11 July 2018

Hurricane Chris accelerating into north-central Atlantic


Since yesterday's update, Chris reached a peak intensity of 105 mph... not quite Category 3 intensity.  As of the 11am EDT advisory on Wednesday, the peak sustained winds have fallen to 100 mph, which is still a Category 2 hurricane.  It's also zipping off to the northeast at 22 mph, not too shabby considering it was parked for four days.


Chris will transition from a tropical to an extratropical cyclone on Friday as it passes over colder and colder water and interacts with a mid-latitude trough. But, Newfoundland will likely experience hurricane conditions on Thursday before it makes its exit. You can watch it cruise through that area via a series of radars on Nova Scotia and Newfoundland: https://weather.gc.ca/radar/index_e.html?id=ERN


[By the way, Chris is a name from the original set of six rotating lists... first used in 1982.  Among its six previous incarnations, the highest intensity reached was 75 kt in 2012, so the 2018 version now holds that title.]

Looking at the seasonal activity to-date, we have had 3 named storms, 2 hurricanes, and 0 major hurricanes, with an ACE (Accumulated Cyclone Energy) of 12.1.  An "average" season would have 1 named storm, 0 hurricanes, 0 major hurricanes, and an ACE of 3.7 by now.

So in terms of ACE (a commonly-used metric that combines the intensity and duration of all storms), we are at 326% of normal activity for the date.  In other way to frame it is that the ACE is currently what it climatologically would be on August 14. And as I mentioned yesterday, the last time we had two hurricanes so early in the season was 2005.


Ex-Beryl is centered over the central Bahamas and is not getting any better organized. Models have backed off on re-developing this disturbance, but it may have a brief resurgence as a subtropical cyclone over the weekend off the New England coast -- nothing to be concerned about.



10 July 2018

Chris upgraded to a hurricane, and has barely moved in four days

Chris is officially the season's second hurricane as of Tuesday afternoon, and it's perhaps slightly disconcerting that the last time there were two hurricanes so early in the year was the infamous 2005 mega-season (Cindy and Dennis).  Climatologically, the second hurricane forms on August 29, so this is 50 days ahead of par.


Peak sustained winds have jumped up to 85 mph, the central pressure has fallen to 980 mb, and it is finally moving to the northeast at 10 mph. Tropical storm force winds extend an average of 80 miles from the center.  Due to a stagnant atmospheric steering pattern, Chris is located just 100 miles from where it formed last Friday... right off the North Carolina coast!

Center positions of TD3/Chris going back to when it formed on July 6.
Chris will continue to intensify as it picks up speed and heads northeast into the north-central Atlantic. It will impact Newfoundland overnight on Thursday, then head over to visit Ireland and the British Isles on Sunday-Monday as a potent extratropical cyclone.
Meanwhile, we still can't completely dismiss the remnants of Beryl.  Currently centered just north of Hispaniola, the disorganized blob of thunderstorms will pass over the Bahamas tonight and encounter an environment more favorable for regeneration on Wednesday-Thursday.  Even if it does regain tropical cyclone status, it is not expected to affect land at all after departing the Bahamas.