The hurricane season for this coming year is already being called one of the most active in recent memory.
Two indications of this come from the NOAA’s ” outlook” and the National Hurricane Center’s ” trend” graphic, that meteorologists use to identify potential activity for a season.
By the following weekend, AccuWeather will determine if this year will be one of the busiest ever for storm activity, or if we should expect a milder than normal season with less frequent tropical hurricanes.
There is great overlap between the two images, with many of the key elements of the “weekend-out” cycle playing out during the height of hurricane season. Inaccuracy has to do with five year trends in outlooks, and so far this model has accurately tracked major storm activity for hurricane season.
From mid-August to the start of hurricane season, there are typically two pieces of information, indicative of potential storm activity.
1) Hurricane track – WHAT was going on in the Atlantic when hurricane season began?
There are two phases to the forecast that we will discuss below.
The first phase is the data available at that time from the NOAA’s ” Atlantic Ocean Storm Outlook ” which tracks storms in the Atlantic basin. Tropical storms form, and those that are given the name Danielle, Ernesto, Erin, Hannah, Hermine, Irma, Jose, Nate, and Matthew, develop.
“The most important part of the forecast track is the westward track of a tropical cyclone. This is what happens in the Atlantic during the fall and winter,” stated AccuWeather Meteorologist Jamie Drake.
“Early track forecast to the west suggests an increased chance of tropical activity, though this is not always the case. This is one element of forecasting because it gives confidence to people in cities like New York City or Miami to prepare for a more active hurricane season,” Drake added.
The other aspect of the forecast that is more of a truism is the early trend.
2) Tropical storm ‘potential’ – This is based on information gleaned from the “Atlantic Ocean Storm Watchout” that forecasts potential tropical activity as a tropical storm or hurricane. The main component of potential activity in this case relates to tropical cyclone cyclone wind speed.
“AccuWeather in 1984 identified that 90% of tropical storms and hurricanes in the past 30 years have had a minimum tropical cyclone wind speed of 74 mph, which is what the U.S. National Hurricane Center uses to designate systems as hurricanes,” says AccuWeather Meteorologist Evan Duffey.
Duffey called this data a “10 out of 10” in his reaction to the future of this season’s activity.
Right now, based on information from the “Atlantic Ocean Storm Watchout,” all signs point to a busy hurricane season.
How we get to that higher end of the potential activity level is in question, however.
From there, there are some things in the next three months that we will need to consider. A lot hinges on the El Nino pattern developing over the Pacific.
If El Nino does materialize, these structures change the atmospheric weather pattern over the Eastern U.S. with more northerly flow which can affect hurricane development.
More importantly in this scenario is the changes over warm water in the Atlantic. A lot of the steering currents that allow storms to take shape in the Atlantic have the most impact over warm water, which limits the amount of hurricanes that can form.
Does El Nino dry out the Atlantic? Because if it doesn’t, there is a good chance that there will be a busy hurricane season.
In the meantime, AccuWeather meteorologists will go back to the drawing board. On the day of the initiation of hurricane season, June 1, we will assess how the forecast has changed and hope that we were better prepared for the upcoming season.