Hurricane season began on June 1^st and even before the official start there had already been two named storms.  We now have tropical storm Colin in the eastern Gulf of Mexico for the third named storm of the year.  This system will bring rain and some gusty winds to Florida, but won’t be a major storm.

It’s been 25 years since a hurricane made landfall here in New England and that was Bob which did quite a bit of damage.  I’ll look back at that storm later this summer, but for now with tropical storm Colin headed for Florida and then the Carolinas, it’s a good chance to think about the pattern we are currently in and our chances of a hurricane or tropical storm later this summer or fall.

El Nino Disappearing

Unless you didn’t look at any media during the fall of 2015 and throughout the winter you know there was a strong El Nino earlier this year.  Since the year began, the strength of the El Nino has been weakening.  To remind you, El Nino is simply the stage when the waters off the coast of Peru become significantly warmer than average.  La Nina is the opposite.   As the waters continue to cool a La Nina (cooler than normal) may develop.  These states have important implications across the globe including the Atlantic basin and Gulf of Mexico where the hurricanes impacting New England form.  During El Nino years the trade winds weaken or reverse direction and this tends to negate tropical development in the Atlantic.  As El Nino disappears, tropical development can increase.

Warm Water

Tropical systems need warm water to form.  This is because warmer water has more potential energy and that’s what these storms require.  It’s why the season typically runs from June through November when the ocean is at its warmest.  The image below shows predicted water temperatures later this summer and fall.  I’ve circled three areas of note.  First, water temperatures are predicted to close to average or even slightly below off the coast of Africa.  If the water is too cool, then hurricanes can have a hard time forming.  However, the waters closer to the United States (area number 2) are forecast to be warmer than average and this can fuel tropical systems.

Lastly, notice the cooler than average water forecast across the Pacific west of Peru.  This is a sign of La Nina and can contribute to more an active season.

In order to get a tropical system to come up the east coast the upper level winds must at the time of the storm be configured in such a way so the storm comes north.  One of the long range models appears to position high pressure to our southwest which tends to bring warm weather, but also can keep storms south and headed into Florida.

When Bob struck the region 25 years ago the jet stream set up was ideal for a storm to come up the east coast.  While impossible to predict where things will stand later this summer, unless we have a similar flow, even an active hurricane season won’t bring one here.

Names Aren’t The Only Big Storms

Lastly, it seems like when we name a storm it somehow becomes more important.   While named storms are easy to follow, those without names, like severe thunderstorms, flooding events and snowstorms can cause an equal or greater amount of death and destruction to a named one.

 

Stay tuned.