What La Niña?
Back in Spring 2016, the expectation around the National Oceanic and Atmospheric Administration (NOAA) was the monster El Niño (also called the “El Niño Southern Oscillation, or ENSO for short) that kept North America so warm over Winter 2015 and squashed 2015 Atlantic hurricanes had faded out, only to be replaced with a La Niña developing in April 2016 and emerging by late summer.
There’s only one problem with such weather predictions: they didn’t happen. Since April 2016, the cooler water that was expected to expand into the part of the Pacific Ocean where the ENSO phenomena forms and affects global air currents diminished until it fizzled completely .
For the time being, La Niña has been cancelled. Instead, the forecast is for neutral ENSO conditions (55-60% chance). A La Niña may still emerge – there’s a 40% chance it could emerge in 2016 and continue through February, 2017- but it’s likely to be weak or marginal.
What Happens Next?
A neutral ENSO tends to bring colder than average winter temperatures to the upper Midwest and Northeast United States from November through March. Some may recall (with a shiver) back in 2014 when a neutral ENSO contributed to an incursion by the Polar Vortex. Weather predictions for this winter might be a little different.
North Pacific sea temperatures continue to be very warm, and the flow of these temperatures into the Arctic drastically reduced sea ice this summer. This created an enormous area north of the Bering Strait above the Arctic Circle that was ice-free, making it the second lowest Arctic ice-minimum ever recorded. While that’s concerning news, research suggests that when the Arctic has below-normal sea ice in the fall and winter, there’s less chance for the polar vortex to dip way down into the lower 48 states. In fact, it’s Siberia that receives the extensive snow cover in the fall.
That’s Cool, I Guess. But What Does that Mean for Me?
With that in mind, the weather predictions from NOAA state that October, November, and December will experience “Increased probabilities of above-normal temperatures across most of the contiguous US and Alaska.” Meanwhile, the southeast will likely see more precipitation. In sum, it looks like a warm fall, possibly followed by a “brown Christmas” in some regions. Check your state’s temperature trends.
Meanwhile, the Atlantic Hurricane season normally peaks sometime between late August through October. While the vanished La Niña won’t likely exert much effect, the season’s certainly not over yet.
How Does This Impact the Rest of the 2016 Hurricane Season?
So far, there have been 13 storm systems in 2016. Sure we had Hurricane Alex in January, but this season really began with Bonnie drenching South Carolina in June, followed by the majority of storms coming out of what hurricane experts call the Main Development Region (MDR). The MDR is the band of Atlantic Ocean stretching from west Africa to the Caribbean where warm water and calm winds spawn hurricanes.
This year’s storms forming in the MDR have moved westward and then gradually turned towards the north Atlantic. As of the August 11, Hurricane update, NOAA’s revised forecast for an 85% chance this season will either be near-normal has held true: 12-17 named storms of which 5-8 are expected to become hurricanes, and 2-4 of those are expected to become major hurricanes.
The reason 2016 has been a more active year than the last two is that some conditions with the MDR encourage hurricane formation and intensification, such as a stronger West African monsoon driving strong upper level easterly winds and an easterly jet stream. Yet, while the current sea surface temperature (SST) in the main development area is above average, it’s still a bit cooler in the eastern Atlantic and is more common to an average hurricane season. NOAA states that if a La Niña emerges this late in the season, it will most likely be weak and have little impact.
One vestige from the faded El Niño may be some vertical wind shear/air sinking over Yucatan/southwestern Caribbean Sea that disrupts storms moving into that part of the Caribbean and may shift their trajectory northward. Recently, Hurricane Matthew entered this area of the Caribbean, but it’s expected to veer north and east to Jamaica, Cuba, The Bahamas, and potentially away from landfall in the United States.
It might be late in the season, but it still only takes one storm to cause a tragedy. And while hurricanes do wreak havoc on the coast, they also cause flooding and destruction inland as well. Make sure you and your family are prepared and have a plan. Check out the Weather Readiness section of the Direct Energy Learning Center for helpful articles like “Hurricane Prep: Before, During, and After the Storm” and “Create a Hurricane Evacuation Plan for Your Family,” as well as our Hurricane Preparedness Checklist.