Irma Becomes A Category 3 Hurricane Over The Eastern Atlantic

NHC ^ | Aug 31, 2017

[Ray76]

Hurricane Irma Advisory Number   6
NWS National Hurricane Center Miami FL       AL112017
500 PM AST Thu Aug 31 2017

...IRMA BECOMES A CATEGORY 3 HURRICANE OVER THE EASTERN ATLANTIC...

SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...17.3N 34.8W
ABOUT 720 MI...1160 KM W OF THE CABO VERDE ISLANDS
ABOUT 1780 MI...2865 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...967 MB...28.56 INCHES

 
WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.

 
DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 500 PM AST (2100 UTC), the center of Hurricane Irma was located
near latitude 17.3 North, longitude 34.8 West. Irma is moving
toward the west-northwest near 12 mph (19 km/h). This motion is
expected to continue today, followed by a westward turn on Saturday,
and a west-southwestward motion by Sunday.

Maximum sustained winds have increased to near 115 mph (185 km/h)
with higher gusts. Irma is a category 3 hurricane on the
Saffir-Simpson Hurricane Wind Scale. Fluctuations in strength,
both up and down, are possible, but Irma is expected to remain a
powerful hurricane for several days.

Hurricane-force winds extend outward up to 15 miles (30 km) from the
center and tropical-storm-force winds extend outward up to 80 miles
(130 km).

The estimated minimum central pressure is 967 mb (28.56 inches).

HAZARDS AFFECTING LAND
----------------------
None

NEXT ADVISORY
-------------
Next complete advisory at 1100 PM AST.

[RayChuang88]

No matter which way it will go, the same posters will be complaining about a), lack of preparedness, or b), needless alarmism. Looking forward to the unintentional humor.

Sadly, I agree. :-/ I'm still waiting until Monday for the weather forecasters to determine where it will go next. The area around Cape Hatteras is notorious for innumerable hurricane strikes historically--and if some models are correct, Irma could make a beeline for that area of North Carolina.

[Leep]

Does this confirm global changing climate warming?

[RayChuang88]

Well, look at what happened to New York City when Sandy went onshore south of the city in 2012. A direct strike would cause massive flooding problems, not mention Coney Island and anywhere east of that along the Atlantic Ocean shoreline being seriously threatened by storm surges.

[Bloody Sam Roberts]

Irma will be nowhere close to any land mass for at least five days.

Yeah...but I'm on vacation for the next two weeks!

If it goes North and comes up the East Coast, I'm screwed...weather-wise.

[Bloody Sam Roberts]

Hopefully, Irma will take a spin northwards and hang out more in the Atlantic Ocean and affect only ships.

Gutterball! Gutterball!

[Veto!]

Hurricanes have minds of their own, and often change them. Really too soon to evacuate anyone anywhere. But always smart to be prepared. When I lived in FL, we had a dedicated hurricane pantry, kept everything in it up to date—canned goods, water, prescriptions, phone chargers, etc.

[NautiNurse]

If it goes North and comes up the East Coast, I'm screwed...weather-wise.

And if Irma never gets near land, you might have a super fun vacation.

[Ray76]

Hurricanes never happened before.

[SoFloFreeper]

Models at 12:30 eastern time, from weatherbell analytics. I think that is Bastardis company...

[WVMnteer]

Everyone said that Houston should have been evacuated as soon as the storm appeared - when it was a disorganized tropical depression in the Gulf.

By that logic, we must evacuate all of the Florida and the eastern seaboard up to the New Jersey. They can go to Ohio.

[Bloody Sam Roberts]

That’s what I’m hoping for. While I don’t want the people living on Hispaniola to get nailed, for me and mine as well as the people in Texas and the Gulf coast, that track would be best and would take a lot of the steam off of Irma.

[cgbg]

This could end up being one of those awful hurricanes that hits North Carolina (Outer Banks) and then follows the contours of the East Coast northward.

Usually that type of hurricane loses a bit of steam in the colder mid-Atlantic waters but still makes one big mess for millions of people.

Low of 40 degrees tonight here in CT—get that water cold!

[SoFloFreeper]

5:30 update from Weather Analytics.

Thank God the models move it more into the Atlantic.

[Ray76]

000
WTNT41 KNHC 012050
TCDAT1

Hurricane Irma Discussion Number  10
NWS National Hurricane Center Miami FL       AL112017
500 PM AST Fri Sep 01 2017

Well, that eyewall replacement cycle didn't last long. Satellite
images indicate that the cycle is now complete, with Irma displaying
a larger warm eye. The initial wind speed has been set to 105 kt,
in agreement with the CIMSS ADT. Since the eyewall cycle is
finished, some strengthening is possible, although SSTs are
currently pretty marginal. Although no increase in winds is shown
in the short term, this could be conservative. During the next few
days, water temperatures along the track will warm significantly,
but there could be some higher shear, and of course more eyewall
replacements. The forecast is a compromise between the
statistical/dynamical models, which bring the intensity down then up
again, versus the global models and hurricane models, which show a
rather strong cyclone.

The westward turn of Irma has begun, and the current motion is
275/12. A building mid-level high should cause the hurricane to
turn west-southwestward tomorrow and continue through early next
week. Later on, Irma should reach the southern periphery of the
ridge, and begin to move west-northwestward. The biggest change
since the last forecast is that the GFS and its ensemble has
trended southwestward, toward the unwavering ECMWF model on the
track forecast. Given the trend in guidance, little change is made
to the official track prediction, although the corrected consensus
models and the HWRF are now southwest of the latest forecast.

KEY MESSAGES:

1. Irma is expected to be a major hurricane when it approaches the
Lesser Antilles early next week, producing rough surf and rip
currents. Irma could also cause dangerous wind, storm surge, and
rainfall impacts on some islands, although it is too soon to specify
where and when those hazards could occur. Residents in the Lesser
Antilles should monitor the progress of Irma through the weekend and
listen to any advice given by local officials.

2. It is much too early to determine what direct impacts Irma will
have on the continental United States. Regardless, 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 POSITIONS AND MAX WINDS

INIT 01/2100Z 18.8N 39.1W 105 KT 120 MPH
12H 02/0600Z 18.9N 40.9W 105 KT 120 MPH
24H 02/1800Z 18.5N 43.4W 105 KT 120 MPH
36H 03/0600Z 17.9N 45.7W 105 KT 120 MPH
48H 03/1800Z 17.2N 47.9W 105 KT 120 MPH
72H 04/1800Z 16.4N 52.2W 110 KT 125 MPH
96H 05/1800Z 17.0N 56.5W 110 KT 125 MPH
120H 06/1800Z 19.0N 61.0W 115 KT 130 MPH

$$
Forecaster Blake

http://www.nhc.noaa.gov/text/refresh/MIATCDAT1+shtml/012050.shtml?

[WVMnteer]

Evacuate New York.

[SoFloFreeper]

Weather bell Analytics as of 10:15 pm on 9/1/17:

[SoFloFreeper]

South Florida Water Management District plots. 10 pm 9/1/17:

[Ray76]

000
WTNT41 KNHC 020242
TCDAT1

Hurricane Irma Discussion Number  11
NWS National Hurricane Center Miami FL       AL112017
1100 PM AST Fri Sep 01 2017

After developing a nearly clear eye during the afternoon hours,
Irma appears to have once again temporarily peaked. A WindSat pass
around 2100 UTC hinted at the beginning of another eyewall
replacement cycle, which would be consistent with the observed
cooling of the eye. However, the small size of the hurricane's
inner core relative to the resolution of the microwave instrument
makes it impossible for me to say for sure. The initial intensity
has been lowered slightly to 100 kt, but it should be stressed that
this is probably just another fluctuation, in what will likely
be a long string of small changes in intensity over the next
several days. Since we do not have the ability to predict
such changes, the NHC forecast shows very gradual intensification
throughout the forecast period, given the warm SSTs and increasing
moisture content along the forecast track. The NHC forecast is near
the intensity consensus, but slightly favors the higher dynamical
models.

The initial motion remains 275/12 kt. The hurricane has moved a
little farther north than previously expected, and the track has
been adjusted in that direction. Overall, the reasoning behind the
track forecast has not changed, and Irma is still expected to turn
west-southwestward on Saturday due to a building ridge over the
central Atlantic. After about 72 h, there remains a large
north-south spread in the guidance, with the GFS continuing to show
a weaker ridge (and a northern track), while the ECMWF shows a
stronger ridge/southern track. The ECMWF has performed better for
Irma thus far, so my forecast continues to favor that solution.

KEY MESSAGES:

1. Irma is expected to be a major hurricane when it approaches the
Lesser Antilles early next week, producing rough surf and rip
currents. Irma could also cause dangerous wind, storm surge, and
rainfall impacts on some islands, although it is too soon to specify
where and when those hazards could occur. Residents in the Lesser
Antilles should monitor the progress of Irma through the weekend and
listen to any advice given by local officials.

2. It is much too early to determine what direct impacts Irma will
have on the continental United States. Regardless, 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 POSITIONS AND MAX WINDS

INIT 02/0300Z 19.1N 40.5W 100 KT 115 MPH
12H 02/1200Z 19.0N 42.3W 100 KT 115 MPH
24H 03/0000Z 18.5N 44.6W 105 KT 120 MPH
36H 03/1200Z 17.9N 46.9W 110 KT 125 MPH
48H 04/0000Z 17.3N 49.0W 110 KT 125 MPH
72H 05/0000Z 16.8N 53.3W 110 KT 125 MPH
96H 06/0000Z 18.0N 57.5W 115 KT 130 MPH
120H 07/0000Z 20.5N 62.5W 115 KT 130 MPH

$$
Forecaster Zelinsky

http://www.nhc.noaa.gov/text/refresh/MIATCDAT1+shtml/020242.shtml

[Shadowstrike]

Praying you’re wrong about that.

[Shadowstrike]

Praying you’re wrong. The last ‘direct’ hit Mobile took was Fred, and that tore the Hell out of Mobile.