Midwestern Autumn

Autumn may have some of the nicest weather of the year here in California, but I still find that I miss autumn in the Midwest.  The combination of mild days (50s and 60s) with low humidity and crisp nights - and the plethora of deciduous trees changing colors and losing their leaves - is less prevalent in coastal California (at least the leaves part).  The image below is a true-color visible satellite image (basically what the human eye would see from space) a couple days ago.  Skies were clear across the Great Lakes region, allowing us to see the vegetation below.  Notice the pockets of orange and red across the region - northern Illinois, Michigan's Upper and northern Lower Peninsulas, much of Ontario, etc.  Those are the dense deciduous forests that have changed color.  Further south, the vegetation is still mostly green.  Also of interest is the Great Lakes themselves.  The hazy swirls in southern Lake Michigan are sediment/sand stirred up from the bottom of the lake.  At the beginning of the month, a powerful low-pressure system moved across the Midwest; as the system moved east, strong northerly winds behind it persisted for several days, blowing down the length of Lake Michigan.  Those winds produced large waves (10-20 feet), which stirred up the lake bottom.

We have some great fall weather for the rest of this week in the Bay Area - high pressure building in will result in sunny skies and offshore flow, which will push the marine stratus westward away from the coast.  Highs should easily be in the 70s in San Francisco and 80s further inland.