NWS: Milder winter in Williamsburg due to jet stream flows

Staff writer

A high of 74 degrees Fahrenheit in February? It’s not fiction; it was reality Feb. 8.

Williamsburg has had record warmth so far this year. From Jan. 1- 6, temperatures were as much as 21 degrees Fahrenheit above the normal observed temperature range, according to preliminary climate data from the National Weather Service.

On Feb. 8, record-setting heat hit Williamsburg with a high temperature of 74 degrees — 24 degrees above normal and an all-time high for that date, according to the National Weather Service.

Some trees have begun to bud around Williamsburg — something to be expected due to the warmer weather, according to York County cooperative extension agent for agriculture Megan Tierney.

“That just means we’ve had enough days over 50 degrees (to allow plants to bud),” Tierney said. “Whether or not (a plant) survives depends on the weather through spring. If we have a cold snap it can cause damages to the buds.”

Tierney said there’s not a particular time we should expect every plant to bud, and it varies plant by plant.

The above-normal temperatures were caused by an air circulation pattern called the North Atlantic Oscillation, according to National Weather Service at Wakefield’s meteorologist-in-charge Jeff Orrock.

The air pattern affects movements in the jet stream, Orrock said.

“The general flow of the jet stream has not allowed cold air to drop south and lock-in,” Orrock said. “There have been a few real cold blasts, but then the pattern retreats and the cold air goes north of us.”

The Arctic fronts Williamsburg has experienced so far in 2019 were significant, but the temperature has trended at the higher end of normal, according to National Weather Service data.

The air patterns are just one of several semi-permanent weather patterns that vary across the world each season, Orrock said.

“Anomalies in these patterns, which occur normally, impact our weather,” Orrock said.

At the Keck Environmental Field Laboratory at Lake Matoaka in Williamsburg, data shows the past three winters and summers have been relatively warmer than normal.

The average temperature for Williamsburg since 2004 has been about 59 degrees Fahrenheit, but in the past three years that temperature has been about 1.25 degrees higher.

Williamsburg’s milder winters are likely a return to normal after regional weather patterns affected the area for several years, College of William and Mary Professor Randy Chambers said.

“Interestingly, the combination of cold winters and mild summers last occurred in 2013 and 2014, so the recent warming trend in 2016-2018 is probably not an indication of climate change per se, but rather an outcome of regional circulation patterns, responses to El Nino events, etc.,” Chambers wrote in an email.

“Some years are hot, some are cold, but the combination of mild winters and hot summers has happened only four of the last 15 years, and three of those years are 2016-2018.”

As Williamsburg-area residents look to the upcoming week, the National Weather Service has called for rain every day through Feb. 21 as temperatures hang in the 40s to 50s.

During the next eight to 14 days, residents should expect warmer than normal temperatures and more rain than normal, according to the National Weather Service.

Roberts can be reached at 757-604-1329, by email at srobertsjr@vagazette.com and on Twitter @SPRobertsJr.

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