Hurricane Irma has expanded its wind field, even as the maximum winds have decreased.
The southeast coast of the Sunshine State, originally primed for a direct hit, breathed more easily as forecasts shifted the path of Irma well to the west.
But the storm is now so large that Miami, 100 miles from the center, has had strong tropical storm force winds with gusts to hurricane category two level.
The worst of Irma, however, is likely to be felt on the west coast in Fort Myers, Naples, and later, Tampa.
An Asymmetric Storm
In its journey across the Atlantic, Irma encountered almost no vertical wind shear — there was no change of wind with height.
There is now some shear, and this is causing the storm to elongate from east to west. Normally the strongest winds in this situation are on the right side of the direction of motion. Strong winds now extend far into the northeast quadrant, including Miami and the rest of the southeast coast.
Bye Bye Keys, Hello West Coast
The latest (11 a.m. EDT) update from the National Hurricane Center places the center of Irma 80 miles south-southeast of Naples.
Movement is slightly west of north at 9 miles per hour. On this course, powerful winds and large tidal surges will affect the southwest Florida coast today and tonight.
As Irma makes landfall and is affected by wind shear and interaction with land, the emphasis will shift from wind and tidal surge to flooding from rain.
Decoded Science will issue a complete update after the 5 p.m. advisory is issued.