Private Weather Forecast
Interested in a private weather forecast/routing for this year's Mac? Contact me at Mark@LakeErieWX.com for details.


Bell's Beer Bayview Mackinac Race
Weather Forecast: Saturday, July 14, 2018

Don't miss the weather briefing at 8:00 am on Saturday morning at the College Center Building on the campus of St. Clair County Community College (click here for a map).


Special Note: The forecast includes the potential for severe thunderstorms. The thresholds for a severe thunderstorm are winds of at least 50 knots, hail greater than 1” in diameter, or the formation of a tornado. Both severe and non-severe thunderstorms can have a significant and unpredictable effect on wind speed, wind direction, and wave heights. Thunderstorms may produce dangerous lightning. A chart explaining the Severe Thunderstorm Risk Categories can be found here. Mac participants should monitor the latest National Weather Service forecasts, watches, and warnings and take necessary precautions.

Saturday

At 8:00 am on Saturday, a cold front extending from an occluded low pressure system in central Ontario will be draped across Lake Huron just south of Saginaw Bay. This cold front will proceed very slowly down Lake Huron during the day on Saturday before stalling near Lake St. Clair on Saturday evening. The boundary will remain near Lake St. Clair well into Sunday morning. The slow movement of the cold front will promote showers and thunderstorms across southern Lake Huron from early morning on Saturday through early on Sunday morning. While thunderstorms are possible, the potential for organized, severe thunderstorms on Saturday is low. Cloudy skies will persist throughout the day. Total rainfall across southern Lake Huron will range between .10" and .25" from Saturday morning through Sunday morning. Daytime highs in Port Huron will reach the upper 80s.

Light southerly winds in the range of two to six knots overnight Friday into early Saturday morning. The light southerlies will diminish to light and variable by mid morning. Building to three to eight knots from the east during the afternoon. Diminishing to light and variable overnight. Waves two feet or less.

NWS Surface Forecast Valid at 8:00 am on Saturday.
SPC Convective Outlook for Saturday

Sunday

On Sunday morning, Lake Huron will be under the influence of high pressure centered just north of the Lake. Saturday's slow-moving cold front is expected to stall across Lake St. Clair while a stronger and somewhat faster-moving cold front approaches Lake Huron from the west. At 8:00 am on Sunday, this cold front will extend across northern Minnesota and is not expected to reach northwestern Lake Huron until early on Monday morning. As mentioned in Saturday's forecast, the chance of showers and thunderstorms across southern Lake Huron will linger until early Sunday morning. No precipitation is expected across Lake Huron for the twenty-four hour period beginning at 8:00 am on Sunday.

Northern Lake Huron -- Light and variable from early Sunday morning to late evening. Light southerlies ranging from three to eight knots developing across northern Lake Huron beginning in the late evening. Slight building to five to ten knots and backing toward the southeast overnight. Northwest Lake Huron -- Light and variable through late evening. Southerly five to ten knots overnight. Waves two feet or less.

NWS Surface Forecast Valid at 8:00 am on Sunday.
SPC Convective Outlook for Sunday

Monday

A cold front extending from a low pressure system in central Ontario will reach northwestern Lake Huron early on Monday morning. This cold front is expected to slowly pass across the Lake during the day on Monday. High pressure will fill in following passage of the cold front. Cloud cover is expected to increase as the front approaches. Showers and thunderstorms are expected with the passage of the front. While thunderstorms are expected, the potential for organized, severe thunderstorms on Saturday is low. Rainfall totals on Lake Huron will range from .10" to .25" on Monday.

Northern Lake Huron -- south three to eight knots from early morning until late evening. Slight weakening and veering to the northwest overnight as the cold front passes. Waves two feet or less. Northwestern Lake Huron -- Southeast three to eight knos overnight into early Monday morning. Weakening to light and variable by mid morning. Increasing to five to ten knots and backing to the northwest by early afternoon with the passage of the cold front. Waves two feet or less.

NWS Surface Forecast Valid at 8:00 am on Monday.
SPC Convective Outlook for Monday

Bayview Mac Weather Resources


The user assumes all risk related to the use of this data. The crew of each participating yacht must determine their ability and willingness to accommodate weather-related challenges. Mac participants should monitor the latest National Weather Service forecasts, watches, and warnings and take necessary precautions.