Hurricane Irma Strengthens Into A Category 5; Dangerous Threat For Florida, Southeast
Source: ABC News
Hurricane Irma, a dangerous Category 5 hurricane, continues to strengthen as it bears down on the Leeward Islands, and will rake through the Virgin Islands, Puerto Rico, Hispañola, the Bahamas and Cuba before posing a serious threat to Florida and parts of the Southeast beginning this weekend.
Irma became the strongest hurricane in the Atlantic basin, outside of the Caribbean Sea and Gulf of Mexico, on record on Tuesday morning, according to the National Hurricane Center.
Below is everything we know about Irma right now, including its latest status, along with potential forecast impacts in the U.S. and the Caribbean Islands.
Irma's Latest Status, Timing
The center of Irma is located just under 150 miles east of the Leeward Islands and is moving westward at about 10 to 15 mph.
Irma's maximum sustained winds are steady at 185 mph based on data from NOAA and Air Force Hurricane Hunter aircraft. Based on wind speed, Irma is the strongest Atlantic hurricane since Wilma in 2005 which also had maximum sustained winds of 185 mph.
Additionally, Irma is just the 5th Atlantic hurricane to have maximum sustained winds of 185 mph or greater, according to Dr. Phil Klotzbach, a tropical scientist at Colorado State University. Hurricane Allen occupies the top spot with 190 mph winds in 1980.
Hurricane warnings have been issued for the northern Leeward Islands, Puerto Rico, the Virgin Islands and for the northern coast of the Dominican Republic. This includes Antigua, Barbuda, Anguilla, Montserrat, St. Kitts, Nevis, Saba, St. Eustatius, Sint Maarten, St. Martin, St. Barthelemy, Vieques and Culebra.
Additionally, both a hurricane watch and a tropical storm warning have been issued for Guadeloupe, and a tropical storm warning is in effect for Dominica and for the southern coast of the Dominican Republic from Cabo Engano westward to the border with Haiti.
A hurricane watch is also now in effect for the north coast Haiti from the border with the Dominican Republic to Le Mole St. Nicholas, the Turks and Caicos Islands and the southeastern Bahamas. A hurricane watch has also been issued for Cuba from Matanzas Province eastward to Guantanamo Province.
Low wind shear, increased mid-level moisture and ample oceanic-heat content favor that Irma will remain a powerful hurricane (Category 4 or stronger) for the next several days, though some intensity fluctuations are likely at times.
For the next five days, Irma will move west-northwest on the south side of a ridge of high pressure called the Bermuda high, centered in the central Atlantic.
By this weekend, Irma will begin to turn north in the direction of a departing southward dip in the jet stream that will set up in the eastern United States. Where that northward turn occurs will be critical for what impacts Irma may bring to parts of the southeastern United States.
Here's a general overview of the timing for impacts from Irma into this weekend.
Potential Impact Timing
Leeward Islands: Late Today-Wednesday; tropical storm-force winds will arrive later today.
Puerto Rico/Virgin Islands: Wednesday- early Thursday; tropical storm force winds will arrive tonight
Dominican Republic/Haiti: Thursday; tropical storm force winds will arrive Wednesday night
Turks and Caicos: Late Thursday-Friday
Bahamas: Friday-this weekend
Cuba: Friday-this weekend
Southeast United States: This weekend into early next week, beginning in south Florida Saturday
U.S. Forecast: Watching Florida, Southeast Closely
While it is still too soon to narrow down specifics on the exact path of Irma's center and eyewall, there is an increasing chance of a major hurricane strike on at least part of South Florida, including the Florida Keys, this weekend.
As mentioned before, the vast majority of the forecast guidance indicates Irma will begin to turn more to the north sometime this weekend.
The strength and expansiveness of the Bermuda-Azores high over the Atlantic Ocean and the timing, depth and location of a southward dip in the jet stream near the eastern U.S. will dictate where and when that northward turn occurs.
According to the latest NHC forecast, the center of Irma may be very close to South Florida by Saturday night, with conditions going downhill already during the day, Saturday and worsening for southwest Florida on Sunday.
However, as the NHC reminds us, average errors in the track of the center of an Atlantic tropical cyclone 4 to 5 days out are between 175 and 225 miles, which can make a large difference in impacts.
For now, all residents along the Southeast coast and eastern Gulf Coast, including Florida, Georgia and the Carolinas, should monitor the progress of Irma closely.
In addition, Irma's wind field will be large, therefore, dangerous surf and coastal flooding will likely exist throughout the southeastern U.S. coastline even well away from Irma's center by late week.
No matter what the future holds for Irma's path and intensity, the NHC advises, "Everyone in hurricane-prone areas should ensure that they have their hurricane plan in place, as we are now near the peak of the season."
Forecast: Leeward Islands, Puerto Rico, Hispaniola, Cuba, Bahamas
Leeward Islands
Irma is likely to make a direct hit on the northern Leeward Islands overnight tonight into Wednesday as a Category 5 hurricane, the strongest to hit that area since Lenny in 1999.
Hurricane-force winds (74-plus mph) are expected within the hurricane warning area of the Leeward Islands by Tuesday night, and tropical-storm-force winds (39-plus mph) are expected by mid-late evening Tuesday.
Preparations should be rushed to completion in the northern Leeward Islands at this time.
Destructive winds, capable of widespread tree damage, power outages, and structural damage can be expected. Storm-surge flooding, high surf and rip currents will also be dangers, and heavy rain could contribute to flooding and mudslides, as well.
The NHC says that a storm surge of 7 to 11 feet above normal tide levels is possible in the extreme northern Leeward Islands near and north of where the center tracks. Battering waves will ride atop the surge, capable of additional damage and erosion at the coast.
Rainfall totals in the Leeward Islands may total 8 to 12 inches, with locally 20 inches in spots, especially in elevated spots.
Conditions should improve by Wednesday night.
Puerto Rico and the Virgin Islands
It will be a very close call whether the eyewall of Irma, containing the highest, most destructive winds, will track over the Virgin Islands and northern Puerto Rico.
Regardless of that, hurricane-force winds (74-plus mph) are expected in the hurricane warning area by late Wednesday, with tropical-storm-force winds (39-plus mph) beginning by late Tuesday. Therefore, hurricane preparations should be rushed to completion by Tuesday in these areas.
The NHC says that a storm surge of 7 to 11 feet above normal tide levels is possible in the Virgin Islands, except St. Croix.
Additionally, a storm surge of 3 to 5 feet is possible along the northern coast of Puerto Rico, along with a storm surge of 1 to 2 feet along the southern coast of Puerto Rico and St. Croix.
Heavy rain bands are also likely to affect Puerto Rico and the Virgin Islands, which may result in flooding and mudslides. Rainfall may total 4 to 10 inches, with locally 15 inches in spots.
Conditions should improve quickly by later Thursday morning.
Hispañola, Turks and Caicos, Bahamas and Cuba
Irma will likely pass near Hispañola, the Turks and Caicos, the Bahamas and Cuba late this week into the weekend as a major hurricane.
Reiterating the timing of the closest approach of the center we mentioned earlier:
Dominican Republic/Haiti: Thursday; tropical storm force winds will arrive Wednesday night
Turks and Caicos: Late Thursday-Friday
Bahamas: late Thursday-this weekend arriving from east to west
Cuba: Friday-this weekend arriving from east to west
Most at risk of the worst impacts near the center are the north coasts of the Dominican Republic and Haiti, the Turks and Caicos, southeast Bahamas, and areas near the north coast of Cuba.
Life-threatening storm surge will arrive Thursday in the Bahamas and Turks and Caicos Islands, with some areas in this archipelago receiving an inundation of 15 to 20 feet above normal tide levels. This surge will be accompanied by destructive waves.
It is possible that Irma will make landfall somewhere on the northern Cuba coast sometime late Friday or on Saturday as a major hurricane. Hurricane conditions will be possible along the coast and a few miles inland if Irma makes landfall.
Residents and visitors in these areas should continue to monitor the progress of Irma and make preparations for a possible direct hit.
It's too early to determine the extent of any impacts at this time. Follow the advice of local officials in the days ahead for instruction.
