Irene continues to weaken

By: Dr. Jeff Masters , 8:46 PM GMT on August 26, 2011

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Satellite data and measurements from the Hurricane Hunters show that Irene continues to weaken. A 1:32 pm EDT center fix by an Air Force Reserve aircraft found that Irene's eyewall is still gone, and the central pressure had risen to 951 mb from a low of 942 mb this morning. The winds measured in Irene near the surface support classifying it as a strong Category 1 hurricane or weak Category 2. Satellite imagery shows a distinctly lopsided appearance to Irene's cloud pattern, with not much heavy thunderstorm activity on the southwest side. This is due to moderate southwesterly wind shear of 10 - 20 knots. This shear is disrupting Irene's circulation and has cut off upper-level outflow along the south side of the hurricane. No eye is visible in satellite loops, but the storm's size is certainly impressive. Long range radar out of Wilmington, North Carolina, shows that the outermost spiral bands from Irene have moved ashore over North Carolina. Winds at buoy 41004 100 miles offshore from Charleston, SC increased to 47 mph, gusting to 60 mph at 3 pm EDT, with significant wave heights of 25 feet.


Figure 1. MODIS satellite image of Hurricane Irene taken at 11:50 am EDT Friday August 26, when Irene was a Category 2 hurricane with 105 mph winds. The eyewall collapsed several hours before this image was taken, and no eye is apparent. Image credit: a href=http://rapidfire.sci.gsfc.nasa.gov/gallery/ NASA.


Figure 2. Distribution of Irene's wind field at 3:30 pm EDT Friday August 26, 2011, as observed by the Hurricane Hunters and buoys. The right front quadrant of the hurricane had about 90% of the storm's hurricane-force winds (yellow and warmer colors, bounded by the heavy black line between the "50" and "60" knot thin black lines.) Tropical storm-force winds (heavy black like bounding the light blue area) extended out 290 miles from the center of Irene. Image credit: NOAA/AOML/HRD.

Forecast for Irene
With its eyewall collapsed and just 18 more hours over water before landfall, Irene does not have time to build a new eyewall and intensify. The storm is too large to weaken quickly, and the best forecast is that Irene will be a strong Category 1 hurricane at landfall in North Carolina on Saturday. Based on the latest wind analysis from NOAA's Hurricane Research Division (Figure 2) and Irene's continued weakening trend, I predict that the 80-mile section of North Carolina coast to the right of where Irene makes landfall will receive sustained hurricane-force winds of 75 - 85 mph on Saturday at landfall; the 80-mile section of coast to the left will receive 55 - 75 mph winds. High wind shear of 30 knots will begin ripping into Irene Sunday morning when it is near Southern New Jersey, and more rapid weakening will occur. By the time Irene arrives on Long Island Sunday afternoon, it will probably have top sustained winds in the 65 - 75 mph range. However, since Irene is such a huge storm--tropical storm force winds extend out up to 290 miles from the center--it has set a massive amount of the ocean's surface in motion, which will cause a much larger storm surge than the winds would suggest. At 3:30 pm EDT this afternoon, a wind analysis from NOAA/HRD (Figure 2) indicated that the potential storm surge damage from Irene still rated a 5.0 on a scale of 0 to 6. This is equivalent to the storm surge a typical Category 4 hurricane would have. While this damage potential should steadily decline as Irene moves northwards and weakens, we can still expect a storm surge one full Saffir-Simpson Category higher than Irene's winds when it impacts the coast. Since tides are at their highest levels of the month this weekend due to the new moon, storm surge flooding will be at a maximum during the high tidal cycles that will occur at 8 pm Saturday night and 8 am Sunday morning. Wherever Irene happens to be at those times, the storm surge damage potential will be maximized. I continue to give a 20% chance that a 3 - 4 foot storm surge high enough to over-top the Manhattan flood walls and swamp the New York City subway system will occur on Sunday. The latest 11 am probabilistic storm surge map from NHC shows a 20 - 30% chance of a storm surge in excess of 3 feet in New York Harbor (Figure 4.) Keep in mind that these maps are calculated for normal tide level, and this weekend's high tides will be nearly 1 foot above normal.

Insurance company AIR-Worldwide is estimating that insured damages from Irene in the U.S. will be $1.5 - $6 billion. They estimate losses in the Caribbean at $0.5 - $1.1 billion from Irene.


Figure 3. Storm surge heights, in feet above normal tide level, which have a 20 percent chance of being exceeded during the next 3 days.  The graphic is based upon an ensemble of Sea, Lake, and Overland Surge from Hurricanes (SLOSH) model runs using the current National Hurricane Center (NHC) official hurricane advisory. The exceedance heights depend on the historical accuracy of NHCs forecasts of hurricane track, and wind speed, and an estimate of storm size. Image credit: NOAA.


Figure 4. Overall chance that storm surges will be greater than 3 feet above normal tide levels during the next 3 days.  The graphic is based upon an ensemble of Sea, Lake, and Overland Surge from Hurricanes (SLOSH) model runs using the current National Hurricane Center (NHC) official hurricane advisory.  Storm surge probabilities depend on the historical accuracy of NHCs forecasts of hurricane track, and wind speed, and an estimate of storm size. Image credit: NOAA.

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.

The National Hurricane Center's Interactive Storm Surge RIsk Map, which allows one to pick a particular Category hurricane and zoom in, is a good source of storm surge risk information.

Wunderblogger Mike Theiss is in Nassau, documenting the storm's impact on the Bahamas.

Internet radio show on Irene at 4:30pm EDT
Wunderground meteorologists will be discussing Hurricane Irene on a special edition of our Internet radio show, the Daily Downpour, today (Friday) at 4:30pm EDT. Shaun Tanner , Tim Roche, Angela Fritz, and Rob Carver will take your questions. The email address to ask questions is broadcast@wunderground.com.

Jeff Masters

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Thinking ahead... How's the wave train looking? Any thoughts on the areas the models keep developing about 7 days out (cmc, gfs, and no gaps)?
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Soon as that batch of dry air is expelled she's going to pop.
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1400. Dennis8
Quoting atmosweather:
Now this is a little better...dropsonde ENE of the eye finds 90 mph surface winds and 120 mph winds at just below 3,000 feet.

So we might get some strengthening huh?
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Quoting Levi32:


So why is there a house there if it floods every other day?


Very good point lol.
Member Since: September 24, 2005 Posts: 33 Comments: 9265
1398. ncstorm
Quoting ShenValleyFlyFish:
You really want a wake up call:

Type in Seaside Heights, NJ in wU search box.
Click on wUnder map on radar.
Zoom in till you begin to identify streets and features on the map.
Choose Hurricane on menu to right.
Uncheck all features.
Toggle Max Storm Surge a time or two.

Works for anywhere at risk right now.

Try it, You might not like it.


If I did this right and the storm surge is in blue..then it comes right up from Kure beach to the Wilmington Airport..thats almost 25 miles inland..that cant be right..
Member Since: August 19, 2006 Posts: 13 Comments: 14592
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Quoting lottotexas:
45 & tidwell. Elect off for 16 days. 10 gals of gas a day for generator.


Shows the expense for those in the affected area. At 3.50 per gallon that's 35.00 per day just for the generator. There are a lot of people out there who don't have that kind of extra cash.
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1395. PTXer
That Topsail Pier cam is indeed amazing.....
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1394. Dennis8
Quoting muddertracker:
So...who has been on the blog the most over the past 24 hours? I've been on for about 14 of the past 24...but I'm sure some of you have done much better...


HMMMMMMMMMMMMMMMM..since I also do drug and alcohol counseling I will plead the 5th on that.
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Watch live streaming video from cbsnews at livestream.com
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Now this is a little better...dropsonde ENE of the eye finds 90 mph surface winds and 120 mph winds at just below 3,000 feet.
Member Since: September 24, 2005 Posts: 33 Comments: 9265
Quoting NJcat3cane:


very strong words...ill be fine i think..im with three other storm fanatics

Where y'at, Jersey? What part? Worried about Asbury Park...
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Quoting FLWaterFront:
I honestly would not be saying, "loving it" right now, if I were in Virginia Beach.

This is an oddball storm. Nothing about it to this point has been textbook. And that means the rules of thumb that define more typical storms are all but thrown out the window. The wind field is much larger than a typical hurricane. That means that even if you are 100 miles WEST of the center when it passes by, you might get much stronger winds than would be the case with a more tightly wound and more typical hurricane.

And because the circulation is so large and spread out, even west of the storm track but along the shoreline can expect to see high water in advance of the center. It will only be after the center passes north of your latitude that the water will be surging back out into the sea. I wish you the best of luck though.


Thanks :) Im just loving it in comparison to 12 hours ago when I thought a cat 3 would be over my house. We arent in a flood prone area so we should be a-ok :)
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Cantore just used the term "ground zero" when he knows that he has an unusually large NY audience...I KNOW he didn't do that on purpose...that would be tacky.
Member Since: August 16, 2007 Posts: 1 Comments: 2337
Quoting wunderweatherman123:
just saying TD 10 in the eastern atlantic downgraded to a remnant low

...DEPRESSION DISSIPATES...THIS IS THE LAST ADVISORY...
11:00 PM EDT Fri Aug 26
Location: 16.0°N 34.0°W
Max sustained: 30 mph
Moving: NNW at 7 mph
Min pressure: 1010 mb
Member Since: July 7, 2010 Posts: 0 Comments: 5630
1387. Remek
Quoting tiggeriffic:
ok press, this isn't working...how bout i email em to you and you do it...imma go nuts


Your pasted link added a space. Use the "Link" button (top of the text entry box) to post http links.
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Quoting owntime:


I was in Ike also, 290 & Tidwell. It was a bad storm even that far away from the coast. I got my power restored 3 weeks later. Thank goodness for generators and planning ahead.
45 & tidwell. Elect off for 16 days. 10 gals of gas a day for generator.
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just saying TD 10 in the eastern atlantic downgraded to a remnant low
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1384. zawxdsk
Quoting ncstorm:


Yeah..if you are talking about wrightsville beach or carolina Beach, the bridges are closed


I don't know where and they are apparently talking to someone on the other line and are going to get back to me later. Might not be so bad because of this low-tide thing.

Of course the storm will still be there tomorrow morning - although in a more favorable quadrant.
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Quoting NJcat3cane:


very strong words...ill be fine i think..im with three other storm fanatics


I still think this is a very foolish move on your part. What area of the city are you in?
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Irene is jogging west
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1381. Skyepony (Mod)
Irene strength.
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So...who has been on the blog the most over the past 24 hours? I've been on for about 14 of the past 24...but I'm sure some of you have done much better...
Member Since: August 16, 2007 Posts: 1 Comments: 2337
1379. hahaguy
Quoting Remek:


Try this one:

Link


nope
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1378. Levi32
Quoting nccanewatcher:


That picture was Canal drive at Carolina Beach. It will flood during a bad rain storm.


So why is there a house there if it floods every other day?
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The AF plane continues to find no greater than 90-95 kt flight level (700 mb) winds on the strongest side of the storm, and well removed from the center...almost 50 miles out.
Member Since: September 24, 2005 Posts: 33 Comments: 9265
Quoting VAbeachhurricanes:


true, but Im feeling alot better now that I was 6 hours ago, weakening and east of track, loving it.
I honestly would not be saying, "loving it" right now, if I were in Virginia Beach.

This is an oddball storm. Nothing about it to this point has been textbook. And that means the rules of thumb that define more typical storms are all but thrown out the window. The wind field is much larger than a typical hurricane. That means that even if you are 100 miles WEST of the center when it passes by, you might get much stronger winds than would be the case with a more tightly wound and more typical hurricane.

And because the circulation is so large and spread out, even west of the storm track but along the shoreline can expect to see high water in advance of the center. It will only be after the center passes north of your latitude that the water will be surging back out into the sea. I wish you the best of luck though.
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1375. Remek
Quoting hahaguy:


page not found


Try this one:

Link
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Quoting NoVaForecaster:


I'm thinking nothing more than TS force winds in some outer bands. Probably a lot of rain though. Widespread power outages when the trees fall, and it could be out for days. Still will be nothing compared to what NC and the NE will be getting.


Sure how it looks. I kept thinking she'd keep heading north for a longer time and we'd get hit harder. Any chance of that now or not so much?
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Frying Pan Shoals slightly lower on winds and gusts, but up to 27' waves.

Quick moment of levity; I hope you enjoy:

My two terriers just killed a skunk in the back yard. My neighbor down the road saw the lights on and called to ask if had shot one. That bad.

Hope all do well with the storm! If you are hunkered down in a small space, please think of the company I am keeping in my basement and smile a little. We can't go into the rest of the house either.

All take care!

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do any of you know where I can get some webcam of the storm conditions in NC right now? I can't seem to find any.
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Quoting AllStar17:
This is where I have the center.
yeah, that looks to be about right
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1369. Dennis8
TS conditions continue in Wilmington

10:28 PM 75.2 °F - 73.4 °F 94% 29.38 in 2.0 mi NNE 39.1 mph 55.2 mph 0.50 in Rain Rain
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ok press, this isn't working...how bout i email em to you and you do it...imma go nuts
Member Since: September 16, 2007 Posts: 0 Comments: 3650
Quoting Neapolitan:
For those who are oohing and aahing over the massive waves at the Topsail Pier, consider this: from tomorrow evening through Sunday night, similar waves will be atop a storm surge and battering billions of dollars in beachfront property from Maryland to Providence.

By way of comparison, here are a few links:

Topsail Beach

Seaside Heights, NJ
You really want a wake up call:

Type in Seaside Heights, NJ in wU search box.
Click on wUnder map on radar.
Zoom in till you begin to identify streets and features on the map.
Choose Hurricane on menu to right.
Uncheck all features.
Toggle Max Storm Surge a time or two.

Works for anywhere at risk right now.

Try it, You might not like it.
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Cantore v. Norcross...round 3...ding ding
Member Since: August 16, 2007 Posts: 1 Comments: 2337
1365. Patrick
Gusts up to 46 for past 2hours just south of New Bern, NC.
Link
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1364. Walnut
Quoting Levi32:
Some semblance of an eye is showing up on IR, but the eyewall remains weak.

Nice looking S on this cane now. This one has been weird with the eye blinking though...
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1363. Patrap
unenhanched IR




Member Since: July 3, 2005 Posts: 421 Comments: 127631
Quoting NoVaForecaster:


Link

Link


Uh-Oh... Definite eye forming! NOT GOOD!!
she's hitting the gulf stream
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A nice view of the mid latitude system moving over southern Canada right now that will begin to influence Irene in around 12 to 24 hours. Her western side will start to interact with the trough and will be enhanced by some baroclinic energy. This is when she will turn a slight bit more to the E and move over the entire mid Atlantic and northeastern coasts.
Member Since: September 24, 2005 Posts: 33 Comments: 9265
1359. Levi32
Quoting Ryuujin:
Levi et all,

Is it just me or is the storm surge really bad already for NC with Irene still how many hours out from landfall?


Based on the pictures posted here, it looks like it. The storm is very large and big waves and surges of water are propagating out pretty far ahead of the center of the storm.
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http://www.ssd.noaa.gov/goes/flt/t2/flash-wv.html
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1357. Levi32
Some semblance of an eye is showing up on IR, but the eyewall remains weak.

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Irene is now hitting the gulf stream, it looks like it might intensify slightly at it approaches the outter banks. She seems to be trying to fight off dry air, and an better defined eye is present. With a Pressure 950, i would expect to see winds sustained at least 115 mph, i'm frankly a little surprised that the HH has not found stronger winds.
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1355. Ryuujin
Levi et all,

Is it just me or is the storm surge really bad already for NC with Irene still how many hours out from landfall?
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Quoting Methurricanes:
its low tide right now?


Low tide around midnight!
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00z NAM takes Irene directly over NYC.
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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.