Texas weather will remain a mystery but in honor of the recent icy conditions across the state, here is a winter weather report courtesy of the Department of Atmospheric Sciences at Texas A&M.
Q: Is an “ice storm” really a storm?
A: Yes it is, says Brent McRoberts of Texas A&M University. “An ice storm is a storm with large amounts of freezing rain that quickly coats trees, roadways, power lines, and other objects with ice,” he confirms. “They result from the accumulation of freezing rain, which is rain that becomes supercooled and freezes upon impact with cold surfaces. Supercooled means that the rain must be in a liquid state at temperatures below 32 degrees Fahrenheit. Water must have something to freeze onto when temperatures are below freezing. Once this rain–which is colder than 32 degrees–falls on an object that is below freezing, it will instantly freeze on that object and form a sheet of ice. As ice forms, it helps to freeze other raindrops that fall onto the sheet, and this process helps freezing rain accumulate quickly.”
Q: What causes an ice storm or freezing rain?
A: “Freezing rain starts out as snow, but the snowflakes fall through a layer of warm air where they melt before entering another layer of cold air near the ground,” explains McRoberts. “The newly formed raindrops typically include dust or other microparticles, so they will freeze again if given enough time in air below 32 degrees Fahrenheit. If they succeed in freezing, these drops become sleet. But if the lower layer of cold air is not thick enough to give the drops time to freeze, they will still be supercooled liquid water when they hit the ground. At the ground, they freeze on contact and become treacherous sheets of ice. Ice storms commonly form along a line from Texas to Newfoundland and can occur any time between late October to early May. Ice storms can be among the most devastating of all weather phenomena and are often responsible for car accidents, power outages, and personal injuries. One of the most disastrous ice storms in history struck Montreal and the upper Northeastern U.S. in January 1998, causing over $1 billion in damage and leaving many areas without power for weeks.”