Robert Miller: Cloudy and chilly — payback for winter
April — cruel this year in ways no one imagined — has also been muddy and drab.
The rain has come, pitter-patter and slam-bang. Instead of the usual 4 inches of spring showers, many towns in and around Danbury have hit the 6-inch mark. We’re sheltering in place, in part, because it’s been so wet.
“December was wet,” said Matt Spies of Brookfield, state coordinator of the Community Collaborative Rain, Hail and Snow Network, whose volunteers now collect precipitation data in 118 stations throughout Connecticut. “January and February were dry. March was average. April was wet.”
And despite the hosts of golden daffodils and the greening grass, it was a gray month above.
“There’s been two rainy days for every non-rainy day,” Spies said.
And cold, this weekend especially.
Gary Lessor, director of The Weather Center at Western Connecticut State University in Danbury, said that, normally, temperatures for May range from 60 to 70 degrees F. This weekend it will be in the 40s and 50s.
“We’ll be 20 degrees below normal,” Lessor said.
Some of this is to be expected.
Michael Rawlins, associate director of the Climate Systems Research Center at the University of Massachusetts at Amherst, said April is generally the cloudiest month of the year in southern New England.
“The jet stream is directly overhead,” Rawlins said.
We’re also getting some payback now for the mild winter we had.
Bill Jacquemin, senior meteorologist at The Connecticut Weather Center in Danbury, said that through most of the winter the flow of the jet stream — the shifting upper wind currents that run about 11miles above North America — stayed just to our west, kept in place by a ridge of high pressure.
Near the end of March, Jacquemin said, the jet stream shifted over Connecticut. It’s brought us the cool, rainy weather we’ve had as storm after storm came our way.
“This is what we expected the in the winter,” he said.
And it’s brought us clouds that block the sun, that rain and snow on everyone. They are complicated as well.
Basically, water on earth can be a solid — ice, and a gas — water vapor, as well as the liquid that we drink and sail on and swim in and is essential for all life.
When the sun hits the earth, it heats it up, causing liquid water to evaporate and become vaporous. That vapor latches onto microscopic particles of solid material floating in the air to form cloud droplets.
Clouds cover about 70 percent of the earth’s surface at any given time, but only account for about one-thousandth of 1 percent of the earth’s total water.
With high clouds — wispy, mare’s tail cirrus clouds — the droplets are frozen. Red skies in the morning and evening, the rings around the moon, and winter sundogs — all glow because of cirrus clouds.
Cumulus clouds — the puffy ones in blue skies — are middle-distance clouds. The family of stratus clouds are the low sky-covering banks of clouds that bring steady rain or snow. Fog is a cloud that forms at ground level.
Nicole LoBiondo, a meteorologist at AccuWeather, the regional weather forecasting company in State College, Penn., said that people assume a blanket of clouds acts, well, like a blanket. It depends.
“Thick clouds during the day can be cooling,” she said. That’s because they reflect the sun’s rays, and warmth, away from the earth’s surface.
But at night, the earth’s surface releases its own heat. Thick clouds then keep that heat near us, and warm the air.
That’s why on clear winter nights, it gets so cold. We’re missing the blanket. Jacquemin said it’s also why we only get record high temperatures on clear summer days when the sun can heat up the air without any clouds intervening.
Climate change may bring changes to cloud cover. Clouds may be getting thicker and forming higher in the sky. That could mean they’ll block more heat that normally would radiate from earth out into space, making things hotter.
There’s also evidence that that cloud formations may decrease in the mid-latitudes — North America — while increasing over the poles.
But the gray skies now? It’s just weather.
Ordinarily, jet stream patterns can stay in place for about six weeks or so. Lessor of The Weather Center at Western said that means for at least the next week, we can expect more of the same.
“We’re getting payback for the winter,” he said.
Contact Robert Miller at firstname.lastname@example.org