Water vapor view of Hurricane Gonzalo (NOAA)

Hurricane Gonzalo brushed by Puerto Rico Monday, causing little damage. But the strengthening storm poses a more severe threat to Bermuda which it may encounter Friday as a major hurricane.

On Monday, Gonzalo passed directly over Antigua and then the smaller islands of St. Barthelemy, St. Maarten, and Anguilla as a tropical storm. After achieving hurricane intensity, it then passed east of the Virgin Islands and Puerto Rico – delivering just a glancing blow. It is now headed north into the open Atlantic.

Gonzalo’s most severe damage was reported in Antigua, reports the Associated Press:

Gonzalo pummeled Antigua on Monday as a tropical storm, tearing off roofs, uprooting trees and knocking out power, with crews working overnight with flashlights to help restore power. About a dozen people were treated at a hospital for light injuries


Satellite image of Hurricane Gonzalo north of Puerto Rico at 10:37am EDT. (NOAA)

Today at 11 a.m. EDT, Gonzalo was  just shy of becoming a Category 3 hurricane with maximum sustained winds are 110 mph (115 mph would be Category 3).  It is very likely to become a major hurricane later today, and it would be the furthest south a major hurricane formed since Sandy in October 2012. Prior to that, you have to go back to Rina in October 2011, and then Karl in 2010.  It would also be the furthest east a major hurricane formed during October since Omar in 2008.  We will wait and see!

There was continuous radar coverage of Gonzalo thanks to sites on Guadeloupe and Puerto Rico… you can find both long loops here. Later this week, it should come within Bermuda’s radar range and that loop will be available in real-time as well.

Last weekend, Tropical Storm Fay made a direct hit on Bermuda, so this will be a most unwelcome second visitor in less than a week.

(Incidentally, contrary to many people’s impression of Florida as a hurricane magnet, it has been nine years since Florida has been hit by a hurricane of any intensity.)

As far as the forecast goes, environmental conditions will remain quite favorable for further intensification for the next three days, and Gonzalo could briefly reach Category 4 status today or tomorrow.  Beyond that, interaction with an area of low pressure will begin to introduce strong vertical wind shear, and by the time it’s up near Bermuda, the ocean temperatures get cooler too – probably inducing slow weakening.

Still, the National Hurricane Center predicts Gonzalo will have maximum sustained winds of 120 mph – category 3 intensity – when it nears Bermuda Friday. A direct strike could thus produce severe damage there.

Models are in close agreement on both the track and the intensity.  And although it’s still far out, Gonzalo could be a significant wind and storm surge event for Newfoundland on Sunday even as it weakens, so that is something our Canadian friends should be monitoring closely.

Forecast track from NHC’s 11am EDT advisory. (NOAA)

A peculiar aspect of this hurricane season is the proportion of named storms that reached hurricane strength.  Climatologically, about 53% of named storms become hurricanes, but so far this year, the fraction is 86%!  In the chart below, the normal accumulated seasonal storm counts are shaded, and 2014’s counts are the colored dots plotted on today’s date.  While the large-scale environment has been abnormally hostile for genesis (especially in the deep tropics), storms that did manage to form have generally fared well.


Average accumulated storm counts and 2014’s values as of today.

(Jason Samenow contributed to this post).