U.S. vulnerability to sea level rise

By: Dr. Jeff Masters , 4:04 PM GMT on June 23, 2009

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In the last century, sea level rose 5 - 6 inches (13 - 15 cm) more than the global average of 7 inches (18 cm) along the U.S. Mid-Atlantic and Gulf Coasts, because coastal lands there are sinking. Over 50% of the U.S. coastline is vulnerable or highly vulnerable to sea level rise, according to the Coastal Vulnerability Index (CVI) developed by the United States Geological Survey (USGS). In the U.S., relative sea level rise (the combined effects of global sea level rise plus the fact the land is sinking) is highest along the Mississippi River Delta in Louisiana, where relative sea level rises of 3.2 ft (.98 meters) have been observed during the 20th century. This is one of the highest relative sea level rises in the world. According to the NOAA Tides and Currents sea level rise interactive tool, the U.S. tide gauges that have shown the highest rates of sea level rise over the past century are at Grand Island, LA (1.8 ft rise since 1947), Galveston, TX (1.1 ft since 1957), and Chesapeake Bay, VA (0.6 feet since 1975). Alaska and some areas along the Pacific Northwest coast are at low risk of sea level rise, because the relative sea level is actually falling at present. Land in these regions is rising as it recovers from removal of the weight of the great ice sheets that covered much of North America during the last Ice Age. For example, relative sea level at Kodiak Island, Alaska has fallen by 1.1 feet since 1975, despite the fact global sea level has been increasing.


Figure 1. Twentieth century annual relative sea-level rise rates in mm/year along the U.S. coast. The higher rates for Louisiana (9.85 millimeters [mm] per year, about 3.3 ft/century) and the mid-Atlantic region (1.75 to 4.42 mm per year, 0.6 - 1.4 ft/century) are due to land subsidence. Sea level is stable or dropping relative to the land in the Pacific Northwest, as indicated by the negative values, where the land is tectonically active or rebounding upward in response to the melting of ice sheets since the last Ice Age. Image credit: Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region (data from Zervas, 2001).

U.S. Coastal Vulnerability
The Coastal Vulnerability Index (CVI) takes into account six factors:

1) The geology of the coast. Barrier islands, river deltas, and marshes are the most vulnerable to erosion and sea level rise, while steep, rocky cliff shores are the least. Sheltered bays like Galveston Bay and Tampa Bay are less vulnerable than the exposed coasts. (Note, however, that hurricane storm surges are typically higher in sheltered bays, at least for slow-moving storms).

2) How steep the land near the coast is. Gently sloping lands are the most vulnerable. In the Gulf Coast region, the slope variable has the highest risk ranking along the Louisiana coast, the Texas coast north of Corpus Christi, and the southwest Florida coast.

3) The local rate of sea level rise. The sea level is rising faster along the western Gulf of Mexico than the eastern Gulf. The highest rates of sea-level rise in the Gulf of Mexico (and in the United States) are in the Mississippi delta region (10 mm/yr, or 1 inch/2.5 years).

4) The amount of shoreline erosion going on. Most of the U.S. coast is moderately or severely eroding, and very few areas are gaining (Figure 2).

5) The mean tidal range. Shores that have a large difference between low and high tide are less likely to get a significant storm tide--the height above mean sea level of the sum of the storm surge plus the tide. For example, in a region like Maine, which has a 12 ft range between low and high tide, a storm having a 9 ft storm surge will have a storm tide below local high tide for a quarter of a tidal cycle. Shores with a very narrow tidal range (e.g., the 2 ft tidal range common along the Texas and Louisiana Gulf Coast) will get a storm tide of 8 - 10 feet with the 9 ft storm surge in the above example. Shorelines with a narrow tidal range always get high storm tides regardless of when the storm surge hits.

6) How high the waves at shore are. Obviously, shores that experience higher wave heights are at greater risk. In the Gulf of Mexico, wave energy is highest along sections of the Texas coast and on the southern tip of the Mississippi delta.

Figure 2. Shoreline change around the United States based on surveys over the past century. All 30 coastal states are experiencing overall erosion due to natural processes (e.g., storms, sea-level rise) and human activity. If the shoreline is uncolored, no data was available. Image credit: USGS, 1985, and taken from Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region).

The Coastal Vulnerability Index (CVI) web page gives detailed maps of each section of the U.S. coast, along with specific reasons why each portion of the coast was assigned the ranking it got. A brief summary:

The Gulf Coast
The Gulf Coast has 55% of its length in the "very high" or "high" vulnerability range. Fully 41% of the coast falls in the "very high" range, far more than the 28% in that category along the Pacific coast and 23% along the Atlantic coast. The region around New Orleans is the most vulnerable region of the entire U.S. coast. The Florida Panhandle, as well as the West Florida coast, are at low to moderate risk because the land is not sinking much, wave heights are lower, and the slope of the land is relatively steep near the coast. The Texas coast is considered to be at a high to very high risk because of the relatively high mean wave height, sinking land, and shallow coastal slope.

The East Coast
The East Coast has 50% of its length in the "very high" or "high" vulnerability range. The highest vulnerability areas are typically high-energy coastlines where the regional coastal slope is low and where the major landform type is a barrier island. A significant exception to this is found in the lower Chesapeake Bay. Here, the low coastal slope, vulnerable landform type (salt marsh) and high rate of relative sea-level rise combine for a high CVI value. The coastline of northern New England, particularly Maine, shows a relatively low vulnerability to future sea-level rise. This is primarily due to the steep coastal slopes and rocky shoreline characteristic of the region, as well as the large tidal range.

The Pacific Coast
The Pacific Coast has 50% of its length in the "very high" or "high" vulnerability range. Areas of very high vulnerability include the San Francisco - Monterey Bay coast and in southern California from San Luis Obispo to San Diego, where the coast is most highly populated. The highest vulnerability areas are typically lower-lying beach areas. The low risk, least vulnerable areas generally occur at rocky headlands along cliffed coasts where the coastal slope is steep, relative sea-level is falling, tide range is large, and wave energy is lower. Examples of these areas are the northern coast of Washington, Monterey, and Cape Mendocino, California.


Figure 3. The Coast Vulnerability Index (CVI) for the U.S.

References
Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region.

National Assessment of Coastal Vulnerability to Sea-Level Rise: Preliminary Results for the U.S. Gulf of Mexico Coast (USGS, 2000).

Jeff Masters

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1227. KEEPEROFTHEGATE (Mod)
just after 9 am its 81.1f with a heat index of 97 going to a high of 86 with heat indexs at or above 100
Member Since: July 15, 2006 Posts: 178 Comments: 56141
KOG, you guys were on the News last night... it would appear that Toronto is getting ummmmm ripe :)
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Is there an upper low forming in the eastern Gulf, seeing rotation going on ...
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Quoting DestinJeff:


re: #6.... you've got to be kidding.


I second that. Way too early to even speculate.
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Blog Update
Reflector site for those at work, which now also includes Weather456, daily updates


AOI #1

AOI #2
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Small waterspout reported over Intercoastal Waterway between Melbourne Florida & Satellite Beach. - Dissipated, Can't see it on Radar, boundary moving N up the coast so could be more.
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I know the NAM is scoffed at for the tropics but it sure is insistent LOL

Still has a 1004 mb low in the NW Caribbean in the next 4 days or so.
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1217. KEEPEROFTHEGATE (Mod)
Quoting TropicalBruce:
Due to the cooler-than-average SSTs in the tropical Atlantic S of 20N and E of 45W, it seems unlikely for any t-waves to do much once they leave Africa, even if they exit at 10N latitude. Maybe things will be different in a couple of months, but right now, any solid t-waves which move off of Africa should fizzle out or become very weak.
yeah but what its surpose to do and will do are two different things
Member Since: July 15, 2006 Posts: 178 Comments: 56141
Due to the cooler-than-average SSTs in the tropical Atlantic S of 20N and E of 45W, it seems unlikely for any t-waves to do much once they leave Africa, even if they exit at 10N latitude. Maybe things will be different in a couple of months, but right now, any solid t-waves which move off of Africa should fizzle out or become very weak.
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1215. KEEPEROFTHEGATE (Mod)
Quoting kmanislander:
Good morning

Looks like the GFS likes that wave that is coming off the W coast of Africa

could be the first long tracker of the season if it holds together
Member Since: July 15, 2006 Posts: 178 Comments: 56141
Good morning

Looks like the GFS likes that wave that is coming off the W coast of Africa

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A lot of moisture associated with the emerging wave.



I just wonder if it'll do the old Cape Verde Poof once it is fully over water.
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Quoting IKE:


Latest GFS has a track across the Yucatan into the western GOM.


Yes, the GFS has been really aggressive with the ridge lately. If one of the vigorous tropical waves off the African coast successfully coalesce into a tropical cyclone, it will likely not go out to sea. The long range GFS keeps the ridge strong, and even invigorates it at times.
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1208. IKE
Quoting futuremet:


No, the A/B high will be ridging in too much into the NW Caribbean.


Latest GFS has a track across the Yucatan into the western GOM.
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1207. KEEPEROFTHEGATE (Mod)
Member Since: July 15, 2006 Posts: 178 Comments: 56141
1206. KEEPEROFTHEGATE (Mod)
Quoting Tazmanian:
# Daniel Swain Says:
June 24th, 2009 at 11:19 pm

Looking at the newest CFS%u2026moderate to strong El Nino probs look even better%u2026
it has happen to fast taz atomsphere will take a little longer to respond we go from neutral to weak from now till mid july then weak to mod from late july early aug by late august early sept to strong by mid sept with a nice mild and wet 09/10 winter by dec
Member Since: July 15, 2006 Posts: 178 Comments: 56141
Quoting IKE:
believable?


No, the A/B high will be ridging in too much into the NW Caribbean.
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1204. IKE
New Orleans long-term discussion.....

"BETTER RAIN CHANCES WILL COME INTO PLAY EARLY NEXT WEEK. AN UPPER
LEVEL TROUGH MOVING THROUGH CANADA WILL TRACK SEWD ACROSS THE
NORTHERN PLAINS. THIS TROUGH WILL STRENGTHEN AS IS MOVES INTO THE
GREAT LAKES REGION AND SEND A COLD FRONT SOUTHWARD. THIS BOUNDARY IS
EXPECTED TO STALL EITHER JUST NORTH OF THE AREA OR VERY CLOSE TO THE
GULF COAST. THE RESULT WILL BE INCREASED RAIN CHANCES MONDAY THROUGH
WEDNESDAY. HAVE CHNC POPS FOR NOW AND MAY HAVE TO INCREASE POPS EVEN
HIGHER."
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1203. IKE
Cold front makes it into the deep south early next week.

This from the Tallahassee discussion...

"AFTER SUN...SYNOPTIC SCALE FORCES GAIN GREATER INFLUENCE OVER OUR WX
THAT THE SEA BREEZE. AS THE SRN NEW ENGLAND TROUGH LIFTS NEWD...
ENERGY OVER THE UPPER GREAT LAKES WILL SWING INTO THE ERN LAKES NEAR
SRN ONTARIO/UPSTATE NY. THIS WILL RESULT IN A MEAN LONG WAVE TROUGH
AXIS OVER THE ERN U.S. THIS TROUGHING WILL HELP ANOTHER FRONT TO
SETTLE INTO THE DEEP S...ATYPICAL FOR THIS TIME OF YEAR FOR SURE...
BUT THEN WHAT HAS BEEN TYPICAL ABOUT 2009. THIS FRONT WILL BE
APPROACHING OUR NRN ZONES ON MON AND BE IN THE VICINITY ON TUE. THE
PRESENCE OF THE FRONT AND DEEP LAYER MOISTURE (WITH PW WELL OVER 2
INCHES) WILL RESULT IN AT OR ABOVE CLIMO POPS. AS THE BOUNDARY
SETTLES S OF THE AREA ON WED AND THU...NRN AREAS WILL BEGIN TO DRY
OUT AND POPS WILL BE LOWERED ACCORDINGLY. TEMPS THROUGH THE PERIOD
WILL BE AT OR SLIGHTLY ABOVE NORMAL...EXCEPT FOR DAYTIME HIGHS ON
MON WHICH WILL BE SLIGHTLY COOLER THAN NORMAL DUE TO ABUNDANT CLOUD
COVER."
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1202. KEEPEROFTHEGATE (Mod)
latest GFS surface anal 00z with 12 24 36 48 hr forecast








Member Since: July 15, 2006 Posts: 178 Comments: 56141
# Daniel Swain Says:
June 24th, 2009 at 11:19 pm

Looking at the newest CFS…moderate to strong El Nino probs look even better…
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1200. KEEPEROFTHEGATE (Mod)
its weaken but still a large and expansive EW

latest mpe prcip eumstat sat image at 1130 utc
Member Since: July 15, 2006 Posts: 178 Comments: 56141
MEDIA ADVISORY: 33-09

NASA SETS COVERAGE FOR GOES-O LAUNCH ON JUNE 26

CAPE CANAVERAL, Fla. -- The Geostationary Operational Environmental
Satellite-O, or GOES-O, is scheduled for a liftoff on Friday, June
26, from Cape Canaveral Air Force Station in Florida. The one-hour
launch window extends from 6:14 to 7:14 p.m. EDT.

NASA will provide television, Internet and photo coverage of the
launch starting with a prelaunch news conference at 1 p.m., on
Thursday, June 25, at the NASA Kennedy Space Center Press Site.

GOES-O is the second of three in the current series of geostationary
weather and environmental satellites built for NASA by Boeing Space
and Intelligence Systems. It will be launched into orbit for NASA
aboard a Boeing Delta IV rocket.

Participating in the June 25 prelaunch news conference will be:



Gary Davis, director, Office of Systems Development
NOAA Satellite and Information Service


Kris Walsh, Commercial Programs manager
United Launch Alliance


Ken Heinly, director, Launch Products and Services
Boeing


Andre Dress, GOES-O deputy project manager
NASA Goddard Space Flight Center


Charlie Maloney, GOES-O program manager
Boeing Space and Intelligence Systems


Bart Hagemeyer, meteorologist in charge
NOAA National Weather Service Forecast Office, Melbourne, Fla.


Joel Tumbiolo, Delta IV launch weather officer
45th Weather Squadron, Cape Canaveral Air Force Station


NASA Television will carry the prelaunch news conference on the
"public channel." On launch day, June 26, NASA TV countdown coverage
will begin on the "media channel" at 4 p.m. and will conclude 30
minutes after liftoff. For NASA TV downlink information, schedules
and links to streaming video, visit:

http://www.nasa.gov/ntv

Audio only of the prelaunch news conference and the launch coverage
will be carried on the NASA "V" circuits which may be accessed by
dialing 321-867-1220, - 1240, -1260 and -7135. On launch day,
"Mission Audio," the launch conductor's countdown activities without
NASA TV launch commentary, will be carried on 321-867-7135 starting
at noon. Launch will also be available on local amateur VHF radio
frequency 146.940 MHz heard within Brevard County.

Prelaunch and launch day coverage of GOES-O mission will be available
on the NASA Web site at:

http://www.nasa.gov

Live countdown coverage on NASA's launch blog begins at 4 p.m., on
June 26. Coverage features real-time updates of countdown milestones,
as well as streaming video and podcast of launch. To access these
features, go to NASA's GOES-O mission Web site at:

http://www.nasa.gov/goes-o

GOES-O will also provide expanded capability for the space and solar
environment-monitoring instruments. Forecasts and warnings for solar
disturbances will be enhanced. GOES-O data will protect investments
of billions of dollars by the government and private sector for
assets on the ground and in space.

GOES-O will feature a highly stable pointing platform, which will
improve the performance of its Imager and Sounder that are important
instruments for creating daily weather-prediction models and for
hurricane forecasting. Data from GOES-O will be valuable for the
National Oceanic and Atmospheric Administration's National Ocean
Service, which provides oceanographic circulation models and
forecasts for U.S. coastal communities.

As with all of NOAA's geostationary and polar-orbiting weather
satellites, GOES-O will be able to relay distress signals detected
from emergency locator beacons on the ground and at sea.

NASA's Goddard Space Flight Center in Maryland is responsible for
designing and developing the spacecraft and its instruments for NOAA.

For further information about GOES-O's launch coverage, contact the
Kennedy Space Center News Center at 321-867-2468.
Member Since: July 8, 2005 Posts: 259 Comments: 24580
1198. KEEPEROFTHEGATE (Mod)
Member Since: July 15, 2006 Posts: 178 Comments: 56141
1197. IKE
Quoting ftpiercecane:
Is the gfs still wanting to develop that wave?


That one and apparently another behind it.
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1196. WxLogic
Quoting Weather456:
Good Morning;

Strongest Wave of the Season



Good morning!!!

If it keeps up its strength it could pretty well materialize into what the GFS has been hinting. If it does... then anything can be expected this early HUR season. Of course it will have to first survive the high shear in the Central ATL.
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Is the gfs still wanting to develop that wave?
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Weather456
you make me a happy man I will watch that wave
I think it will be our first ts soon after passing 50 w
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1193. IKE
Impressive looking wave for the end of June.
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1192. KEEPEROFTHEGATE (Mod)


AOI
MARK
11N/13W
Member Since: July 15, 2006 Posts: 178 Comments: 56141
1191. IKE
Looks like a cold-front will make it to the gulf coast by early next week....Birmingham,AL. discussion has it going south of that area, into southern AL. and NW FL.
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Quoting panamasteve:


If this happens--could be a busted 4th of July somewhere on the Gulf Coast.
We do need some rain,,,and a little relief from the heat..
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Good morning all :)
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morning
456 very good analysis this morning. total agrement with your take on the two possible threat areas today. the one that takes my interest is the Afican disturbance, since i reside in St Lucia. i remember in august of 2007 when the GFS was consistently hinted of the genesis of a disturbance coming off the african coast. this eventually evolved into hurricane Dean , which passed in channel between St Lucia and Martinique. the disturbance exiting the African coast looks almost the same strengh like the one that formed Dean. Looking at the factors that could caused cyclogenesis, it is only the SST in the far eastern atlantic that might be an inhibiting factor. the teperature is about 78deg F and gets better westward to about 50 deg W where the temperature is about 83 deg F, and increases all the way to the lesser antilles

i believe that the other models will come on board very soon and we will have something to monitor towards the weekend. the partial qs this morning is showing the possibility of a LLc which is part over water and on the coast. a further QS is neccessary to confirm this. if this so then the GFS could be right with the formation of a cyclone as soon as the tropical wave emerge over water. Time will tell
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Quoting IKE:
believable?


If this happens--could be a busted 4th of July somewhere on the Gulf Coast.
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Are any of you interested in reporting daily rainfall to assist National Weather Service, the media, university studies, etc? CoCoRaHS is a volunteer organization currently 8000 strong that report rain/hail/snowfall on a daily basis to do just that. We are striving to have a volunteer for every square mile of the country, and have a long way to go. Those of you living in Florida understand how it can be sunny in your front yard and storming in the back yard. We could really use your assistance to help get a complete picture of this state's crazy weather, especially during tropical events. If you are interested, please email me at sandhockey@yahoo.com or visit the CoCoRaHS.org website. Thanks for your consideration.
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Good Morning;

Strongest Wave of the Season

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1182. IKE
believable?
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Morning everyone. Had quite the flood event here yesterday. Good thing it didn't rain anymore. In 2 hours time we ended up with this. This is a street not too far away from the house.



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1180. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #21
TROPICAL STORM NANGKA (T0904)
15:00 PM JST June 25 2009
===================================

Subject: Category One Typhoon In The South China Sea

At 6:00 AM UTC, Tropical Storm Nangka (994 hPa) located at 15.9N 118.0E has 10 minute sustained winds of 40 knots with gusts of 60 knots. The storm is reported as moving northwest at 12 knots.

Gale-Force Winds
================
150 NM from the center in southern quadrant
120 NM from the center in northern quadrant

Dvorak Intensity: T2.5

Forecast and Intensity
=====================
24 HRS: 19.8N 115.8E - 40 knots (Tropical Storm/CAT 1)
48 HRS: 23.4N 116.1E - 35 knots (Tropical Storm/CAT 1)
72 HRS: 26.7N 119.3E - Tropical Depression
Member Since: May 24, 2006 Posts: 52 Comments: 47099
1178. GatorWX
I feel like such a douche saying that!, night man
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1177. GatorWX
in a while crocodile.....yeah, lol
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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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