Hurricane Irene Weakens on its Approach to North Carolina

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

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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

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Quoting zoomiami:
All the damage that is being reported through Hampton roads, Virginia Beach etc -- and they aren't even in the worst of the weather.

I agree with the post earlier that people are saying not so bad right now, but I think when its over it will be worse than people believed.

Discussing this yesterday, my opinion is that people judge these storms against Andrew or Katrina, and then think its not so bad. Which it isn't, but doesn't make this storm less dangerous.


++++++!!!!!!!!
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Member Since: July 7, 2010 Posts: 0 Comments: 5690
All the damage that is being reported through Hampton roads, Virginia Beach etc -- and they aren't even in the worst of the weather.

I agree with the post earlier that people are saying not so bad right now, but I think when its over it will be worse than people believed.

Discussing this yesterday, my opinion is that people judge these storms against Andrew or Katrina, and then think its not so bad. Which it isn't, but doesn't make this storm less dangerous.
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Quoting atmoaggie:
Re-thinking this...if it truly is intended to be a measure of KINETIC energy, the land roughness-slowed 10 m winds may be exactly the data to use in the calculation.

Without the drag, it would include potential rather than truly kinetic.


Yeah but all it's doing is losing energy to the property that it is impacting, and realistically the total energy of the storm isn't going to decrease all that much due to friction alone if you consider the winds above the surface.
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clear rightward movement now, might go back out over open water again.
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Got pics from my friends back in New Bern. The Neuse is way up.

It appears the radar estimates are about 20% high. When they said 6" had fallen, it was more like 5.
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this sure dos not looking like its moveing 14mph lol
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885. h0db
Well west and north of NHC track--COC is over eastern mainland NC, not the Outer Banks as forecast. Needs to turn NNE, but VA Beach at least is going to get more than it expected yesterday.
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Quoting Levi32:


His name was Dr. Mark Powell. He's with AOML HRD, and Bob had him on the show specifically for the I.K.E. index, which he is working on, but I don't know if he's one of the "lead" guys on it.
Ah, Mark Powell at HRD and COAPS has another version than the RAMMB guys.

That's the same guy that developed H*Wind.
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Quoting Patrap:
Oz is a fool in the Rain,,and a danger to Himself and others.

Reed is Reed,

Anything else ?


Like I said,,there are no amatuer mets,,just like there are no amateur Astronauts.

A Hobbyist can say anything,,and most do.
If I'm not wrong, isn't an amateur someone who is not being compensated. Would someone actually pay or compensate in any way most of bloggers on here who forecast anything under the sun?


Definition of AMATEUR

1
: devotee, admirer
2
: one who engages in a pursuit, study, science, or sport as a pastime rather than as a profession
3
: one lacking in experience and competence in an art or science

Source:
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881. Skyepony (Mod)
Damage reports out of Newport, NC NWS..lots of 70+mph winds, trees down, some on houses & 7+" of rain so far.


1110 AM FLOOD SWANQUARTER 35.40N 76.32W
08/27/2011 MAINLAND HYDE NC EMERGENCY MNGR

WATER HAS TOPPED THE DIKE IN SWANQUARTER WITH MAJOR
FLOODING ONGOING.


1123 AM HURRICANE NEWPORT 34.74N 76.93W
08/27/2011 CARTERET NC NWS EMPLOYEE

TREE OVER 2.5 FEET IN DIAMETER DOWN ON 9 MILE ROAD. ROAD
IS IMPASSABLE.




1110 AM FLOOD SWANQUARTER 35.40N 76.32W
08/27/2011 MAINLAND HYDE NC EMERGENCY MNGR

WATER HAS TOPPED THE LEVY IN SWANQUARTER WITH MAJOR
FLOODING ONGOING.




1046 AM HURRICANE SCRANTON 35.50N 76.45W
08/27/2011 HYDE NC EMERGENCY MNGR

MULTIPLE REPORTS OF DOWN TREES AND POWERLINES ALONG
HIGHWAY 264. SCRANTON AND SLADESVILLE AREAS EXPERIENCING
MAJOR FLOODING ISSUES.


1036 AM HURRICANE 1 N DUCK 36.18N 75.76W
08/27/2011 OUTER BANKS DARE NC EMERGENCY MNGR

DUCK PIER REPORTING SUSTAINED WINDS 67 MPH WITH GUSTS TO
84 MPH.

1035 AM HURRICANE ATLANTIC BEACH 34.69N 76.74W
08/27/2011 CARTERET NC TRAINED SPOTTER

SUSTAINED WINDS 85 MPH WITH GUSTS TO 101 MPH.


0800 AM HURRICANE CEDAR ISLAND 35.00N 76.33W
08/27/2011 CARTERET NC DEPT OF HIGHWAYS

WIND GUSTS TO 115 MPH AT CEDAR ISLAND FERRY TERMINAL.

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91L has had the appearance of an erupting volcano.



Loop
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879. jpsb
Quoting Levi32:


Hmmm, that is strange, I figured I could get good info from the WU stations at Virginia Beach. Apparently not.
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Quoting aquak9:
Quoting 996tt:
Guys saying people are stupid for being on the streets in their cars, but wait, he is standing in the streets with nothing but googles on.


GOGGLES go on the eyes...but where do GOOGLES go?

lol
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This could go down as a hundred year flood.....hope people have flood insurance cause Hurricane will not cover this..
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The NHC got the intensity wrong too - just about everybody did, but those forecasts would have been correct if Irene had been able to maintain an eyewall. Her central pressure does speak for itself. This should have been a Cat 3, but we were lucky enough to have just enough dry air to disrupt her core and force the wind field to spread out, at the expense of the maximum speeds.
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Quoting atmoaggie:
Knaff or DeMaria?

And, depending on the wind analysis, they could make a marine exposure-only version for the IKE calculation. We do the same thing for generating input wind field data for storm surge modeling (and then apply land roughness drag at surge modeling grid points at a much higher spatial resolution than the input wind data).

HRD also makes a marine exposure-only version of the H*Wind data. (but not the plots, usually)
Re-thinking this...if it truly is intended to be a measure of KINETIC energy, the land roughness-slowed 10 m winds may be exactly the data to use in the calculation.

Without the drag, it would include potential rather than truly kinetic.
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We are getting hammered with this band right now. Easily 55-60+ mph. Wish we had a vid. camera to post video! Still pics just don't do it justice!
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Quoting 996tt:
Guys saying people are stupid for being on the streets in their cars, but wait, he is standing in the streets with nothing but googles on.


GOGGLES go on the eyes...but where do GOOGLES go?
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Quoting goldenpixie1:


I second that "hey!"


I'll third that.
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Quoting zoomiami:


Hey!


I second that "hey!"
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865. MahFL
Quoting charlottefl:
Sorry guys had to change the link. Technology :(


NC Hurricane Irene


it's still not working.
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Quoting presslord:
not only is it his blog....but he has...well...a PhD...and a couple of decades of experience...in the subject...


Besides his experience as a Hurricane Hunter...
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Quoting atmoaggie:
Knaff or DeMaria?

And, depending on the wind analysis, they could make a marine exposure-only version for the IKE calculation. We do the same thing for generating input wind field data for storm surge modeling (and then apply land roughness drag at surge modeling grid points at a much higher spatial resolution than the input wind data).

HRD also makes a marine exposure-only version of the H*Wind data. (but not the plots, usually)


His name was Dr. Mark Powell. He's with AOML HRD, and Bob had him on the show specifically for the I.K.E. index, which he is working on, but I don't know if he's one of the "lead" guys on it.
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Quoting 996tt:
Guys saying people are stupid for being on the streets in their cars, but wait, he is standing in the streets with nothing but googles on.


He must have been cold.
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Quoting jpsb:
Just checked the WU stations in Virginia Beach 23454, those actively reporting are reporting winds of around 20-25mph.


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Quoting atmoaggie:
lol, you went there...

True. Irene's size is the difference between her being of Charley's peak winds speed and Irene's peak wind speed.

Not sure how the heck you put in the PDE and rho, though.



You think the ρv might be displaced? Momentum, I want to see momentum.
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Quoting Patrap:
Norfolk
NEXRAD Radar

Storm Total Surface Rainfall Accumulation




geez,look at maryland already 3-5 inches
Member Since: September 18, 2010 Posts: 0 Comments: 5234
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Quoting Patrap:
The blog is never the focus,,the Landfalling Storm is.

Plus,,with Fla out the mix,well..you understand.


Hey!
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852. hamla
for those that think thay irene is a duh storm just go get the results from google on tropical storm allison
do not take these storms lightly just because they are not a cat 3,4,5
allison was the most costly tropical storm on record 6.4 billion dollars 41 deaths
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Quoting Levi32:


Yeah, we had a guy from that project interviewed on the Barometer Bob show on Thursday, and he said they only use 10m winds to estimate the kinetic energy.
Knaff or DeMaria?

And, depending on the wind analysis, they could make a marine exposure-only version for the IKE calculation. We do the same thing for generating input wind field data for storm surge modeling (and then apply land roughness drag at surge modeling grid points at a much higher spatial resolution than the input wind data).

HRD also makes a marine exposure-only version of the H*Wind data. (but not the plots, usually)
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Oz is a fool in the Rain,,and a danger to Himself and others.

Reed is Reed,

Anything else ?


Like I said,,there are no amatuer mets,,just like there are no amateur Astronauts.

A Hobbyist can say anything,,and most do.
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BLOG UPDATE:

Hurricane Irene Video Update
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Just got a call from Wilson County Emergency Management. Numerous trees down in town and flooding in downtown and lots of drainage creeks. Emergency responders have been recalled to stations until storm subsides. We have 30-40 mph sustained with gusts as high as 62 in past hour and another strong band is about to hit the area now! 10-15 thousand without power also.

Tree fell on man in Nashville NC about 15 miles north of us.
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Quoting Patrap:
Quoting reedzone:
Hurricane Hunters left at the wrong time. I bet Irene is up to 90 mph., maybe 95 mph... Whens the next recon?

If one cant find the HH POD, well then that say tons about His er, skill set.


Patrap : I appreciate the graphics you often put up on the blog even though I know where they all are as it is a service to others. Reedzone has been on this blog for a few years and generally has been not far off in his estimates, I have watched Irene for the last 20 hours including all of Ozs stream and in my opinion there is every chance that irene will remain a Hurricane to long Island, the NHC have yet to say otherwise either
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Quoting FLdewey:


But... but Reed has Jesus on his side.

In more important news, All Starbucks closed in NYC. Now this is getting serious.


LOL!!!
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845. jpsb
Just checked the WU stations in Virginia Beach 23454, those actively reporting are reporting winds of around 20-25mph.
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Yep, Florida is out of the mix, so we don't waste space with repetitive nonsense posts that offer no real information. You're welcome blog.
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842. 996tt
Guys saying people are stupid for being on the streets in their cars, but wait, he is standing in the streets with nothing but googles on.
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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.