Archive for May, 2009

Why Does The Sunset Change?
May 17, 2009

I was watching the sunset yesterday and am still amazed at how much farther north the sun sets on the horizon this time of year. Many of you may have never understood why this occurs. I will try to give you the simple explanation.

It takes 365 days for the earth to rotate around the sun. The earth is constantly tilted at 23.5 degrees. During the winter, the northern hemisphere is pointed away from the sun. This is why there is no sunlight above the arctic circle during the winter and why our temperatures are cold. The earth is actually closer to the sun during our winter than during the summer, but this does not make too much of a difference in global temperatures. Because of the tilt of the earth, the daylight hours are much shorter in the winter than the summer.  During winter, the sun actually rises in the southeast and sets in the southwest. In the summer, the sun rises in the northeast, travels all the way around during the day to set in the northwest. Our longest daylight hours of the year come on the first day of summer.

Thankfully, we have some warmer days to enjoy the longer daylight hours in this forecast. Highs by Wednesday will be in the low 80s.

Mark Baden

5/17/2009

Watch Out For Frost
May 10, 2009

Happy Mother’s Day! It was not the prettiest Mother’s Day around here, especially near the lake. After a nice morning with very little wind the temperature warmed to 60 by 11:00 AM. Then the lake breeze kicked in and the temps dropped rapidly.

With clearing skies, temperatures are going to get pretty chilly tonight. Many of you may have planted a lot of flowers, etc. this weekend and you may want to cover up the plants. Frost is possible tonight and maybe again on Monday night. Frost is most likely away from Lake Michigan. Air temperatures are not expected to go below freezing, but keep in mind that the official temperature is taken 5 1/2 feet above the ground. The closer you get to the earth’s suface on a clear, calm night the colder the temperature gets. Sometimes, there can be as much as a 5 degree difference closer to the ground. This means that even though the official low temperature may be 36 degrees, it may actually be 31 degrees on the ground. That is why frost is possible with lows expected inland around 35 degrees.

If you have tender plants that are temperature sensitive, you may want to cover them with a sheet or bring potted plants inside.

Mark Baden

5/10/2009

Finally, spring
May 4, 2009

Those of us living in Wisconsin this time of year are often tormented by looking at the surrounding temperatures of area states. This is especially true for people living near Lake Michigan. In short, we get gypped on spring weather. When I show the regional temperature map, Milwaukee is often the coldest temperature shown. This includes places like Rhinelander, International Falls, Fargo, etc. I often hear, “why do we live here?”

Lake Michigan is a treasure, but in the spring it is usually rather cruel. The reason is because it takes water a whole lot longer to warm up than surrounding land masses. The current temperature of the lake is still in the upper 30s. This creates its own weather on almost a daily basis. Depending on wind direction and speed, the lake breeze often develops late morning to early afternoon. This happens when you have a sunny day and the land areas warm quickly. This creates a small area of low pressure over the land. The cold waters of Lake Michigan create an area of high pressure. The wind always blows from high to low pressure, so the lake breeze is formed. The only way that lakeshore areas stay warm throughout the day is if the wind is strong enough (generally greater than 1o miles per hour) out of the northwest, west, or southwest.

It was nice to finally have a nice spring weekend with highs in the sixties, but be prepared for more lake breezes to come. The great thing about the lake is the nice natural air conditioning we get in the summer when the winds turn off the lake on a hot day while the surrounding states are baking.

Mark Baden

5/4/2009