Category Archives: Marine Weather Forecasting

A New Spin on Waterspout Forecasting

Introduction
Several waterspouts, the intense columnar vortices considered “tornadoes over water”, have been reported across the Great Lakes over the past two weeks. Waterspouts come in two varieties – tornadic and fair weather—with the fundamental difference between them being the type of storm they are associated with, and the manner in which they form.
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Feeling The Pressure: The Value of A Barometer

Introduction
Every cruising boat should have a reliable barometer on board. Invented by Italian physicist and mathematician Evangelisata Rorricelli in 1643, a barometer helps a weather-wise boater stay abreast of developing weather patterns. The approach of a strong low pressure system with high winds, a squall line, or a hurricane is typically signaled by falling barometric pressure.  The steepness of the decline in pressure provides valuable insight into the strength of the approaching system. In contrast, rising barometric pressure usually heralds the arrival of fair weather and light winds. The ability to measure the rise and fall of barometric pressure only scratches the surface, however. What is barometric pressure, and what does it represent?
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Dramatic Differences: The Effects of Lake Temperature on Gusty Winds

Introduction
The Great Lakes — individually and collectively — play a significant role in the region’s weather. This is especially evident in the spring and early summer when cold lake waters promote the development of fog, suppress temperatures along the shore, and diminish the potential for strong thunderstorms offshore. One phenomenon of particular interest to sailors is the significant impact a relatively cold lake has on the wind well into the summer months.
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Bell’s Beer Bayview Mackinac Race Climatology

Introduction
Although the 2014 Bell’s Beer Bayview Mackinac Race is a less than two weeks away, it’s still too early for competitors to start working on their weather forecast. However, reviewing the long-term average conditions on Lake Huron during July is great way to set the stage for a weather forecast, particularly for those who are participating in the Race for the first time.

Wind and Wave Observations
The National Data Buoy Center (NDBC) maintains two floating discus bouys in Lake Huron. Buoy 45003 is located in the northern basin, while buoy 45008 is located in southern Lake Huron near the entrance to Saginaw Bay (click here for a map of Lake Huron).
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Chicago Yacht Club’s Race To Mackinac Climatology

Introduction
The Chicago Yacht Club’s Race to Mackinac is a little over two weeks away. It’s too early to begin working on your weather forecast. However, reviewing the long-term average conditions on Lake Michigan during July is great way to set the stage for a weather forecast, particularly for if you are participating in the Race for the first time.

Wind and Wave Observations
The National Data Buoy Center (NDBC) maintains two floating discus bouys in Lake Michigan. Buoy 45002 is located in the northern basin north of the Manitou islands, while buoy 45007 is located in southern Lake Michigan approximately 43 nautical miles southeast of Milwaukee, Wisconsion (click here for a map of Lake Michigan).
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