Thursday, September 06, 2012

Leslie's Slow March Towards Bermuda

The Atlantic has two hurricanes spinning about -- Leslie and Michael. Leslie is the closer of the two to the US and sports max winds of 75 mph, just over the threshold of hurricane status. The storm is a slow mover, having crawled north and northwestward very little over the past three days as it is stuck in an area of very minimal atmospheric steering thanks to a high pressure ridge over the Central Atlantic.  That ridge will break down in a few days, with Leslie poised to begin moving more quickly northward in advance of a trough that will sweep across the East Coast this weekend (bringing us a round of rain and thunder on Saturday night).

Computer modeling suggests that Leslie's circulation will pass relatively close to Bermuda this weekend, perhaps as an intensifying hurricane as it works over warmer ocean waters than the waters it is currently churning up in its current location. The National Hurricane Center is projecting Leslie could have 100-105 mph max winds as the storm passes by Bermuda, although modeling at this point keeps the storm's eastern half (worse half) to Bermuda's east. Leslie's churning up the surf across the Western Atlantic and has generated an increased risk for rip currents along the East Coast, a threat that will continue through the weekend and into next week. However, because the storm will gradually move north or just east of due north this weekend there is no threat of direct impact along the East Coast.

Farther out in the Atlantic, Michael sports 115 mph max winds and is the season's first major hurricane.  Michael had rapidly intensified overnight from a tropical storm to a hurricane to a major hurricane in just 24 hours, thanks in large part to its small size.  This smaller sized storm can more rapidly intensify (and in many instances just as quickly unwind).  It is a threat only to shipping interests, fish, and will not impact anyone in North America.  It will gradually weaken in the coming days as it pushes into higher latitudes.   For those who like watching hurricane evolution, Michael is a great example of a storm that we can watch, enjoy on satellite, and be glad it's out in the middle of the Atlantic and safely far away from land interests.