Irene sends 4.5 foot storm surge up Chesapeake Bay

By: Dr. Jeff Masters , 12:45 AM GMT on August 28, 2011

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The eye of Hurricane Irene is back over water, after the hurricane completed a 11-hour crossing of eastern North Carolina. Irene came ashore over Cape Lookout, North Carolina at 7:30 am EDT this morning as a Category 1 hurricane with 85 mph winds. The Cedar Island Ferry Terminal measured sustained winds of 90 mph, gusting to 115 mph at 7:19am, as measured by a Department of Transportation official. I suspect this measurement came when a thunderstorm near Irene's center collapsed, sending a powerful downburst to the surface. A trained spotter on Atlantic Beach, NC measured sustained winds of 85 mph, gusting to 101 mph at 10:35 am. The Hurricane Hunters measured 80 mph winds over water at the time of landfall. However, no regular weather station or buoy has measured sustained hurricane force winds in Irene, with the highest winds being 67 mph at the Cape Lookout, North Carolina buoy as Irene made landfall. Winds have peaked along the coast of Virginia, where sustained winds of 61 mph were observed at 6 pm EDT at Chesapeake Bay Light. Irene's passage over land weakened the storm slightly, and satellite loops show more dry air has wrapped into the storm. The radar presentation of Irene visible on the Norfolk, VA radar is still very impressive--Irene is dropping torrential rains over a huge area--but there is much less rain over the storm's southeastern quadrant, over water. Radar-estimated rainfall shows a 50 mile-wide band of 8+ inches of rain has fallen from where Irene made landfall at Cape Lookout, North Carolina, northwards to Dover, Delaware. Some isolated amounts of 15+ inches may have fallen, according to the radar estimates. Bunyan, NC has received 14.00" so far, and the towns of Washington, New Bern, Grifton, Newport-Croatan, Wonona, NC, all received more than ten inches. Norfolk, Virginia had received 7.73" as of 7pm EDT, and Suffolk, Virginia, 8.00".


Figure 1. True-color MODIS image of Hurricane Irene over North Carolina taken at 11:35 am EDT August 27, 2011. At the time, Irene was a Category 1 hurricane with 85 mph. Image credit: NASA.

Storm surge damage from Irene
The storm surge and wave action from Irene is likely to cause the storm's greatest damage. High tide is near 7 - 8 pm EDT tonight, meaning that the storm surges occurring now will be some of Irene's most damaging. The highest surges measured at any of NOAA's regular tide gauges at 8 pm were 4.5 feet at Sewells Point in Norfolk Virginia and Oregon Inlet, NC. Higher surges are occurring father inland where narrow inlets funnel the storm surge to higher elevations. It remains unclear if the ocean will overtop Manhattan's sea wall at The Battery Sunday morning during the 8 am high tide. Latest storm surge forecasts from SUNY Stony Brook predict a peak water level of 2.4 meters above Mean Lower Low Water (MLLW) at 7:15 am Sunday, which would put the ocean right at the top of the sea wall. Presumably, waves from the hurricane's winds would then push some water over the top of the wall, but it is uncertain whether or not this would cause significant flooding. The storm surge was already 1 foot at 8 pm tonight. Storm surge flooding continues to be a major concern all along the coast of Long Island Sound; I recommend the SUNY Stony Brook storm surge page for those interested in looking at observed and predicted storm surge levels along coast New Jersey, New York, and Connecticut.


Figure 2. Storm surge at Sewell's Point in Norfolk, Virginia as of 8 pm EDT Saturday August 27, 2011. The green line is the storm surge, which is the difference between the observed water level (red line) and what the water level should have been without the hurricane (blue line). At 8 pm, the storm surge was 4.5 feet. Image credit: NOAA Tides and Currents.


Figure 3. Distribution of Irene's wind field at 6:30 pm EDT Saturday August 27, 2011, as observed by the Hurricane Hunters, land stations, and buoys. The right front quadrant of the hurricane had all of the storm's shrinking hurricane-force winds (yellow and orange colors.) Tropical storm-force winds (heavy black like bounding the light blue area) extended out 290 miles from the center of Irene over water, but very few areas of land were receiving tropical storm force winds. Image credit: NOAA/AOML/HRD.

Wind damage
The emergence of Irene's eye over water will slow the storm's rate of weakening, but the storm is under too much wind shear to allow it to intensify. The latest wind distribution map from NOAA's Hurricane Research Division (Figure 3) shows that all of Irene's hurricane-force winds are on the storm's east side, and also the large majority of the tropical storm-force winds. When Irene makes its 2nd landfall on Long Island, NY on Sunday, coastal locations to the right of the eye will likely experience top sustained winds of 50 - 60 mph. Coastal areas of Maryland, Delaware, New Jersey, and the New York CIty area will mostly see top winds in the 40 - 55 mph range, since they will be on the weaker left side of the storm. Winds on the upper floors of skyscrapers will be up to 30% higher, but I expect there will be only isolated problems with New York City skyscrapers suffering blown out windows. The winds from Irene in New York City will be no worse than those experienced during some of the city's major Nor'easter winter storms of the past twenty years.

Tornadoes
Four tornadoes have been spawned by Irene, two in coastal North Carolina last night, and two in coastal Virginia today. At least two homes have been destroyed, and ten others damaged by the tornadoes. NOAA's Storm Prediction Center has issued a tornado watch for all of coastal Delaware, New Jersey, New York, and Connecticut.

Links
Our Weather Historian, Christopher C. Burt, has an excellent post on Historic Hurricanes from New Jersey to New England.

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.

Jeff Masters

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Quoting WaterWitch11:


It explains so much. Lol....Lots of love.


you ain't kiddin'
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Quoting violet312s:


It seems like the "inlets" got hit the worst with really bad flooding. Craven, Beaufort and of the sounds areas. WRAL has a county by county listing of updates on damages.
That is a very common occurrence with storm surge. The highest water level in any event is almost always in a bay, inlet, river, etc. where the water gets trapped and momentum and/or wind forcing cause it to eventually go "up" as there is no where else for it to go.

Contrastingly, along a coast, the water can eventually go "side ways" parallel to the coast, rather than up.
Member Since: August 16, 2007 Posts: 6 Comments: 12461
185. DFWjc
Quoting redwagon:


Generally a Texan could view any storm diving off Africa at 10o or below as ours, or potentially ours once it shoots the gap.


HEY HEY, I resemble that !!!
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Quoting P451:
Thanks for all the replies to the discrepancies regarding Dr. Masters' forecast and the NWS/NHC forecast.


Dr. Masters didn't go into any detail which is unfortunate. You'd think to make such a bold statement that contradicts the NHC and NWS forecasts that you'd be detailed in explaining your thinking.


Just wondering is all. I guess we will find out as tomorrow wears on.



+1
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Quoting presslord:


I'm a Marine Corp officer's son...I suppose I could have just walked across the Bay and saved myself the aggravation ;-)


It explains so much. Lol....Lots of love.
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Quoting P451:
Doc continues to downplay the winds yet people are reporting an awful lot of damage for such supposedly non existent winds.

The NWS also does not agree.

630pm updated forecast, coastal NJ:
NORTHEAST WINDS 55 TO
75 MPH WITH GUSTS UP TO 90 MPH

820pm updated forecast, Manhattan:
NORTHEAST WINDS 55 TO 75
MPH...BECOMING NORTHWEST 55 TO 65 MPH IN THE AFTERNOON. GUSTS UP
TO 80 MPH.


So what to believe? Those of us who have yet to receive the storm are curious.


Now for Irene the maximum rain is on the left or west side, as was predicted, The maximum wind is on the right or east side, as was also predicted. I don't see a problem here unless somebody has wind data that is averaged over 2 minutes that would be contrary to the reported numbers so far. We're not talking about landfall and the eye wall collapsing in a giant downburst here, but more recent stuff.
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Quoting bassis:


Next question. When they display gust are they knots or mph
Station plots (circle with barbs) are not usually used to display gusts, only sustained winds. Sometimes the gusts will be printed in text.

As to the units, that depends on the source. NWS/NOAA sources will use knots in those plots. Other, commercial entities will sometimes use mph for the barbs.
Member Since: August 16, 2007 Posts: 6 Comments: 12461
176. Skyepony (Mod)
NHC skywarn Feed.
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Quoting Tazmanian:
here are the mode runs for 92L and its vary far S and the mode runs take this thing W but how far W dos it get




Generally a Texan could view any storm diving off Africa at 10o or below as ours, or potentially ours once it shoots the gap.
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172. DFWjc
Quoting FLWaterFront:
It is past your bed time, young kiddie troll.


Thanks for that, now i need a washcloth to clean up the DP i just spat out...
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Great shot from Empire State Building cam on now on CNN.
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Any takers on peak wind gust at JFK?

I think we will see 65 mph.

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Quoting presslord:
How we take care of the most vulnerable over the next few days will be the ultimate test of all the 'planning' which has gone on since Katrina......I am not optimistic...


It seems like the "inlets" got hit the worst with really bad flooding. Craven, Beaufort and of the sounds areas. WRAL has a county by county listing of updates on damages.
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Quoting presslord:


I'm a Marine Corp officer's son...I suppose I could have just walked across the Bay and saved myself the aggravation ;-)


ew rah!
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Quoting PcolaDan:
@cnnbrk
CNN Breaking News
Newark, N.J,, mayor going door to door, warning residents to flee #hurricane on.cnn.com/nNZItz
? Is all of Newark below sea level, or something? Unless you are beach front:
1. You prolly don't need to evacuate
2. And if you should evac, due to near-sea level elevation, you should already have done so.
Member Since: August 16, 2007 Posts: 6 Comments: 12461
Quoting rkay1:
Irene will go down for the most hyped CAT1 hurricane in recent history.  I don't care what tweets TWC reads, what flashing/strobing background CNN/Foxnews has or what huge size they have "HURRICANE IRENE" on the bottom of the screen.  This is just a huge rain storm.
It is past your bed time, young kiddie troll.
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Quoting presslord:


I'm a marine Corp officer's son...I suppose I could have just walked across the Bay and saved myself the aggravation ;-)


OO-RAH! Marine here myself for 12 1/2 years, married to a 30 1/2 yr Leatherneck. We've got a dynamite son of our own, presslord, who used to call hinseklf "a Marine kid", lol. You're doing great work. {8^)
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Quoting indianrivguy:


click on storms and either slow down the frames or stop it altogether


ty!
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Entraining more dry air...pressure going to level off and start rising...
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Does eastern New England bust with a dry slot?
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Quoting PrivateIdaho:


Over and under...lol....its like a mini-submarine ride.


hmmm, I dunno, I always felt safer on the submarine than I did in that dang tunnel....
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Quoting Skyepony:


Here's one.


Next question. When they display gust are they knots or mph
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Quoting CybrTeddy:


Just ignore him, he's a complete idiot and not to be taken seriously. IMO, he should be gone when Irene is gone.


That's too long.
Member Since: October 16, 2008 Posts: 0 Comments: 544
156. Skyepony (Mod)
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MELBOURNE FL
547 PM EDT SAT AUG 27 2011

..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..

1115 AM HIGH SURF NEW SMYRNA BEACH 29.02N 80.93W
08/27/2011 VOLUSIA FL BROADCAST MEDIA

*** 1 FATAL *** 55-YO SURFER KNOCKED OVER IN SHALLOW
WATER BY A WAVE AND HIT HIS HEAD. NO VITAL SIGNS UPON
RESCUE AND LATER PRONOUNCED DEAD.


&&

$$

ARB
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Quoting atmoaggie:
? I thought it cool...but I'm an engineer's son.


I'm a Marine Corp officer's son...I suppose I could have just walked across the Bay and saved myself the aggravation ;-)
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Quoting Appalachiangypsy:

It's not the OVER part that's creepy to me ;)

Did they close that one? The Bay bridge is closed here.


Love the bridge ... the tunnel freaks me out. I've been away from the area for 20 years, but they used to have one day every year when it was closed to traffic, and open to walkers. Did that quite a few times.
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Quoting P451:
They're still playing around in Irene? I thought it was a nothing storm....so why waste the time?





Iceland anyone?



Bjork'll have something new to write about!

Sorry, bad pop culture reference.
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150. Oct8
Quoting rkay1:
Don't worry, this blog will have to do lot of wishing and rain dancing for that thing to make it far enough West and to develop.



My bother to hang on a blog when you talk like that. It is worthless really and a waste of your time I think.
Member Since: August 26, 2011 Posts: 0 Comments: 39
Quoting presslord:



Ever been over that thing? Creeps me out...


Over and under...lol....its like a mini-submarine ride.
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My niece in NC is 1 1/2 miles from the New Bern Mall and says she is supposed to be 1/2 mile outside the flood zone but she says over three feet of water in the roads and rising. No way out of her neighborhood. She said the winds weren't too bad but the rain was very heavy.
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@cnnbrk
CNN Breaking News
Newark, N.J,, mayor going door to door, warning residents to flee #hurricane on.cnn.com/nNZItz
Member Since: August 22, 2008 Posts: 12 Comments: 6010
Quoting lilasc:


We really need to wait until the storm is over for everyone and all the damage reports come in before deciding what's overhyped and what isn't... it's disrespectful to the people who have lost life or property to call it just a rainstorm. And just speaking for myself, I know I'd much rather have overhype than underwarning.


Just ignore him, he's a complete idiot and not to be taken seriously. IMO, he should be gone when Irene is gone.
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Quoting Skyepony:


Here's one.


Thank you Skye!!!

Learn something new every day
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Quoting Tazmanian:
i was wanting too no how far a way this storm is from this cam


Link


Couple hundred miles from eye i think
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Quoting presslord:



Ever been over that thing? Creeps me out...
? I thought it cool...but I'm an engineer's son.
Member Since: August 16, 2007 Posts: 6 Comments: 12461
139. Skyepony (Mod)
Quoting bassis:
Where can I find a chart that will help me define the wind barbs on the map. I never known what 1,2,3 etc hashes meant. Hope someone knows what i'm talking about. Levi posted a map by nws mesonet observations and trying to figure out what I'm looking at


Here's one.
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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.

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