first updated June forecast for Atlantic hurricanes in 2017 has been released by the Colorado State University Tropical Meteorology Project.
(April 6 )
This year, 2017, the expectation is for a “below average” year, based on 29 years of observations from 1981 to 2010. There is the potential for shear-enhancing El Niño conditions to develop over the next several months. The tropical Atlantic has cooled over the past month, and the far North Atlantic is currently colder than normal. These cold anomalies tend to force atmospheric conditions that are less conducive for Atlantic hurricane formation and intensification.
(June 1) We have increased our forecast and now believe that 2017 will have approximately average activity. The odds of a significant El Niño in 2017 have diminished somewhat, and portions of the tropical Atlantic have anomalously warmed over the past two months. While the tropical Atlantic is warmer than normal, the far North Atlantic remains colder than normal, potentially indicative of a negative phase of the Atlantic Multi-Decadal Oscillation. We anticipate a near-average probability for major hurricanes making landfall along the United States coastline and in the Caribbean.
From http://tropical.colostate.edu :-
We anticipate that the 2017 Atlantic basin hurricane season will have slightly below- average activity. The current neutral ENSO is likely to transition to either weak or moderate El Niño conditions by the peak of the Atlantic hurricane season. The tropical Atlantic has anomalously cooled over the past month and the far North Atlantic is relatively cold, potentially indicative of a negative phase of the Atlantic Multi-Decadal Oscillation. We anticipate a below-average probability for major hurricanes making landfall along the United States coastline and in the Caribbean. As is the case with all hurricane seasons, coastal residents are reminded that it only takes one hurricane making landfall to make it an active season for them. They should prepare the same for every season, regardless of how much activity is predicted.
by Philip J. Klotzbach and Michael M. Bell (as of 6 April 2017)
An analysis of a variety of different atmosphere and ocean measurements (through March) which are known to have long-period statistical relationships with the upcoming season’s Atlantic tropical cyclone activity indicate that 2017 should have slightly below-average activity. The big question marks with this season’s predictions are whether an El Niño develops, as well as what the configuration of Sea Surface Temperatures will look like in the tropical and far North Atlantic Ocean during the peak of the Atlantic hurricane season.
June 1 – Our confidence that a weak to moderate El Niño will develop has diminished since early April. While upper ocean content heat anomalies have slowly increased over the past several months, the transition towards warm ENSO conditions appears to have been delayed compared with earlier expectations. At this point, we believe that the most realistic scenario for the 2017 Atlantic hurricane season is borderline warm neutral ENSO to weak El Niño conditions. There remains a need to closely monitor ENSO conditions over the next few months. Additional discussion of ENSO will be included with the July 1 and August 4 updates.
2017 Forecast numbers:
|Atlantic Hurricane Season||29-year Median|
|Named storms (>35mph winds)||12|
|Hurricanes (>72mph winds)||6.5|
|Major hurricanes (>111mph winds)||2 2||2|
|US landfall likelihood||52%|
|Gulf Coast landfall probability||30%|
|Major Hurricane in Caribbean
|Manatee County hurricane landfall
|Manatee County tropical storm
|Manatee County >75mph wind gusts