Hurricane Irene Prepares to Leave the Bahamas and Head for the US

By: Dr. Jeff Masters , 7:51 AM GMT on August 25, 2011

Share this Blog
17
+

As of 2AM EDT, Hurricane Irene was located at 24.2N, 76.0W, 105 miles east-southeast of Nassau or 760 miles south of Cape Hatteras. It was moving northwest at 12 mph with maximum sustained winds of 115 mph, making it a Category 3 storm on the Saffir-Simpson scale. Irene has a minimum central pressure of 950 mb. Hurricane force winds can be found up to 70 miles from Irene's center, and tropical storm force winds can be found out to 255 miles from the storm's center.

Hurricane warnings are in effect for all of the Bahamas. Hurricane and tropical storm watches will likely be posted for the Carolina coastlines later this morning. At this time, Dare County Emergency Management has issued a mandatory evacuation order for all visitors in their county. Dare County Schools will also be closed Thursday and Friday.

Satellite Views
Figure 1 is the infrared satellite image of Irene at 135EDT. The convection is a bit unbalanced around the storm center, which is going to cause Irene to wobble like an unbalanced clothes washer (Analogy courtesy of Angela Fritz) over the next few hours. At the time this image was taken, the convection around Irene's center appears to be getting more vigorous, as cold cloudtops are starting to increase around the storm center. This is important to note because microwave satellite imagery from Wednesday evening suggested Irene was starting an eyewall replacement cycle. Figure 2 shows passive microwave imagery from a Air Force DMSP polar-orbiting satellite. The two concentric green/yellow bands in the image suggest that two eyewall features are present in Irene, and Hurricane Hunter observations confirm this. This has important consequences for Irene's intensity, because in an eyewall replacement cycle, as the inner eyewall weakens, the storm's intensity drops. However, once the inner eyewall is gone, and the outer eyewall contracts to replace it, the storm intensity will increase again.


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


Figure 2 DMSP F18 microwave overpass of Irene at 824PM EDT, August 24, 2011. Image courtesy of the Naval Research Laboratory

Track Forecast

Irene is forecast to move to the northwest, passing over the northwest Bahamas by Thursday evening, then curving to the northeast. 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. Sunday, Irene may make secondary landfall anywhere from New Jersey to Long Island and the southern New England coastline. In my opinion, New York City may be significantly impacted by Irene. 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 Category 4 storm (winds faster than 130 mph) by Thursday morning. As Irene moves northward into cooler water, the intensity is expected to drop slowly to a Category 2 storm before making landfall in the Outer Banks.


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

Forecast models and today's planned flights
The different forecast models are still in fairly good agreement about Irene's track through the Bahamas and along the east coast of the US. The 00Z GFS run is in close agreement with the 12Z ECMWF run, but the 00Z ECMWF run (shown in figure 4) is continuing the ECMWF's trend of shifting the track westward with each run. NHC forecasters have been placing emphasis on the ECMWF's forecast track when making their forecasts for IRene, so it is possible that the NHC track will shift westwards at the 5AM update.

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 (Gonzo), and two flights for NOAA 42, a WP-3D (Kermit). They may have to give NOAA a littering permit for all of the dropsondes used to monitor Irene and her environment, but the forecast improvements they generate are worth the effort.


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

Impacts

Hurricane force winds will arrive in the northwestern Bahamas today. Storm surge near the center of Irene will be 7-11 feet above tide level. The Bahamas can expect 6-12 inches of rain over the next day or so, and it looks like the Turks and Caicos islands will receive a total of 6-12 inches from Irene. Large, swells from Irene will start landing on the southeastern US coastline later today. Please don't go in the water, as these swells can cause dangerous rip currents. Dr. Masters has catalogued the worst-case storm surge surge scenarios as a function of storm intensity here.

In my opinion, people living from the Carolinas to Cape Cod should pay close attention to Irene and prepare for a wide range of impacts. I think that there is a 75% chance of Irene's secondary landfall will be somewhere between JFK airport and Cape Cod. That said, Irene's size will cause significant impacts for people living far from it's center.

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

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: 746 - 696

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22Blog Index

Quoting surfsidesindy:


Darn.. no birds here and cat's been acting crazy all morning..must be heading our way...
fire ants are going crazy now birds are in orlando with all the loonies
Member Since: September 11, 2010 Posts: 0 Comments: 4018
743. ackee
IRENE movement seem a bit west to me not a westcaster I am in the carrb K that how it look not sure thow
Member Since: Posts: Comments:
Quoting southbeachdude:
The first outer band of Irene is reaching SE Florida. The problem with not issuing any type of tropical storm watch is that trash cans are already flying around the neighborhood. Many did no preparation since we are not in the cone.


Sometimes you have to use common sense and take precautionary measures, like securing garbage cans, etc.

You can't wait for the experts to tell you to do these things.
Member Since: Posts: Comments:
Quoting surfsidesindy:


Darn.. no birds here and cat's been acting crazy all morning..must be heading our way...


All the birds disappeared before Katrina, too. And Gustav. And every other one I've been through.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting Speeky:
Has anyone here been through a cat 2 hurricane? I live in New York City and I am a little afraid of the possiblity hurricane Cat 1+ hitting here.


I've been through a CAT 4 Andrew and CAT 3 Wilma. Lets just say they were not fun. Living without electricity for 2 weeks SUCKS!
Member Since: Posts: Comments:
Honestly why aren't Tropical Storm warnings out for the Florida coastline??? The advisory states Tropical Storm Force winds extend 255 miles from the center and Irene is passing at less than 200 miles from the Florida coast. It's also possible they could see tornadoes from Irene and coastal flooding. Very strange.
Member Since: Posts: Comments:
Quoting DFWjc:


Cat 3 here, and no it wasn't fun...no electricity for 3 days and 10 inches of standing water in our downstairs condo. I was 7 at the time and all we could do is stay upstairs and wait for the water to slow go away...


No power is the biggy. 8 days with Frances and 10 days with Jeanne. You simply can't imagine how much power affects your daily life until you don't have it!
Member Since: Posts: Comments:
CNN reports 27 Navy ships moving out of port in Virginia - happening now. This should "speak" to all of you up in Mid Atlantic...
Member Since: Posts: Comments:
Quoting NCSaint:


With all of the latest models shifting to between Jacksonville and Morehead City, I can't imagine them not including Wilmington in the watch area at 11am either


which model is pointing at Jacksonville?
Member Since: Posts: Comments:
734. Vero1
Quoting surfsidesindy:


Darn.. no birds here and cat's been acting crazy all morning..must be heading our way...

The "tree rats" are acting squirrelly.
Member Since: July 21, 2008 Posts: 4 Comments: 2233
What a HORRIBLE FORECAST TRACK now for the EAST COAST.......don't know of a worse track a storm could move to do MAXIMUM DAMAGE. This is really gonna be bad for Thousands if not Millions of people..... :((
Member Since: Posts: Comments:
Any body have a link to the best current radar?
Member Since: Posts: Comments:
large boats are leaving norfolk aircraft carrier is currently moving out
Member Since: September 11, 2010 Posts: 0 Comments: 4018
Quoting drews5150:
Hang10z, yes, your mom needs to stay where she is at in FL and your bro needs to go to get any high value items from your mom's house. By the sounds of it, her house sounds like it is in a evac/flood area. He needs to do that today as not to get caught in any evac traffic.


Quoting hang10z:
I have a serious question....

Currently my mother is in FL visiting. She lives on Long Beach Island in NJ, second house from the ocean. She is considering staying down here since her flight leaves friday night from Fort Lauderdale to Atlantic City Airport. Landing a little before midnight SAT. My brother lives outside of Philly but on the Jersey side of the river (Cherry Hill Area)

Should I have my brother head over to LBI, grab her car, get anything of value and bring it to his house 70 miles of so west of the coast? I figure if this thing hits NJ straight on LBI will be underwater.


He doesn't think its going to be that bad.. then again he doesn't really read this blog and watch model runs.. just listens to whatever the radio or TWC is saying.

He went to bed thinking a little rain and wind.. now it looks otherwise...


Thanks for your help..


In my opinion, yes. Yes you should. Keep your Mom with you - reschedule her flight. Have your brother go secure things at her house. Get everything of value off the floor - get everything out of the fridge, lift everything as high as he can, do the needful with the utilities, etc. Board the windows if he can. All that. Keep her out of harm's way. There's no sense in having her be uncomfortable or in danger. My teenaged son left NJ/NY area yesterday - a week before he planned to, because he said nobody would listen to him about the preparations they needed to take - they all took it way too lightly. We're from NOLA, and he felt like, hey - if you guys can't take MY word for it, I can't help you. Good luck. Peace out.
If you can't get her to stay, at least make arrangements for her as far away from her coastal home as possible. It's a death trap.
Member Since: Posts: Comments:

Quoting OSHNBLU:
Good thing I trust the NHC and my Local Emergency Offices, otherwise that radar would scare the heck out of me.

God gave us (some more than others) brains and also those little hairs on the back of our necks (some more than others). If you choose to put your 'faith' in the NHC -or any gov't agency for that matter... well... uh.... I guess your like most folks these days and I will help you out as much as I can while you're waiting for FEMA to show up and clean up the mess that was your home...
Member Since: Posts: Comments:
Quoting surfsidesindy:


Darn.. no birds here and cat's been acting crazy all morning..must be heading our way...


Well, the Native American's watched the animals. Sometimes they have more sense than we do!!! LOL
Member Since: Posts: Comments:
Quoting wxobsvps:
12Z sounding from Bermuda has 594dm ht at the 500mb lvl. Atlantic ridge holding strong right now.


Bah. Not a very large gap for Irene to shoot through... Looking more and more likely she gives the north coast of SC a very close shave.
Member Since: Posts: Comments:
Quoting cat5hurricane:

I anticipate Wilmington will be put under a hurricane watch by the NHC for the next advisory at 11am EDT. However, if that is the case, that doesn't necessarily mean they would be expecting a direct landfall there. It could just be for the likelihood of experiencing sustained hurricane force winds.


With all of the latest models shifting to between Jacksonville and Morehead City, I can't imagine them not including Wilmington in the watch area at 11am either
Member Since: Posts: Comments:
Quoting presslord:


yes...and you should be...
Yes...several...be prepared, and watch local information as it is posted on tv, and radio. Oh and follow this blog!!
Member Since: Posts: Comments:
723. DFWjc
Quoting Speeky:
Has anyone here been through a cat 2 hurricane? I live in New York City and I am a little afraid of the possiblity hurricane Cat 1 hitting here.


Cat 3 here, and no it wasn't fun...no electricity for 3 days and 10 inches of standing water in our downstairs condo. I was 7 at the time and all we could do is stay upstairs and wait for the water to slowly go away...
Member Since: Posts: Comments:
Quoting Speeky:
Has anyone here been through a cat 2 hurricane? I live in New York City and I am a little afraid of the possiblity hurricane Cat 1+ hitting here.


Yes, and you should take it seriously. It is no picnic.
Member Since: Posts: Comments:
Fresh Japanese model:

Member Since: Posts: Comments:
Hello friends. Klaatu from Cape Cod. Just checking in. Irene's track so far is eerily similar to Hurricane Bob which hit here in 1991. Has there been any comparisons? I wonder if I could get the coordinates that Bob took and superimpose them on what Irene is doing, but perhaps that is already available somewhere else? Anyone?

Let me know. In the meantime, already have water, batteries, and prayer book.
Member Since: Posts: Comments:
Quoting cat5hurricane:

I anticipate Wilmington will be put under a hurricane watch by the NHC for the next advisory at 11am EDT. However, if that is the case, that doesn't necessarily mean they would be expecting a direct landfall there. It could just be for the likelihood of experiencing sustained hurricane force winds.


Thanks. Thats all I am wondering really. I dont expect the center to pass directly over us, but even another slight shift west and I agree with you we'd be seeing some hurricane force winds. Big difference between that and the currently predicted 40-50 mph winds. Guess I'll wait for this stupid turn a few more hours before I decide how to prepare
Member Since: August 4, 2011 Posts: 0 Comments: 631
Jacksonville is getting pounded...ahhhh....oooops nope sorry, just a little cloudy at the moment :)
Member Since: Posts: Comments:
Quoting Landfall2004:


Yeah, Stuart got a really nice gust and now I have 60-80 palm fronds in my yard (not exaggerating!) Have not clue why I went out to start cleaning them up! 10 avacadoes down--tree rats beat me to 5 of them! But the Cardinals are happy around the bird feeder b/c the yard cats won't come out in this weather.

Moral of this story--the birds are here, so Irene is NOT coming!


Darn.. no birds here and cat's been acting crazy all morning..must be heading our way...
Member Since: Posts: Comments:
Member Since: Posts: Comments:
We're 4 hours into an outgoing tide and the marshes around St. Augustine are still completely full. The next few tide cycles are going to be rather interesting to watch. I'm might drop a few hoop nets to see if the blues are feeding or if they went deep. Anyone who has a moored boat in the area might consider loosening some ropes or moving it out to a buoy.
Member Since: Posts: Comments:
Quoting Speeky:
Has anyone here been through a cat 2 hurricane? I live in New York City and I am a little afraid of the possiblity hurricane Cat 1+ hitting here.


yes...and you should be...
Member Since: Posts: Comments:
Eye about to pop up again...I think.
Member Since: August 11, 2010 Posts: 0 Comments: 768
Has anyone here been through a cat 2 hurricane? I live in New York City and I am a little afraid of the possiblity hurricane Cat 1+ hitting here.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
709. Jax82
NEFL first rainband from Irene!!! lol

Member Since: September 2, 2008 Posts: 1 Comments: 1261
Squall lines moving in farther west... maybe more than expected? Nasty here is in Weston which is 20-25 miles inland from coast.....

Link
Member Since: Posts: Comments:
got some cloths hanging on the line sunny here mer isl fl.
Member Since: September 11, 2010 Posts: 0 Comments: 4018
Quoting Abacosurf:
The sad part about that statement is the fact that people need to be told by their govt. what to do.

What happened to personal responsibility??


Hey George there's a storm headed this way.
No common sense either...very sad...
Member Since: Posts: Comments:
Quoting weathers4me:
A co-worker in Palm Beach just said that the winds are kicking there and she may be without power soon. I feel they should have been atleast under some type of watch etc.


I don't get it either. In East Central FL there is a TS warning for the WATERS but not the land.

.WATCHES/WARNINGS...
FOR MARINE INTERESTS...A TROPICAL STORM WARNING IS IN EFFECT FOR
ALL PORTIONS OF EAST CENTRAL FLORIDA ATLANTIC WATERS.

Last time I checked my beach is next to my water here in Cape Canaveral.
Member Since: Posts: Comments:
Quoting CarolinaHurricanes87:
p451... what ARE the models doing? Can they really keep shifting left without putting Wilmington in a hurricane watch?

It is getting too close for comfort but as soon as I go spend $200 at the store it'll make "the turn" and i'll be easily on the west side of the storm and out of harms way.



Dont6 spend extra money yet. I havent. I have however secured som e loose objects in my yard. Just be responsible and listen to the local forecast.
Member Since: Posts: Comments:
Looks like Irene will skirt the eastern edge of the gulf stream to NC. Should stay at or above 28C almost until landfall.

Intensity forecasting is going to be critical for the situation up east.
Member Since: Posts: Comments:
Quoting carolinabelle:
I don't know a whole lot about meteorology other than what I've observed over the years, so this is an honest question... looking at the satellite in the link below, which shows projected path as well...

SFWMD Satellite Image

... it would seem that the path has shifted west twice in about 14 hours. I pretty much assumed that here in Charleston we were out of the woods, but does this mean that points south of the Outer Banks still have something to be concerned about or not? Or is it still too early to tell?
Even if you don't get a direct "hit" this is a big storm and it is pushing a lot of seawater in front of it. Expect wind and surge. Depending on where you are, when the storm passes and when high tide is would be a good indicator whether or not you want to get ready "just in case". Charleston is low tidal area. Do you flood with a heavy rain? In Key West, 150 miles west of Miami, we are being affected by 20 knot winds, but the seas are being pushed against the land by the wind and it is high tide right now. You will be a lot closer to the storm.
Member Since: Posts: Comments:
Has anyone here been through a cat 2 hurricane? I live in New York City and I am a little afraid of the possiblity hurricane Cat 1+ hitting here.
Member Since: Posts: Comments:
NYC had 20 inch of snow this year and now possibly a CAT 2 hurricane!
Not many places in the world can beat that me thinks!!
Member Since: Posts: Comments:
Quoting carolinabelle:


no takers? just looking for some honest opinions, thanks :)


I think, the weaker Irene becomes the farther West it will go...plus there is this role trough nonsense. Follow your local NWS WFO to stay informed.
Member Since: Posts: Comments:
Quoting weathers4me:
A co-worker in Palm Beach just said that the winds are kicking there and she may be without power soon. I feel they should have been atleast under some type of watch etc.

we should be under a watch cause we might have some 20-30 mph winds in S. FL today?
Member Since: Posts: Comments:
696. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #15
TROPICAL STORM TALAS (T1112)
21:00 PM JST August 25 2011
============================

SUBJECT: Category One Typhoon In Sea Near Ogasawara Shoto

At 12:00 PM UTC, Tropical Storm Talas (994 hPa) located near 20.1N 140.1E has 10 minute sustained winds of 40 knots with gusts of 60 knots. The cyclone is reported as moving northwest at 9 knots

Dvorak Intensity: T2.5

Gale Force Winds
=================
180 NM from the center in southeast quadrant
120 NM from the center in northwest quadrant

Forecast and Intensity
=======================

24 HRS: 22.1N 139.7E - 55 knots (CAT 2/Severe Tropical Storm)
48 HRS: 23.1N 139.7E - 70 knots (CAT 3/Strong Typhoon)
72 HRS: 25.0N 139.7E - 75 knots (CAT 3/Strong Typhoon)
Member Since: Posts: Comments:

Viewing: 746 - 696

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22Blog Index

Top of Page

About JeffMasters

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.