Hurricane Irene Approaches the Bahamas

By: Dr. Jeff Masters , 7:42 AM GMT on August 24, 2011

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As of 2AM EDT, Hurricane Irene was located at 21.3N, 72.6W, 400 miles southeast of Nassau. It was moving west-northwest at 9 mph with maximum sustained winds of 100 mph, making it a Category 2 storm on the Saffir-Simpson scale. Irene has a minimum central pressure of 966 mb. Hurricane warnings have been issued for all of the Bahamas and the Turks and Caicos Islands. Tropical storm warnings are in effect for Haiti from Le Mole St. Nicholas to the Dominican Republic border.

Satellite Views
Figure 1 shows that Irene has a large eye visible in infrared imagery, (26 miles across accoring to a report from the Hurricane Hunters at 130AM) with well-defined outflow cirrus bands. Tuesday evening, TRMM, NASA's tropical research satellite, flew directly overhead Irene, getting a radar scan of the storm using it's downward pointing radar, shown in Figure 2. It is immediately apparent that Irene has well-developed bands of rain showers, with strong storms present in the eyewall.


Figure 1 IR satellite view of Irene taken at 113AM EDT, August 23, 2011


Figure 2 TRMM radar overpass of Irene at 713PM EDT, August 22, 2011. Image courtesy of the Naval Research Laboratory

Track Forecast

Irene is forecast to move to the northwest, passing over all of the Bahamas by Thursday evening, then curving to the north. Irene then makes landfall in the US near or at the Outer Banks Saturday afternoon, then traveling along the mid-Atlantic coastline of the US. After Saturday, Irene may pose a threat to Long Island and the New England coastline. However, NHC is quick to remind us that the average forecast error for day 4 is 200 miles, so don't stop your hurricane preparations if you aren't in the immediate area of landfall. It is also important to note that the windfield of Irene is expected to be large, affecting areas distant from the immediate track of Irene's center. Tropical storm forces winds are expected to be found out to at least 150 miles away from Irene's center on Friday afternoon.

NHC is forecasting for Irene to become a major hurricane (winds faster than 110 mph), within 24 hours.


Figure 3 Official track forecast of Irene at 2AM EDT.

Forecast models and adaptive observations
The different forecast models are in fairly good agreement about Irene's track through the Bahamas and along the east coast of the US. The GFDL, a dynamical hurricane forecasting model, which had been a western outlier from the other models is now agreeing with them. When a set of weather models using slighly different initial views of the atmosphere and slightly different ways of simulating how the atmosphere works all agree on a forecast, then meteorlogists tend to believe that the forecast is more likely to occur. The 00Z GFS and ECMWF (wind swath shown in Figure 4) forecasts are nearly identical, which furthur boosts forecaster confidence.

In the 11PM forecast discussion, the NHC forecaster praises the NOAA Gulfstream IV (aka Gonzo) for providing infomation about the atmosphere around Irene that will influence it's track. Looking at the plan of the day valid for today, it will be a busy day for airborne reconnaissance. Three flights for the Air Force hurricane hunters, two flights for the Gulfstream IV, and two flights for NOAA 42, a WP-3D (aka Kermit).


Figure 4 Plot of the maximum sustained winds in mph over the next week from the 00Z ECMWF forecast.

Impacts

In the immediate future, Irene will have a significant impact on the Bahamas and surrounding islands. Hurricane force winds are ongoing over the Turks and Caicos islands and southeastern Bahamas. These locations can expect storm surges that are 5-8 feet above tide levels. The northwestern Bahamas can expect hurricane force winds Thursday, and storm surges that are 7-11 feet above tide levels. The Turks and Caicos islands and all of the Bahamas can expect 6-12 inches of rain over the next two days.

I still think people living along the east coast of the US should closely monitor Irene and review their hurricane preparations. Irene will be a large storm, impacting areas far from the storm center track.

Dr. Masters will have a new blog entry this morning, and Angela Fritz will be covering the afternoon. I'll be back on third shift tonight.

Thanks for reading,

Dr. Rob Carver

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Morning guys... Nassau is still relatively quiet. According to Baha, we had a rain band from Irene this morning, and now at my place it's relatively sunny with winds around 15 mph. Should increase late tonight as the circulation approaches from the southeast. Will update you as it nears! :)
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577. hamla
if irene stays 200 miles from center in all directions = 400 miles of tropical force winds.if the center goes north across long island conn.ri,mass at 20 mph that would be 20 hours of a lot of destruction that most folks who live there have never seen but all they are talking about is the 5.8 shake should be starting a wake up call soon that shake wont be nothing compared to a week or so with out power/grocerys/water just a thought
Member Since: August 29, 2008 Posts: 0 Comments: 167
8:00am Advisory
*Click on graphic for enlarged view
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575. Gorty
Quoting robert88:
Looks like Irene is Earl 2.0...Models have been absolutely horrible this season and where is that strong subtropical ridge that was glamourized by the almighty king EURO and GFS??? Looks like a possible repeat of 2010 on the way. Pattern change my a$$...lol


No...... especailly since two reliable models went WEST! HWRF AND GFDL
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Is the gap closing ???

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Quoting CaneHunter031472:


Really? Look at the end of this movie. and yes it is updated.

''

the date on the video is 23Aug. Please verify......
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Quoting robert88:
Looks like Irene is Earl 2.0...Models have been absolutely horrible this season and where is that strong subtropical ridge that was glamourized by the almighty king EURO and GFS??? Looks like a possible repeat of 2010 on the way. Pattern change my a$$...lol


gotta agree with u
Member Since: August 4, 2011 Posts: 0 Comments: 631
Storm Relative 1km Geostationary Visible Imagery




Member Since: July 3, 2005 Posts: 426 Comments: 128639
Once this cold front moves through the Northeast on thursday the models should really get a good idea on where this is going to go
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I will ride this storm out as I have every storm to hit N.C. the last 30 years. There are some very old houses on the Island I live on, built before the civil war and they did not bolt them down either!
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Quoting rmbjoe1954:


?????

No way is that possible at this point. Irene has already started her NW track and in time will go N, then NNE.

The GOM is 99% safe froom Irene. I say 99% because in weather nothing is 100% certain.


Please 99%? I give the GOMEX 100% of chance that Irene will not even look that way. My conern is SC and NC. I'll eat RAW crow feathers and all and will post a picture if Irene enters the Gomex. As a matter of fact I give a 50/50 chance that the season is about over for the Gomex.
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Quoting CaneHunter031472:


Really? Look at the end of this movie. and yes it is updated.


that is not updated. that stops around 72W and Irene is already at 73.3W

just look at satellite and you can see its moving nw.
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Quoting CaneHunter031472:
Irene made abaut 100mile jog to the nnw and then bounced back sw about another 100miles if this continue, wouldn't this add up to a westward movement. Today is the day in which the turn need to happen for the model to prove correct. Anyone? comments?



The eyewall may have just reformed a little.
Member Since: September 3, 2008 Posts: 0 Comments: 65
Looks like Irene is Earl 2.0...Models have been absolutely horrible this season and where is that strong subtropical ridge that was glamourized by the almighty king EURO and GFS??? Looks like a possible repeat of 2010 on the way. Pattern change my a$$...lol
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Three buoys reporting at 1200 GMT have it at 21.9N and 73.3W. On the National Data Buoy Center They state that not all buoys are operated by National Data Buoy Center
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Quoting NOLALawyer:
Come on Irene!!!!!


Okay, now you know I love you man, and we're in the same dinghy pulling oars on opposite sides, so a word of gentle reminder: egging her on in your outside voice is considered to be in very poor taste. A nice demur golf clap is about all you can really allow yourself in public
Member Since: August 2, 2006 Posts: 10 Comments: 9922
flight level winds of 102 knts now in the SE quadrant... one of the weakest quadrants on IR sat
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561. Gorty
TWO RELIABLE MODELS THE HWARF AND GFDL WENT WEST... THIS PUTS ME ON THE STRONGEST SIDE OF THE STORM.

THIS IS WHY THERE IS SO MUCH UNCERTAINTY.

I live in western Mass.
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560. HiWay
Quoting CaneHunter031472:


Really? Look at the end of this movie. and yes it is updated.


Wow, that's bizzare, it almost teleports back south in between those two frames??
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THis is a link that CRS gave us for a web cam yesterday and its still operating this morning. You can look at recent images and see yesterday vs. today. Unfortunately I am not sure exactly where this cam is located.

www.theregentgrandresort.com/regentwebcam.html
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Quoting CaneHunter031472:


Really? Look at the end of this movie. and yes it is updated.



movement plz?
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Quoting Gorty:


Are you kidding me? The cone pretty much stayed the same maybe they extended it a little west.


really? how did the cone go from tampa to miami to jacksonville to savannah to the outer banks to connecticut without trending significantly east?

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Quoting ILwthrfan:
Looks like Irene is making a solid jog north in the last hr.


Really? Look at the end of this movie. and yes it is updated.

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Quoting JNCali:
If Irene strengthens further she could still wind up in the GOM .. There are to many crazy tracks 'on the books' ... we should not assume with this one yet ..IMO


?????

No way is that possible at this point. Irene has already started her NW track and in time will go N, then NNE.

The GOM is 99% safe froom Irene. I say 99% because in weather nothing is 100% certain.
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Good morning my friends,

I see the northward jog has started.. thank goodness for Florida but now worried about NCarolina and to points north.

I sent my daughter in Boston a message that this one may come to her area to be ready.


will be lurking in and out today as I can!

Thanks or all the good info and (and the giggles from Dewey and the funny gang!)
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Quoting DookiePBC:


Would there be something ironic to New Yorkers fleeing to South Florida to avoid a hurricane!? LOL...it would be Snowbirds in August!


The beauty thing about that? I had friends in '05 that ran to Texas (Orange and thereabouts) to escape Katrina and then ran to Southwest Florida to escape Rita...
Member Since: August 2, 2006 Posts: 10 Comments: 9922
Quoting K8eCane:

.

I wonder if they will start school tomorrow..I havent heard anything though..
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21.1n71.9w, 21.3n72.5w has been re-evaluated&altered for H.Irene's_12pmGMT_ATCF
21.0n71.9w, 21.3n72.5w, 21.9n73.3w are now the most recent positions
Starting 23August_12pmGMT and ending 24August_12pmGMT

The 4 eastern line-segments represent HurricaneIrene's path
and the westernmost line-segment is the straightline projection.

Using straightline projection of the travel-speed&heading derived from the ATCF coordinates spanning the 6hours between 6amGMT then 12pmGMT :
H.Irene's travel-speed was 11mph(17.7k/h) on a heading of 308.9degrees(NW)
H.Irene was headed toward passage over DelectableBay(Acklins)Bahamas ~3&2/3rd hours from now

Copy&paste 20.4n70.6w-20.7n71.2w, 20.7n71.2w-21.0n71.9w, 21.0n71.9w-21.3n72.5w, 21.3n72.5w-21.9n73.3w, iga, axp, 21.3n72.5w-22.396n73.97w, eyw, bct into the GreatCircleMapper for more info

The previous mapping (for 24August_6amGMT)
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Either way I will be in New Bern, NC on fri aft.
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If Irene strengthens further she could still wind up in the GOM .. There are to many crazy tracks 'on the books' ... we should not assume with this one yet ..IMO
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Quoting BahaHurican:
Morning kman... I haven't heard from CRS yet this morning. He was on around 2 a.m. with power out, to crank his generator and check the 2 a.m. update. So far reports out of TCI have been that damage has been relatively minimal. However, I've only heard from Grand Turk residents, and Provo was much closer to the centre.

Hopefully he'll be in once he gets up and cranks his generator again.....


thanks Baha I was wondering same thing as Kman as I just got to computer this morning to check this out.
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.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...ONSHORE FLOW AND MOISTURE ADVECTION THU/THU
NIGHT PLUS THE PRESENCE OF WEAK SURFACE BOUNDARY IN THE REGION
WOULD SUGGEST A HIGH PROBABILITY OF PRECIP DURING THE FIRST HALF
OF THE PERIOD. HOWEVER...THE GFS REALLY DRIES OUT MID LEVELS
AHEAD OF IRENE. THIS IS LIKELY DUE TO SINKING AIR BEING EJECTED
FROM THE TOP OF THE STORM. HOW STRONG THIS SINKING MOTION IS WILL
DEPEND ON HOW STRONG THE HURRICANE IS AS IT APPROACHES THE
CAROLINAS. THE NAM DOES NOT SHOW THIS DRYING BUT IS NOT TYPICALLY
KNOWN FOR ITS SKILL WITH TROPICAL SYSTEMS AND THE GFS HAS SUPPORT
FROM THE ECMWF. ANY STORMS THAT DO DEVELOP ARE GOING TO BE SLOW
MOVING AND COULD END UP DROPPING A LARGE AMOUNT OF RAIN OVER A
VERY SMALL AREA. ALTHOUGH PRECIPITABLE WATER VALUES ARE NOT
EXCESSIVE FLOODING COULD BE AN ISSUE THU...WELL BEFORE THE
ARRIVAL OF PRECIP ASSOCIATED WITH IRENE.

LATE THU NIGHT OR FRI MORNING TROPICAL MOISTURE ASSOCIATED WITH
IRENE WILL START SPREADING OVER THE REGION. THROUGHOUT FRI WINDS
WILL PICK UP AS WILL PRECIP CHANCES. FIRST RAIN BANDS ASSOCIATED
WITH IRENE ARE LIKELY TO ARRIVE FRI NIGHT...BUT LOW LEVEL
CONVERGENCE AND DEEP TROPICAL MOISTURE WELL AHEAD OF THE
STORM...WHICH WILL BE QUITE LARGE...WILL RESULT IN SHOWERS AND
POSSIBLY THUNDERSTORMS AS EARLY AS FRI MORNING.

ALTHOUGH DIFFERENCES REMAIN WITH RESPECT TO TIMING/TRACK OF
IRENE...IT DOES NOT APPEAR THAT THE STORM WILL MAKE A DIRECT HIT.
THE LATEST NHC FORECAST KEEPS THE STORM ABOUT 70 MILES EAST OF
CAPE FEAR...AND THIS DISTANCE MAY CONTINUE TO GROW AS MOST OF THE
00Z GUIDANCE HAS COME IN ON THE RIGHT SIDE OF THE NHC TRACK. STORM
IS LIKELY TO BE CLOSE ENOUGH THE TROPICAL WATCHES/WARNINGS WILL
PROBABLY BE RAISED FOR THE AREA...BUT THE CURRENT FORECAST
SUGGESTS LITTLE MORE THAN MINIMAL TROPICAL STORM FORCE WINDS. WITH
THAT SAID...THE STORM IS STILL CLOSE TO 4 DAYS OUT AND TRACK
ERRORS WITH IRENE HAVE AVERAGED 175 NM. WHILE UNLIKELY...IRENE
COULD STILL END UP PASSING WEST OF CAPE FEAR BRINGING HIGHEST
WINDS/SURGE TO THE NORTHERN SC/SOUTHERN NC COAST. CONTINUE TO
MONIT
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Looks like Irene is making a solid jog north in the last hr.
Member Since: February 2, 2010 Posts: 0 Comments: 1526
Quoting HiWay:


Well, I hear they have this big rubber sheath they roll down over it to prevent any debris from damaging the surface...


it cracked in some spots yesterday with that earthquake
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544. Gorty
Quoting BobinTampa:


still trending east though. if that continues over the next day or too, than it is buh-bye.



Are you kidding me? The cone pretty much stayed the same maybe they extended it a little west.
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Quoting overwash12:
Joe Bastardi is probably going crazy,see I told you guys....LOL


If you say the same prediction over and over and over without any time constraints, eventually it will probably come true.
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Quoting CHinFL:
Question from an older rookie- I have heard and read how a hurricane can get large enough to "effect its own weather- ie. moisten the envirement, push out shear , etc" but can a hurricane that grows strong and large actually impact its on stearing- can it influence the highs and troughs that usually stear it? I'm facinated by weather and trying to learn!


well the actual diameter of the storm isnt want counts. it is the height of the vertical stacking that counts. The better the storm is stacked vertically the more chances it can feel the weakness of a broken down ridge. The weakness is what is is looking for. Hope that explaines it a lil bit for ya.
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Quoting Jax82:
With all the technology out there with smart phones and iphones, Irene could be the most videotaped Hurricane ever if it hits the Northeast. I wonder where Cantore is going to set up shop, OBX or NY?


He will chain himself to the torch atop the Statue of Liberty.
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Looks like we will be in for some heavy surf along the Palm Beach County coast on Thursday into Thursday night. May have to issue a level 1 jellyfish alert. Watch where you step if you take a walk on the beach Friday morning! Stay vigilant!

(In all seriousness...good luck to everyone in the Bahamas right now!)
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Irene made abaut 100mile jog to the nnw and then bounced back sw about another 100miles if this continue, wouldn't this add up to a westward movement. Today is the day in which the turn need to happen for the model to prove correct. Anyone? comments?

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It will be interesting to see what kind of shape the EC beaches are in for Labor Day weekend
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Has anyone herd from "CaicosRetieredSailor"?
He may have lost power.
Irene's eyewall came very close to him.
Member Since: September 3, 2008 Posts: 0 Comments: 65
Quoting ProgressivePulse:



Just the eye filling in eyy? I was about to pull a "Pinhole Alert" for the Taz man.


Wait, that was an old image you posted.
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535. Jax82
With all the technology out there with smart phones and iphones, Irene could be the most videotaped Hurricane ever if it hits the Northeast. I wonder where Cantore is going to set up shop, OBX or NY?
Member Since: September 2, 2008 Posts: 1 Comments: 1261
Quoting K8eCane:
RENE NOW A CATEGORY 3 STORM, EXPECTED TO STRENGTHEN MORE

Hurricane Irene has developed into a Category 3 storm with winds near 115 mph, and the storm is expected to strengthen further throughout the day.

Photo Galleries

Hurricane Irene
The 8 a.m. update from the National Hurricane Center reports that hurricane-force winds extend out 40 miles from the storm's center, with tropical storm-force winds up to 205 miles.

Irene is now over the southeastern Bahamas, bringing storm surge of 7 to 11 feet, and rain from 6 to 12 inches.

Forecast models continue to keep Irene east of Wilmington, instead making landfall closer to Morehead City or on the Outer Banks.

Southeastern North Carolina is still in the cone of uncertainty, and Wilmington is still likely to be affected by strong winds and rain.

but NOT cat 3 or 4 winds thank God


Latest wilmington NWS says current path will only bring weak tropical storm force winds. Beginning to think we will see nothing more than a showery breezy day... quite the change from yesterday morning at this time.
Member Since: August 4, 2011 Posts: 0 Comments: 631
Quoting DookiePBC:


Would there be something ironic to New Yorkers fleeing to South Florida to avoid a hurricane!? LOL...it would be Snowbirds in August!
Please dear god, No.

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Quoting Rainman32:
Exactly, that is the intent of the graphic, to show the trend.. buh-bye


my bad. I thought you said 'can NO longer say buh-bye.'


Now the blog knows my secret.....I can't read (sobbing)!!
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Quoting FLdewey:


Thanks!

Buh byyeeeeeee! ;-)




Just the eye filling in eyy? I was about to pull a "Pinhole Alert" for the Taz man.
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Quoting BahaHurican:
Just want to say for those concerned about when Irene is going to make the turn...

SUMMARY OF 800 AM EDT...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...21.9N 73.3W
ABOUT 55 MI...85 KM SE OF ACKLINS ISLAND BAHAMAS
ABOUT 335 MI...540 KM SE OF NASSAU
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...957 MB...28.26 INCHES

This storm hasn't been doing much on the 300 heading so far. That slowdown overnight was because Irene was turning.

Let's see how many more 295 headings we see out of this baby...

BTW, the track takes the eye right over the settlement of Delectable Bay, Acklins. Sure hope it's still delectable after Irene is gone...

I gotta run. I'll be back in a few hours, and should have a few pictures of what's happening in Nassau today.

Again, if you are in the Bahamas or TCI and have information or queries, please feel free to post them in my blog. Just lick on my handle in any of messages to get there.

Ya'll have a GREAT day!


the 8am discussion mention this morning that the storm was making west wobbles..hmmm
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Quoting superpete:
Morning Kman. I saw the early models showing it moving NW early in the run.Hope Irene has not inflicted too much on T & C overnight.


We will get updates from there soon I am sure.
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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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