Here is the latest info from the 11am update from the National Hurricane Center. Irma is now the strongest Atlantic Hurricane ever recorded by the NHC outside of the Gulf of Mexico. WOW.
Irma is an extremely impressive hurricane in both infrared and visible satellite images. Experimental GOES-16 one-minute visible
satellite pictures show a distinct 25-30 n mi wide eye with several mesovortices rotating within with eye. The aircraft have not
sampled the northeastern eyewall where the strongest winds were measured shortly before 1200 UTC this morning, but the Air Force
plane will be entering the eye in that quadrant momentarily. A peak SFMR wind of 154 kt was reported, with a few others of 149-150 kt.
Based on these data the initial intensity is set at 155 kt for this advisory.
This makes Irma the strongest hurricane in the Atlantic
basin outside of the Caribbean Sea and Gulf of Mexico in the NHC records.
Irma is expected to remain within low vertical wind shear, a moist mid-level atmosphere, and high upper-ocean heat content as it moves
west-northwestward during the next several days. These conditions should allow the hurricane to remain very intense throughout much
of the forecast period, however, fluctuations in intensity are likely to occur as eyewall replacement cycles take place. The NHC
intensity forecast is near the upper-end of the guidance and assumes little overall interaction of Irma with the islands of the Greater
Antilles.
Irma continues to move westward at about 12 kt, and a strong subtropical ridge centered over the central Atlantic should steer
Irma generally westward today. The ridge is expected to remain in place over the western Atlantic during the next several days and
Irma is forecast to move west-northwestward throughout the most of remainder of the forecast period. Around day 5, a shortwave trough
dropping southward over the central United States is expected to begin eroding the western portion of the ridge, allowing a Irma to
gain some latitude. The new NHC track forecast is close to the HFIP corrected consensus model and is very similar to the previous
forecast.
Since Irma is a large hurricane, users are reminded to not focus on the exact forecast track since tropical-storm and hurricane-force
winds and life-threatening storm surge extend far from the center. Residents in the Leeward Islands should complete their preparations
very soon as the weather will begin to deteriorate over the easternmost Leeward Islands later this afternoon.