Land interaction with the northern coast of Cuba has caused Hurricane Irma to weaken to a category 3 hurricane. However, some slight restrengthening is possible on Sunday morning when Irma emerges into the Florida Straits. Meanwhile, Hurricane Jose has weakened slightly today, but is likely to remain a hurricane for several days as it moves erratically across the western subtropical Atlantic.

Irma weakens to a category 3 hurricane; no longer expected to make landfall as a category 4 hurrricane but still expected to bring dangerous storm surge

As of 11:00 p.m. EDT Saturday, Hurricane Irma was centered near 23.5°N 81.0°W, and was moving northwestward at about 6 mph. Maximum sustained winds were 105 knots (120 mph), with an estimated minimum pressure of 933 mb, based on data from a reconnaissance aircraft. Irma has remained closer to Cuba than originally anticipated, and has been unable to restrengthen since reaching its secondary peak as a category 5 hurricane late Friday. Irma also appears to have a double eyewall structure, indicating an eyewall replacement cycle may be occurring. If Irma can complete the eyewall replacement cycle quickly, some slight re-intensification is possible tomorrow morning as Irma moves over the very warm waters of the Florida Straits in a very favorable environment. However, re-intensification is less likely to occur if Irma is unable to complete the cycle quickly. Irma still remains a powerful hurricane, and it should be stressed that although Irma is no longer expected to be a category 4 or 5 hurricane at landfall, major impacts are still anticipated.  Irma is beginning to turn to the northwest, and is expected to pass through the Florida Keys on Sunday morning as a category 3 major hurricane. Irma is then expected to make a second landfall, likely in between Tampa and Naples, on Sunday evening. Southwesterly wind shear is expected to increase by late tomorrow, and this increase in shear, along with land interaction, should cause Irma to quickly weaken after landfall. After landfall, Irma is expected to take a northwestward path into Georgia, Alabama, and eventually Tennessee. The official National Hurricane Center (NHC) forecast calls for Irma to eventually become a post-tropical remnant low by Tuesday. Since Irma is a large storm, impacts will be felt across the entire Southeastern United States.

All preparations and/or evacuations should have been rushed to completion, as the effects of Irma are already beginning across Southern Florida. Irma is the expected to become the first major hurricane to make landfall in Florida since Wilma in 2005. However, it should be noted that Florida major hurricane landfalls are not overly unusual, as a season has approximately a 21% chance of seeing a major hurricane make landfall in Florida. Irma has really helped boost the Atlantic’s Accumulated Cyclone Energy (ACE) total, which now stands at 111 units – more than the average full Atlantic hurricane season.

A Hurricane Warning is currently in effect for:

• Fernandina Beach southward around the Florida peninsula to Indian
• Florida Keys
• Lake Okeechobee
• Florida Bay
• Cuban provinces of Ciego de Avila, Sancti Spiritus, Villa Clara, Matanzas and La Habana
• Andros Island, Bimini, and Grand Bahama

A Storm Surge Warning is currently in effect for:

• South Santee River southward to Jupiter Inlet
• North Miami Beach to Ochlockonee River
• Florida Keys
• Tampa Bay

A Hurricane Watch is currently in effect for:

• North of Fernandina Beach to Edisto Beach

A Tropical Storm Warning is currently in effect for:

• West of Indian Pass to the Okaloosa/Walton County Line
• North of Fernandina Beach to South Santee River

Hurricane Jose weakens slightly, expected to slowly weaken over the next several days but remain a hurricane

As of 11:00 p.m. EDT, Hurricane Jose was centered near 19.8°N 63.4°W, and was moving northwestward at about 14 mph. Maximum sustained winds were 115 knots (130 mph), with an estimated minimum pressure of 944 mb, based on data from a reconnaissance aircraft. Jose is likely to slowly weaken during the next several days due to an increase in wind shear, but most global models indicate that Jose will maintain hurricane intensity. By Monday, Jose is expected to begin to move slowly and erratically, with global models showing the cyclone possibly looping around and eventually turning back west. Although models are currently generally in agreement that Jose will turn out to sea without any United States impacts, it is too soon to rule out this possibility. Jose will likely remain a hurricane for the next week or longer.

Another African tropical wave may develop, but not expected to threaten land

A tropical wave exited the coast of Africa this morning, and has a medium chance to develop into a tropical cyclone. The National Hurricane Center (NHC) gave this wave a 30 percent chance of development within 48 hours, and a 50 percent chance within five days. This wave is likely to turn northwestward or northward and not threaten any land areas. I don’t expect this wave to develop into a hurricane. The next name on the Atlantic naming list is Lee.

I will be back with another post tomorrow.