A new update from Colorado State University, released Monday morning on June 2, now calls for a below-average Atlantic hurricane season this year. This is the third forecast released for this year’s season. In their first forecast released on April 5, 14 named storms were forecast. The same number was given in their May 31 forecast. Now in their most recent forecast, they have lowered the number of expected storms down to 11, which includes Alberto. If you may recall, Alberto was a subtropical storm that made landfall on the Gulf Coast during the Memorial Day holiday.
The forecast also calls for now only 4 hurricanes, 2 of which are expected to become major (category 3 or greater). This is a rather large decline compared to their April 5 forecast, when they initially called for 7 hurricanes and 3 major hurricanes. The typical Atlantic hurricane season features 12 named storms (tropical storm or hurricane), 7 hurricanes, and 2 major hurricanes according to Colorado State University.. As such, a below-average season is now forecast.
There are several factors on why a quieter Atlantic hurricane season is now expected. One of them is the cooler sea surface temperatures across the Main Development Region. This area, located from the Caribbean Sea through the western coast of Africa, is the region that often feature the origins of the most intense tropical cyclones during the most active time of the season. These tropical cyclones derive much of their energy from ocean waters, so since temperatures are below-average and are not expected to warm much, it will be an inhibiting factor on tropical development this year.
Another feature that suggests below average activity is the potential development of an El Niño by the end of this year. An ‘El Niño Watch’ has been issued by NOAA’s Climate Prediction Center based on the increasing chances that the equatorial Pacific waters warm up to 1 degree Celsius above-average. El Niños tend to suppress tropical cyclone formation in the Atlantic basin because it increases wind shear over the region. This shear rips apart the thunderstorms as they try to organize, making it extremely difficult for a cyclone to form.
Based on these factors, Colorado State University and other tropical scientists are betting on a quieter hurricane season. This is definitely welcome relief for many following the extremely active 2017 Atlantic hurricane season, when 3 major hurricanes made landfall on the United States.
That being said, it only takes one storm to define a hurricane season. Water temperatures are actually above-average near the US coastline, so that may make for at least a somewhat favorable environment for tropical cyclones to form. The best advice we can give you is to prepare, as just because this season may feature below-average tropical cyclone activity, doesn’t mean a storm won’t form and won’t make landfall.