21ºF

Metro Detroit weather forecast: Rain reigns tonight

Flood watch issued for southeast Michigan

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DETROIT – We just can’t win.

First we couldn't get enough rain. Now we're getting too much.

Very heavy rain will develop Monday night, with most areas near or exceeding 1 inch of total rainfall, and areas north and west of a line from roughly Anchor Bay to Adrian probably between 2 and 3 inches. That amount of rain in even a 10-hour period can cause flooding, so make sure your sump pumps are working and that storm drains on your street are cleared of yard waste and trash.

The National Weather Service has issued a flood watch from midnight Monday through Tuesday morning.  I highly doubt that we’ll be able to get the Tigers game in, so keep an eye on my tweets and I’ll let you know as soon as I hear anything.

Lows Monday night will be near 70 degrees (that’s 21 degrees Celsius for our Canadian friends). Southeast winds will shift to the southwest, at 10 to 15 mph.

Any steady rain still here when we wake up Tuesday morning should become much more scattered as the morning progresses, and should end altogether during the afternoon. With a bit of luck, perhaps we’ll catch some breaks of sun by evening. Highs in the upper 70s (26 degrees Celsius). Southwest winds will become northwest winds late in the day, blowing at 10 to 20 mph.

Tuesday’s sunrise is at 6:42 a.m, and Tuesday’s sunset is at 8:32 p.m.

It will be partly cloudy Tuesday night and, as long as the wind lightens up (which I think it will), we’ll have some areas of dense fog developing later at night. Lows in the mid 60s (18 degrees Celsius).

Partly cloudy on Wednesday with scattered thunderstorms developing during the mid- to late afternoon period.  Highs in the mid 80s (29 degrees Celsius).

Partly cloudy Wednesday night, with lows in the upper 60s (20 degrees Celsius).

Partly cloudy on Thursday with only a slight chance for a stray afternoon thunderstorm. Highs in the mid 80s (30 degrees Celsius).

Partly cloudy Thursday night, with lows in the upper 60s (20 degrees Celsius).

Partly cloudy on Friday, with highs in the upper 80s (31 degrees Celsius).

Partly cloudy Friday night, with lows near 70 degrees (21 degrees Celsius).

Partly cloudy on Saturday, with thunderstorms developing during the afternoon or evening at the latest. Highs in the mid- to upper 80s (29-30 degrees Celsius), depending upon the timing of the rain’s arrival.

Showers and thunderstorms are likely Saturday night, with lows in the upper 60s (20 degrees Celsius).

Even if we start Sunday with some rain, as long as the current timing holds, it should end during the morning, and possibly become partly cloudy and pleasant Sunday afternoon. Highs in the upper 70s (26 degrees Celsius).

Then get ready for some very comfortable weather for the first half of next week.

A word about the Louisiana Floods:

By now you’ve heard about the unbelievable flooding in Louisiana, with some areas receiving 25-30 inches of rain, and one location over 31 inches.

I checked the rainfall return frequencies for southern Louisiana, and this amount of rain in seven days (it fell in six) is 500 to 1,000 years.  So, it’s safe to say that what they experienced down there was close to a once-in-1,000-year rain event.

Sound familiar? That’s what happened in Maryland this summer, and in Houston late in the spring. Naturally, I continue to get asked if all of this is because of global warming.

As one of the national leaders in being able to explain the truth about this subject (without consideration to politics), let me make it perfectly clear that we cannot say that any particular storm system was directly caused by global warming.

However, global warming is increasing our planet’s atmospheric humidity, as a warmer climate means that more ocean water is evaporating into the atmosphere, and storm systems use this water vapor to generate precipitation.

So, while the storms that caused these significantly historic floods this year might have happened anyway, the added atmospheric humidity made the amounts of rain that they generated heavier.

A great analogy is to look at baseball players on steroids: Barry Bonds, Alex Rodriguez, Mark McGwire, and Sammy Sosa all hit more home runs because of their steroid use, but they were still very, very good baseball players who would have hit a lot of home runs without the steroids.

The steroids simply made them stronger, which made some of the balls they hit go farther. That turned some long fly ball outs into home runs. But good baseball players have come and gone for decades without steroids, just like storm systems.

If you aren’t buying this analogy (which many highly respected climate scientists are now using), then take a look at this graphic:

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As you can see, the top 1 percent of precipitation events (i.e., the most intense rain events) are increasing across the entire nation, and especially east of the Mississippi River. We are now seeing the impact of our climate on steroids.