Category Four Irma Takes Aim at Florida as state declares emergency

Irma, already a category four hurricane, is likely to strike several eastern Caribbean islands in the next 18 to 36 hours and continue on a track very likely to impact Florida this weekend as a major Hurricane.

Note: this is an older post, please look for more information by Following our latest Irma coverage HERE.

2300 AST (0300 UTC) Update from National Weather Service

• Location: 16.7 N, 55.6 W
• Strength: 140mph max sustained winds (Category 4)
• Movement: W (270 deg.) at 13 mph
• Pressure: 943 mb and stable since last update – low enough to continue strengthening

The barometric pressure inside the storm is 943 mb and the satellite presentation of Irma shows a more distinct eye wall than the last several hours.

Irma is a category four storm and is expected to continue strengthening to 150 mph, just 7 mph under category 5, over the next 24 hours.

Catastrophic damage will occur: Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.

Hurricane-force winds extend outward up to 40 miles (65 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km).

Computer Models for Hurricane Irma

5-day weather models put Irma just South of Florida on Saturday. The models separate slightly after that, but consensus shows an increasing chance that Irma will directly impact Florida. A lot of new information was input into the models for the 0000 UTC (2000 AST) run which helped understand how two external weather systems may steer Irma in the coming days. The chance that Florida takes a direct south-to-north hit by a major hurricane is increasing by the hour.

A lot of new information was input into the models for the 0000 UTC (2000 AST) run which helped understand how two external weather systems may steer Irma in the coming days. The chance that Florida takes a direct south-to-north hit by a major hurricane is increasing by the hour.

Note: models become drastically more error-prone beyond a 5-day range.

U.S. Impacts

Model consensus continues to point to an increasingly likely impact to Florida and the Florida Keys from Hurricane Irma. Florida’s Governor Rick Scott has declared a state of emergency to help the state prepare for what could be a major hurricane when it reaches the sunshine state.

Today, Governor Rick Scott issued Executive Order 17-235 declaring a state of emergency in all 67 counties within the State of Florida in response to Hurricane Irma – a major Category 4 storm approaching Florida. By declaring a state of emergency in all 67 Florida counties, Governor Scott is ensuring that local governments have ample time, resources and flexibility to get prepared for this dangerous storm and are not hindered, delayed or prevented from taking all necessary actions to keep communities safe.

If the storm takes the current model’s predicted course, straight up the middle of the Florida peninsula, damage could be catastrophic for the state. The storm could devastate communities from the Keys to Jacksonville in a matter of just over 24 hours. Floridians should start preparing now to either shelter in-place or evacuate. Don’t wait until the last minute and please listen to local authorities for instructions.

Watches and Warnings

The government of Antigua has issued a Hurricane Warning for the islands of Antigua, Barbuda, Anguilla, Montserrat, St. Kitts, and Nevis. A Hurricane Watch has been issued for the British Virgin Islands.

The government of the Netherlands has issued a Hurricane Warning for the islands of Saba, St. Eustatius, and Sint Maarten.

The government of France has issued a Hurricane Warning for St. Martin, Guadeloupe, and Saint Barthelemy.

A Hurricane Watch has been issued for the U.S. Virgin Islands, Puerto Rico, Vieques, and Culebra.

The government of Barbados has issued a Tropical Storm Watch for Dominica.

Areas under Hurricane Warning

* Antigua, Barbuda, Anguilla, Montserrat, St. Kitts, and Nevis
* Saba, St. Eustatius, and Sint Maarten
* Saint Martin and Saint Barthelemy
* British Virgin Islands
* U.S. Virgin Islands
* Puerto Rico, Vieques, and Culebra

Areas under Hurricane Watch

* Guadeloupe

Areas under Tropical Storm Warning

* Guadeloupe

Areas under Tropical Storm Watch

* Dominica

What to Expect from Hurricane Irma

STORM SURGE: The combination of a dangerous storm surge and large breaking waves will raise water levels by as much as 6 to 9 feet above normal tide levels along the coasts of the extreme northern Leeward Islands within the hurricane warning area near and to the north of the center of Irma. Near the coast, the surge will be accompanied by large and destructive waves.

The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water is expected to reach the following heights above ground if the peak surge occurs at the time of high tide…

• British and U.S. Virgin Islands except St. Croix…4 to 6 ft
• Northern coast of Puerto Rico…2 to 4 ft
• Southern coast of Puerto Rico and St. Croix…1 to 2 ft

The deepest water will occur along the immediate coast in areas of onshore winds, where the surge will be accompanied by large and destructive waves. Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office.

WIND: Hurricane conditions are expected within the hurricane warning area by Tuesday night, with tropical storm conditions expected by late Tuesday. Hurricane conditions are possible within the hurricane watch area in the Virgin Islands and Puerto Rico by late Wednesday, with tropical storm conditions possible by early Wednesday. Tropical Storm conditions are expected within the tropical storm warning area by late Tuesday.

RAINFALL: Irma is expected to produce total rainfall accumulations of 3 to 6 inches across the Leeward Islands, with isolated maximum amounts of 10 inches across the northern Leeward Islands. These rainfall amounts may cause life-threatening flash floods and mudslides.

SURF: Swells generated by Irma will affect the northern Leeward Islands during the next several days. These swells are likely to cause life-threatening surf and rip current conditions

When to Expect Hurricane Irma

NOW 05/0300Z 16.7N 55.6W 120 KT 140 MPH
12H 05/1200Z 16.9N 57.4W 125 KT 145 MPH
24H 06/0000Z 17.5N 60.0W 130 KT 150 MPH
36H 06/1200Z 18.3N 62.7W 130 KT 150 MPH
48H 07/0000Z 19.3N 65.5W 125 KT 145 MPH
72H 08/0000Z 21.2N 71.0W 120 KT 140 MPH
96H 09/0000Z 22.5N 76.0W 115 KT 130 MPH
120H 10/0000Z 24.0N 80.0W 115 KT 130 MPH