11:10 AM | **Irma is now a category 5 major and dangerous hurricane…appears to be headed towards the Florida Straits**
Paul Dorian
Colorized infrared satellite imagery loop of Irma; courtesy NOAA/NHC
Overview
Hurricane Irma has intensified into category 5 status with max sustained winds at around 175 mph. It continues to move on a general westward track and it is looking increasingly likely that it will approach the Florida Straits by the weekend. Strong high pressure ridging over the central Atlantic continues to steer Irma to the west and it looks like this trend will continue for the next couple of days. While Irma can fluctuate between a category 4 and 5 hurricane over the next few days, unfortunately, there is no reason to believe it can weaken significantly in the near term.
500 mb height anomaly pattern with strong upper-level high pressure ridging (orange). This upper-level feature will continue to push Irma on a general westward track in coming days. courtesy tropicaltidbits.com, NOAA
Discussion
Irma has a well-defined eye and is a very symmetrical looking system – all signs of a strong storm. Irma is moving over very warm waters of the Atlantic and those favorable conditions will continue in the near term. In addition, dry air from the Saharan Desert is nowhere to be found right now and this too favors Irma to maintain “major” hurricane status.
00Z Euro ensemble run of forecast tracks for Irma
As the central Atlantic ridge extends to the southwest, Irma will likely continue on a general westward track. There is a deep upper-level trough headed towards the Northeast US, but it is very likely not going to steer Irma out-to-sea as it is simply too far away.
All residents in the southern half of Florida including the Keys should begin plans for possible evacuation. If the storm continues towards the Florida Straits, conditions will likely begin to deteriorate early this weekend in that region. At some point this weekend, the general westward track should change to a more northward track and this could push Irma from south-to-north over the middle of Florida or perhaps even over the western side. In any scenario, all of Florida must continue to monitor closely the movement of Irma.
Meteorologist Paul Dorian
Vencore, Inc.
vencoreweather.com
Extended video discussion on Irma: