Monday, July 16, 2018
Tampa Bay Weather

NOAA releases bleak update on hurricane season, now forecast to be most active since 2010

Times Staff Writers

The National Oceanic and Atmospheric Administration is now predicting an above-average hurricane season driven in part by warmer-than-normal water temperatures in the Atlantic Ocean.

The agency's updated 2017 Atlantic forecast, released Wednesday, should stand as a warning for coastal residents as we enter the most active period for hurricane development, forecasters said.

"Today's updated outlook underscores the need for everyone to know their true vulnerabilities to storms and storm surge," said Brock Long, administrator of the Federal Emergency Management Agency. "As we enter the height of hurricane season, it's important for everyone to know who issues evacuation orders in their community, heed the warnings, update their insurance and have a preparedness plan."

Forecasters now say there's a 60 percent chance of an above-normal season, "with the possibility now that it could be extremely active," said Gerry Bell, the lead seasonal hurricane forecaster at NOAA's Climate Prediction Center, which published the report. There is only a 30 percent chance for an average season and a 10 percent chance for a below-average season.

Those numbers are up from NOAA's May prediction of a 45 percent chance for an above-average season. Wednesday's forecast said it's likely there will be 14 to 19 named storms, with five to nine hurricanes and two to five major hurricanes this season, which runs through Nov. 30. It factors in the six named storms we've already seen this year, including Hurricane Franklin, which grew from a tropical storm to a hurricane on Wednesday while bearing down on the Mexican gulf coast.

A major hurricane is a Category 3 or stronger, with wind speeds of at least 111 m.p.h.

RELATED:Franklin becomes first hurricane of the season, aims at Mexico's gulf coast

In May, NOAA predicted 11 to 17 named storms, with two to four major hurricanes. Its forecast of five to nine hurricanes remains unchanged since May.

The season, meteorologists say, has the potential to be the most active since 2010. An average season comprises 12 named storms, with six hurricanes, three of them major, according to NOAA.

Several factors have combined to make the tropical Atlantic conducive to hurricane development, said Bell, with NOAA's Climate Prediction Center. One is that El Niño, the phenomenon of warmer-than-normal water in the tropical Pacific Ocean, didn't materialize. That warmer water creates high-altitude winds above the tropical Atlantic, which contributes to wind shear that helps to keep thunderstorms from coalescing into cyclones.

Another factor, Bell said, is that the water in the tropical Atlantic Ocean is one to two degrees Fahrenheit warmer than normal, because the surface winds across that part of the ocean have been weak. Strong winds will churn water near the surface, said Phil Klotzbach, a climate research scientist at Colorado State University, which puts out its own hurricane seasonal outlooks. That churn results in cooler surface water. When the winds are weaker, he said, the top layer of water bakes in the sun.

The warm water doesn't just fuel hurricanes, Klotzbach said. It also lowers the air pressure over the water, making the atmosphere more unstable, which gives cyclones more opportunities for development. Also, he said, warmer water often contributes to more moist air, which is better for cyclones than drier air.

Klotzbach's most recent seasonal outlook, released Aug. 4, is similar to NOAA's, predicting 16 named stormed, eight hurricanes and three major hurricanes.

He said the six storms we've already seen — twice the average for this time of year — doesn't play a great role in forecasting the rest of the season. Most of those storms were weak and marginal, he said, and didn't contribute much to the expected seasonal total of accumulated cyclone energy, a measure that combines both the strength and duration of storms.

But Bell said what those storms indicate is that the conditions in the Atlantic hurricane basin for storm development are already set entering the peak of the season.

"The wind and air patterns in the area of the tropical Atlantic and Caribbean where many storms develop are very conducive to an above-normal season," Bell wrote in the news release.

 

Klotzbach said climate change likely hasn't played a role in the active seasons we've seen this year and last, in which Florida was hit by its first hurricane in 11 years. It's difficult, he said, to try to pinpoint climate change's effect on storms amid all the noise created by more influential weather factors, such as El Niño.

In general, Klotzbach said, science suggests climate change could actually decrease the frequency of hurricanes, but increase their intensity. But it depends how the planet, which warms unevenly, grows hotter.

"What really matters for tropical cyclones is how the Atlantic warms relative to the rest of the globe," he said.

Contact Josh Solomon at (813) 909-4613 or [email protected] Follow @josh_solomon15.

Comments
Thick humidity fuels sweltering conditions, increasing rain chances for Tampa Bay

Thick humidity fuels sweltering conditions, increasing rain chances for Tampa Bay

Scattered showers and thunderstorms are expected to pick up throughout Tampa Bay on Tuesday afternoon, along with continued blistering sunshine and high humidity.An increased chance of rain, around 60 percent, will continue throughout the week. A hig...
Updated: 8 hours ago
Forecast: Dry start to work week, but rain chances will build across Tampa Bay

Forecast: Dry start to work week, but rain chances will build across Tampa Bay

The work week will start of relatively dry across Tampa Bay, but rain chances will increase throughout the week with a chance of scattered showers and thunderstorms near 50 percent on Friday.Skies will be mostly sunny on Monday, with only a 20 percen...
Published: 07/16/18
Seasonal weather remains consistent across Tampa Bay through weekend

Seasonal weather remains consistent across Tampa Bay through weekend

Tampa Bay residents can expect typical July weather patterns Friday and heading into the weekend as warm weather and sunshine leads to possible afternoon storms.The National Weather Service has most of the storms developing inland during the afternoo...
Published: 07/13/18
Chris downgraded to post-tropical cyclone, will bring rain, dangerous surf to Canada

Chris downgraded to post-tropical cyclone, will bring rain, dangerous surf to Canada

Although Chris may no longer be a hurricane, the storm could still have a significant impact on weather both on the East Coast and Canada as it races across the Atlantic and toward Canada.Hours after being downgraded to a tropical storm, Chris was de...
Published: 07/12/18
Continued high humidity with increased chance for afternoon thunderstorms in Tampa Bay

Continued high humidity with increased chance for afternoon thunderstorms in Tampa Bay

It should be a sunny Thursday around Tampa Bay with partly skies and a 20-30 percent chance of rain by the late afternoon.Most of those storms will be driven further inland by the coastal breeze sweeping in from the Gulf of Mexico, according to the N...
Published: 07/12/18
Continued heat and humidity across Tampa Bay, and more rain this weekend

Continued heat and humidity across Tampa Bay, and more rain this weekend

The second half of the week will continue Tampa Bay’s slow trek through the dog days of summer with afternoon heat indexes surpassing 100 degrees.Expect a hot and humid Wednesday as highs reach 92, with high humidity making it feel more like 100-105,...
Published: 07/11/18
Hurricane Chris quickly strengthens, generates dangerous surf on path to Canada

Hurricane Chris quickly strengthens, generates dangerous surf on path to Canada

The second hurricane of the 2018 season has quickly strengthened into a Category 2 storm that is moving away from the U.S. but making a bee-line toward Canada and, eventually, Iceland.As of Wednesday at 5 a.m., Hurricane Chris was situated about 315 ...
Published: 07/11/18
Pasco residents, officials use Irma’s lessons for upcoming hurricane plans

Pasco residents, officials use Irma’s lessons for upcoming hurricane plans

NEW PORT RICHEY — Melissa Detwiler, a resident of Seven Springs Trailer Park, bought her travel trailer in May 2017. When Hurricane Irma hit in September, she left it on the highest ground in the park and evacuated to Orlando.She and her trailer were...
Published: 07/11/18
Hurricane season 2018: Hernando County looks back on lessons learned from Irma

Hurricane season 2018: Hernando County looks back on lessons learned from Irma

Hurricane Irma last year left Hernando County with lots of flooding and downed trees, but also lessons about what to do better if another storm hits the area this year.About a month into hurricane season, the Tampa Bay Times spoke with county staff m...
Published: 07/11/18
Plenty of sunshine for Tampa Bay with chance of afternoon rain

Plenty of sunshine for Tampa Bay with chance of afternoon rain

It should be a bright, partly cloudy Tuesday with plenty of sunshine over Tampa Bay with a slight chance of scattered afternoon showers.There is a 20-30 percent chance that folks around the Tampa Bay area could see thunderstorms by the late afternoon...
Published: 07/10/18