekend forecast is extremely challenging. The majority of my computer models suggest a strong upper level ridge of high pressure, which would squash most of our thunderstorm activity both days. However, this is not a slam dunk forecast. Right now, I am forecasting partly cloudy, warm and humid weather on Saturday and Sunday, with a slight thunderstorm chance, as some of the models still show some precipitation despite the upper level ridge. Highs in the low to mid 80s and overnight lows in the upper 60s. If you have outdoor plans, just keep an eye on the radar on the FREE Local4Casters weather app -- just search for WDIV in the app store.

Shower and thunderstorm chances then return Monday through Wednesday, with highs continuing in the low to mid 80s and overnight lows in the upper 60s. And, yes, it will still be warm and humid.