Category 2 Irene Approaches The Bahamas

By: Dr. Jeff Masters , 7:51 AM GMT on August 23, 2011

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As of 2am EDT, Hurricane Irene was located at 20.1N, 69.7W, 135 miles southeast of Grand Turk Island. It was moving west-northwest at 12 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 978 mb. Hurricane warnings have been issued for the northern coast of the Dominican Republic from the Haiti board to Cabo Engano, the southeastern and central Bahamas, and the Turks and Caicos islands. Hurricane watches have been posted for the north coast of Haiti from Le Mole, St. Nicholas to the Dominican border and the northwestern Bahamas. Tropical storm warnings are in effect for all of Haiti and the southern coast of the Dominican Republic from Cabo Engano to Santo Domingo.

5AM Update
As of 5am EDT, Hurricane Irene was located at 20.3N, 70.1W, 105 miles southeast of Grand Turk Island. It was moving west-northwest at 12 mph with maximum sustained winds of 100 mph, keeping it a Category 2 storm on the Saffir-Simpson scale. Irene has a minimum central pressure of 978 mb.

Figure 1 shows that Irene is maturing into a vigorous storm, with apparent waves in the western edge of the cirrus outflow.


Figure 1 IR satellite view of Irene taken at 135AM EDT, August 22, 2011

Track Forecast

Irene is forecast to move to the north-northwest, passing over all of the Bahama islands by Thursday evening, at which points it starts curving to the north. Irene is forecast to make landfall in the US near Wilmington, NC Saturday evening. However, it is important to note that this is not a definitive forecast, the average forecast error for day 5 is 250 miles. The timing of Irene's recurvature depends on how quickly several small troughs of low pressure in the Northeastern US move to the east. After Saturday, Irene may pose a threat to the mid-Atlantic coastline and locations further north, but it is too early to make a skillful forecast for those regions.

NHC is forecasting for Irene to become a major hurricane (winds faster than 110 mph), within 24 hours, then reaching peak intensity at 130 mph (Category 4 storm) by 8pm EDT Thursday evening.

Forecast models and adaptive observations
The different forecast models are in rough agreement until Irene nears the Carolinas. The dynamical hurricane forecasting models, GFDL and HWRF, have Irene making landfall near Charleston, SC. NGFDL (a variant of the GFDL that uses NOGAPS for background conditions) has landfall near Morehead City, NC, and the GFS has Irene crossing the Outer Banks. The UKMET forecast track splits the difference, placing Irene near Myrtle Beach, SC at landfall.

To reduce the model spread, and improve the track forecast error, the NOAA Gulfstream IV and an Air Force WC-130J have been flying dropsonde missions north of Irene. A dropsonde is an meteorological instrument package dropped from a plane that can tell you the vertical profile of temperature, pressure, moisture, and winds. By flying these missions, the dropsondes can improve all of the numerical weather prediction models initial picture of the atmospheres, which improves the forecast. Also, NHC has asked NWS offices in the southeastern US that launch weather balloons to do so every 6 hours instead of the normal 12 hour frequency.


Figure 2 Official track forecast of Irene as of 2am.

5AM update
The 00Z ECMWF forecast is available and Figure 3 shows the maximum wind speed over the next week for the eastern coast of the US. Green indicates tropical storm force winds, while yellow and orange are hurricane-force winds. The important thing is not to fixate on the predicted landfall location, but to see that Irene's winds will affect areas far away from landfall. The GFS, not shown, agrees with ECMWF that Irene will have a large area of tropical-storm force winds associated with it.

Figure 3 Maximum wind-speed in mph from the 00Z August 23 ECMWF forecast for the next week.

Impacts

In the immediate future, Irene is expected to have a significant impact on the Bahamas and surrounding islands. Hurricane force winds are forecast to reach the southeastern Bahamas and the Turks and Caicos sometime this afternoon or evening. These locations can also expect 5-10 inches of rain. Three to six inches of rain are forecast over northern Hispaniola, with isolated areas receiving up to 10 inches. This could lead to flash flooding and mudslides in mountaineous terrain. NHC is predicting a storm surge of 9-13 feet above normal tide level for the southeastern Bahamas and the Turks and Caicos.

Outside of the islands immediately impacted by Irene, it is my judgement that everybody living on the eastern coast of the US should monitor Irene and review their hurricane preparations over the next few days.

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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Quoting overwash12:
Hey yesterway,where do you live,if I may ask?


20 miles east of Gainesville, Fl in Melrose...
Member Since: October 26, 2003 Posts: 0 Comments: 363
but just waiting to see which beach to go surf at...i do believe it's going to miss the E.C. but just always have that "well it could do...." but i'm sure there are a tone of boards getting ready for a good waxen!!
Member Since: June 3, 2008 Posts: 0 Comments: 1928
good morning everybody. any earth shattering changes to Irene in the last couple of hours??
Member Since: September 18, 2010 Posts: 0 Comments: 5220
Quoting E46Pilot:


SE FL rarely gets hit with storms. At least it's been that way for the last 30 years. We've only got hit with 3 storms that have caused major headaches. David, Andrew, and Wilma.

SE Fl is the number 1 place int he country for strikes.

I would also argue that Irene in 1999 caused major headaches as the entire city was flooded and people died. As well as Katrina since a few people died in Miami for that too. Not too mention that on avaerage the SE FL area is hit my at least one tropical storm a year.

Jean, Fay and Francis also hit SE Fl. so yea ur wrong.
Member Since: August 26, 2008 Posts: 0 Comments: 2165
Quoting TampaSpin:



NEXT UP........:(



sad face?? why??
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Quoting wolftribe2009:
Hurricane Irene's path brings to mind several storms to me.

Fran 1996
Link

Floyd 1998
Link

However, the storm that came to my mind first for some reason was Hurricane Bonnie 1998

Photobucket


The only problem with these storms is that they all made landfall on the lower end of a CAT 3 or CAT 2; therefore, a strong CAT 3-4 is something that hasn't been seen in the Carolinas in a long time.


It should be noted that these storms also had tracks a bit further north than where Irene is sitting. I do hope people have noticed that.
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Godspeed to those of you in the Bahamas and along the East Coast. I saw footage of people purchasing supplies this am and had flashbacks of doing the same many times here along the LA coast. You get a knot in your stomach. Be prepared, but also heed he warnings when they tell you to get out.
A side note - make sure you have activities for the little ones to keep them distracted (coloring books small games,etc...) They feel your anxiousness.
Hope everyone stays safe!
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Quoting NICycloneChaser:


Speaking of Jose....



Whoops, wrong pic.
Member Since: August 10, 2010 Posts: 2 Comments: 1971
Member Since: September 10, 2007 Posts: 0 Comments: 11111
Quoting JNCali:

Soon it will be sub-contracted out to Jose's Crop Dusting


Speaking of Jose....

Member Since: August 10, 2010 Posts: 2 Comments: 1971
Quoting MahFL:
We've had 2 aircraft failures this year so far. Obviously not enough funding, sadly.


In NO WAY is that from funding...........Come on! We have seen this many times over other years. Let's be honest. Do we need New equipment yes but that didn't just happen from this year.
Member Since: September 2, 2007 Posts: 178 Comments: 20439
Quoting cat5hurricane:
Didn't Dr. Masters fly into Gilbert in 1988. Hey, if they can successfully complete a recon mission through a massive category 5 hurricane like that, I'd say there pretty damn reliable.

Nuff said :)


They're probably still flying the same aircraft. And it isn't like driving across town, when a mechanical failure is just an inconvienience. If I was flying into a hurricane, I'd want everything and it's back-up to be totally perfect.
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Quoting MahFL:
We've had 2 aircraft failures this year so far. Obviously not enough funding, sadly.


In any aviation endeavor (government or profit motivated) the first area to get cut back is maintenance. That doesn't make sense but the people doing the cutting are not the ones doing the flying.
Member Since: October 26, 2003 Posts: 0 Comments: 363
Quoting wolftribe2009:
Hurricane Irene's path brings to mind several storms to me.

Fran 1996
Link

Floyd 1998
Link


Just a minor (very minor) nit pick..

Floyd was 1999.... :D

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Quoting Nolehead:
rememeber....no one is out of the picture until it makes that n then n/e turn..till then ALL options are still open for her...just sayin..



Well said, if anything Irene doesn't look like she's in a hurry to go anywhere fast! She's been hanging out by Puerto Rico and Hispanolia for two full days now.
Member Since: August 25, 2006 Posts: 1 Comments: 3022
Quoting TampaSpin:


Bro, it does not really matter to me as long as they keep turning or come ashore as only a 74mile storm right over St. Pete beach Condo's..........LOL
,i can see the beach from my window,its right accrross the street so yea any tc stronger than a cat 1 woukd be problematic for me considering im about 1000ft from the gom and about 300 ft from a canal on the other side elevation 5ft,wouldnt take much,i ve lived here 3yrs and not a problem though!!
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Quoting Orcasystems:


Those planes are not getting any younger... I wonder what the hour ratios are?

Hours Maint per hour flying?


Try this URL, Orca. Still have some old ones around, I believe, but slowly growing the supply of 'new' c130-Js.

http://www.hurricanehunters.com/plane.html
Member Since: June 19, 2006 Posts: 63 Comments: 4175
Quoting yesterway:


Ah..."Overwash"..love sayin that name...
Hey yesterway,where do you live,if I may ask?
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667. MahFL
Looks like a track of 275 now...
Member Since: June 9, 2004 Posts: 0 Comments: 3468

Quoting CoopsWife:


If you think that now, just wait until the funding gets cut further this fall. There's only so much maintenance money to go around....
Soon it will be sub-contracted out to Jose's Crop Dusting
Member Since: September 9, 2010 Posts: 5 Comments: 1034
Hurricane Irene's path brings to mind several storms to me.

Fran 1996
Link

Floyd 1998
Link

However, the storm that came to my mind first for some reason was Hurricane Bonnie 1998

Photobucket


The only problem with these storms is that they all made landfall on the lower end of a CAT 3 or CAT 2; therefore, a strong CAT 3-4 is something that hasn't been seen in the Carolinas in a long time.
Member Since: Posts: Comments:
Quoting E46Pilot:


SE FL rarely gets hit with storms. At least it's been that way for the last 30 years. We've only got hit with 3 storms that have caused major headaches. David, Andrew, and Wilma.



Mmmmm..........not quite sure how you could say that..........Stuart, FL was hurt badly by Frances, Jeanne AND Wilma. Shoot, Wilma just added insult to injury and was blowing "blue roofs" off 13 months later.
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Quoting Methurricanes:
Why dont the Hurricane Hunters use Jet airplanes?


Could you imagine a Flame out..
Member Since: September 2, 2007 Posts: 178 Comments: 20439
Quoting hotrods:
Maybe this year will be the year of the troughs!


Just like the previous few.
Member Since: July 13, 2007 Posts: 0 Comments: 1111
Quoting Methurricanes:
Why dont the Hurricane Hunters use Jet airplanes?


You do not want to use jet engines in heavy rain fall and strong turbulence, they're not designed for it.
Member Since: December 18, 2006 Posts: 7 Comments: 2686
Hopefully Irene will just graze the OBX. We do have a swamp fire that needs putting out,so we could use the rain just not the wind!
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Quoting overwash12:
I thought it was Hugo.


Ah..."Overwash"..love sayin that name...
Member Since: October 26, 2003 Posts: 0 Comments: 363
656. MahFL
We've had 2 aircraft failures this year so far. Obviously not enough funding, sadly.
Member Since: June 9, 2004 Posts: 0 Comments: 3468
rememeber....no one is out of the picture until it makes that n then n/e turn..till then ALL options are still open for her...just sayin..

Member Since: June 3, 2008 Posts: 0 Comments: 1928
Fired up the generator last night and have 20 gals fuel on hand that was supposed to go in the boat for this weekend... Sitting tight on the Chesapeake Bay watching anxiously. Will clean the garage and outside around the house tonight... oh lots of work to do if this doesn't turn. Having a hard time determining what surge effects will be in the Chesapeake bay if this thing hit carolina and keeps coming up to us. Isabel and Nor'Ida (2009) both were big surge events for us...
Member Since: September 4, 2008 Posts: 0 Comments: 65
The BAM models are in no way the best models in looking at a category 3/4 hurricane..People in SC/NC should not be discounting yourself from the equation right now..the ECWMF which Dr. Masters himself stated was the best performing model still brings this over NC and up the east coast..this storm could probably have a windspan of over 400 miles (almost floyd) so Tropical force winds would be felt well inland up the east coast..the Bahamas have my prayers as well any anyone northward from there..If you do not work for the NHC, there is no way anyone should be telling people that this is going out to sea..I havent read any of that in their discussions..
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Quoting cat5hurricane:

Hmmm. Excellent point. Way to think outside the box. I like that. And yeah, probably very true.


Dr. Masters could probably confirm or deny this better than anyone..
Member Since: December 18, 2006 Posts: 7 Comments: 2686

This is what Irene started from...
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Very large windfield and Growing! This could still impact many and still the Center miss you by 200miles.
Member Since: September 2, 2007 Posts: 178 Comments: 20439
Why dont the Hurricane Hunters use Jet airplanes?
Member Since: Posts: Comments:
sorry, I was referring to other AOI'S other than Irene

the other AOI's could be interesting if it takes another westward path

from what I hear, the High is going to pretty strong soon
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Quoting stillwaiting:
,how many times a yr do we here this is a floridia storm the last couple years and they go poof,towards the yucatan or out to see,dam we have good wx!!!


SE FL rarely gets hit with storms. At least it's been that way for the last 30 years. We've only got hit with 3 storms that have caused major headaches. David, Andrew, and Wilma.
Member Since: August 4, 2011 Posts: 0 Comments: 289
man this andriod tablet keyboard sucks when posting in wu,only time it lags and messes up,wonder if this site has security issues??,anyone else using droid have this problem,also some wx images posted mess up the whole page sometimes..
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Quoting cat5hurricane:

That I have noticed, yes. Probably no reason for it though. At least not that I could think of. Just observation though. I don't have the actual specification statistics on hand. lol


Those planes are not getting any younger... I wonder what the hour ratios are?

Hours Maint per hour flying?
Member Since: Posts: Comments:
Quoting stillwaiting:
,how many times a yr do we here this is a floridia storm the last couple years and they go poof,towards the yucatan or out to see,dam we have good wx!!!


Bro, it does not really matter to me as long as they keep turning or come ashore as only a 74mile storm right over St. Pete beach Condo's..........LOL
Member Since: September 2, 2007 Posts: 178 Comments: 20439
Quoting NICycloneChaser:


It is glaringly obvious, and I know that that is why they have problems, I was just commenting on the fact that they seem to have had more problems this year than in other years.


Don't know whether is more common this year so much as the fact that we have all these recent technology upgrades that allow us to instantaneously access info from recon, which draws more attention to mechanical issue that may have never been brought to light before (i.e. google earth)
Member Since: December 18, 2006 Posts: 7 Comments: 2686
Click for enlarged image.
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Quoting FLdewey:
This thing may indeed miss the CONUS all together.

I'm sure the weather channel will have people on the beach waving as it goes by.

buh-bye.



Dangit, if you save one more life, I'm calling you a hero no matter what you say!!
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Quoting overwash12:
I thought it was Hugo.


it was
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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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