For the first time on record, both the Atlantic and the East Pacific have had tropical storms form before the opening of hurricane season.
In the Pacific, Tropical Storm Aletta began swirling four hours before the official opening of the East Pacific Hurricane Season on May 15. In the Atlantic, Tropical Storm Alberto started the Atlantic Hurricane Season 13 days before the official June 1 beginning.
Does this mean we will have long and active hurricane seasons? It all depends on El Niño. If El Niño develops in the Pacific, it will put a break to the storm development in the Atlantic. It won’t stop the weather disturbances altogether, but it will stop most from growing large enough to become tropical storms and hurricanes.
Remember—the recipe for a tropical storm is:
- Take a normal rainstorm and combine it with an ocean.
- Simmer gently over warm water (+80˚F)
- Stir with favorable winds.
Where Atlantic tropical storms usually form in June. SOURCE: NOAA
Thanks to the fast flowing Gulf Stream, we have some very hot waters in the Gulf of Mexico and off the East Coast. These are the areas where early season hurricanes start. Now, we even have favorable winds over these regions. Tropical Storm Alberto developed last week and scientists are watching waters off the Florida coast for another possible storm.
That’s where an El Niño changes the situation. The El Niño is a huge weather phenomenon. Over a million square miles of the Tropical Pacific change temperatures. The warmer water heats the air above it, which changes air pressure. That changes winds, especially tropical winds. Since the phenomenon is so huge, it changes tropical winds all around the globe.
In the Atlantic, the high altitude winds tend to be strong and sheering. As a storm grows, the high winds sheer the top off, keeping it from growing into a hurricane. There always are some hurricanes in El Niño years, but usually a lower number.
The warm waters of the El Niño shape tropical high and low level winds and weather.
This year, we are seeing early tropical storm development in the Atlantic. We probably will even see an active hurricane season in the early part of the year, as storm after storm simmers over the warm Atlantic. Then if the models are right, El Niño will develop sometime in late summer or early autumn and rescue us.
It’s shaping up to be a story tale season. The damsels in distress—Georgia, Florida and the Carolinas—will be threatened by monstrous tropical storms. Then El Niño charges in on a white horse and quells the monsters by chopping off their tops. Happy ending!
Evelyn Browning Garriss, historical climatologist, is a longtime writer for The Old Farmer's Almanac. She is also editor of The Browning World Climate Bulletin and has advised farmers, businesses, and investors worldwide on upcoming climate events and their economic and social impact for the past 21 years.