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Hello

This is the Bill of the Alex and Bill refraction show. I have neither
the training or mental horsepower to explain what we observed, but can
provide more details for those interested.

Before the details, I would urge you to get an overview by visiting:
http://www.glerl.noaa.gov/res/glcfs/

Under Michigan, click on surface temps and run the animation.

Then, use Google Earth and fly to N 42d 06!891, W 86d 29.301
The coordinates were taken from my GPS.  Google Earth shows our location
approximately 15'NNW of our true location. This will give you a
birds-eye view of the wide range/smorgasbord of possible temperatures
within a 1500' radius.

As an overview, this area has been setting record highs for over a week
  (this winter!), as well as record high lows. Low to mid 80's F, 20 F
or more over normal. (It is not unusual to have snow on the ground on
Easter.)

The southern end of Lake Michigan is the shallow end (often 60-30 feet
under the boat well offshore. Being shallow and and 307 miles south of
the north end, it warms up faster.

Drilling down, according to the first URL above, surface temperatures
offshore (5 or more miles) were in the 44-45F range on the 17th .Sub
surface temps (10 meters) were almost uniform for the lake at 40 F, with
a few isolated cooler spikes. As the day wore on, near shore surface
temperatures on the south-eastern side (our location) of the lake
exceeded 50F.

Regarding our observation location, it was at very least interesting. We
were on the north concrete pier/breakwater perhaps 15 feet from the
dredged channel which ran out to the lake at approx 290d.  Sand behind
us, sand along side us to the north, and sand running west along the
north side of the pier about 500 feet to the beach. Across the channel,
a beach about 500 feet to the east of us. Throw in an asphalt parking
lot about 150 feet north of us. I would love to see a aerial thermal
1500' radius image of our location. I imagine it would look like a Leroy
Neiman lithograph.

The wind was approx. 8 kt out of the SSW and parallel to the shore
(based on my observations of kites flying). Given the short fetch there
was little wave action, or opportunity to churn the water.

I did take a walk to the end of the pier, and the air temperature 7-13
feet above the water level dropped by at least 15 F. A graphic
description:  People on the beach in swimwear, walkers in shorts and
T-shirts. Folks fishing or lingering on the pier in jeans and hooded
sweatshirts.

Sadly our off-shore buoys (45002 and 45007) are still decommissioned for
winter, so I could not obtain air temperatures 4 meters off the surface.

The Green Bay, Wisconsin station

   

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