What signs of forming La Niña in Pacific could mean for South Carolina hurricane season

It’s been a very wet winter in the Upstate this year, with this past January the rainiest on record in Greenville. Meteorologists say the current El Niño in the Central Pacific Ocean is largely to blame."We've been in that since last autumn," says Matthew Rosencrans, NOAA’s lead forecaster for the seasonal hurricane outlook. "And that typically results in more wetness across Southern California to Texas, and the strongest signal is actually for the wetness in the southeast US… And we've seen some pretty heavy rainfall events there across the southeast during the winter time."Related: Why meteorologists say new 'category 6' for hurricanes is a bad idea in warming worldThere is some evidence suggesting the current El Niño may be coming to an end this summer. Long-range forecast models are indicating ocean temperatures in the Central Pacific may start to cool over the next few months, showing a transition from an El Niño to a La Niña."From the North American Multi-Model ensemble – the Copernican climate change Multi-model ensemble – little bit of difference as far as the timing of when we start to cool Rosencrans said. "And so that's why we have a 55% chance of developing a La Niña in the June, July and August time period – that meteorological summer."This could have impacts on the Atlantic heading into hurricane season.Related: Data collected at highest mountain in northeast US help track changes in climate"The main way that La Niña and El Niño can change the tropical storm and hurricane activity is through the changing of the wind shear," Rosencrans said. "And it impacts it through changing the wind shear in the tropics by La Niñas reducing that wind shear and El Niños typically increase that wind shear, and that's really kind of in the Gulf of Mexico and Caribbean. Because you need low wind shear and good relative moisture and warm sea surface temperatures. That's kind of the ingredients that go into a hurricane – and La Niña is now impacting two of those three."Currently, in the tropical Atlantic Ocean, ocean temperatures are already significantly warmer than usual – On par with what average temperatures are in July.More weather news: Military leaders look for ways to conquer heat while training troopsIt’s never too early to begin putting together a hurricane evacuation plan or storm plan before the season ramps up--even now in February. For more tips on how to prepare, be sure to head to the South Carolina Emergency Management’s Division website.