La Niña Sticking Around: What It Means For Tampa Bay’s Summer

TAMPA, Fla. (WFLA) — We’ve been in the La Niña weather pattern for the year and a recent outlook from the National Oceanic and Atmospheric Administration (NOAA) shows that there’s a very good chance that we will remain in the La Niña pattern for the summer.

The NOAA report says there’s a 59% chance we will be in the La Niña weather pattern through August and a 50 to 55% chance the pattern will continue past August and through the fall season.

What are La Niña and El Niño?

La Niña, and it’s opposite counterpart El Niño, are defined by the Pacific Ocean’s temperatures. According to NOAA, trade winds weaken in the El Niño pattern and warmer water is pushed back east, towards the west coast of South, Central, and North America. This pattern is identified by warmer temperatures in the Pacific Ocean. That causes the Pacific Jet Stream to move south of it’s normal position, making for dryer and warmer weather in the northern U.S. and Canada. In the Gulf and southeast, we see wetter weather and an increased chance for flooding.

NOAA – El Niño causes the Pacific jet stream to move south and spread further east. During winter, this leads to wetter conditions than usual in the Southern U.S. and warmer and drier conditions in the North.

It appears we will be in the La Niña weather pattern this summer, which means stronger trade winds pushing the warm water toward Asia. The cooler water from deeper moves upward to fill the void, called an upwelling. This results in much cooler water temperatures in the Pacific along the west coast of the U.S., and pushes the Pacific jet stream further north, resulting in colder, wetter weather in the northwest.

NOAA- La Niña causes the jet stream to move northward and to weaken over the eastern Pacific. During La Niña winters, the South sees warmer and drier conditions than usual. The North and Canada tend to be wetter and colder.

What it means for Tampa Bay

For us in the Tampa Bay area, La Niña means drier, warmer weather across the southeast and Gulf. This could increase our fire danger in the long term. Locally, our rain chances are building, which will help make this less of a danger.

In Tampa Bay, we’re seeing a slightly early start to our rainy season, which is very good news for our spring fire danger. We are exiting a very dry time of the year for us – late fall and winter are our driest times – and until we see rainy season beginning, our fire danger builds. We have good chances for afternoon showers and thunderstorms to fire up this weekend and even into next week we have chances for showers each day, although they grow more isolated.

It’s possible that we may be drier in a few weeks but by the end of May, our rainy season will be in full swing, significantly lowering our fire danger. We’ve been in the La Niña weather pattern for the last two summers for reference. Often times, we see the effects of the drier part of the La Niña pattern realized to the north of the Gulf, where the summertime tropical rains are not a daily factor in the weather pattern.

Hurricane season impact

When it comes to hurricanes and La Niña, Max Defender 8 Chief Meteorologist Jeff Berardelli explains, “between 1995 and 2016, in La Niña years, we average about 8.4 hurricanes in the Atlantic. But in an El Niño year, we average only 4.7 hurricanes.”

We will be prone to a higher number of hurricanes in the current weather pattern.

“The last two hurricane seasons – which were hyperactive – we have had La Niñas… this will likely be the third in a row,” he explained. “We call this a ‘Triple Dip’ La Niña. It has only happened a couple of times before. The number of successive La Niñas really has no bearing on the outcome of this season… but the simple fact that we have a La Niña means that, statistically speaking, we should have another active hurricane season upcoming. That’s because, in a La Niña, the upper-level winds which come out of the Pacific tend to be weaker and that means the atmosphere is less disturbed and thus tropical systems are less impacted and better able to get organized.”

According to NOAA, El Niño and La Niña usually last nine to 12 months, but can sometimes last for years. El Niño and La Niña events occur every two to seven years, on average, but they don’t occur on a regular schedule. Generally, El Niño occurs more frequently than La Niña.

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