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Category Archives: Seasons
What is lake effect snow?
Lake effect snow forms when cold air passes over the warmer water of a lake. As cold air moves over water, the lower layers are warmed and moistened by the lake below. This makes the air mass unstable. Evaporation increases the moisture content of the air mass, which is then precipitated in the form of snow on the land downwind.
Maximum heat and moisture exchanges occur when the air is cold and the temperature difference between the air and the water is large. This condition tends to occur during early winter; this is when the most lake effect snow is produced. A long path across warm water by the air mass results in heavy precipitation over the land. Continue reading
What is a November gale?
A gale is a sustained wind between 39 mph and 54 mph. Gales are usually caused by large differences in the air pressure between a low pressure system and a strong high pressure system. Gale winds are common in November on the Great Lakes.
This week marks anniversaries of some strong November gales in the Great Lakes region. The most famous of these include the White Hurricane (Nov. 7-10, 1913), the Armistice Day Blizzard (Nov. 11, 1940), the Edmund Fitzgerald Storm (Nov. 9-10, 1975) and the storm Nov. 10-11, 1998. Continue reading
How are fall colors impacted by our weather?
The most vibrant fall color will occur on years with ample moisture in the summer and dry, clear weather in the fall. Extreme heat and moderate-to-severe drought may negatively affect the fall foliage season.
In summer and spring, leaves are green because they contain chlorophyll, which reflects green light more than other colors. Other colors are absorbed by chlorophyll for photosynthesis. Continue reading
Why is fog more common in the early morning?
Fog can occur any time of day throughout the year. In southern Wisconsin, fog is most frequent in the morning, between about 6 and 8 a.m.
Fog formation is the result of two primary processes. First, the air is cooled to the dew point, and the relative humidity reaches 100%. When the air temperature is the same as the dew point temperature, condensation of the atmospheric water vapor occurs forming fog droplets. Another method of fog formation requires water to evaporate from the surface into the air, increasing the relative humidity until condensation occurs. Continue reading
When will we stop seeing 80F this year?
At the time of this writing, Madison is in its 6th straight day of temperatures at or above 80F and it is likely we will have one more to reach seven in a row. As recently as 2022, we have … Continue reading
