Make us your home page
Instagram

Today’s top headlines delivered to you daily.

(View our Privacy Policy)

Shifting of Bermuda High is leading to morning thunderstorms

Just a month ago we were coping with drought: yellow lawns, dirty cars, record heat.

Suddenly, flood advisories are popping up like mushrooms.

What happened? And is the July 4 weekend about to be spoiled?

You may get a reprieve. Most forecasters see a 40 percent to 50 percent chance of rain through the weekend, nothing like the Wednesday morning monsoon that dumped up to 4 inches.

"Keep an eye on the sky over the long weekend," said Mike Clay, chief meteorologist for Bay News 9. "It's that time of year."

But the factors that caused all the rain for 10 days likely will re-emerge next week. Why?

The primary culprit is the Bermuda High, a vast weather system that significantly affects Tampa Bay weather.

This time of year, the high normally is centered over Bermuda, stretching hundreds of miles. It turns clockwise, bringing easterly winds across Florida.

Those winds heat up as they cross the peninsula and eventually meet cooler air from the Gulf of Mexico, producing afternoon thunderstorms.

Not lately, though.

The Bermuda High has been pushed well south, closer to the latitude of the Florida Straits. That means the air guided by the high travels well south of Florida, ultimately making it here from the south or southwest, said Rick Davis, meteorologist with National Weather Service in Ruskin.

Laden with moisture from the warmer waters, the air arrives on the peninsula, begins heating up with the rising sun and — boom! — we have morning thunderstorms.

Wednesday morning's storm "train" — several storm pockets on the same track producing one thunderstorm after another — dumped as much as 4 inches of morning rain on parts of Pasco, Pinellas and Hillsborough counties.

This southwesterly influence will continue until the Bermuda High moves back north into its normal summer position.

When will that happen? Who knows? The high has been pushed south by a massive low-pressure system to the north, centered over the Great Lakes.

And that's the rub.

Some weakening of the low is expected during the long holiday weekend. Much of Florida, from Tampa Bay south, could get a break from the recent deluge. Typical summer thunderstorms, caused by the easterly flow of air, could still produce showers, but probably not as widespread as the last few days.

But the low over the Great Lakes is expected to restrengthen by the start of next week, meaning a return to the southwesterly flow and more early morning storms.

We could use the rain, you know.

"We need a lot more rain," said Robin Felix, spokeswoman for the Southwest Florida Water Management District. "We've been in a drought for years. We're still at a 22-inch rainfall deficit."

Shifting of Bermuda High is leading to morning thunderstorms 07/01/09 [Last modified: Thursday, July 2, 2009 6:43am]
Photo reprints | Article reprints

© 2017 Tampa Bay Times

    

Join the discussion: Click to view comments, add yours

Loading...
  1. Why Noah Spence could be the Bucs' X-factor

    Bucs

    JACKSONVILLE — Noah Spence crouched in a four-point stance, bending low like a sprinter in starting blocks. At the snap, he took one step to his right, startling Jaguars left tackle Josh Wells with his explosiveness. Wells went for the move and Spence countered with an inside swim move, flying past Wells' right …

    Tampa Bay Buccaneers defensive end Noah Spence (57) participates in training camp at One Buccaneer Place in Tampa, Fla., on Wednesday, Aug. 2, 2017. LOREN ELLIOTT   |   Times 

  2. After Charlottesville, Charlie Crist sees turning point with GOP and Trump

    Blogs

    Rep. Charlie Crist was at his St. Petersburg condo building today when a painter suddenly said, "Can you believe what he said yesterday?"

    John McCain and Charlie Crist
  3. Lefty quarterback's task? Make sure nothing's lost in translation

    College

    GAINESVILLE — When Florida receiver Brandon Powell first met new quarterback Malik Zaire this summer, he was struck by the Notre Dame grad transfer's enthusiasm and outgoing personality.

    Florida quarterback Malik Zaire talks with the press during the NCAA college football team's media day in Gainesville. Zaire is a lefty quarterback, just like Tim Tebow. (Brad McClenny/The Gainesville Sun via AP, File)
  4. The Lincoln Memorial is seen in the early morning light on the National Mall on June 30, 2017. The National Park Service says someone defaced the memorial with an anti-law message early in the morning on Aug. 15, 2017. [Associated Press]
  5. Bail hearing underway for woman accused in Selmon crash that killed three

    Criminal

    TAMPA — Amber Nicole Perera sobbed and hung her head at the defendant's table Wednesday as prosecutors displayed photos of the charred remains of a Tampa family who died in a flaming crash that Perera is accused of causing Thursday on the Lee Roy Selmon Expressway.

    Angela Perera, charged with DUI manslaughter in a crash that killed three on the Lee Roy Selmon Expressway on Aug. 10, 2017, bows her head as she appears in court on Aug. 16, 2017. Circuit Judge Margaret Taylor tells Perera to compose herself or she'll be removed from courtroom. [MONICA HERNDON | Times]