Texans know how temperatures can swing wildly from day to day. But why does it happen?
The near-record highs in the mid 70s to lower 80s that are in the National Weather Service forecast for Fort Worth Tuesday may seem like thermal whiplash.
“These values are 20 or more degrees above normal for this time of the year,” according to the NWS.
The heat comes on the heels of frigid temperatures over the holidays and the relatively cooler days that started the new year. By the weekend and into next week, temperatures are going to cool back down to the mid-60s.
So, how exactly do these large temperature variances occur?
This happens more often in Texas and Oklahoma
Texas and Oklahoma are unique in that they see some of the largest temperature swings in the country, says the NWS.
“The relatively high elevation, dry air, proximity to the north-south oriented Rocky Mountains, and frequency of strong cold fronts all contribute to this area having some of the wildest temperature swings in the country,” says the NWS
The weather service website states these wide variances occur mostly in winter and spring, “with the highest average ranges occurring during the month of March.”
In the winter, a 30-degree drop in temperature within hours is not unheard of. Fort Worth experienced the phenomenon referred to as a “Blue Norther” days before Christmas.
One day the weather was lovely and sunny with a high of 79 degrees. The next day storm clouds roll in and the temperature drops 20 degrees. At least a dozen tornadoes were spawned when that cold front struck the Metroplex Dec. 13, 2022, damaging structures across the DFW area including collapsing the roof of a home in Decatur..
“A Blue Norther is a fast-moving cold front that causes temperatures to drop dramatically and quickly. Common characteristics are a dark blue-black sky, strong winds, and temperatures that can drop 20-30 degrees Fahrenheit in a few minutes,” according to weather.com.
Temperature swings are not a new phenomenon
What is more perplexing to many are the days when temperatures can fluctuate 50 degrees without a cold front moving through the area.
“This is because during the spring very dry air flows down from the southern Rocky Mountains into the High Plains,” according to the NWS website. “This dry air allows temperatures to warm up quickly during the day and cool down very quickly at night. Temperatures could be in the 30s when residents leave for work and school in the morning and warm up into the 90s by the time they return home that afternoon.”
Weather service data show the average temperature range in March is 30 degrees or more, while many other areas of the country average near 20 degrees.
There is nothing new about the temperature fluctuations. It is more a result of geography.
“Temperature ranges of 50 degrees or more are just as common now as they ever have been. In fact, 2008 tied with 1950 for the year that had the most days with temperature ranges of 50 degrees or more in Amarillo. Both years had 4 days,” according to the NWS.
This story was originally published January 9, 2023 at 2:10 PM.