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New storm: Powerful Hurricane Irma could be next disaster
Powerful Hurricane Irma could be next weather disaster
Story highlights
- Hurricane Irma is a powerful Category 3 and has rapidly intensified
- Irma is in the open Atlantic, and it's too early to know where it will hit
(CNN)While much attention remains on Texas and the destruction left by Hurricane Harvey and its historic rainfall,
powerful Hurricane Irma is rapidly intensifying in the open Atlantic
and poses a major threat to the Caribbean and potentially to the United
States next week.
Satellite image taken at 8 a.m. ET Friday shows Hurricane Irma in the eastern Atlantic
With
the storm still five days away from the outermost Caribbean islands and
at least a week away from any potential US impacts, there is still a
lot of uncertainty about where it will go.
The
range of possibilities presented by the forecast models more than a
week out literally spreads from Mexico to Canada -- and everywhere in
between.
Irma was designated a
tropical storm Wednesday morning, and by Thursday afternoon, it had
strengthened into a large Category 3 hurricane, with winds of 115 mph.
How are hurricanes named? 01:38
Such
explosive strengthening is known as "rapid intensification," defined by
the National Hurricane Center as having its wind speed increase at
least 30 knots (35 mph) in 24 hours.
"Irma
has become an impressive hurricane," the National Hurricane Center said
Thursday, noting the rapid intensification. "This is a remarkable 50
knot (58 mph) increase from yesterday at this time."
Hurricane
Harvey underwent rapid intensification just before it made landfall
late last Friday, strengthening quickly from a tropical storm into a
Category 4 hurricane when it moved onshore near Corpus Christi, Texas.
Hurricane kryptonite not in the mix
Irma is a classic "Cape Verde hurricane,"
a type of hurricane that forms in the far eastern Atlantic, near the
Cape Verde Islands (now known as the Cabo Verde Islands), then tracks
all the way across the Atlantic. Cape Verde storms frequently become
some of the largest and most intense hurricanes. Examples are Hurricane Hugo, Hurricane Floyd, and Hurricane Ivan.
Hurricane
Irma is forecast to continue to strengthen as it moves westward over
the next five days, and the official forecast from the National
Hurricane Center puts a dangerous Category 4 Hurricane Irma on the
doorstep of the Caribbean by the end of the five-day forecast on Tuesday
afternoon.
A strong high-pressure ridge
to the north of Irma, over the Atlantic, is steering the storm to the
west and limiting the wind shear in the upper levels of the atmosphere,
which has allowed the storm to grow so quickly. Wind shear is like
hurricane kryptonite, and prevents storms from forming or gaining
strength.
Unfortunately, Irma will
remain in a low-shear environment for the next several days, so there
isn't much hope that Irma will weaken any time soon.
There
is considerable confidence that Hurricane Irma will track to the west
through the weekend and then take a slight jog to the southwest early
next week in response "to a building ridge (of high pressure) over the
central Atlantic."
From there, the
forecast becomes a lot less clear, with some major differences among
some of the key models meteorologists use to forecast hurricanes. The
differences are so drastic that one prediction has Irma sliding
harmlessly back out to sea, while in another, it makes multiple
disastrous landfalls in the Caribbean and likely hits the United States
after that.
Dueling prediction models
The
European model, or ECMWF, and the American GFS model have had some
notable showdowns before, most notably with Hurricane Sandy.
With
Sandy, the ECMWF correctly predicted a landfall in the Northeast nearly
a week ahead, while the GFS continually kept the storm offshore in what became a major black eye for the US weather-modeling industry.
There have been other examples in which the GFS model has outperformed
its European counterpart, such as with a few major snowstorms in the
Northeast.
Right now, the GFS has
Irma taking a more northerly track that curves to the north before it
reaches the Caribbean, thus making a US landfall much less likely.
The European model keeps the storm tracking further west and into the Caribbean by the middle of next week.
"The
ECMWF sees a much stronger ridge or Bermuda High (than the GFS) which
forces Irma west, whereas the GFS has a weaker ridge and a more
rightward, parabolic track," said Ryan Maue, a meteorologist with
WeatherBell Analytics.
European vs American weather models
"The prospects for major impacts anywhere from Cuba to Carolinas is concerning for this very reliable model," Maue said.
Irma
is still more than 1,700 miles east of the Leeward Islands, and any
impacts from the storm wouldn't be felt until Tuesday or Wednesday for
the Leeward Islands and Puerto Rico.
The forecast picture should become clearer after the weekend.
Bottom
line: Hurricane Irma is already a powerful hurricane and looks to only
become more so. Those with interests in the Caribbean and southeast US
coast should pay close attention to the forecast.
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