National Weather Service United States Department of Commerce

Winter Storm To Impact Parts Of The Ohio Valley and Great Lakes To Northern New England

A developing winter storm will sweep up through the Northeastern quadrant of the U.S. over the next two days. A swath of heavy snow will be followed by lake effect snow from parts of the Ohio Valley and Great Lakes to northern New England. Also, locally heavy rain will be possible across portions of the Northeast, while a potential line of strong thunderstorms may roll through the Mid-Atlantic. Read More >

Back to Main Page Storm Warning: Advancements in Marine Forecasting since the Edmund Fitzgerald
  Background Information:
The Edmund Fitzgerald
The Fall Storm Season
Forecast and Warning Definitions
Resources, Links and Credits
 
Advances in:
Scientific Understanding
Numerical Weather Prediction
Communications
Radars and Satellites
Observations and Forecasts
 
Back to:
Main Page
NWS Marquette Home Page
   

Forecast and Warning Definitions

National Weather Service Marquette marine responsibility The National Weather Service issues forecasts and warnings for the U.S. open waters (waters beyond five nautical miles from shore) and for the nearshore waters (waters within five nautical miles from shore) of the Great Lakes - darker shaded areas in image to the left.

Lake Superior Forecasts for the open waters are issued four times daily throughout the year, at 4:00am, plus every six hours with intermediate updates as necessary. Nearshore Marine Forecasts are issued four times daily, at 5:00am plus every six hours with intermediate updates as necessary.

Forecast wave heights are for the average of the highest third of the waves at the end of the fetch in the forecast area. Wind directions and speeds are forecast for roughly 33 feet above the lake surface.

Marine warnings and advisories are headlined within marine forecasts:

  • Small Craft Advisories for winds 22 to 33 knots inclusive and/or average waves greater than four feet for nearshore waters
  • Gale Warnings for winds 34 to 47 knots inclusive
  • Storm Warnings for winds 48 to 63 knots inclusive
  • Hurricane Force Wind Warnings for winds 64 knots or greater

Credits | Disclaimer | Privacy Notice | Site Map | Feedback