Friday, June 22, 2018
Tampa Bay Weather

Extreme weather could be tied to jet stream fluctuations

Death Valley will be unbearable this weekend. Forecasters predict temperatures of up to 129 degrees, approaching the world record of 134, set in 1913.

A week ago, historic heat struck several Alaskan towns, with highs in the 90s. About the same time, the Canadian city of Calgary experienced another extreme — torrential rains and flooding that inundated the city.

Dramatic fluctuations in weather have occurred repeatedly in recent years, including unrelenting snow in New England and monster tornadoes in Oklahoma.

The culprit? Some scientists and forecasters are pointing to abnormal shifts in the jet stream.

"When your large-scale jet stream patterns are funky, that's when you get extreme weather," said Jeff Masters, director of meteorology for Weather Underground.

The polar jet stream blows from west to east across the United States and is a key determinant of weather in much of the country.

Normally, cold air from the north and hot air from the south collide near the middle of the nation, accelerating the jet stream in a slightly wavy pattern.

As the Arctic has warmed in recent years, some scientists say, the temperature differential between cool and hot air has decreased, slowing parts of the jet stream and allowing it to meander more like a roller coaster.

"The north-south waves, or undulations, that the jet stream takes as it travels around the Northern Hemisphere are slowing down," said Jennifer Francis, an atmospheric scientist at Rutgers University who co-wrote a paper on the subject last year.

These waves lift warm air north and drive cold air south. It was a particularly high wave that carried 90-degree weather into Alaska. Another wave is blanketing the West with oppressive heat this weekend.

Waves, or undulations, have always been a part of the jet stream.

But they have been more pronounced in recent years, Masters said. Some scientists, such as Francis, think that such variations are tied to climate change. Others are not certain.

Bay News 9 meteorologist Josh Linker said the jet stream is a factor in odd weather, but he is less convinced that anything extraordinary is happening with its movement. "I don't think that dips and peaks and valleys in the jet stream are anything unusual," he said.

He said the polar jet stream generally travels well north of Florida at this time of year and should not have much effect on Tampa Bay this summer.

Still, Masters said, it was an unusually sharp dip in the jet stream in 2004 that pushed Hurricane Charley toward the west coast of Florida.

If the Arctic continues to warm, more significant weather could be on the way, he said.

"We should expect that as the Arctic continues to heat up more and more relative to the rest of the globe, we'll see an increase in extreme jet stream behavior," Masters said.

Information from the Associated Press was used in this report. Zachary T. Sampson can be reached at [email protected] or (727) 893-8804. Follow him on Twitter @zacksampson.

     
Comments
Romano: You better hope Iím wrong about flood insurance

Romano: You better hope Iím wrong about flood insurance

Chances are, Iíll go down as the Boy Who Cried Flood.You might have noticed, Iíve been shouting about the imminent calamity of flood waters for quite a few years now. If I wasnít trying to frighten you into buying flood insurance, I was worrying you ...
Published: 06/22/18

Forecast: Muggy and hot with a chance of rain for Pride festivities

As the first weekend of summer swings in, it appears Tampa Bay should expect more heat, humidity and a chance of afternoon showers.Increased moisture in the Gulf of Mexico will result in scattered showers and isolated storms for coastal areas of Tamp...
Published: 06/22/18
Forecast: Hot and humid on summerís eve across Tampa Bay, with rain chances increasing

Forecast: Hot and humid on summerís eve across Tampa Bay, with rain chances increasing

Wednesday will be the longest day of the year, literally, as the day before the official start of summer yields the most amount of sunshine.Tampa Bay has already seen lots of sunshine, heat and humidity this year, and while that sunshine may be obscu...
Published: 06/20/18
Forecast: High humidity, searing temperatures and little rain across Tampa Bay

Forecast: High humidity, searing temperatures and little rain across Tampa Bay

Dry air will keep rain chances down Tuesday, which could be a good or bad thing depending on your afternoon plans.While showers will be at a minimum, the searing heat wonít be as high humidity and mostly sunny skies will push the heat index at ar nea...
Published: 06/19/18
Forecast: Hot and humid across Tampa Bay, with potentially wet weekend

Forecast: Hot and humid across Tampa Bay, with potentially wet weekend

Summer officially doesn’t start for another three days, but that won’t stop the searing temperatures and stifling humidity from making for a hot and sticky week across Tampa Bay. Temperatures will climb well into the 90s — and feel...
Published: 06/18/18
Forecast: Plenty of sunshine for Fatherís Day with small chances of isolated showers

Forecast: Plenty of sunshine for Fatherís Day with small chances of isolated showers

As the week comes to a close, Tampa Bay can expect some pretty standard summer-like days with highs near the 90s and afternoon showers popping up around the bay.Friday morning, Tampa Bay will rise with a lot of sunshine. Some scattered showers may dr...
Published: 06/15/18
Strong winds from Tropical Storm Bud hit Mexicoís Los Cabos

Strong winds from Tropical Storm Bud hit Mexicoís Los Cabos

SAN JOSE DEL CABO, Mexico ó Tropical Storm Bud lashed the southern end of Mexicoís Baja California Peninsula, home to the popular beach resorts of Los Cabos, with heavy winds Thursday as locals and tourists braced for an expected landfall later in th...
Published: 06/14/18
Check out this waterspout that formed in waters off Egmont Key

Check out this waterspout that formed in waters off Egmont Key

ST. PETERSBURG ó While the chance for an isolated shower or thunderstorm along the coast will remain just that this week, that doesnít preclude the possibility a strong cell could form in the morning.That exact scenario occurred Thursday morning as T...
Published: 06/14/18
Forecast: Early taste of summer for Fatherís Day across Tampa Bay

Forecast: Early taste of summer for Fatherís Day across Tampa Bay

Summer officially starts one week from today, but the familiar summertime pattern is firmly intact across Tampa Bay.That means warm days, high humidity and a small chance for an isolated popup afternoon storm. In other words, a great opportunity to h...
Published: 06/14/18
Forecast: Hot days, scattered showers are still the rule across Tampa Bay

Forecast: Hot days, scattered showers are still the rule across Tampa Bay

Tampa Bay should continue seeing summer-like days through the rest of the week with sunny, partly cloudy skies and a chance for pop-up afternoon showers.A light westerly flow off the Gulf of Mexico will help push coastal breezes further inland, carry...
Published: 06/13/18