Weather Preview

The day before the start of the Chicago Mackinac Lake Michigan is boisterous. The south Lake Michigan weather buoy shows west winds at 21 knots with 5 foot waves. The northern buoy has NNW winds at 23 knots with smaller waves. These conditions would be fast and favorable for the fleet.

Unfortunately for the sailors on the nearly 300 boats, conditions for the race don't look as favorable. Remember Mr. Murphy manipulates weather too!

The overall weather will be driven (or not) by a weak high pressure Saturday and into Sunday. By that point low pressure will start to have some affect.

Winds for the forecast are a mere NW at 10 knots in the Chicago area. The first night does not hold promise with a forecast of winds of variable under 10 knots called for.

This lack of wind near the rhumb line might cause boats to want to head for the shore. Saturday night on the Illinois/Wisconsin shore is pretty grim: SE winds of 5 knots going SW 5-10. The Michigan shore is perhaps a little better with NW winds 5-10 backing (moving counter clock wise) to SW under 5.

Another condition that maybe crucial to strategy is the presence of a sea breeze. In the morning as the land heats air rises, and cool winds from the open lake can blow in. Typically there must be a 10 degree difference in the temperature of the water and land.

Current Lake Michigan water temperatures range from 55 to 65 degrees. This means land temps of at least 65 degrees will be needed to produce a sea breeze. Temperatures in the 80's would make a sea breeze more certain.

The presence of clouds is also a good sea breeze sign. Forecasts for the Michigan side show a lot of clear and mostly sunny.

The Illinois shore would not seem to be good sea breeze territory. If a sea breeze as to build it could collide with the light offshore SE winds and be cancelled out.

On the Michigan shore a sea breeze will have a better chance of taking affect and being slightly enhanced by the NW wind forecast.

During the first day and night it would appear that conditions will be light with neither help from the forecast gradient breeze or the sea breeze.

Sunday as the fleet heads north up the lake they're supposed to still be in light air mode with the forecast saying SW at 5-10 knots.

By Monday good sailing conditions once again appear, with predictions of SW winds 15-25 knots.

By the time the breeze increases the fleet will be in the northern part of Lake Michigan. Perhaps setting a course outside of Beaver Island will allow boats to benefit from getting the building South Westerly breeze first.

Last year Pyewacket set a new elapsed time record. This years potential record breaker is Alchemy an Andrews 77 from California. Although Alchemy is supposedly faster than Pyewacket, it doesn't look like conditions will be conducive to record breaking.

While an elapsed time record perhaps a record for sail changes maybe set. Crews who keep working for every mile made good in what could be way fluky conditions may have the best chance to succeed. For when there isn't a decided weather advantage working the boat hard on the rhumb line can pay off over many mile long excursion for wind.