BRYAN-COLLEGE STATION, Texas – A record-setting early season cold front will cover much of the U.S. this week, dropping temperatures more than 60 degrees in many locations.
This means summer in much of Texas will end Tuesday, said John Nielsen-Gammon, the Texas State Climatologist at Texas A&M University.
The arctic front is expected to set at least 150 record low temperature records in many locations around the country, including Texas.
“People define the end of summer in different ways,” Nielsen-Gammon said. “For me, the end of summer happens when the first strong cold front moves through.”
Nielsen-Gammon, who is also Regents Professor of Atmospheric Sciences at Texas A&M, says many will experience this on September 8- 9.
“All of the ingredients are in place,” Nielsen-Gammon said. “A stationary front in Kansas and Colorado will get an extra kick from the jet stream. Midday Tuesday, it will be sweeping through the Texas Panhandle. By late afternoon, there will be a 50-degree temperature difference across 250 miles of the Texas High Plains.”
After this, fall’s onset is less certain.
“The front will stall somewhere in Central Texas on Wednesday,” he said. “Half the state will feel like fall, while the other half will still be stuck in summer.”
In the United States, summer is generally regarded as starting on the summer solstice (June 20) and ending on the autumnal equinox (September 22). But this is just one of many possible definitions in use, he said.
“Less formally, Americans typically consider the real summer to start on Memorial Day weekend and end on Labor Day weekend,” Nielsen-Gammon said.
Europe, he notes, doesn’t celebrate those particular holidays, and treats summer as June through August, which makes it a bit shorter.
“For weather and climate purposes, even in the United States the seasons are three-month periods,” Nielsen-Gammon said. “Summer is June, July and August, while fall is September, October and November.”
By that standard, he said last year’s end of summer was very late. Most of Texas didn’t get a decent cold front in 2019 until October 9 or 10, said Nielsen-Gammon.
“In an average year, the first strong cold front reaches central and southern Texas around mid to late September, so this year it’s ahead of schedule for a change,” he said.
The cold front doesn’t mean hurricane season is over for Texas, however.
“Anything that cools the water in the Gulf of Mexico helps reduce the threat of hurricanes,” Nielsen-Gammon said. “Also, this cold front means that the jet stream is more likely to drive hurricanes away from Texas into the eastern gulf. But we still have a couple more weeks before we can really start to relax.”
September is also the peak season for air pollution in Texas. By the end of the week, Texas will be getting relatively dirty, lower-visibility air from the eastern United States. “That, combined with light winds, increases the risk of high levels of ozone,” he said.
For a lot of people, though, summer is nowhere near ending, Nielsen-Gammon said. “In the Southern Hemisphere, summer won’t even start for another three months.”
Source: Texas A&M University