Irma is on a rampage across the Western Atlantic this evening. Top winds have reached 140 mph, making Irma the strongest hurricane since Ophelia in 2011. What's both remarkable and worrisome is the storm should continue on a westward track for the next several days, maintaining strength and moving unimpeded as it skirts the British Virgin Islands and Puerto Rico.
The setting is a familiar one for storms of this magnitude: light upper level winds, stupendous storm structure, and very warm ocean water. We see no reason to veer from this forecast, as Irma keeps everyone in suspense as it nears the US Mainland. Of course, that's where the forecast becomes more nebulous. A deep upper level low across New England ensures that the storm has no chance of landfall here, but it also befuddles the steering currents farther south across Florida.
Many of the models shift it north along the East Coast of Florida, in response to the deep area of upper low pressure in New England. This seems plausible, since the storm may interact with a front associated with the upper low and subsequently creep up the Eastern Seaboard with time. Of course, this is all preliminary and speculative, given that we are talking about 7-10 days into the future. For now, the storm remains a near-term threat to the Anquilla and the British Virgin Islands. Beyond that, everyone is holding their breath.