Powerful Category 3 Irene enters the Bahamas

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

Share this Blog
20
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 90 - 40

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30Blog Index

Quoting WaterWitch11:


because some people believe that weather events and earthquakes have connections


That's silly.
Member Since: Posts: Comments:
Quoting Levi32:
It is true that shifts can still occur with Irene's track, as we are 3 days from what a potential NC landfall would be. The trend in the models has been east, and with recon data in them, the consensus is very tight. Once we get to this point, the large shifts are basically over. To say that SC is safe is unwise, but they are out of the NHC cone, so it's expected that people will start dismissing the storm there. If I were still living there I would be keeping a close eye on Irene, as things can and do change. Right now, the track depends on fine details of upper shortwave troughs coming across the United States, and to be honest there is not a whole lot that forecasters can do beyond using the models to predict the behavior of those small troughs. We are relying on the models more than usual with this storm. The overall pattern is what we forecasted for this to move up the eastern seaboard. Now only a shift of a couple dozen miles could mean the entire world for some people, as the coastline angle means that small shifts in the track translate to much greater shifts in the landfall point up and down the coastline.

levi can you tell me the difference between the trough that recurves irene and the trough that recurved earl from last year? irene is further south and west of earl and irene has a 50/50 chance of ACTUALLY MAKING LANDFALL IN NORTH CAROLINA AND NEW ENGLAND unlike Earl. thanks
Member Since: Posts: Comments:
would the heavy rainfall in NYC area last week make the region more susceptabile to flooding?
Member Since: Posts: Comments:
SC on north must watch this
Member Since: Posts: Comments:
WOW
Member Since: August 4, 2011 Posts: 46 Comments: 4481
Hurricane Irene: National Resources in Case of Emergency

As Hurricane Irene makes its way through the Caribbean, current forecasts from the National Hurricane Center project that the storm may continue to strengthen and could make landfall anywhere along the East Coast. Yesterday, President Obama signed an emergency declaration for Puerto Rico and ordered federal aid to supplement commonwealth and local response efforts in the area.

While the future path of Irene is uncertain, it’s important that those along the East Coast take steps to get prepared and stay informed. Ready.gov/hurricanes offers complete advice on how to prepare for severe storms, and hurricanes.gov always has the latest forecast from the National Hurricane Center

Member Since: Posts: Comments:
Quoting Levi32:
It is true that shifts can still occur with Irene's track, as we are 3 days from what a potential NC landfall would be. The trend in the models has been east, and with recon data in them, the consensus is very tight. Once we get to this point, the large shifts are basically over. To say that SC is safe is unwise, but they are out of the NHC cone, so it's expected that people will start dismissing the storm there. If I were still living there I would be keeping a close eye on Irene, as things can and do change. Right now, the track depends on fine details of upper shortwave troughs coming across the United States, and to be honest there is not a whole lot that forecasters can do beyond using the models to predict the behavior of those small troughs. We are relying on the models more than usual with this storm. The overall pattern is what we forecasted for this to move up the eastern seaboard. Now only a shift of a couple dozen miles could mean the entire world for some people, as the coastline angle means that small shifts in the track translate to much greater shifts in the landfall point up and down the coastline.


Nicely spoken Levi-Thanks. You are always a voice of reason.
Member Since: Posts: Comments:
Really tight looking storm.
Member Since: Posts: Comments:
that 12z gfs model looks like it would destroy my house in CT
Member Since: August 20, 2009 Posts: 0 Comments: 97
Quoting AussieStorm:

lick Image for GOES-13 Movie


Now that was funny
Member Since: Posts: Comments:
Quoting belizeit:
Check out the latest dropsonde 147mph winds at 925mb that means surface winds could be around 130mph


whoa! I don't want that... chances for making it to cat 5 are higher then
Member Since: Posts: Comments:
Quoting SCwannabe:


They said Hugo was going to miss CHS too...


Well, forecast models have come a long way in 22 years. When you see every model tightly clustered like they are now and Irene now at a 305 heading, confidence grows considerably that Irene will continue on course.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting RitaEvac:
East coast gonna be caught with their pants down, I can already tell.


rita...you got cyber script... :)
Member Since: Posts: Comments:
Quoting SCwannabe:


They said Hugo was going to miss CHS too...


I believe you are correct..
Member Since: Posts: Comments:
Quoting knightdog:


Why?


because some people believe that weather events and earthquakes have connections
Member Since: Posts: Comments:
It is true that shifts can still occur with Irene's track, as we are 3 days from what a potential NC landfall would be. The trend in the models has been east, and with recon data in them, the consensus is very tight. Once we get to this point, the large shifts are basically over. To say that SC is 100% safe is unwise, but they are out of the NHC cone, so it's expected that people will start dismissing the storm there. If I were still living there I would be keeping a close eye on Irene, as things can and do change. Right now, the track depends on fine details of upper shortwave troughs coming across the United States, and to be honest there is not a whole lot that forecasters can do beyond using the models to predict the behavior of those small troughs. We are relying on the models more than usual with this storm. The overall pattern is what we forecasted for this to move up the eastern seaboard. Now only a shift of a couple dozen miles could mean the entire world for some people, as the coastline angle means that small shifts in the track translate to much greater shifts in the landfall point up and down the coastline.
Member Since: Posts: Comments:
Quoting tiggeriffic:


considering Charleston is at 32 N and 80 W i would have to agree...still wouldn't even want her near 79 or even 78...just sayin


Yeah, if she makes it to 78 that will be bad-she is at 74 now...FYI
Member Since: Posts: Comments:
Quoting ecupirate:
Irene is getting ready to wobble NORTH


just had a big wobble to the west
Member Since: Posts: Comments:
Quoting Sflabuck:
no eye = another fish storm for S. Fla
thankfully one day but im not sure when they will get a big one again
Member Since: Posts: Comments:
Quoting Chucktown:


Yes, we are looking pretty good here now. As long as it gets to 32 N before 80 W, we are fine. Current NHC track has it only getting as far west as 77.2 W, which will put the center about 200 miles just east of CHS Saturday morning. If the track holds, very little impact if any will be seen here.


They said Hugo was going to miss CHS too...
Member Since: Posts: Comments:
Thanks Dr. Masters... best wishes for those in the Bahamas that will be impacted today and tonight.
Member Since: Posts: Comments:
Quoting RitaEvac:
Regardless of what happens, this storm is going to have a GIGANTIC wind field by the time it's in the NE, and that alone is gonna shock people up there. Put it this way, after the quake, and what is awaiting the NE, these folks will think the world is coming to an end literally.


If I'm not mistaken wind-field is most important factor contributing to storm surge. Irene's going to be pushing quite a bit of water.
Member Since: Posts: Comments:
Quoting Chucktown:


Yes, we are looking pretty good here now. As long as it gets to 32 N before 80 W, we are fine. Current NHC track has it only getting as far west as 77.2 W, which will put the center about 200 miles just east of CHS Saturday morning. If the track holds, very little impact if any will be seen here.


considering Charleston is at 32 N and 80 W i would have to agree...still wouldn't even want her near 79 or even 78...just sayin
Member Since: Posts: Comments:
Quoting Neapolitan:

Keep note of any neighbors laughing, and charge them extra to stay at your house when it's the only one on the block still standing after the storm passes...


+1000
Member Since: Posts: Comments:

Click Image for GOES-13 Movie
Member Since: Posts: Comments:
Quoting MoltenIce:
So, there are no humans in Puerto Rico?


no according to him since i am not living in florida or united states i am not human but thats ok i think i like my fish neighbors better than that partivular human
Member Since: Posts: Comments:
Quoting SCwannabe:


It really is unbelievable how much faith people put in the models. I live in Charleston, SC and they have pretty much told everyone that it's a done deal and not to worry about it anymore....wow.


Yes, we are looking pretty good here now. As long as it gets to 32 N before 80 W, we are fine. Current NHC track has it only getting as far west as 77.2 W, which will put the center about 200 miles just east of CHS Saturday morning. If the track holds, very little impact if any will be seen here.
Member Since: Posts: Comments:
East coast gonna be caught with their pants down, I can already tell.
Member Since: Posts: Comments:
Quoting TropicalXprt:
I hope all your Floridians are not paying attention to these loony's on here claiming Florida will get nothing from this storm. Giving the current track , this storm isnt even thinking about turning soon.

You guys can modelhug all day long, but at the end of the day a model is programmed by some nerd on a computer. Nerds dont take into account changes in mother nature.


This storm is heading west.


the storm WILL NOT PASS 77 WEST
fla is safe minus some costal surf breezy conditions
and i don't forecast i track
Member Since: July 15, 2006 Posts: 169 Comments: 53296
Quoting Gorty:


She's going wnw with wobbles to the west.
its stepping
Member Since: Posts: Comments:
Quoting SCwannabe:


It really is unbelievable how much faith people put in the models. I live in Charleston, SC and they have pretty much told everyone that it's a done deal and not to worry about it anymore....wow.


hey neighbor lol...i know...rule of thumb...never iggy a storm till it is at least due east of you, then only close one eye...i pay attention until i hear it has disipated...
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting Sflabuck:
no eye = another fish storm for S. Fla
So, there are no humans in Puerto Rico?
Member Since: Posts: Comments:
Quoting SCwannabe:


It really is unbelievable how much faith people put in the models. I live in Charleston, SC and they have pretty much told everyone that it's a done deal and not to worry about it anymore....wow.


Could not AGREE more, I really think people here in Charleston nee to keep a CLOSE eye on this monster..

Member Since: Posts: Comments:
Quoting Grandpato4:
Our local weather folks seem to think we won't get more than a few gusty winds with the current forecast track. I am not letting my guard down, but I feel a bit silly sitting in a house with hurricane shutters up right now.

Keep note of any neighbors laughing, and charge them extra to stay at your house when it's the only one on the block still standing after the storm passes...
Member Since: Posts: Comments:
Quoting TropicalXprt:
I hope all your Floridians are not paying attention to these loony's on here claiming Florida will get nothing from this storm. Giving the current track , this storm isnt even thinking about turning soon.

You guys can modelhug all day long, but at the end of the day a model is programmed by some nerd on a computer. Nerds dont take into account changes in mother nature.


This storm is heading west.


Lol, I agree completely.
Member Since: September 2, 2008 Posts: 0 Comments: 744
Quoting TropicalXprt:
I hope all your Floridians are not paying attention to these loony's on here claiming Florida will get nothing from this storm. Giving the current track , this storm isnt even thinking about turning soon.

You guys can modelhug all day long, but at the end of the day a model is programmed by some nerd on a computer. Nerds dont take into account changes in mother nature.


This storm is heading west.


It really is unbelievable how much faith people put in the models. I live in Charleston, SC and they have pretty much told everyone that it's a done deal and not to worry about it anymore....wow.
Member Since: Posts: Comments:
Quoting TropicalXprt:
I hope all your Floridians are not paying attention to these loony's on here claiming Florida will get nothing from this storm. Giving the current track , this storm isnt even thinking about turning soon.

You guys can modelhug all day long, but at the end of the day a model is programmed by some nerd on a computer. Nerds dont take into account changes in mother nature.


This storm is heading west.


Thanks Chicken Little. Please post back AFTER the turn to the north and admit you were wrong. Okay?
Member Since: September 4, 2009 Posts: 0 Comments: 158
On Friday I'd like to say "Hey DC...CheckMate"
Member Since: Posts: Comments:
Quoting ecupirate:
Irene is getting ready to wobble NORTH


She's going wnw with wobbles to the west.
Member Since: November 8, 2008 Posts: 12 Comments: 1058
Quoting definer:
Would anybody have any stats about an area being impacted by a substantial earthquake AND a hurricane within days of each other?

Ken


Why?
Member Since: Posts: Comments:
Quoting nash28:


50 miles makes a huge difference for FL and SC.


ummmmm YEAH...that is the diff between no rain or wind and school closing lol
Member Since: Posts: Comments:

Viewing: 90 - 40

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30Blog Index

Top of Page

About

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

Local Weather

Scattered Clouds
66 °F
Scattered Clouds