Saturday Irma Update: Cuba, Keys, and beyond

As of 7:30am CT on Saturday, Hurricane Irma continues to move westward, with its center just inland over the northern coast of Cuba. This more westward track, taking the storm over Cuba, is a scenario I discussed a couple of days ago—the Cuban—which would spare the Miami area the worst effects of Irma.

The track over Cuba has weakened the storm’s maximum winds to 130mph, and additional weakening is possible before Irma moves back into the Straits of Florida later today or tonight. Here’s a quick look at the official forecast track:

4am CT Official track forecast from the National Hurricane Center.

Here are the implications of this changing track:

Cuba: The island nation is being battered by the storm

Florida Keys: Still in line for a major hurricane today and Sunday. Expect devastating winds, rainfall and storm surge.

Miami area: As Irma continues to move westward, its center will bypass the Miami metro area, sparing the heavily populated southeastern coast of Florida from the worst effects of winds and storm surge. Hurricane force wind gusts are still likely, but they will probably not cause widespread damage. Inland rainfall amounts of 15 to 20 inches are possible, and flooding is a significant concern.

See full post

Hurricane Irma: What we know, and what we don’t yet know

There’s not a whole lot to say new about Hurricane Irma this evening. So far, the storm is threading the needle through the area between Cuba and the Bahamas, and heading toward the Florida Keys. The Keys face widespread damage and this near hysterical tweet from the National Weather Service is entirely appropriate.

Now that we’re about 48 hours from a final landfall somewhere in Florida we can have a fair amount of confidence in the track forecast for Irma, but there are still some important questions that ultimately will determine which parts of Florida see really bad conditions, and which see catastrophic conditions.

Cuba?

As of 4pm CT, here is the official track for Irma:

Official forecast for Hurricane Irma at 4pm CT Friday. (National Hurricane Center)

If you look closely at the hurricane center’s forecast track between now and Saturday evening, it brings the eye of Irma very close to Cuba. Recent satellite images from Friday evening show a westward movement that may, in fact, bring the center of the storm over the island for a time. If this happens, we may well see some weakening from the storm’s present 155-mph winds.

See full post

Irma’s Florida impacts unfortunately coming into focus

On the local front: All remains calm and quiet. We continue to see optimal weather to help us dry out and continue picking up the pieces after Harvey. This weather will last well into next week. Either later this weekend or on Monday, we’ll probably have to talk a bit about some potentially hotter temperatures by mid to late next week. In the meantime, the weather looks delightful for September in Texas through the weekend. Otherwise, the eyes of the weather world are focused on Irma (and also Jose, which is taking an unfortunate track near the Caribbean). Let’s start with the latest on Irma.

Irma Now

In the last 18 hours or so, Irma has been undergoing some internal reshuffling (in meteorology speak, an eyewall replacement cycle and probably some land interactions) that has caused its maximum wind speeds to drop a bit. It’s now a category four storm with maximum sustained winds of 155 mph. This is actually quite common for storms of Irma’s character. What’s been so uncommon about Irma has been its reluctance to see any fluctuations in intensity until just recently. So for all intents and purposes, Irma is now behaving like a typical high-end, major hurricane.

Irma continues to present a near-perfect appearance on satellite. This is a healthy hurricane. (NOAA)

Irma is currently west of the Turks and Caicos Islands and just north of Baracoa and Guantanamo, Cuba. It continues to move north of due west and should just graze the coast of Cuba today.

Hurricane and storm surge watches and warnings have been posted for most of South Florida.

See full post

Still some time for a change, but right now Irma looks really bad

This afternoon I wrote a post for Ars Technica on how confidence in the track forecast for Hurricane Irma is increasing now that we are only about 60 or 70 hours from landfall. Track errors shrink with shorter lead times, and the fact that the official forecast has been so consistent with a likely landfall from the Florida Keys to Miami to West Palm Beach means that there is now a high likelihood in a landfall in one of those locations.

Essentially, this is a worst-case scenario for southern Florida. And this afternoon, the European model forecast had nothing but bad news for the state with the release of its 12z operational run. It made a slight shift west, with a landfall over the Florida Everglades.

12z operational run of the European model for Thursday. (Tropical Tidbits)

This is really bad, because it not only keeps some of the strongest winds over the Miami region of southeastern Florida, it also pushes a very large storm surge into the beachfront property there. I am running out of words to describe the destructive potential of this storm.

See full post