Category Archives: Seasons

How does frost form?

Frost on objects is just water vapor in the air that has deposited itself as ice onto a surface. Frost forms on objects close to the ground, such as blades of grass.

At night, a blade of grass loses energy by emitting radiation (a non-lethal kind) while it gains energy by absorbing the energy emitted from surrounding objects. Under clear nighttime skies, objects near the ground emit more radiation than they receive from the sky, and so a blade of grass cools as its energy losses are greater than its energy gains. If the temperature of a grass blade gets cold enough and there is sufficient water vapor in the environment, frost will form on the grass. Continue reading

Category: Meteorology, Seasons

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Do trees need cold weather?

Extreme cold weather can kill trees, and cold weather at the wrong time can damage trees. For example, a warm February and March in Michigan in 2012 brought early blooms to apple trees that then were killed by an April frost.

Some trees require cool temperatures, such as some fruit trees (peaches, cherries and blueberries) and nuts (almonds). Cold air along with less sunlight that comes with winter halts tree growth, preparing the tree to withstand freezing temperatures and then resume their growing the following spring. Continue reading

Category: Meteorology, Seasons

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What’s up with all the wild weather?

Another week of destructive weather around our country culminated in the passage of Hurricane Maria over the island of Puerto Rico on Wednesday of last week. Some of the rainfall totals from automated stations on the island were of truly biblical proportions.

Though still subject to verification and a check on accuracy, 12.20 inches of rain fell in one hour at Gurabo Abajo, one of several stations on the southwest side of El Yunque, the high mountainous area in the northeast. Continue reading

Category: Meteorology, Seasons, Tropical

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When does fall begin?

Even the least observant person has probably recognized by now that the days are growing shorter.

In fact, on Friday at 3:02 p.m., we will reach the autumnal equinox and the night will be as long as the day for the first time since late March. Continue reading

Category: Meteorology, Seasons

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What does the State of the Climate Report tell us?

The National Oceanic and Atmospheric Administration (NOAA) released its 27th annual State of the Climate report Thursday, and it was full of attention-grabbing news.

Topping the list was the fact that analysis of global temperature measurements revealed that 2016 bumped 2015 as the warmest year in 137 years of record keeping. In fact, 2016 was the third consecutive year of record warmth. Continue reading

Category: Climate, Meteorology, Seasons

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