Storm Surge Maps?

[Jam151]

Are they any maps online that display storm surge heights and extent for past hurricane landfalls?

[margiek]

Are they any maps online that display storm surge heights and extent for past hurricane landfalls?

FEMA has storm surge maps for Katrina and Rita and probably others, online.

USACE has Hurricane Evacuation Studies that include maps of storm surge potential online as well.

[wxman57]

FEMA has storm surge maps for Katrina and Rita and probably others, online.

USACE has Hurricane Evacuation Studies that include maps of storm surge potential online as well.

Can't find anything on FEMA's page. Link, please?

There aren't many good post-storm storm surge maps online. Probably the most-studied storm with maps online is Ike. The Houston and Lake Charles NWS offices have posted some great maps:

http://www.srh.noaa.gov/hgx/projects/ik ... erview.htm

http://www.srh.noaa.gov/lch/ike/ikesurge.php

[margiek]

All you had to do was Google ("fema katrina surge"). I don't have the hard links saved because they've been changed a couple times.

These FEMA post-storm surge maps are excellent.

http://www.fema.gov/hazard/flood/recove ... _maps.shtm

http://www.fema.gov/graphics/hazard/flo ... erview.gif

There are another set of maps for LA.

Rita: http://www.fema.gov/hazard/flood/recove ... _maps.shtm

I couldn't believe that MEMA did not use the HES maps for MS and still does not have a link to them on the MEMA website. The HES are based on thousands of SLOSH runs and provide a detailed worst case (MOM) for each SSHS category for any coastal location, to get an understanding of flood potential in that area.

HES Home: http://chps.sam.usace.army.mil/ushesdata/heshome.htm

Example, surge map for Jackson Cty, MS: http://chps.sam.usace.army.mil/ushesdata/heshome.htm

[wxman57]

Those FEMA images look pretty bad. I don't see any inundation maps, just squares with letters/numbers that don't represent water depths. Below is an example of what I consider to be an excellent surge map. It's one from the Lake Charles Ike Surge page:

http://www.srh.noaa.gov/lch/ike/Jeffers ... dation.pdf

Another good place is the ADCIRC web site. ADCIRC is short for "ADvanced CIRCulation", a new high-res storm surge model. Researchers are currently using LIDAR (radar that measures topography) to map the Texas coast for inclusion into their model. The model already has the Louisiana coast in it. They have excellent maps from recent storms like Gustav, Ike or Katrina:

Gustav:
http://www.unc.edu/ims/adcirc/hurricanes/gustav.html

Ike:
http://www.unc.edu/ims/adcirc/hurricanes/ike.html

Here's a surge inundation map (not height above MSL) from ADCIRC:

http://www.unc.edu/ims/adcirc/hurricane ... thline.jpg

[margiek]

Those FEMA images look pretty bad. I don't see any inundation maps, just squares with letters/numbers that don't represent water depths.

Each of those squares identfies a map by letter and number. You could have tried at least reading the first paragraph of the first link that I posted upon your request:

"Maps showing the extent and magnitude of Hurricane Katrina’s surge, as well as information on advisory flood data, were created for the areas of Harrison, Hancock, and Jackson Counties in Mississippi that were most severely impacted by coastal flooding. These maps show high water marks surveyed after the storm, an inundation limit developed from these surveyed points, and FEMA’s Advisory Base Flood Elevations (ABFEs) and estimated zone of wave impacts. To access the Katrina Recovery Maps for each Mississippi county, click on the links below or on the map above."

And below, sure enough, there is a link to each of the three coastal counties.

And, if you click on one of those links, there are maps corresponding to each section on the overview. For instance, here is section F-10 of Hancock County:

http://www.fema.gov/pdf/hazard/flood/re ... ms-f10.pdf

The Katrina overview maps for MS and LA (I gave the link for the MS one) are useful because they show the unprecedented scope of the surge at a high level.

SLOSH has a proven track record of accurate surge prediction.

[MGC]

I would not use the surge maps as they are inaccurate. Katrina, a Cat-3 flooded areas listed as Cat-5. Camille, a Cat-5 only flooded areas listed as Cat-3.....MGC

[hurricanetrack]

FWIW, my company produced the public version of North Carolina's storm surge maps back in, uh, 1999. Yikes. That long ago. Anyhow, I still have them hosted on hurricanetrack.com for anyone interested:

http://www.hurricanetrack.com/ncstormsurge

I also prepared the maps for Georgia's six coastal counties in 2000. I have no idea where those are now.

I enjoyed working with the COE and their flood plain specialists. It was an exciting project- funded by FEMA's Project Impact program. We printed 30,000 of these maps and gave them out all over eastern NC through gorcery stores, etc. It was a great project and I won an award from FEMA for it. I can only imainge what could be done using today's technology. Geez- you could CG an entire city and show different scenarios of storm surge flooding from any hurricane track that you wanted. And it could all be done on a new Mac- not some Silicon Graphics machine. Heck, you might get it done on an iPhone (JK).

[wxman57]

Those FEMA images look pretty bad. I don't see any inundation maps, just squares with letters/numbers that don't represent water depths.

Each of those squares identfies a map by letter and number. You could have tried at least reading the first paragraph of the first link that I posted upon your request:

"Maps showing the extent and magnitude of Hurricane Katrina’s surge, as well as information on advisory flood data, were created for the areas of Harrison, Hancock, and Jackson Counties in Mississippi that were most severely impacted by coastal flooding. These maps show high water marks surveyed after the storm, an inundation limit developed from these surveyed points, and FEMA’s Advisory Base Flood Elevations (ABFEs) and estimated zone of wave impacts. To access the Katrina Recovery Maps for each Mississippi county, click on the links below or on the map above."

And below, sure enough, there is a link to each of the three coastal counties.

And, if you click on one of those links, there are maps corresponding to each section on the overview. For instance, here is section F-10 of Hancock County:

http://www.fema.gov/pdf/hazard/flood/re ... ms-f10.pdf

The Katrina overview maps for MS and LA (I gave the link for the MS one) are useful because they show the unprecedented scope of the surge at a high level.

SLOSH has a proven track record of accurate surge prediction.

Yes, I see know. It wasn't obvious on the web page. By the way, those heights are above MSL. They're not inundation depths.

[margiek]

By the way, those heights are above MSL. They're not inundation depths.

Of course surge height is measured as the height above a tidal datum: local mean sea level (or, for example, MLLW). Surge is roughly defined as a rise from the normal water level.

The way to determine the inundation depth at any point on the surge inundation map is to go to the corresponding topographic map that FEMA provided (on the same web page), which uses, as you would expect, NAVD-88. You can then use the height the water reached at nearby HWM (also in NAVD-88) to give a rough estimate of the inundation at that location (keeping in mind that this does not include wave height or wave runup). You can also eyeball the estimated surge height from the overview map for a rough estimate, even though, strictly speaking, you can't translate from the surge height to a fixed geodetic datum without referencing the tidal datum from a tidal benchmark at one of the nearby NOS stations (which is how the surge heights are determined from the HWM in the first place), but that would get you in the ballpark.

The detail in the inundation shown in the FEMA maps (that is, identifying the areas that were inundated by the surge) was made possible by use of recent LIDAR data, which provided a pretty good approximation.

The corresponding topo map:

http://www.fema.gov/pdf/hazard/flood/re ... po-f10.pdf

[MGC]

And don't forget that those high water marks were with no wave action. I would take the measurment that used an interior water level mark with a grain of salt as the entire interior of the structure may not have flooded completely thus not reavealing the true exterior water hight....MGC

[margiek]

And don't forget that those high water marks were with no wave action. I would take the measurment that used an interior water level mark with a grain of salt as the entire interior of the structure may not have flooded completely thus not reavealing the true exterior water hight....MGC

The process of obtaining the HWM includes ranking the quality of each one (it's something like poor, good, excellent, or similar type wording). I believe the final assessment used only the HWM that have the highest rating, so the confidence in these were high.