One of the great things about Internet, technology, and personal weather stations today is that I can sit comfortably in my home in California and watch the storm progress on the other coast. This map from Weather Underground suggests that Irene isn’t packing hurricane force winds as it makes landfall in North Carolina, and is rapidly weakening.
click image to enlarge
When I look at the station with the highest wind speed on the map above, it is rather surprising.
Maybe there are hurricane force wind speeds nearer the eye?
Nope.
So what we have here at this point appears to be a tropical storm. By the time it reaches New York, it may very well just be a tropical depression on par with a Nor’easter in intensity.
The next NHC bulletin will probably see a further downgrade in this storm, which now looks to be not as bad as forecast at this point. This is good. Storm surge for the outer banks will of course be an issue, but the fact that we are still getting automated station reports from there is encouraging.
If anyone needs help reading the weather station surface plot symbols for wind, see this.
UPDATE: TWC seems to concur. If they have a reporter standing on the beach, then I suppose it isn’t all that bad:
UPDATE2: latest from NHC, it’s still a hurricane, that’s our story and we are sticking to it:
BULLETIN HURRICANE IRENE INTERMEDIATE ADVISORY NUMBER 29A NWS NATIONAL HURRICANE CENTER MIAMI FL AL092011 200 PM EDT SAT AUG 27 2011 ...IRENE MOVING ACROSS EASTERN NORTH CAROLINA... SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION ---------------------------------------------- LOCATION...35.5N 76.3W ABOUT 45 MI...70 KM WNW OF CAPE HATTERAS NORTH CAROLINA ABOUT 95 MI...155 KM S OF NORFOLK VIRGINIA MAXIMUM SUSTAINED WINDS...85 MPH...140 KM/H PRESENT MOVEMENT...NNE OR 15 DEGREES AT 15 MPH...24 KM/H MINIMUM CENTRAL PRESSURE...950 MB...28.05 INCHES WATCHES AND WARNINGS -------------------- CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY... ENVIRONMENT CANADA HAS ISSUED A TROPICAL STORM WARNING FROM THE UNITED STATES BORDER NORTHEASTWARD TO FORT LAWRENCE INCLUDING GRAND MANAN...AND FOR THE SOUTH COAST OF NOVA SCOTIA FROM FORT LAWRENCE TO PORTERS LAKE. SUMMARY OF WATCHES AND WARNINGS IN EFFECT... A HURRICANE WARNING IS IN EFFECT FOR... * LITTLE RIVER INLET NORTH CAROLINA NORTHWARD TO SAGAMORE BEACH MASSACHUSETTS...INCLUDING THE PAMLICO...ALBEMARLE...AND CURRITUCK SOUNDS...DELAWARE BAY...CHESAPEAKE BAY SOUTH OF DRUM POINT...NEW YORK CITY...LONG ISLAND...LONG ISLAND SOUND...COASTAL CONNECTICUT AND RHODE ISLAND...BLOCK ISLAND...MARTHAS VINEYARD AND NANTUCKET A TROPICAL STORM WARNING IS IN EFFECT FOR... * CHESAPEAKE BAY FROM DRUM POINT NORTHWARD AND THE TIDAL POTOMAC * NORTH OF SAGAMORE BEACH TO EASTPORT MAINE * UNITED STATES/CANADA BORDER NORTHEASTWARD TO FORT LAWRENCE INCLUDING GRAND MANAN * SOUTH COAST OF NOVA SCOTIA FROM FORT LAWRENCE TO PORTERS LAKE INTERESTS ELSEWHERE IN EASTERN CANADA SHOULD MONITOR THE PROGRESS OF IRENE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ AT 200 PM EDT...1800 UTC...THE CENTER OF HURRICANE IRENE WAS LOCATED NEAR LATITUDE 35.5 NORTH...LONGITUDE 76.3 WEST. IRENE IS MOVING TOWARD THE NORTH-NORTHEAST NEAR 13 MPH...20 KM/H. A NORTH-NORTHEASTWARD MOTION AT A SLIGHTLY FASTER FORWARD SPEED IS EXPECTED DURING THE NEXT DAY OR SO. ON THE FORECAST TRACK...THE CENTER OF IRENE WILL MOVE ACROSS NORTHEASTERN NORTH CAROLINA THIS AFTERNOON. THE HURRICANE IS FORECAST TO MOVE NEAR OR OVER THE MID-ATLANTIC COAST TONIGHT AND MOVE OVER SOUTHERN NEW ENGLAND ON SUNDAY. MAXIMUM SUSTAINED WINDS REMAIN NEAR 85 MPH...140 KM/H...WITH HIGHER GUSTS. SLIGHT WEAKENING IS FORECAST AS IRENE CROSSES EASTERN NORTH CAROLINA...BUT IRENE IS FORECAST TO REMAIN AT OR NEAR HURRICANE STRENGTH AS IT MOVES NEAR OR OVER THE MID-ATLANTIC STATES AND APPROACHES NEW ENGLAND. IRENE IS A LARGE TROPICAL CYCLONE. HURRICANE-FORCE WINDS EXTEND OUTWARD UP TO 90 MILES...150 KM...FROM THE CENTER...AND TROPICAL- STORM-FORCE WINDS EXTEND OUTWARD UP TO 260 MILES...415 KM. A WIND GUST TO 78 MPH WAS RECENTLY MEASURED AT CAPE HATTERAS NORTH CAROLINA. A WIND GUST TO 67 MPH WAS RECENTLY REPORTED AT LANGLEY AIR FORCE BASE IN SOUTHEASTERN VIRGINIA. THE LATEST MINIMUM PRESSURE REPORTED FROM A DROPSONDE RELEASED BY AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT WAS 950 MB...28.05 INCHES.
UPDATE3: From a comment left on Goddard’s site:
Out of the local NWS office in Morehead City, NC:
First, in the northeast part of the eyewall at landfall, and about 30 minutes before your radar map posted above…
0719 AM HIGH SUST WINDS CEDAR ISLAND 35.00N 76.33W
08/27/2011 M90 MPH CARTERET NC DEPT OF HIGHWAYS
CEDAR ISLAND FERRY TERMINAL REPORTS SUSTAINED WINDS 90
MPH WITH GUSTS TO 110 MPH.
Secondly, in the southwest (weakest) part of the eyewall…
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.
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So I think what we have here is a narrow area of hurricane force winds, and a broad area of tropical storm force winds associated with this storm. Near the eyewall it would of course be quite dangerous, whether or not Irene can sustain hurricane intensity will be the question of the day.
==========================================================
UPDATE4: That question seems to be answering itself, just over a 90 minutes after I posted the first images, we see the eye disappearing:
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Brendan Loy, Pajama Media’s Weather Nerd, has commented that intensity prediction is no where near as good as track prediction. Irene absolutely looked like a monster, but failed an “eyewall replacement cycle“, whatever that is, and never recovered.
I believe, very much against my inclination, that the officials were right to be cautious. Had they waited until they knew it was going to be bad, it would have been too late.
It’s wrong to look at these storms from the viewpoint of climate change. Each hurricane is its own storm, highly unpredictable, completely outside the global climate context.
I understand that flooding and power outages are still a real risk. In that light, “Closure of NYC subway & other mass transit systems” does not remotely imply “disintegration of social fabric”. It implies thousands of unprepared, even smug, New Yorkers trapped underground in flooding, blacked out tunnels. The social fabric might or might disintegrate, but it would have nothing to do with AGW.
I suppose if this storms fizzles out then Bloomberg and Christie who put so much on the line, wasted resources and cause so much disruption to so many people’s lives can make the the excuse, “What did you expect, we were stupid enough to believe the CONSENSUS of all these expert weather and climate scientists”
AccuWeather is cracking me up! No food for New Yorkers!
http://www.accuweather.com/video/1805489410/no-food-for-new-yorkers.asp
William Biggs has a good take on this hurricanette
http://wmbriggs.com/blog/?p=4275http://wmbriggs.com/blog/?p=4275
I just don’t understand. I have been watching the data presented here all day and can not see any hurricane force winds in the picture that is updated every 30 minutes. Why are we saying 80 mph wind speeds when your map shows under 50? Am I missing something here — perhaps I can’t read the map correctly?
Please advise.
Drudge just linked to this story. The comments are priceless…
http://news.yahoo.com/obama-takes-charge-hurricane-command-center-172139005.html
Leslie says:
August 27, 2011 at 1:23 pm
Models have been doing much better with storm tracks than intensity. I assume the difference is that the track is affected by big things, like high pressure “ridges” and low pressure “troughs” that themselves are fairly easy to measure and predict.
Intensity is affected by thing in the storm’s immediate vicinity. Some of these are smaller structures, some are hard to notice, some are hard to track, and some are quick to change.
Some of them:
Warm water.
The source of energy for the storm. Cold air aloft helps with convection, so that’s important too.
Low wind shear (change in wind speed and direction with altitude).
Shear can literally blow the top off the storm and it will take time for convection to build things back up. El Ninos bring a high shear environment and can pretty much shut down an active season.
Land effects.
The more land a tropical storm is over the less energy goes into it. The eye needs a lot of energy to maintain its shape.
Dry air advection.
If a tropical storm (especially the stronger ones) sucks in some dry air near the surface, that cuts the storm off at its knees. Storms need moist air which releases heat as the air rises and cools, that helps drive convection. Not only does the storm need to get the dry air saturated, (which cools the sea surface), it will have to restart convection through the whole air column.
A Cat 4 or 5 storm really needs all the elements to come together, and it’s often quite a thing of beauty (well, from Earth orbit) when it does.
I think what happened to Irene was it got a little wind shear while it was in the Bahamas, then pulled in some dry air as it began to interact with the mainland, then took a course closer to the mainland, and then got a bigger chunk of dry air. The warm water of the Gulf stream wasn’t enough to counteract the problems, plus the storm is wider than the Gulf Stream anyway. I thought the breadth of the storm and lowish category would let it absorb the dry air, but it certainly wasn’t able to handle all of the recent big chunk.
One thing that’s interesting is that the hurricane hunters use several tools to determine the wind speed. Flight level winds generally follow a standard speed curve down to the surface, the shape of the wave tops and spray vary with wind right at the surface, and radar and satellite data provide useful data too. Irene is a bit odd that the wind speed close to sea level is less than is typical for the barometric pressure (another clue to speed). I’m not sure what affects that, land, size, humidity of inflow probably all have an impact. This anomaly is just in the bottom few hundred feet or so – the NYC skyscrapers may scrape some hurricane force winds down to street level.
djmooretx says:
August 27, 2011 at 4:28 pm
I’m not as confident about this as other parts, but I think what goes on is that the eyewall is a balance point where the low pressure of the eye pulling in air from outside is balanced by the force needed to keep the wind bending around the eye. (It would be a lot easier to refer to centrifugal force, but someone will squawk.) At this point there’s no place for incoming air to go but up, so the eyewall has major updrafts from that in addition to the convection from the warm, moist air.
At some point the pressure gradient outside the eyewall weakens a bit and a new eyewall begins to form. This cuts of the air flow to the original eye which breaks down and dissipates, but that leads to more suction on the new eyewall and that begins to contract to the new balance point and the eyewall cycle is complete. As this happens, the wind speed of the outer eyewall increases as it’s pulled back in – since hurricane intensity is the peak wind, and that in the eyewall, a replacement cycle forces the hurricane into a lower intensity even though all the rest of the storm is unaffected and is just as destructive.
I hope Ryan Maue sees this and straightens me out on all the misinformation that may be here.
I’m not sure how this relates to Irene, it may be the new eyewall let enough air through to keep the old eyewall in existence but weaker than it was. Mostly speculation.
[RyanMaue: the failed eyewall replacement cycle occurred in concert with the dry air ingestion. usually the inner-core mixes out this dry air and it again contracts into another wind maxima at a higher intensity and lower pressure. but a short-wave trough cut off the equatorward outflow channel and induced southwesterly shear + more dry air. once the inner core is gone, that’s pretty much it]
Thanks to global warming, the reduced temperature gradient has limited the destructive power of the storm. That’s my story and I’m sticking to it!
Theo Goodwin says:
August 27, 2011 at 4:26 pm
Using eyewall wind speeds as a measure of storm risk is unscientific as it measures a small amount of the storm. However, wind damage doesn’t vary linearly with wind speed or even speed squared, so other metrics like total kinetic energy near the surface doesn’t work well either (and is even harder to determine than eyewall speed).
Size is an important attribute, so is wind speed, water content time of landfall (both day/night and lowtide/hightide), population density, topography, novelty, and so on.
A lot of people here denigrate them, but the wind speed estimates reported by the NHC do include the rationale of how it is determined. The sea surface wind speed is rarely measured directly.
As a former resident of New Orleans and a current resident of Virginia, I really do not mind an overhyped storm. A storm one is over prepared for is far more preferable that a storm one is poorly prepared for. Seriously, falling victim to those that cry wolf is not a reason to fail at being careful when wolf is cried.
When the media was announcing that the storm would strengthen to a cat 4, the satellite maps clearly showed that the hurricane was not breathing well on the West side. I went to bed suspecting that the storm was weakening (yeah, all those years in New Orleans listening to the experts paid off). The next day while the MSM kept claiming the storm would strengthen again, it was still clear the the outflow to the west was weak and when the storm wrapped that slug of dry air it was a sign the storm was going to seriously weaken. Irene was a cat 1 the next day and encountering land.
Make no mistake! The East coast was one day away from a disastrous storm. Personally, I would much rather sit down with a sigh of relief than to bitch about a weak storm and to cast aspersions on those weather people who spent a lot of effort and personal stress in trying to predict what is known to be fickle weather. Shame on those who do cast such aspersions! I suppose you’d rather sit fat dumb and happy until one of these storms blast you out of your seats and destroys your property?
I spent seven days without power or water after Isabel, a supposedly weak storm, roared on through. I lost trees on all four sides of my house and suffered several thousand dollars of wind damage. And Isabel was a pussycat in the world of hurricanes! All of my tubs and water bottles are filled. All movable items normally outside are inside. The Coleman lantern and stove are set up; every one in the household has flashlights and batteries. The car is parked away from trees. I expected to lose power hours ago and though that hasn’t happened yet it is likely. I am prepared and I don’t mind one bit. If Irene turns out to be a light puff, I sit down relieved.
As for those who call those who got prepared for a hurricane, “thumbsuckers”; I am reminded of a yankee boss we got in New Orleans who ranted about his employees making plans for helping each other get ready for a storm. Then he went through his first hurricane, a small cat 1 no less. When the next storm showed up in the gulf he and his wife were involved in getting ready and helping others. Amazing how one night of lashing wind and rain makes believers out of those who marginalize others preparations.
No, Katrina did not make me move out of NOLA, my job did a couple of years before that storm hit. I’d happily move back though, even after Katrina. Really great town and people!
The million dollar question becomes, did they do the right thing by evacuating the critical areas?
Will there be a critique of the forecasts and actions?
I hope so
Watching the “NEWS” reports on Television, I feel like I am watching a low-budget SciFi disaster movie. I am monitoring the real-time weather stations in the Weather Underground, including hobbyist stations, official stations and airports. There is a total disconnect between what we are being told on Television and reality. Lies, lies and more lies. I can hardly wait to see tomorrows headline: “East Coast Save From Hurricane Irene by Global Warming”.
Michael Ronayne, Nutley, NJ
Don’t believe weatherunderground OBs.
Plus, this meteorologist has lost all respect for Steve Goddard. What a puss.
Yahoo headline via Dr. Dave: “Obama takes charge at hurricane command center”.
Facepalm?
Facepalm.
You’re going to tell those weather boffins what to do, O? Seriously?
And Janet Napolitano is going to be second in command here? What you gonna do, Nappy? Give Irene a pat down? Make sure she’s only carrying water in 3.4 oz bottles? See to it that the proles are helpless?
===
Thanks, Ric, for the eyewall explanation.
What do climate change deniers and hurricane deniers have in common?
REPLY: LOL! In case you can’t read (and it appears you can’t) the title of the post in fact has “hurricane” in it. So, go ahead, make my day, try to show we are denying a hurricane exists. Chortle – A
I do admit that the news hyped this thing, but for fairly good reason. It weakened more than expected but is still formidable. Winds have gusted above 80mph in some parts of eastern NC. Not 33mph STEVE-O! Unless he was parodying, Goddard is shameful.
I’m sorry but not one of you mentioned Hurricane Ike. The size of the storm does matter, the size of the wind field does matter. Ike made landfall with winds of 110 mph, a pressure of 950 in Texas. Ike caused $30 billion in damages and killed 123. Didn’t anyone learn a lesson from Ike? Instead of focusing energy around the core of the Hurricane, Ike and Irene have spread out the energy. I live in south central Massachusetts and between 2-4 PM today 3.74 inches of rain fell in Uxbridge, MA nearly 350 miles from the center of Irene. We we’re forecast by most local TV Mets and the Taunton NWS to receive 4-6 inches of rain. This wasn’t caused completely by Irene, it was a combination of an old frontal boundary and Irene interacting. I am with WUWT with 99% of the time but right now I am slightly baffled. 18 hours of 45-60 mph winds with gusts to 75 on top of 5-8 inches of rain will cause widespread tree damage and power outages. 14 inches of rain will cause major flooding. The northeast has been pounded with rain in August, increasing the flood and tree damage threat. I’m pretty sure 53.6 million people live in the way of this.
I do think people like Diane Sawyer and NBC want people to think this is because global warming. That doesn’t mean everyone forecasting a major impact is doing so with an agenda. Some people just did not want residents to take a cavalier attitude to Irene. Over 1 million people are without power right now and the center is off the coast of VA. The force of such a large area of strong winds is going to create a large surge along a vulnerable coast. Perhaps we should let Irene play out before calling political motives into question.
If a Cat 1 is correctly defined as having sustained winds of greater than 64kts and less than 82 kts, what am I missing in the data provided here;
http://www.ndbc.noaa.gov/radial_search.php?storm=at4
I can’t find recorded gusts of >64 kts. much less a sustained wind speed…
Are we ignoring surface winds in determining scale? I
dp says:
August 27, 2011 at 6:40 pm
What do climate change cultists and Lemmings have in common?
Alec,aka Daffy Duck says:
August 27, 2011 at 3:55 pm
Lameman here… Is it normal for hurricanes to have almost no lightning???
http://image.weather.com/images/maps/severe/map_light_ltst_4namus_enus_600x405.jpg
YES.
Who is this man on Obama’s right?
I’ve got the sense this is holding together pretty well. I think when all is said and done this will find a secure place in the record books with widespread flooding, tree damage, and power outages. I think Bastardi will be vindicated concerning his general ideas. I think the consensus that seems to be developing here is underplaying the situation.
Geeze, the link to SteveGoddard’s site on Drudge has some people having an absolute conniption in his comments. very entertaining