Hurricane Irene Weakens on its Approach to North Carolina

By: Dr. Jeff Masters , 7:58 AM GMT on August 27, 2011

Share this Blog
9
+

As of 300AM EDT, Hurricane Irene was located at 33.7N, 76.5W, 60 miles south of Cape Lookout. It was moving north-northeast at 14 mph with maximum sustained winds of 90 mph, making it a Category 1 storm on the Saffir-Simpson scale. Irene has a minimum central pressure of 952 mb.

Hurricane warnings are in effect for the US Atlantic coast from the Little River inlet in North Carolina to Sagamore Beach, Massachusetts. Tornado watches are also in effect for the North Carolina/Virginia/Maryland coast. Figure 1 shows the hurricane, tropical storm, and tornado watches and warnings for Irene. Remember, a hurricane warning means hurricane conditions are expected, and tropical storm force winds (greater than 34 mph) will occur within 36 hours. Tropical storm warning means that tropical storm force winds are expected in the next 36 hours, but hurricane conditions are not. A tropical storm watch means tropical storm force winds are possible within 48 hours.

To find out if you need to evacuate, please contact your local emergency management office. They will have the latest information. People living in New York City can find their evacuation zone here or use this map. FEMA has information on preparing for hurricanes. FEMA also has a blog describing their response to Irene.


Figure 1 Map of watches and warnings taken at 225AM EDT, August 27, 2011

Satellite Views
Figure 2 shows that Irene is a large storm, with outflow reaching from South Carolina to Long Island, NY. Irene's eye is not visible.


Figure 2 IR satellite view of Irene taken at 226AM EDT, August 27, 2011

Track Forecast

Irene is forecast to make landfall on the North Carolina coast Saturday morning as a category 1 storm with sustained winds around 90 mph. I believe that Irene's center of circulation will make landfall somewhere between Cape Lookout and Okracoke on the Outer Banks around 9-10 am. Irene should then move roughly north, along the mid-Atlantic coastline before making landfall in western Long Island. However, it is important to not focus solely on the track forecast. Irene is a large storm with a large windfield and equally large areas of storms and showers. It's impact will be felt over a wide swath of the northeastern US.


Figure 3 Official track forecast of Irene at 11PM EDT, Aug. 26.

Irene and Flooding
Six to ten inches of rain are possible along Irene's track from North Carolina north into New England, with 15 inches possible in isolated areas. Radar estimates indicate at least 5 inches have already fallen near Morehead City, NC. As a result, flooding is very likely. The Hydrometeorological Prediction Center (HPC) has issued their Significant River Flood Outlook for the next five days shown in figure 4. HPC thinks that river flooding from the Delmarva peninsula to northwestern Maine is likely, while river flooding in much of the rest of the northeastern US is possible.


Figure 4 Significant River Flood Outlook issued by HPC.

Impacts

Tropical storm forces winds are occuring at Cape Lookout now, with hurricane force winds expected on the North Carolina coast later today. Use this Wundermap to keep track of how the winds are behaving around the North Carolina coastline. Within the hurricane warning area in North Carolina, storm surge is expected to be 6-11 feet above ground. This is our storm surge forecast map. To see how high the tides are running, NOAA has an excellent page collecting all of the relevant tide gauges.

People living on the the east coast of the US from the Carolinas to Cape Cod should continue monitoring Irene and be in the process of finishing their hurricane preparations. If you have not started preparing for this storm, start immediately. If an evacuation order is given, please follow it, unless it is unsafe to do so. Irene will be a large storm, impacting areas far from the storm center track.

Links

If you're curious about power outages, here are some maps: Dominion Power Outage Map (NC/VA), Progress Energy Outage Map (NC/SC), and NOVEC Outage Map (Northern Virginia).

Dr. Masters will have a new blog entry this morning, and there will be another blog this afternoon. I'll be back with another blog entry late tonight.

Stay safe,

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: 792 - 742

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

What is more surprising than the blog being dead while we have a NE Coast landfalling hurricane is that Dr Masters hasn't updated his blog yet. I take it that he may be busy doing media interviews. One of the other WU Meteorologists should have made a post by now.

How long will it take the NE coast to dry out from Irene? September is the busiest hurricane month and things could get pretty ugly if another storm rides up the NE Coast.
Member Since: Posts: Comments:
Quoting wunderweatherman123:

did you hear rick knabb talk about how the land actually helped irene look better on satalite? its some pretty interesting stuff and for a cat 1 with a pressure of 952 is just incredible..


maybe the winds are working down to surface,give her a better appearance,think i saw from 110-123 at what was it 900's mb ranges just prior to landfall?
Member Since: September 18, 2010 Posts: 0 Comments: 5219
Hurricane Hunters left at the wrong time. I bet Irene is up to 90 mph., maybe 95 mph... Whens the next recon?
Member Since: Posts: Comments:
Quoting unc70:
Oz is still transmitting. He just woke up after an hour nap. I have family members who live in Atlantic Beach on the sound side directly opposite Oz's location last night on Arendell St.

He is really tired. Surprised that he still has a connection out of MHC. Afraid he may screw up and lose the link he had established already.


Yea, I think he just did... but the last band he streamed was really great!
Member Since: Posts: Comments:
Quoting o22sail:

I'm becoming a little more concerned for us as well. It appears to be tightening up and heading almost due north.

i hope that doesnt continue, i have relatives in Norfolk so im hoping Irene actually follows its projected path, but then again, it never really has.
Member Since: Posts: Comments:
Quoting charlottefl:


Gust of wind blew them off the road into a tree.

Ouch. Curse you IRENE!
Member Since: July 7, 2010 Posts: 0 Comments: 5672
785. bwi
Very heavy rain now in the DC area. Fresh water flooding here we come if this keeps up all day at this rate.
Member Since: Posts: Comments:
Cape Hatteras

10:51 AM 80.1 °F 85.4 °F 75.9 °F 87% 28.75 in 2.0 mi SSE 44.9 mph 71.3 mph 0.01 in Rain Light Rain
Member Since: Posts: Comments:
Quoting nola70119:


What do you make of the water vapor....? It looks wet after that trough pulls through..


Oh yeah it's going to be very wet. HPC has 6-10 inches of rain all the way up through the mid-Atlantic and the core of New England.
Member Since: Posts: Comments:
782. unf97
It seems to me that not only is Irene is moving more due north, but that the center has tightened up considerably in the past couple of hours. IR satellite and radar showing very impressive convective tops and banding building on the north and northwest side of the circulation center.
Member Since: Posts: Comments:
781. unc70
Oz is still transmitting. He just woke up after an hour nap. I have family members who live in Atlantic Beach on the sound side directly opposite Oz's location last night on Arendell St.

He is really tired. Surprised that he still has a connection out of MHC. Afraid he may screw up and lose the link he had established already.
Member Since: Posts: Comments:
Quoting LightningCharmer:


Link


Oh yeah--too fuuny!!! He said he's got a "lot of nature inside him" and he's doing all he can to hold it back. Roll another one, dude!!! LOL
Member Since: Posts: Comments:
Quoting Hhunter:


any barometric readings out of NC? Pressure started dropping from 952mb just prior to landfall and saw a 950.3mb overland 1 1/2 after the 952 reading.thought i saw the HH leaving,wonder if it is still dropping while Irene is running over the sounds in east carolina?
Member Since: September 18, 2010 Posts: 0 Comments: 5219
Quoting Smikey:
Can someone tell me why the Pressure is still at 951mb with only 85mph reported winds? Something doesn't make sense. Pressure that low after a while must increase winds to balance out, or increase in pressure to balance out. (its meteorological physics) Neither has happened for the past 12 hours..


Actually, there is a third variable there: size. If we look at a one-dimensional Navier-Stokes equation, you have ∂u/∂t +u*∂u/∂x = -(1/ρ)*dP/dx + ν*((∂^2)u)/(∂(x^2)) - friction. From there, we can see that an increase in dP can be offset simply by increasing dx by a similar amount.

Irene for some reason decided to expand its radius instead of increasing its winds, and is now a gargantuan storm. If it hadn't expanded as much, you'd have a storm with stronger winds.
Member Since: Posts: Comments:
Quoting WeatherNerdPR:

TWC just said someone died in the Rocky Mount area in NC, didn't say how or why though.


Gust of wind blew them off the road into a tree.
Member Since: December 18, 2006 Posts: 7 Comments: 2686
Quoting WeatherNerdPR:

TWC just said someone died in the Rocky Mount area in NC, didn't say how or why though.


Irene is a KILLER storm and means to do so if you are in her way. PERIOD. I hope everyone REALLY Understands that in all the excitement of pressure readings, wind and radar and satellite etc. GET OUT OF HER WAY.
Member Since: Posts: Comments:
CAT 3 PRESSURE AND SURGE DON'T FORGET THAT FACT LAND FRICTION AFFECT WILL HELP THE WIND APPEAR MORE COMBINE A 25 STOREY BUILDING AND WOW...MORE THAN YOU BARGAIN FOR I WOULD SAY..
Member Since: Posts: Comments:
Quoting stillwaiting:
,she's slowly weakning ,look at the ragged apperance of her southern side,not going to till be a cane by 11pm imo


I don't expect to see a tropical storm at sub-960mb pressures. The NHC tried to downgrade Earl like that last year in Canada, and Canada said it was still a hurricane, and it was, based on observations.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Sorry guys had to change the link. Technology :(


NC Hurricane Irene
Member Since: December 18, 2006 Posts: 7 Comments: 2686
Quoting KeysieLife:
I have a bad feeling some further north of Virginia are going to get complacent with "it's not as bad as we thought" coverage. Virginia Beach is getting pounded right now and there are a lot of people out driving! Yikes!


Driving is not too bad until about 50 sustained or so, so long as you have the sense to not drive a high profile vehicle, drive like a maniac, or drive in a place that is or is likely to be flooded.
Member Since: Posts: Comments:
BEAUFORT

11:03 AM 77.0 °F - 73.4 °F 89% 28.43 in 1.5 mi WSW 52.9 mph 70.2 mph 0.02 in Rain Rain
Member Since: Posts: Comments:
Quoting Levi32:
TWC just made a good point....radar of Irene looks the best that it ever has, and she looks extremely impressive for a Cat 1 hurricane. The banding and rain shields are very intense, and remind me more of the strong Category 2 hurricanes that I have seen make landfall.


TWC just said someone died in the Rocky Mount area in NC, didn't say how or why though.
Member Since: July 7, 2010 Posts: 0 Comments: 5672
Quoting o22sail:

I'm becoming a little more concerned for us as well. It appears to be tightening up and heading almost due north.


Agreed. Could we please have some big pressure bump Ms. E back east?
Member Since: Posts: Comments:
Quoting kathyvb:

Levi, how bad do you think it will get here in Va Beach? Wouldn't it make a signifigant difference if the center passes over or to the west of us? And thank you for your information, I've really appreciated reading your opinions on this situation.


Well looking at the current forward motion, VA Beach could get a direct hit from the center, which would obviously bring the worst conditions. In terms of storm surge, a direct hit would bring the most water in due to easterly winds north of the center. In terms of wind and rain, being just west of the eye would actually be worse than being east of it, as the northwest quad is now the worst part of the storm due to baroclinic influence. Think of it like a nor'easter....the northwest part of the storm is going to be the worst.
Member Since: Posts: Comments:
765. zingo
With Floyd and Fran, right after the storm you did not worry about the flooding as number one. The first day the rain was in the fields. The second day the water had made its way to the little streams and then going into the creeks. Last to the rivers. Then around Raleigh they get full lakes and start to open the spillways releasing waters into the rivers on their way to the ocean. That is when the flooding really starts. You should have time to leave if you keep watching the news.

One good thing ( and probably the only) about NC hurricanes is the fact homes were brought by FEMA after they were flooded. Now the land is free to be flooded and no lives would be lost. That is NC, don't know about any threat of flooding up north. I do seem to remember the large amountt of water that fell with Floyd breaking records.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
762. 996tt
Quoting reedzone:
Irene has the pressure of a Category 3 storm.. This is still a VERY dangerous storm.


You have been consistent. Not sure about accurate though. I guess depends on definition of dangerous. Mike Slidel standing knee deep in hurricane surf with baggy clothes that would suck him under if hit with chest high rogue wave is dangerous. Dangerous to me is houses being cleared from their foundations or at least roofs being removed. If people use common sense, people should be fine. Pressure does not cause damage and kill people. Surge and wind does which is not cat 3, but cat 1 like.
Member Since: Posts: Comments:
Quoting Bayside:
Is oz transmitting from obx? Is there a link? TIA

Blog index> tampaspin> link on his website
Member Since: Posts: Comments:
Quoting Levi32:
TWC just made a good point....radar of Irene looks the best that it ever has, and she looks extremely impressive for a Cat 1 hurricane. The banding and rain shields are very intense, and remind me more of the strong Category 2 hurricanes that I have seen make landfall.

,she's slowly weakning ,look at the ragged apperance of her southern side,not going to ßtill be a cane by 11pm imo
Member Since: Posts: Comments:
Quoting oracle28:


Sounds like "Severe Thunderstorm Warning" criteria.


Yes, one that lasts for hours......
Member Since: Posts: Comments:
Having seen a Landfall from TV,,compared to actually experiencing Multiple Landfalls, is quite a difference.

Always.

Member Since: Posts: Comments:
Quoting wunderweatherman123:

did you hear rick knabb talk about how the land actually helped irene look better on satalite? its some pretty interesting stuff and for a cat 1 with a pressure of 952 is just incredible..


Yeah the land will regularly tighten up systems. Hurricane Ivan exhibited a burst in his radar presentation after landfall as well. That's why we talk about centers tightening up as they near landfall. The reason for that is when the wind slows down, the Coriolis force acting on it is reduced, and thus the pressure gradient force and work more on the air and bring it closer to the storm center faster, causing the tightening and convergence that Knabb talked about.
Member Since: Posts: Comments:
Live stream outside of Raleigh. Pressure is 981.8

Link
Member Since: December 18, 2006 Posts: 7 Comments: 2686
Quoting NoVaForecaster:


Either Irene is trying to strengthen or is doing a great job giving me that illusion. I have been wrong about it attempting to organize before so I don't want to jump the gun here....

I'm becoming a little more concerned for us as well. It appears to be tightening up and heading almost due north.
Member Since: Posts: Comments:
Quoting ncCANEiac:
Just had 61 mph gust here!! Rain coming down in sheets!


Sounds like "Severe Thunderstorm Warning" criteria.
Member Since: Posts: Comments:
Quoting reedzone:
Irene has the pressure of a Category 3 storm.. This is still a VERY dangerous storm.


The pressure of a Cat 3 and the hype of a Cat 4 and the winds of a Cat 1.

A very interesting storm indeed.
Member Since: Posts: Comments:
Quoting Levi32:
TWC just made a good point....radar of Irene looks the best that it ever has, and she looks extremely impressive for a Cat 1 hurricane. The banding and rain shields are very intense, and remind me more of the strong Category 2 hurricanes that I have seen make landfall.


did you hear rick knabb talk about how the land actually helped irene look better on satalite? its some pretty interesting stuff and for a cat 1 with a pressure of 952 is just incredible..
Member Since: August 23, 2011 Posts: 0 Comments: 1566
not too take any one a way from are hurricane but has any one noted this little guy i think this little guy is what mode runs where forcasting last night that takes it in the gulf i all so looked at wind shear and it dos not seem bad i would keep a eye on it

Member Since: Posts: Comments:
Quoting Levi32:
TWC just made a good point....radar of Irene looks the best that it ever has, and she looks extremely impressive for a Cat 1 hurricane. The banding and rain shields are very intense, and remind me more of the strong Category 2 hurricanes that I have seen make landfall.



BECAUSE BY PRESSURE IT IS A MODERATE CAT 3
Member Since: Posts: Comments:
Quoting kathyvb:

Levi, how bad do you think it will get here in Va Beach? Wouldn't it make a signifigant difference if the center passes over or to the west of us? And thank you for your information, I've really appreciated reading your opinions on this situation.


With the wind charts still showing that almost all of the hurricane-force winds are just to the east of the CoC, a more westward course that pushes the center over or to our west would place that wind field on us rather than just off shore.
Member Since: Posts: Comments:
looks like irene's loosing her innercores structure,you can see the innerbands becoming uncemetric on her sw side,surge should be the only large problems in nyc,doubt sustained winds get over 50moh in nyc maybe gusts over 65...rhodeisland ,providence imo will see historical floding along with sect,wich could get gusts over 80mph,which will knock alot of power out in thoase areas r.i and sect
Member Since: Posts: Comments:
Quoting Levi32:
TWC just made a good point....radar of Irene looks the best that it ever has, and she looks extremely impressive for a Cat 1 hurricane. The banding and rain shields are very intense, and remind me more of the strong Category 2 hurricanes that I have seen make landfall.



What do you make of the water vapor....? It looks wet after that trough pulls through..
Member Since: Posts: Comments:
the a guy swimming in the water on the web cam at surf city topsail !!!
Member Since: Posts: Comments:
Quoting sunlinepr:
Big baby NE of PR...






When that trough clears out and the water vapor moves into the NE, that could make things interesting...
Member Since: Posts: Comments:
TWC just made a good point....radar of Irene looks the best that it ever has, and she looks extremely impressive for a Cat 1 hurricane. The banding and rain shields are very intense, and remind me more of the strong Category 2 hurricanes that I have seen make landfall.

Member Since: Posts: Comments:
742. 996tt
Sad to hear about two possible surfing deaths. This is actually surprising as I have surfed storms all over the globe in my 44 years and deaths are a rarity except when inexperienced people try to wade into storm waters which are to blown out to even surf.

Seriously, kids stay out of water up that direction unless you have a lot of experience. I have been around 100s of surfers in last two days down here and only incidents have been jelly fish or sea lice issues on Thursday early. If you go surf, do the buddy system and if you think for a second it may be too big, it is.
Member Since: Posts: Comments:

Viewing: 792 - 742

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

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