Here Comes the Sun!

A crazy Michigan winter has gifted us with one of the most extended stretches of cloudy, dreary weather on record. The first eight days of 2023, as reported by television meteorologists, yielded only five minutes of sunlight in total! Yikes! Further statistics indicate the entire month of January provided only 11% of the amount of sunshine that could be experienced. I’m trying to practice gratitude, but it’s hard to be grateful for unrelenting cloudiness day after day.

Has this really been a cloudier winter season than usual? Or is it our habit to complain about the same conditions every year when our current weather is actually “normal?” Depressing, perhaps, especially if you suffer from Seasonal Affective Disorder (SAD), but not significantly worse than many other years.

Of course, there is data to help provide insight into our current weather conditions. (Have I mentioned how much I absolutely ADORE data?) Here in southwest Michigan, we are unbelievably lucky to be sitting very near a weather data goldmine! The Grand Rapids office of the National Weather Service (NWS), an agency of the National Oceanic and Atmospheric Administration (NOAA), is the keeper of the golden data.

At one time, many NWS offices collected solar data for their regions. In southwest Michigan, for over seventy years, the minute-by-minute presence of sunshine was measured by a photoelectric sunshine switch that gathered data for analysis. The instrument initiated an electronic signal when a threshold level of sunlight was received by a sensor. When triggered, it timed the length of the signal. Many weather offices across the nation used similar, now very oldfashioned technology. As might be expected, over the years the switches failed, became damaged, and were otherwise taken out of service. As a result, most areas have lost the ability to collect current solar data.

Fortunately, in 2021, the Grand

Rapids office partnered with a local observer, a citizen scientist, to install a new experimental recorder, and the old switch was retired. Hooray for progress! The good news (and I believe more data is always “good news”) is that our own NWS office is one of only a handful with complete measurements of daily and monthly percentages of possible sunshine readings going back as far as 1903! It’s a massive data set, and how lucky we are to have it available, just a computer click away.

Since solar panels are becoming more cost-effective and easier to interface with the power grid, I’m amazed more interest has not been placed on current and historical solar data. The information would be helpful not only to meteorologists and weather buffs but also to energy producers, environmental engineers, and data hounds like me. Alas, no one asked for my opinion!

I examined the spreadsheet of monthly percentages of possible sunshine for all 119 years of reported data. My aim was to see if we really are receiving less sunshine in winter months than “usual.” Deciding to limit my analysis to December through March, I surveyed each year to determine which of those months were the most and least sunny and whether there appeared to be a pattern.

My observations are as follows: December is the cloudiest month more than half the time, with percent sunlight measurements in the mid-20s and 30s. Sometimes that “prize” goes to January, but more often December. This pattern has held consistently over the past, with the other winter months of January and February also demonstrating considerable cloudiness. Beginning in the late 1990s, however, those values began to drop into the low 20s and teen percents. Although this is only a 10% drop, it can be perceived as a significant difference, since there are just a few more cloudy days, but some of the days are actually cloudier.

March is almost always the sunniest of the four months studied. This makes sense since meteorological spring (the second quarter of the calendar year) begins on March 1st. Likewise, although there is much more sunshine than in previous months, the amount of March sunlight received in recent years is slightly lower than previous average values in the reporting period. Despite the extra cloudiness we have been experiencing in past decades, the amount of sunshine we receive annually has remained consistent, hovering between 45% to 50%.

I think it’s not so terrible when we consider Michigan’s great geographic location. The cloudiness vexing us is perfectly understandable. Our “pleasant peninsula,” referenced in the state motto, is surrounded on three sides by Great Lakes. Most of the prevailing winds influencing our weather pass over a large body of fresh water on its way to land. In middle school science, most of us learned that water can “hold” a lot of heat. Therefore, as cold winter winds pass over the warmer lakes, they accumulate moisture that is carried onto land as clouds. If conditions are right, that moisture can fall as either lake-effect snow or rain. If not, the sky is laden with low-hanging, dreary clouds.

These processes have been more noticeable in recent years because of changing climatic patterns resulting in less lake ice. Great Lakes ice coverage, reported on February 8th, is “significantly below average”- currently only 13% compared to the average of 37%. Not good news if you’re an ice fisherman! These warm lake temperatures provide the ample moisture exhibited as cloudiness over land.

As for me, I will happily put up with cloudy winters in exchange for the beauty of the Great Lakes. My remembrance of dreary days will surely fade when I’m back on the beach at South Haven with an ice cream treat, and my favorite beach read! Take heart, friends; the worst of winter is past!

Cheryl Hach Retired Science Teacher Kalamazoo Area Math and Science Center

References:

Solar Data for Grand Rapids, Michigan. Retrieved February 2nd, 2023. https://www.weather.gov/grr/ solardata

House, Kelly, “Michigan winters are super cloudy and getting worse. Here’s how to deal.” Retrieved February 5th, 2023. https://www.bridgemi.com/ michigan-environment-watch/michigan-winters-are-super-cloudy-andgetting-worse-heres-how-deal

White, Max, “Great Lakes ice coverage is well below average; what are the impacts?” Retrieved February 8th, 2023. https://www.wxyz.com/news/ great-lakes-ice-coverage-is-well-belowaverage-what-are-the-impacts