Powerful Category 3 Irene enters the Bahamas

By: Dr. Jeff Masters , 3:49 PM GMT on August 24, 2011

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Powerful Category 3 Hurricane Irene stormed through the Turks and Caicos Islands overnight, bringing hurricane-force winds, torrential rains, and storm surge flooding. On Providenciales in the Turks and Caicos Islands, where half of the population of these islands live, winds reached a sustained 65 mph at a personal weather station at Pine Cay, and the pressure bottomed out at 989 mb. The eyewall of Irene missed the island, with the center of the storm passing about 60 miles to the southwest. The center of Irene passed about 60 miles to the northwest of Grand Inagua Island, and Category 1 hurricane conditions were probably experienced on that island. Damage in the Turks and Caicos is likely to be much less than the $50 - $200 million wrought by Category 4 Hurricane Ike of 2008, since Irene's eyewall missed populated islands.


Figure 1. Morning satellite image of Irene.

Monday, Irene hit Puerto Rico as a tropical storm with 70 mph winds, but reached hurricane strength as it emerged into the Atlantic northwest of the capital of San Juan. One drowning death is being reported from the island, and the storm dumped up to 20 inches of rain in some areas. About 11% of the island was still without power this morning, and numerous roads were closed due to flooding and landslides. Irene did an estimated $17 million in damage to agriculture and $2 million to ports in Puerto Rico. Satellite estimates suggest that Irene has brought only 1 - 2 inches of rain to Haiti. With Irene now pulling away from Hispaniola, Haiti can expect only another 1 - 2 inches from the hurricane, and appears to have dodged a major bullet. Heavy rains of 3 - 6 inches were common across the Dominican Republic, where moderate flooding but no deaths occurred.


Track forecast for Irene
Continuing dropsonde missions by the NOAA jet have helped to significantly narrow the uncertainty in the 1 - 3 day forecasts from the computer models. Irene will track through the central Bahamas today, the northwestern Bahamas on Thursday, and approach the Outer Banks of North Carolina on Friday. However, the models still diverge considerably on their 4 - 5 days forecasts, and we don't know if Irene will plow up the mid-Atlantic coast into New Jersey, as the GFDL model is predicting, hit New England between Long Island, NY and Massachusetts, as the ECMWF, GFS, and HWRF models are predicting, or miss the U.S. and hit Canada, as the NOGAPS model is predicting.

Intensity forecast for Irene
Latest data from the Hurricane Hunters shows that Irene has paused in its intensification cycle. A gap has opened in the eyewall, and the central pressure has remained constant at 956 - 957 mb over the past few hours. However, the hurricane is embedded in a large envelope of moisture, and wind shear is expected to remain low to moderate, 5 - 20 knots, for the next three days. With water temperatures very warm, 28 - 30°C, these conditions should allow for intensification to a Category 4 storm sometime in the next two days. Satellite loops show that Irene is well-organized, with excellent upper-level outflow, and impressive spiral banding.

Irene's impact on the Bahama Islands
Irene is making a direct hit on Crooked Island (population 350) in the Bahamas, and will continue west-northwest and hit Rum Cay (population 80) and Cat Island (population 1700) late tonight. These unfortunate islands will bear the full brunt of Irene's 115+ mph winds and 8 - 13 foot storm surge, and suffer major damage that will take months to recover from. Major damage is also likely on Long Island (population 3000) and San Salvador Island (population 1000.) Shortly after midnight tonight, winds at the capital of Nassau, home to 70% of the population of the Bahamas, will rise above tropical storm force, and increase through the night. By late morning on Thursday, sustained winds will peak on Nassau at just below hurricane force, 60 - 70 mph. Nassau will miss the brunt of the storm, and I expect the airport should be able to re-open on Friday. Winds on Grand Bahama Island in Freeport will rise above tropical storm force late Thursday morning, and increase to a peak of 45 - 60 mph late Thursday afternoon. Grand Bahama will also miss the brunt of the storm, but Abaco Island to its east will likely experience Category 2 hurricane conditions Thursday afternoon. However, Abaco will probably miss the right front eyewall of Irene with the strongest winds and highest storm surge.


Figure 2. Wind distibution around Irene as of 1330 UTC (9:30am EDT) August 24, 2011. Irene was a Category 3 hurricane with 115 mph winds at the time. Hurricane force winds (yellow colors) extended over Crooked Island to the storm's northwest, and over Mayaguana Island to the east. Image credit: NOAA/AOML. Irene is a large storm, and its potential storm surge damage rated 3.9 on a scale of 0 to 6, with its wind damage potential rated at 2.5 on a scale of 0 to 6.

Irene's impact on the Southeast U.S.
Long-period ocean swells from Irene will reach the coast from Florida to North Carolina tonight, and continue to build as the storm approaches. The outermost rainbands of the hurricane will reach South Florida by Thursday morning, and spread over much of the eastern coastal portion of Florida during the day Thursday. If Irene follows the official NHC forecast through the Bahama Islands, the storm's expected radius of tropical storm-force winds of 130 - 170 miles will keep tropical storm conditions just off the east coast of Florida. Sustained winds of 20 - 30 mph can be expected along the coast of Florida during Irene's point of closest approach, and rainfall amounts of 1 - 2" will be common along the coast. Georgia, which could use the rain, will get very little. It is unlikely any airport in Florida or Georgia will need to close for Irene.

Late Friday night or early Saturday morning, Irene's outer spiral bands will move over the southern coast of North Carolina and the northeastern portion of South Carolina, and tropical storm-force winds of 39+ mph will arrive. Winds will steadily increase to hurricane force on the Outer Banks by Saturday night. The main damage from Irene in North Carolina will come from the storm's flooding rains of 4 - 12" that will fall in coastal areas. Fortunately, this region is under moderate to severe drought, so the damage will not be as severe as that experienced during Hurricane Floyd of 1999. Significant wind damage can be expected in the Outer Banks of North Carolina, and considerable storm surge damage may occur along the shores of Pamlico and Albemarle Sounds. If Irene's eye misses making landfall in North Carolina, total damage from the storm should be less than $200 million, and could be considerably less than that.


Figure 3. Sea surface temperatures for August 24, 2011. Temperatures of 26°C (79°F) are typically needed for a hurricane to maintain its strength (black line). This boundary lies just off the southern coast of New Jersey this year, which is much farther north than usual.


Figure 4. Predicted 5-day rainfall for the period ending Monday morning, August 29, at 8am EDT. Image credit: NOAA/HPC.

Irene's impact on the mid-Atlantic and New England
The impact of Irene on the mid-Atlantic and New England is highly uncertain at this point, because we don't know if the core of the storm will miss the coast or not. In general, the heaviest rains will fall along a 100-mile swath just to the west of where the center tracks, and the worst wind and storm surge damage will occur to the east. If the core of Irene stays offshore, the mid-Atlantic and New England may escape with a few hundred million dollars in damage from flooding due to heavy rains and storm surge. If Irene hits Long Island or Southeast Massachusetts, the storm has the potential to be a $10 billion disaster. Irene is one of those rare storms that has the potential to make landfall in New England as a Category 2 or stronger hurricane. It is difficult for a major Category 3 or stronger hurricane crossing north of North Carolina to maintain that intensity, because wind shear rapidly increases and ocean temperatures plunge below the 26°C (79°F) level that can support a hurricane. We do expect wind shear to rapidly increase to a high 30 - 50 knots once Irene pushes north of Delaware, which should knock the storm down by at least 15 - 30 mph before it reaches New England. However, this year sea surface temperatures 1 - 3°F warmer than average extend along the East Coast from North Carolina to New York. Waters of at least 26°C extend all the way to Southern New Jersey, which will make it easier for Irene to maintain its strength much farther to the north than a hurricane usually can. During the month of July, ocean temperature off the mid-Atlantic coast (35°N - 40°N, 75°W - 70°W) averaged 2.6°F (1.45°C) above average, the second highest July ocean temperatures since record keeping began over a century ago (the record was 3.8°F above average, set in 2010.) These warm ocean temperatures will also make Irene a much wetter hurricane than is typical, since much more water vapor can evaporate into the air from record-warm ocean surfaces. The latest precipitation forecast from NOAA's Hydrological prediction center shows that Irene could dump over 8 inches of rain over coastal New England.


Figure 5. Soil moisture profiles from yesterday show that a region of very moist soils ranking in the top 1% in recorded history (dark green colors) lie over northern New Jersey, Southeast New York, and Northeast Pennsylvania. Image credit: NOAA/CPC.

Tropical storm-force winds and heavy rains will move into Eastern Virginia Saturday afternoon, and push northwards to Delaware and coastal Maryland by late Saturday night. Tropical moisture through a deep layer of the atmosphere will also stream well ahead of Irene into New England on Saturday afternoon and evening, bringing what is called a "Predecessor Rain Event" (PRE). The Washington D.C., Baltimore, and Philadelphia airports will be right at the edge of the heavy rain and high wind area, and it currently appears they will not have to close for an extended period. The Philadelphia and New York City airports may not be as lucky, and it is possible they will suffer extended closures Sunday morning and afternoon. By late Sunday night, Irene's rains will move north of New York City, allowing the airports to re-open. The highest potential for damaging fresh-water flooding is in northern New Jersey, Southeast New York, and Northeast Pennsylvania, where soil moisture is near record high levels, and there is nowhere for the rain to go (Figure 5.) Heavy rains of 4 - 12" are likely across all of coastal New England if Irene passes within 100 miles of shore.

Links
For those of you wanting to know your odds of receiving hurricane force or tropical storm force winds, I recommend the NHC wind probability product.

Wunderground has detailed storm surge maps for the U.S. coast.

Elsewhere in the tropics
A tropical wave far out in the eastern Atlantic about 200 miles southwest of the Cape Verde Islands, Invest 90L, is showing signs of organization. NHC is giving this disturbance a 50% chance of developing into a tropical depression by Friday. Several of our models do develop 90L into a tropical storm by early next week, but long-range models are showing that this system will not be a threat to any land areas over the next seven days, and will probably move too far north to ever be a threat to land.

Internet radio show on Irene at 4:30pm EDT today
I'll be discussing Hurricane Irene on a special edition of our Internet radio show, the Daily Downpour, today (Wednesday) at 4:30pm EDT. Fellow wunderground meteorologists Shaun Tanner, Tim Roche, and Angela Fritz will also be there. Listeners can email in or call in questions. The email address to ask questions is broadcast@wunderground.com.

Jeff Masters

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Quoting Crawls:
I am having problems reading some of the posts. The right side is cut-off. I have adjusted view to smallest text but that still doesn't help. It is very difficult to guess at the last few words in each sentence. Can someone help me correct this problem. Thanks
Use something besides IE.. Firefox will handle it.
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Quoting alvarig1263:


Probably a few more hours at the least. First the trough has to come down, break the ridge that has been filling the gap for the past day or two, and then Irene has to be moving fast enough and be close enough to feel the trough. Then it will start being pulled more northward. If Irene goes too slow, the trough isn't strong enough, or the trough doesn't come south enough, then we'll have a whole other situation.....
hopefully not "Hugo" situation...
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For those just joining us:


Hurricane Irene Video Update
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Quoting MrsBoomerNC:


Cantore is headed to Providence RI. My kids used to joke about his presence being more reliable than the NHC.


He is from NE-Maine I believe
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Quoting tiggeriffic:


NO thank you please...i was here for hugo...just glad i didn't listen back then and because of that i am vigilant in preparing each and every year...hoping that bermuda high pulls back to the east instead of trending west....


Somehow I remember there being adequate warning for Hugo... we knew it was coming our way, or so I thought... was I wrong?
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Quoting Jax82:
Irene is currently over these islands.
for a brief moment, i thought most of South America had flooded :P
j/k
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Quoting Zaphod:
Was just down in NC a few weeks back. Would hate to see Irene wash those quaint little beach areas away.


Glad you enjoyed our beaches :) We are hoping they dont get washed away too!
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Quoting JeffM:


2005'er here. While I do not post much, I still lurk every year. :)

Same here and I appreciate the advice. I usually manage to ignore the crazy stuff....
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Quoting Bluestorm5:
ok... how much longer until it's forecasted to turn?


Probably a few more hours at the least. First the trough has to come down, break the ridge that has been filling the gap for the past day or two, and then Irene has to be moving fast enough and be close enough to feel the trough. Then it will start being pulled more northward. If Irene goes too slow, the trough isn't strong enough, or the trough doesn't come south enough, then we'll have a whole other situation.....
Member Since: September 2, 2008 Posts: 0 Comments: 744
Irene is still tracking slightly left of tropical forecast points but I imagine that won't last too much longer. NHC pretty good on track (with a few exceptions) , lousy on intensity.
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Quoting Grandpato4:


Trending west? They keep saying trending east on the tv. I hope you are wrong otherwise I will be making a trip inland soon.


Dont let the wishcasters get you go'n.
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Quotin

That trough is not impressive...very shallow in appearance right now-JMO however. The Hurricane is sill below Florida
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Quoting Jax82:
Irene is currently over these islands.


She's left that island behind, now. 2 small ones in front of her. Looks like the large one just to the west (Long island pop 4,000) will avoid a direct hit by the eye.
Member Since: July 20, 2008 Posts: 0 Comments: 2925
No kidding. The maps and the accuracy of the professionals are astonishing.

Well, back to work! Good to see so many old-timers.
Member Since: February 2, 2009 Posts: 21 Comments: 1464
Quoting notabubba:
Time to tune up the 'genny. Last hurricane to really impact me in RI was Bob. That little guy dropped a 36" black locust tree on my roof. Took out the chimney, which actually saved the house from total destruction. But will never forget the sound of bricks tumbling down...thud thud thud. Were without power for 10 days. To the folks worried that the northeast isn't ready - true we don't get +75mph storms as often, do get more than enuf tropical force storms and winter Nor'easters. Believe me, rather be without power 10 days in the summer, than in the winter under 3' of white stuff! I do worry that too many of the "new money" folks who took little, throw-away beach cottages and turnd them into year-round waterfront McMansions are gonna be too confident to get their butts inland.


Cantore is headed to Providence RI. My kids used to joke about his presence being more reliable than the NHC.
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Quoting angiest:


Remember you are looking at a snapshot. Those charts are updated every three hours. There is a trough moving in (based on seeing others earlier today) that will most likely reopen the gap between the ridges.



Looks like the trough has gotten weaker and weaker with each run (the one to the north of the storm) and with the ridges moving closer together, the ridges may flatten out the trough and not have as much of an impact on the storm.
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Quoting nash28:
FL is out of the equation here. It would take some serious atmospheric shenanegans for a FL hit to occur. GA also appears to be off the hook.

SC is still in play. Would only take a relatively small deviation off path to put SC in the crosshairs. Unfortunately, it is a wait and see.


It is nice that you put it that way instead of the people that constistantly put down people asking the questions on where it could go. GulfBashers, Floridabashers etc. It nice that some of the veteran people like yourself to put it in a pleasent way.

Thank You.
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Quoting Grandpato4:


Trending west? They keep saying trending east on the tv. I hope you are wrong otherwise I will be making a trip inland soon.


The models and forecast track are E. The upper air dynamics are trending W. Temporarily. At this point, Irene hasn't done anytbing off the wall. Now, if by tomorrow night Irene is still moving at 300 to 305 degrees, then I'd start to wonder.
Member Since: July 11, 2005 Posts: 190 Comments: 16972
Quoting charlottefl:
NEW STEERING




Is this the steering for her level? If so, looks like the escape path is closing up on Irene.
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Quoting nash28:
FL is out of the equation here. It would take some serious atmospheric shenanegans for a FL hit to occur. GA also appears to be off the hook.

SC is still in play. Would only take a relatively small deviation off path to put SC in the crosshairs. Unfortunately, it is a wait and see.


guess that's why the meetin eh? still watching that bermuda high...not making me feel all that good as far as how far west Irene could go before the turn
Member Since: September 16, 2007 Posts: 0 Comments: 3650
815. IMA
Quoting Beachfoxx:
Yep! Someone said it looked like a 2005 Reunion! Good to see you guys! : )

I'm here, & have been here a lot, but have finally learned to keep my mouth shut (most of the time). {{{{{{Beachfoxx}}}}}} - you have FB mail about a teleconference (lol) tomorrow afternoon.
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Quoting alvarig1263:


Not gonna happen just yet, steering currents not allowing it at present, and trough not digging deep enough yet to pull her out. She's being controlled by the ATL ridge for now and that's pulling here WNW to NW.
ok... how much longer until it's forecasted to turn?
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I know Irene is the talk of the blog right now but Invest 90L up to 60% on NHC website
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Had forgotten about GS. Looks like Emmy still has a blog. And then there were the girls - Gatorgrl, 27W, Saddlegai, Oshnblu.

Was definitely a smaller and more personal WU back then. More drama, less trolls, than today.


Better models and maps these days for sure, though!
Member Since: October 5, 2005 Posts: 15 Comments: 3239
http://en.wikipedia.org/wiki/Rum_Cay
Member Since: September 11, 2010 Posts: 1 Comments: 4598
I wonder what the psychic twins are thinking right now! How often do you get a cat 4/cat 5 affecting the entire south east coast?
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Quoting atmoaggie:
Whoa, had forgotten that one. He was phunny...


We would also need Lefty, he may be lurking, was last year.
Member Since: September 23, 2005 Posts: 14 Comments: 11179
FL is out of the equation here. It would take some serious atmospheric shenanegans for a FL hit to occur. GA also appears to be off the hook.

SC is still in play. Would only take a relatively small deviation off path to put SC in the crosshairs. Unfortunately, it is a wait and see.
Member Since: July 11, 2005 Posts: 190 Comments: 16972
805. Jax82
Irene is currently over these islands.
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Okay, I am a novice at this, so please educate me if I'm reading this wrong.

The 12:00Z ECMWF seems to show Irene's eye passing right over Cape Hattaras with a final landfall at Cape May/Delaware Bay, in line to do very bad things to South Jersey and Eastern Pennsylvania.

GFS seems to be a bit to the east, hitting Long Island head-on.

Is that what y'all are seeing? Thanks.
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802. TX2FL
Quoting xtremeweathertracker:

If the Euro scenario should come true you would experience 100 plus MPH winds over much of New England with the center of Irene passing over or near New York and New Jersey!!!


Anyone have any idea when Jersey may start evacuation plans? Trying to convince some friends that it's pointless going there on Friday even though planned to leave on Sunday.
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If the gap doesnt oen by tomorrow night, then Irene would be pushed westward further more towards the Carolinas, then if the gap did open, it would probably skirt the Carolinas coast,right? NOT WISHCASTING, SUGGESTING A THEORY
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kinda stupid question but can the eye wall replacement affect the track of the storm at all? TIA
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Quoting Grandpato4:


As forecasted now I should have said. I realize things change but so far the trend is further east meaning I see less and less from the storm.
Grandpa, it's trending west again. The high is building more west and the weakness is above SC/NC. This is starting to shows landfall between Wilmington and Morehead City for now... keep preparing for the storm and leave for Raleigh tomorrow if you want to play it safe.
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I know our main focus is Irene and definitely understandable, however I was just wondering what the models are saying with the wave off of Africa? Any hints on this one?
Member Since: July 2, 2009 Posts: 0 Comments: 2811
TRMM Sat just passed over it... looks like the inner eyewall is getting squeezed. EWRC definitely beginning.

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Quoting oreodogsghost:
And oakland!

Dang - we only need emmy and swlaaggie now.

And even gulfscotsman, my friend/nemisis! He could quote Rush lyrics.

Woof
Whoa, had forgotten that one. He was phunny...
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Quoting wxobsvps:
ULL (200mb lvl) depicted below by the positive vorticity off the SC coast



Charleston getting rain right now...guess that is the spot on the map
Member Since: September 16, 2007 Posts: 0 Comments: 3650
I really dont think florida has to worry too much . the dynamics of the atmosphere does not support a hit on florida,however intrest further north has some concern
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To watch the trough:
http://www.goes.noaa.gov/GSSLOOPS/ecwv.html
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Check out this video... (around the 4 minute mark +)

So this is what New England can expect at 100-110 mph winds?

http://www.youtube.com/watch?v=tjo_yBTIPmo&featur e=relmfu


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First time poster here.....does anyone know if Directv is planning on following local tv coverage of Irene's approach? I remember that Directv simulcasted KHOU during Hurricane Ike.

Thanks!
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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