Irene continues to weaken

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

Share this Blog
25
+

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

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: 1052 - 1002

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 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44Blog Index

Holy moley! That Topsail pier is getting creamed!
Member Since: Posts: Comments:
Quoting Tazmanian:



you need a laptop
and a battery operated router...
Member Since: August 28, 2005 Posts: 0 Comments: 153
1050. ncstorm
Carolina Beach

Member Since: Posts: Comments:
1049. Walnut
Quoting Levi32:


It entirely depends on where you are. If the eye happens to pass just west of a certain location, it won't get the kind of storm surge that will occur east of the eye. We could play with the track in terms of a couple dozen miles, but overall impacts in the northeast U.S. are going to be about the same.
With the central pressure being so low, that is gonna be a lot of water that has to go somewhere. The jutting coast along LI and MA is going to be inundated unless she gets pushed east more - but doesn't look like those folks are going to be that lucky.
Member Since: Posts: Comments:
Quoting animalrsq:
NYC evacuation shelters will be pet-friendly. Please don't leave them behind. And this is a major step forward! Kudos to NYC! See our site for more info.

http://www.aspca.org/Blog/08-26-11-1-aspca-pet-pa rents-prepare-for-hurricane-irene.aspx


That is major progress for taking care of the entire family, including the furry ones! Kudos to New York for taking that step!
Member Since: Posts: Comments:
Quoting aislinnpaps:
Most in NYC do not have cars to evacuate in. Too expensive and hard to find parking. They use public transporation. I don't think they could evacuate NYC.
They are shutting down the MTA at 12:00pm tommorrow.
Member Since: August 1, 2011 Posts: 0 Comments: 679
Quoting TropicalAnalystwx13:
Sorry I was gone - lost power literally. Its back on now.



you need a laptop
Member Since: Posts: Comments:
Quoting CybrTeddy:
One thing is for certain, Irene is one hell of a lot worse than her predecessor Irenes have been. She really wants to get retired after being in use for 30 years.




any ch that Irene geting retired ?
Member Since: Posts: Comments:
Quoting victoriahurricane:
Hey Levi or atmos I heard on the TWC that this year the storm surge values given are what is expected on top of the land, is this true? a 3 foot surge wouldn't be pretty then.


I had not heard of that change...I always thought storm surge was the water rise in excess of the current sea level. If that is true, then yes, that kind of a storm surge would be significant throughout much of the mid Atlantic and Northeast. But I'll check on that for you.
Member Since: September 24, 2005 Posts: 33 Comments: 9265
Quoting TropicalAnalystwx13:
Sorry I was gone - lost power literally. Its back on now.


Glad you're back!
Member Since: Posts: Comments:
Most in NYC do not have cars to evacuate in. Too expensive and hard to find parking. They use public transporation. I don't think they could evacuate NYC.
Member Since: August 22, 2009 Posts: 0 Comments: 3115
Quoting TropicalAnalystwx13:
Our yard has major problems...


ahhh, no vague-posting! What kind of problems? Are you OK?
Member Since: Posts: Comments:
1039. Remek
Quoting CosmicEvents:
Yes it is.
That's one wide girl.
This cyclone's gonna' cancel the opening of the US tennis OPEN, with Serena Williams.


I haven't heard about that NFL game (JETS?)
Did that get canceled finally?
Member Since: August 29, 2005 Posts: 0 Comments: 118
Hey guys, I'm in ILM and somehow i still have power. probably won't after that next band though.
Member Since: Posts: Comments:
1037. jdjnola
Quoting P451:
12hr wv imagery loop



That's a big girl.


For the first time in her life really she seems to be building a solid band of convection to her SW. I guess that SWerly shear is dropping... she might still have time to build/maintain an eye if she stays East enough on the OBX.
Member Since: August 4, 2008 Posts: 0 Comments: 238
Sorry I was gone - lost power literally. Its back on now.
Member Since: July 6, 2010 Posts: 113 Comments: 31462
Quoting summerland:

I have an acquaintance who lives in midtown on the 18th floor of her building. She insisted she would be fine! If the windows break, she can go stand in the hallway! I just. God. There was NO getting through to her about winds, the basement flooding, living days without power or water, nothing. Just the thought of being on the 18th floor in a swaying tower makes me seasick! I have no idea what she's going to do. I'm hoping she decides on a quick trip upstate.
Midtown will be fine. Lived in Lower East Side for 3 yrs. Pull up the reliable storm surge predictions. She would face statistically higher hazard traveling. IMHO

If you aren't in an evacuation ordered area, sit tight, don't clog up the roads. You may decide to leave afterwords Midtown will be fine. Lived in Lower East Side for 3 yrs. Pull up the reliable storm surge predictions. She would face statistically higher hazard traveling. IMHO

If you aren't in an evacuation ordered area, sit tight, don't clog up the roads. You may decide to leave afterwords due to power outage or other conditions but you will be alive to do so. Conversely if you are in an evacuation area, get the #3!! out! You can't protect your stuff from mother nature in any case and looters wouldn't stay away if you are dead.
Member Since: Posts: Comments:
1034. Dennis8
Wrightsville Beach

21:20 75.0 °F -32.1 °F 28.91in NNW 47.0mph 65.0mph 1% 0.88in
Member Since: August 15, 2008 Posts: 0 Comments: 446
1033. Levi32
Quoting victoriahurricane:
Hey Levi or atmos I heard on the TWC that this year the storm surge values given are what is expected on top of the land, is this true? a 3 foot surge wouldn't be pretty then.


I saw Brian Norcross say that. I could be uninformed about all of the new NHC updates, but I haven't heard of that one. A quick google search didn't really give me anything. I can neither confirm nor deny that.
Member Since: November 24, 2005 Posts: 635 Comments: 26547
Within the last 5 minutes the rain and wind have really kicked up. Crossing my fingers that the power stays on.
Member Since: Posts: Comments:
1031. 900MB
Quoting NoVaForecaster:
Who has the DOOM:CON chart and what is the current level?
TY!


just upticked!
Member Since: Posts: Comments:
Quoting P451:
12hr wv imagery loop



That's a big girl.
Yes it is.
That's one wide girl.
This cyclone's gonna' cancel the opening of the US tennis OPEN, with Serena Williams.
Member Since: August 3, 2005 Posts: 10 Comments: 5527
Quoting padirescu:


As for where the 5 million people should go? Well I'm sure we would all agree that 5 million people evacuating to safe locations (shelters, friends, family, co-workers) is much better then hundreds or thousands of deaths from emergency situations in high rises that first responders simply couldn't reach due to flooding.
But, what about the hundreds or thousands of deaths caused by 5 million people all trying to evacuate in a single day?
Member Since: August 22, 2007 Posts: 0 Comments: 376
1028. 900MB
Quoting NoVaForecaster:
Latest Dvorak showing increased organization with banding showing up, and hot towers appearing at the center.



View full animation: Link

Definitely looks like a restrengthening system IMO.


Best looking Dvorak since the wee hours of the morning. This storm has been improving for past 3 hours. Wonder when/if this translates to higher wind speeds?
Member Since: Posts: Comments:
Irene interacting with warmer waters once again. Even barring any hurricane landfalls on the US, the sheer size of this storm will mean significant surge and dangeous inland flooding.
Member Since: Posts: Comments:
1025. Levi32
Quoting Walnut:
Agree - looks like the OBX is going to take the brunt. Not sure what that means for further up the coast though. Better? Worse?


It entirely depends on where you are. If the eye happens to pass just west of a certain location, it won't get the kind of storm surge that will occur east of the eye. We could play with the track in terms of a couple dozen miles, but overall impacts in the northeast U.S. are going to be about the same.
Member Since: November 24, 2005 Posts: 635 Comments: 26547
Irene is getting a tad stronger it seems.
Member Since: Posts: Comments:
Here on the water on the Raritan Bay in NJ, a few more things to more out of the garage, then we are ready for the water...
Member Since: Posts: Comments:
Reposting due to blog rotation shortly after my post and the need for people in high rises in zone A to know what their Mayor said regarding whether they are safe in a high rise.

Quoting 996tt:


Nope the dude talking right now said unsafe, flying stuff, debris and etc. He was diagraming venturi effect, but he did not call it as such. Justified. Seriously, if you are going to say something like this a day before, you need to have a solution. Where does he expect 5 million people to go to. If stretch it to make a problem of this magnitude, need to offer a solution.


Well considering you referenced him as "dude" I couldn't pinpoint who you were actually referring to. However, at 7:50 EST this evening, Mayor Boomberg was televised on TWC stating exactly what I referenced above.

In response to a question from a reporter saying a lot of people in high rises in Battery Park have a false sense of security saying their safe on the upper levels, what would you say to them?

Michael Bloomberg - "The trouble is that the basements get flooded and a lot of the mechanical equipment and power equipment is in the basement. And if you had to get in or out or if we had to get emergency service people there, an ambulance, a doctor, a firefighter or policeman, we probably couldn't do it. So yes, I'm sure you would be fine if you stayed in the upper floors of the building, but it's just not safe to be in a building where in an emergency you can't get help."

Gotta love DVR's sometimes. :-)

In all seriousness, if you're in zone A and live in a high rise, regardless what floor you live on, please heed the evacuation order. As for where the 5 million people should go? Well I'm sure we would all agree that 5 million people evacuating to safe locations (shelters, friends, family, co-workers) is much better then hundreds or thousands of deaths from emergency situations in high rises that first responders simply couldn't reach due to flooding.
Member Since: Posts: Comments:
Quoting chicagowatcher:

webcam from topsail island is really impressive.

cam


That's a sturdy pier, so far...
Member Since: September 23, 2008 Posts: 0 Comments: 22
One thing is for certain, Irene is one hell of a lot worse than her predecessor Irenes have been. She really wants to get retired after being in use for 30 years.
Member Since: July 8, 2005 Posts: 259 Comments: 23571
Hey Levi or atmos I heard on the TWC that this year the storm surge values given are what is expected on top of the land, is this true? a 3 foot surge wouldn't be pretty then.
Member Since: Posts: Comments:
000
WFUS52 KMHX 270109
TORMHX
NCC013-095-137-270145-
/O.NEW.KMHX.TO.W.0039.110827T0109Z-110827T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
909 PM EDT FRI AUG 26 2011

THE NATIONAL WEATHER SERVICE IN NEWPORT HAS ISSUED A

* TORNADO WARNING FOR...
MAINLAND HYDE COUNTY IN EASTERN NORTH CAROLINA
NORTHEASTERN PAMLICO COUNTY IN NORTH CAROLINA
SOUTHEASTERN BEAUFORT COUNTY IN EASTERN NORTH CAROLINA

* UNTIL 945 PM EDT

* AT 902 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
TORNADO 12 MILES SOUTHEAST OF ENGELHARD...MOVING NORTHWEST AT 40
MPH. ANOTHER POSSIBLE TORNADO WAS LOCATED JUST WEST OF SWAN
QUARTER.

* LOCATIONS IMPACTED INCLUDE...
ENGELHARD...MIDDLETOWN...
LAKE LANDING...NEBRASKA...
FAIRFIELD...
PAMLICO BEACH...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER. IF NO SHELTER IS
AVAILABLE LIE DOWN IN A LOW LYING AREA. PROTECT YOURSELF FROM FLYING
DEBRIS.

NIGHTTIME TORNADOES ARE EXTREMELY DANGEROUS AS THEY ARE DIFFICULT TO
SEE. TAKE COVER NOW. DO NOT SEEK VISUAL CONFIRMATION.

HEAVY RAINFALL MAY HIDE THIS TORNADO MAKING IT DIFFICULT TO SEE. DO
NOT WAIT TO SEE OR HEAR THE TORNADO. TAKE COVER NOW.

PLEASE REPORT SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE BY
CALLING...1...8 0 0...8 8 9...6 8 8 9 OR NOTIFY YOUR LOCAL LAW
ENFORCEMENT AGENCY.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 500 AM EDT SATURDAY MORNING
FOR EASTERN NORTH CAROLINA.

&&

LAT...LON 3536 7606 3532 7615 3536 7625 3531 7628
3539 7634 3534 7634 3518 7656 3515 7653
3516 7659 3519 7656 3535 7667 3534 7658
3538 7657 3542 7670 3553 7675 3563 7629
3560 7621 3567 7613 3554 7591
TIME...MOT...LOC 0107Z 129DEG 33KT 3541 7587

$$

8
Member Since: Posts: Comments:
NYC folks amaze me, they have no clue about wind in a tropical system. If the storm is only 70mph when it gets there they think ohhhhh, not a big deal people told ya, yeaaaaaaaaaaa, that's at the surface fool, go up hundreds of feet on up on those skyscrapers it'll be 100mph EASY. That's gonna be a lot of glass raining down, and don't even forget about the funneling affect on the city streets that are going to be stronger between bldgs than it will be on the coast.

Big time learning lesson on the way for the BIG APPLE
Member Since: Posts: Comments:
1016. scott39
Quoting Levi32:


She made the turn yesterday a little earlier than the NHC forecasted, but she is more or less following the projected track, but she's slightly east of it right now, and the short-term track may be slightly too far inland over NC right now.
Too late and too bad for NC, lets hope that she keeps trending more to the E for the rest of the NE states.
Member Since: Posts: Comments:
Did TropicalAnalystWx lose power?
Member Since: Posts: Comments:
Quoting Remek:


Thx for the link. Not sure how long that pier's going to last. It's really getting battered.


Whens the surge supposed to come in because that water is going far up almost at the camera!!!
Member Since: July 27, 2008 Posts: 0 Comments: 108
Member Since: July 7, 2010 Posts: 0 Comments: 5627
1011. Walnut
Quoting Levi32:


She made the turn yesterday a little earlier than the NHC forecasted, and she is more or less following today's projected track, but she's slightly east of it right now, and the short-term track may be slightly too far inland over NC right now.
Agree - looks like the OBX is going to take the brunt. Not sure what that means for further up the coast though. Better? Worse?
Member Since: Posts: Comments:
Quoting FLdewey:
BREAKING: Broadway cancels all weekend performances because of Hurricane Irene.

The Broadway debut of "grandpa wrestling with shutters" will have to wait till next week.
lol....Motion for immediate induction of post into blog Hall Of Farsical Fame.
Member Since: August 3, 2005 Posts: 10 Comments: 5527
Quoting muddertracker:


Have you ever heard those calls that people make to 911 when storm surge is coming in their house? The 911 operators take names and socials and wish them the best. I think everyone should have to listen to those...then maybe more people would leave. There are always some that will refuse no matter what, though. It's easy for me to say I'd leave...but I've never had to leave everything I've worked for in my life behind..that's got to be tough..but yeah..I agree..I hope your sister stays safe.


I agree 100% hi mom k8ecane
Member Since: Posts: Comments:
Quoting mojofearless:


WOW. How long do you suppose that pier is going to hold?
LOL i KNOW. I sat here staring at that for about 15 minutes just waiting for a huge swell to overtop it and knock all the lights out.

Impressive and scary.
Member Since: August 28, 2005 Posts: 0 Comments: 153
Quoting yoboi:
from a first responders point of view if you decided to stay in an EVAC zone please write your name and ss number not only on your arm but in 3 places because during katrina seemed like crabs ate alot of flesh away when we were in recovery mode it helps us out a bunch please use an sharpie or some sort of perm marker... thanks.......


I was thinking of the dog tags you can make at the PX on Post. People who stay should be required to make one with their info on it and wear it. Like the sharpie, any help in identification...
Member Since: August 22, 2009 Posts: 0 Comments: 3115
Quoting yoboi:
from a first responders point of view if you decided to stay in an EVAC zone please write your name and ss number not only on your arm but in 3 places because during katrina seemed like crabs ate alot of flesh away when we were in recovery mode it helps us out a bunch please use an sharpie or some sort of perm marker... thanks.......


That request should go out to all people in an EVAC zone. Seriously.
Member Since: Posts: Comments:
Eye on Wilmington radar, tornado warning for Hyde county, NC
Member Since: Posts: Comments:
1003. Remek
Quoting chicagowatcher:

webcam from topsail island is really impressive.

cam


Thx for the link. Not sure how long that pier's going to last. It's really getting battered.
Member Since: August 29, 2005 Posts: 0 Comments: 118
I was surfing in the same area as the young man who drowned earlier. It is a very tragic situation that could have been easily avoided. He appeared to be a novice surfer. It is devastating. People seem to always underestimate the power of the ocean. I am located less than 5 miles from the oceanfront and will provide updates as long as I can.
Member Since: Posts: Comments:

Viewing: 1052 - 1002

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 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44Blog 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.