Tuesday, June 29, 2010

June 27 1900 CDT

Sunday, June 27, 2010
1900 CDT

In regards to Alex's potential S TX surge, I found three historical events that came off of the Yucatan Peninsula, made landfall in NE Mex, and produced 4-foot or greater surges in S TX. I've included images of those tracks in this blog. The storms are:

Hurricane Emily
Max surge: 5 feet at South Padre Island, TX
Cat 3 at landfall
Landfall wind speed 110 kts
Landfall position 75 nautical miles S of Brownsville, TX

Hurricane Gilbert
Max surge: 6 feet at South Padre Island, TX
Cat 4 at landfall
Landfall wind speed 115 kts
Landfall position about 130 nautical miles S of Brownsville, TX

Unnamed Storm
Max surge: 6 feet at South Padre Island, TX
Cat 3 at landfall
Landfall position about 120 nautical miles S of Brownsville, TX

All three of these hurricanes produced surges between 5-6 feet at S Padre Island

Comparison to Alex:
The average NHC forecast right now puts Alex's landfall at least 130 nautical miles S of Brownsville, which means it would make landfall at least as far south as all of these storms, if not farther. Also, all of these historical events interacted less with the Yucatan Peninsula, so they lost less strength, enabling all of them to make landfall as at least Cat 3 storms. Alex spent more time over the Yucatan Peninsula and will likely make landfall as a Cat 1 or 2 hurricane if the forecasts hold.

Therefore, a quick historical comparison would lead one to believe the peak surge heights in extreme S TX should be lower than these three historical events, perhaps around 3-4 feet. However, wave heights tend to be relatively high along the S TX coast, so we could see some decent waves and minor/ moderate beach erosion.

However, keep in mind that the models are divergent at this time and the surge could drastically change with a changing storm track. Just wanted to provide a quick historical comparison. Hopefully, we can get some similar discussions/ maps out to stakeholders before hurricanes strike this season.

Hurricane Hal

Disclaimer: This product is not a forecast. It is a surge estimate based on comparisons to historical storm surge events. This product is experimental and should not be used for decisions included, but not limited to, evacuations, storm preparations, insurance claims, or any decisions that may result in loss of life, injury, or personal, corporate or public economic losses. Louisiana State University, the University of Oklahoma, the SCIPP program, as well as Hal Needham and associated faculty, staff and students involved in developing this product, are not liable for any decisions that lead to injury, death, or any personal, corporate or public losses, including economic losses associated with this storm surge event.

No comments:

Post a Comment