Massive weather changes looming for Metro Detroit; First frost on the way?

Warm weather comes to end this week

DETROIT – Enjoy the warm weather while it lasts, because this will likely be summer's last gasp.

The balmy conditions continue overnight, with mostly clear skies. Like this past night, lows will only drop into the mid to upper 60s (18 to 19 degrees Celsius), with a light southeast wind.

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Tonight’s mostly clear skies means that we’ll be able to see the International Space Station fly overhead, and it’ll be early enough for most of your kids to see it before bedtime!  

The event begins at 8:24 p.m. 

Face west-northwest (to the right of where the sun will set), and you’ll notice a bright “star” fade into view low in the sky -- that’s the Space Station! Over the next three minutes, it will fly overhead, and then fade from view in the southeast. This is a good night to view it, since it’ll fly high overhead.

Wednesday

Wednesday will begin mostly sunny, warm and humid. By lunchtime it’ll be partly cloudy, and then become mostly cloudy during the afternoon.

A scattered shower or thunderstorm is possible by late afternoon, but most of the activity should hold off until Wednesday night.  

Highs, as long as we keep the sun into the early afternoon, should reach the upper 70s to low 80s (26 to 28 degrees Celsius).  It’ll become breezy, too, with a south wind at 10 to 20 mph.

Wednesday’s sunrise is at 7:40 a.m., and Wednesday’s sunset is at 7:00 p.m.

A couple of rounds of showers and thunderstorms are likely Wednesday night ahead of the approaching cold front (the front edge of the approaching much colder air mass).  

The wind field aloft is strong enough that a few strong to severe wind gusts are possible, but the one limitation is that, as has been the case most of the past couple of months, this will occur at night, when the atmosphere is more stable than during the day.  

Still, remain alert and keep your weather radios set in case any warnings are issued. Temperatures will remain very mild ahead of the front in the low 70s (22 degrees Celsius), then dramatically fall into the upper 50s (14 to 15 degrees Celsius) by the time most of us head out to work or school.

Thursday

Skies become partly sunny on Thursday, and it’ll be quite windy and much colder.  

Temperatures may rise a few degrees into the low 60s (16 degrees Celsius), but that’ll be it, if the temp even rises at all.

Becoming mostly clear Thursday night, with lows in the upper 30s (4 degrees Celsius).

Partly cloudy on Friday, and possibly becoming mostly cloudy as an upper level disturbance slides across the southern part of the state, with highs in the low 50s (10 to 11 degrees Celsius).

Mostly clear Friday night, with lows dropping into the mid to upper 30s (2 to 3 degrees Celsius). This means that frost is possible in rural locations far from our Urban Heat Island, as well as in low areas where colder air tends to settle.  

Obviously, this is bad news if you want to keep those tender annuals a little longer into the season you’ll have to put stakes in and cover them with old bedsheets or burlap (don’t let the cover touch the flowers).  Or, this is the start of some good news if you’re an allergy sufferer -- let’s kill those pollen-producing plants.  

One thing that still needs to be considered is that the ground is still quite warm this time of year, so that tempers the frost chances in many areas.

The Weekend

Mostly sunny on Saturday, a crisp, spectacular autumn day, with highs in the low 50s (11 to 12 degrees Celsius).

Increasing clouds Saturday night, with a shower possible later at night our evening date-night plans are safe, as is the big Michigan -- Wisconsin game at The Big House in Ann Arbor.  

Lows in the low 40s (5 to 6 degrees Celsius).

Showers are likely on Sunday, with highs in the mid 50s (12 to 13 degrees Celsius).

The Latest on Hurricane Michael

As of 2:00 p.m. this afternoon, Hurricane Michael was 335 miles south of Panama City, Florida, moving north at 12 mph. Maximum sustained winds near the storm’s center are blowing at 110 mph, with higher gusts.

The forecast philosophy remains unchanged, and has been very consistent for the past few days: Michael will track toward the “Big Bend” area of Florida’s panhandle, and cause widespread flooding and destruction.  As we tell you with all hurricanes, even though the media focuses on the storm’s wind, it’s the water that causes the most destruction and casualties.  

Over the next few days, we want you to think “water,” not “wind” as you follow this storm.  Of greatest concern is the storm surge, a push of higher water levels inland. The wind to the right of the approaching hurricane is blowing toward shore, and this drives that ocean water inland.  

Given that Michael will be a Category 3 storm when it hits, and also given the geography of the Florida panhandle coastline, the hardest hit areas will likely see a six to twelve foot surge of water pushed inland.  Moving water is very, very destructive.  

If you have any family members who are visiting or live in any of the mandatory evacuation areas there, we urge you to tell them to get out while they can. This is a very serious storm.

Yesterday, we contacted Florida’s state climatologist, David Zierden, and asked how much sea levels have changed there due to global warming.  

David says that sea levels have risen just under ten inches over the past century. “So the take home is that yes, sea level rise will make the storm surge worse,” said Zierden. “If you are on the far periphery and get a 1 foot surge, sea level rise will add another 40%. If you are near the core of strongest winds, an added 10 inches is not that much more of a threat increase when talking about a 15 ft surge.”  

Zierden also discussed an important criteria to the eventual height of Michael’s incoming storm surge: “(T)his is the week of "King Tides" around the Gulf and Atlantic coasts, when astronomical and seasonal tides are at their highest. Storm surge will be greatly compounded if it coincides with astronomical high tide this week.”  

So the upshot is that Hurricane Michael’s angle of attack on the coastline and the coastline’s geography, combined with the storm’s potential timing with King Tide occurrence, and already higher sea levels due to global warming, have created a very destructive storm surge potential scenario.

Following landfall, Michael’s center will continue inland and pass over Albany, Augusta (potentially damaging Augusta National Golf Club), and Columbia before heading across the rest of the Carolinas and then out into the Atlantic. That’s really bad news for areas there still recovering from Hurricane Florence.

Remember that our free Local4Casters weather app has one of the best hurricane trackers you’ll find anywhere.  If you’re one of the few who still don’t have the app, just search under WDIV in the app store, and it’s right there.

Here are some maps to show you the storm’s strength and timing:


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