Saturday, July 30, 2011

TS Don's Peak Storm Surge Was Generally 1-2 Feet



Image: NOAA Tides and Currents provided a webpage that provided quick access to water levels along the Gulf Coast as TS Don approached.

NOAA Tides and Currents provided a website to quickly access water levels along the Gulf Coast during Tropical Storm Don. Gauges along the Texas Coast reported elevated water levels as Don approached. The highest storm surge levels near Don's path ranged from 1-2 feet. Corpus Christi, TX reported a surge level of 1.83 feet at 9:06 PM CDT on 7/29/11, while the surge level at 8:48 PM reached 1.12 feet at Port O'Connor.

Friday, July 29, 2011

TS #1 (1960) and TS Arlene (1993) May Provide Helpful Context for TS Don's Surge



Infrared Satellite Image of TS Don (downloaded at 8:22AM CDT 7/29/11)



NHC forecast track for TS Don (downloaded at 8:22AM CDT 7/29/11)



Track of TS #1 (1960)



Track of TS Arlene (1993)


Image Source: Unisys Corporation (2011)

The National Hurricane Center's best track forecast for TS Don has shifted slightly south over the past 36 hours. This means that TS #1 (1960) and TS Arlene (1993) may provide the best historical context for TS Don's potential storm surge. Here is some information about those events:

Storm Name: TS #1
Storm Year: 1960
Landfall Location: S Texas
Maximum winds at landfall: ~ 46 MPH
Peak Surge: 3.5 feet
Peak Surge Location: Corpus Christi Bay

Storm Name: TS Arlene
Storm Year: 1993
Landfall Location: S Texas
Maximum winds at landfall: ~ 40 MPH
Peak Surge: 4 feet
Peak Surge Location: South and Central Texas Coast

Please stay tuned to your local media, local National Weather Service Forecast Office and the National Hurricane Center for official wind and storm surge forecasts.

Wednesday, July 27, 2011

Three tropical storms that generated surges in "Zone 2"







Images courtesy Unisys Corporation (2011)


Three tropical storms generated surges that reached their peak height in "Zone 2," which covers the Central Texas Coast. Here is a summary of these three events.

Name: Tropical Storm Abby
Year: 1964
Max winds at landfall: ~ 63 MPH
Peak Surge Height: 4 feet
Peak Surge Location: Matagorda to Freeport, Texas

Name: Tropical Storm Candy
Year: 1968
Max winds at landfall: ~ 69 MPH
Peak Surge Height: ~ 4.5 feet
Peak Surge Location: Palacios, Texas

Name: Tropical Storm Frances
Year: 1998
Max winds at landfall: ~ 63 MPH
Peak Surge Height: 8 feet
Peak Surge Location: Matagorda Locks, Texas


SURGEDAT identified 202 historical storm surge events along the U.S. Gulf Coast. Most tropical storms in this dataset generated surges in the 3-5 foot range. Tropical Storm Frances' 8-foot surge was very large for a tropical storm; this surge level is perhaps the highest generated by a tropical storm along the U.S. Gulf Coast.

These surge events may provide some general guidance regarding possible surge levels produced by Tropical Storm Don. Hopefully Don's surge will be closer to the typical storm surge levels generated by tropical storms in this region (3-5 feet), minimizing coastal damage.

Focus on Zone 2




The SCIPP program has recently divided the Gulf Coast into 10 storm surge zones for statistical analysis. Tropical Storm Don will likely impact "Zone 2," an area of the Central Texas Coast from near Port Lavaca to Freeport, Texas.

Surge research through the SCIPP program identified 14 surge events between 1900 and 2010 that peaked in Zone 2. The image above provides a snapshot of these surge events. The highest surge was 18.5 feet in Hurricane Carla (1961), the lowest was four feet in three separate events. Three of these events were generated by tropical storms: Tropical Storm Abby (1964), which produced a 4-foot surge between Matagorda and Freeport, TX; Tropical Storm Candy (1968), which produced a 4.5-foot surge in Palacios, TX; and Tropical Storm Frances (1998), which produced an 8-foot surge at Matagorda Locks.

These comparisons may help provide a very general guidance of surge potential from Tropical Storm Don, as Don should approach the Central Texas Coast as a tropical storm. Stay tuned to the National Hurricane Center, your local National Weather Service Forecast Office and local media outlets for the latest forecasts.

Tropical Storm Don forms in the Southern Gulf of Mexico





Tropical Storm Don formed in the Southern Gulf of Mexico this afternoon. The National Hurricane Center expects Don to the NW or WNW and approach the Central Texas Coast by Friday evening. They predict that Don will remain a tropical storm.

Stay tuned to Hurricane Hal's Storm Surge Blog for historical storm surge comparison to Don. I reference historical storm surge data on this blog to provide context for active surge events.