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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1952. KEEPEROFTHEGATE (Mod)
Member Since: Posts: Comments:
Quoting Levi32:


I believe we have a regular GOES blackout at this time of night for a couple hours.
A couple of hours, that is unfortunate
Member Since: Posts: Comments:
Quoting WthrBearSF:
It's absolutely disheartening to see people complaining about a storm that's turned into "nothing", or speak about things being overhyped, or wasting time and money preparing for a fizzle.

Over the last several years, hundreds of thousands of human beings have been washed out into the ocean by tsunamis because they weren't fortunate enough to have enough advanced notice to prepare, or technology that could give them several days to get to safety, or even a moment to speak with their loved ones before their lives ended.

Whether Irene is the monster that was predicted is beside the point of all of this. We, as citizens of the United States, have the fantastic fortune to have satellites, and bouys, emergency responders, and hurricane experts working in unison to prevent such horrific tragedies from happening!

Donate your supplies to a charity, save them for the future and consider yourself prepared, or use them up. Take a moment to reflect on how fortunate you are to even be able to complain at this moment in time because you have electricity, and a computer, and you haven't been washed away by a monster.

Let's get back to keeping people safe and stop wasting blog space with complaint and one-upmanship.
Quoting WthrBearSF:
It's absolutely disheartening to see people complaining about a storm that's turned into "nothing", or speak about things being overhyped, or wasting time and money preparing for a fizzle.

Over the last several years, hundreds of thousands of human beings have been washed out into the ocean by tsunamis because they weren't fortunate enough to have enough advanced notice to prepare, or technology that could give them several days to get to safety, or even a moment to speak with their loved ones before their lives ended.

Whether Irene is the monster that was predicted is beside the point of all of this. We, as citizens of the United States, have the fantastic fortune to have satellites, and bouys, emergency responders, and hurricane experts working in unison to prevent such horrific tragedies from happening!

Donate your supplies to a charity, save them for the future and consider yourself prepared, or use them up. Take a moment to reflect on how fortunate you are to even be able to complain at this moment in time because you have electricity, and a computer, and you haven't been washed away by a monster.

Let's get back to keeping people safe and stop wasting blog space with complaint and one-upmanship.


Fantastic post and message!!!!!! Words and actions to live by!!! Mel
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1949. KEEPEROFTHEGATE (Mod)
09L/H/I/C2
RI FLAG (off)
RD FLAG (OFF)
WEAKENING FLAG (OFF)
MARK
36.00n/76.98w forecast point





ALWAYS FOLLOW NHC/TPC FORECASTS FOR ALL WARNINGS REGARDING THIS STORM
Member Since: Posts: Comments:
1948. Levi32
Quoting ShenValleyFlyFish:
Carefull with those links guys. Character is a hoot but perma banned for cause.
Quoting Orcasystems:


He is a guy who was permanently banned from WU by Dr Masters... but some people like to rub Jeff's face in it by intentionally posting information about it.


I apologize...just thought a live look at Irene was worth seeing. That was my only intention.
Member Since: November 24, 2005 Posts: 635 Comments: 26701
Quoting Levi32:


The movement has been NNE for several hours, towards the very outer banks if North Carolina. It will pass east of Morehead City.


Correct. It wobbled north a few hours ago but quickly resumed a NNE movement... should make landfall between Morehead City and Hatteras... probably around 8/9am.
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ok
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Quoting StormTop5000:
So who is This guy streaming live?



He is a guy who was permanently banned from WU by Dr Masters... but some people like to rub Jeff's face in it by intentionally posting information about it.
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1944. Ryuujin
Quoting Levi32:
There is nothing like listening to that weather radio voice listing off the current information on the hurricane when it is blowing on top of you.


Did you hear the offshore wave heights? 22 feet every 15 seconds? That's crazy. That's just nuts sort of surge coming towards the coast.
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1943. Levi32
Quoting drg0dOwnCountry:
GOES is black?


I believe we have a regular GOES blackout at this time of night for a couple hours.
Member Since: November 24, 2005 Posts: 635 Comments: 26701
1942. docrod
Ok - out till the 5AM ... my "wishcast" is that this apparent NE move continues and Irene slips to the east of Hatteras and also that folk in the NE don't become complacence if it misses.

g'nite
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GOES is black?
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So who is This guy streaming live?

http://www.ustream.tv/channel/live-severe-weather -webcam
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Quoting atmosweather:


The strech of coastline from Wilmington E-ward to the OBX is just going to get ripped by unbelievable rainfall through tomorrow afternoon. We're going to see some totals in excess of 15 inches in NC by the end of the day on Saturday.


Irene is moving so slow........this is really gonna bring down trees like crazy. Power is gonna be out off for hours if not days!
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Quoting Levi32:


Carefull with those links guys. Character is a hoot but perma banned for cause.
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1937. IMA
Updated NHC cone shows Irene still expected to hit NY as a hurricane NHC Cone of UNcertainty
*edit to include the word "still"
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1936. Levi32
There is nothing like listening to that weather radio voice listing off the current information on the hurricane when it is blowing on top of you.
Member Since: November 24, 2005 Posts: 635 Comments: 26701
Quoting TampaSpin:


The strech of coastline from Wilmington E-ward to the OBX is just going to get ripped by unbelievable rainfall through tomorrow afternoon. We're going to see some totals in excess of 15 inches in NC by the end of the day on Saturday.
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Quoting Levi32:


Um...that was him blowing on it to cool it off. LOL
Oh ok haha, I thought for a second there he went outside. I wonder how come his camera overheats?
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I don't know what it is about hurricanes....seems they always want to make land fall at night...
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1932. MahFL
35 K out of power in SC, from progress Energy.
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Quoting Levi32:


Um...that was him blowing on it to cool it off. LOL



LOL LOL LOL
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I got both of those feeds OZ is talking about already on the site for you all
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1929. docrod
Quoting TexasHurricane:


looks to be going more east?


Am seeing about 35 degrees over the past 4 hours or so ...
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Best tell OZ to get that camera fixed, he's got about 20-30 minutes and a serious band is going to come through.

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Quoting Levi32:


looks to be going more east?
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Tornado Watch #809 and #810 in NC/VA both got HIGH CHANCE of Tornadoes, but LOW CHANCE of EF2+ tornadoes. There will be MANY tornadoes ranging from EF-0 to EF-2 overnight into tomorrow (can't rule out EF-3 to EF-5, but they are VERY RARE in hurricanes)
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1924. 7544
he fixed the camarea great show going on there nowthanks for the link
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1923. Levi32
Quoting GTcooliebai:
Wow! when OZ takes that camera down you can really hear how that wind is howling!


Um...that was him blowing on it to cool it off. LOL
Member Since: November 24, 2005 Posts: 635 Comments: 26701
1922. njdevil
So now it's moving almost full NE. This storm is a real pain in the ass. Commit to SOMETHING. lol
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Wow! when OZ takes that camera down you can really hear how that wind is howling!
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1920. Levi32
Quoting docrod:


I would not call that north as some have suggested.


The movement has been NNE for several hours, towards the very outer banks if North Carolina. It will pass east of Morehead City.
Member Since: November 24, 2005 Posts: 635 Comments: 26701
Just starting to rain here in ORF... looks like we'll be 'enjoying' quite the weekend. Winds are fairly minimal... think that'll change once we get closer to daybreak.
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1917. docrod
Quoting Levi32:


I would not call that north as some have suggested.
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Quoting GTcooliebai:
That OZ is a funny guy, I think it is very cool we can get live feed at this time in the morning, been watching him since 7 o'clock. By the way I bookmarked your website very cool images, well organized...



Thanks,,,,,,i just had Roger Edwards from the Storm Prediction Center on the site.....he is very frightened as to the very bad chance for Tornados....NOW in North Carolina.
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1914. cwf1069
Quoting TampaSpin:



Go to my blog......the link is there
Ok, Thank you
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1913. Levi32
Member Since: November 24, 2005 Posts: 635 Comments: 26701
1912. whitewabit (Mod)
Sat Page
Member Since: Posts: Comments:
Quoting Beachfoxx:
I keep telling you to leave your umbrella at home & to wash & wax your car -- guaranteed to rain soon afterward!


Been doing that all summer, not working, even tried the rain dance, complete failure.
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Quoting TampaSpin:
RogerEdwardsSpc: Mhx now shows large looping hodographs and the area Profilers are detecting 50 - 60 1km wind fields


RogerEdwardsSpc: People in the area sleep with a weather radio as the tornado risk is huge.
That OZ is a funny guy, I think it is very cool we can get live feed at this time in the morning, been watching him since 7 o'clock. By the way I bookmarked your website very cool images, well organized...
Member Since: Posts: Comments:
Quoting WthrBearSF:
It's absolutely disheartening to see people complaining about a storm that's turned into "nothing", or speak about things being overhyped, or wasting time and money preparing for a fizzle.

Over the last several years, hundreds of thousands of human beings have been washed out into the ocean by tsunamis because they weren't fortunate enough to have enough advanced notice to prepare, or technology that could give them several days to get to safety, or even a moment to speak with their loved ones before their lives ended.

Whether Irene is the monster that was predicted is beside the point of all of this. We, as citizens of the United States, have the fantastic fortune to have satellites, and bouys, emergency responders, and hurricane experts working in unison to prevent such horrific tragedies from happening!

Donate your supplies to a charity, save them for the future and consider yourself prepared, or use them up. Take a moment to reflect on how fortunate you are to even be able to complain at this moment in time because you have electricity, and a computer, and you haven't been washed away by a monster.

Let's get back to keeping people safe and stop wasting blog space with complaint and one-upmanship.


Post of the night by far, bravo.
Member Since: October 16, 2008 Posts: 0 Comments: 544
1905. JGreco
Quoting MississippiWx:
186...Jose deepens and begins to feel a weakness to the north. Anyway, pretty far out now...but the GFS is showing the potential for the Atlantic to explode.



Wonder if the later Jose deepens, the more likely it could get into the Caribbean.
Member Since: Posts: Comments:
Quoting floodzonenc:


Will be interesting to see next week's drought map for NC :)
this storm might had gotten us back down to D0 or D1 level drought from D2/D3... Most of NC coast is under D3/D4 right now and it's a relief for MOST of NC except for the coastal area which is getting tornadoes and surge added to the mix.
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Latest NOAA Hurricane page satellite pics for Irene are all black with 00 00 00 date - AL10 pics are o.k.

What's up??

Dave
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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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