Tuesday, June 16, 2015

TS Bill Blows a 3-ft Storm Surge into Matagorda Bay/ Port Lavaca, Texas

Tropical Storm Bill was blowing a storm surge into Matagorda Bay, Texas, this morning. As the center of circulation was located south the of the bay, sustained southeast winds were blowing water into the bay. Water levels at Port Lavaca were rising rapidly and approaching 3 ft above predicted tide levels after 11:00 AM CDT.

TS Bill was blowing sustained SE winds into Matagorda Bay, Texas, this morning. Storm surge levels approached 3 ft at Port Lavaca after 11:00AM CDT.

The National Hurricane Center predicts that storm surge could inundate coastal areas with 2 to 4 feet above ground level in coastal Texas if storm surges occur near the time of high tide. Bill's large circulation was pushing water levels above normal all the way from Corpus Christi, Texas, to portions of Louisiana.

 A NOAA/ NOS/ TCOON tide gauge in Port Lavaca, Texas showed water levels (red line) rising rapidly this morning. The difference between actual water levels (red line) and predicted tide levels (blue line) is the storm surge. The surge was approaching 3 ft after 11AM CDT this morning.

Bill is producing the highest tropical surge along the Central Texas Coast near Matagorda Bay/ Port Lavaca, since Hurricane Alex produced a 4.94-ft storm surge at Port Lavaca, in June, 2010. Alex was a June hurricane that made landfall in Mexico but produced a storm surge along the Texas Coast.

Tuesday, March 17, 2015

Did Pam’s Widespread Storm Surge Provide a Glimpse into the Future?

Tropical Cyclone (TC) Pam devastated a large region of the South Pacific last week, as it slammed into Vanuatu, packing winds of 165 mph (265 kph). According to Dr. Jeff Masters’ WunderBlog, TC Pam ranks among the top two most intense cyclones to visit this region; the other was TC Zoe in 2002.

MSNBC quotes Oxfam’s Vanuatu Director, Colin Collet van Rooyen, as stating, “This is likely to be one of the worst disasters ever seen in the Pacific.”

Wind and storm surge inflicted mass destruction across Vanuatu.
Image: Luo Xiangfeng/Xinhua/Associated Press

The world is just beginning to get a better picture of Pam’s destruction in Vanuatu, as aid workers are arriving in rural villages. Beyond the fatalities, injuries and material destruction, food and water shortages are also severe in some locations. ABC NEWS Australia has reported that residents on Vanuatu’s island of Moso were forced to drink salt water to stay alive. Unfortunately, storm surges often destroy the freshwater drinking supplies as they overwash small islands, leaving them without fresh water.

 Although Pam's winds were most severe in Vanuatu, its surge inundated this beach at Tarawa, Kiribati as well.
Image: Plan International Australia

Pam's surge severely damaged the causeway between Betio and Bairiki in Kiribati.
Image: Otobina Karissa Temakei

Although Pam’s fury was greatest in Vanuatu, perhaps the most surprising aspect of this cyclone was its ability to inundate island nations far from its path. Pam’s surge overwashed portions of both Kiribati (pronounced Kiribash) and Tuvalu from great distances. Pam was centered approximately 700 miles (1126 km) southwest of Tuvalu as it inundated this island nation. This remarkable span is equivalent to an Atlantic hurricane striking Georgia while inundating New York City with saltwater, or a non-tropical cyclone centered along Ireland’s southwest coast inundating Portugal.

 Pam's surge severely damaged the Nanumea School House in Tuvalu.
Image: @UNDP_Pacific

The impacts of this widespread surge are tremendous. Solomon Star News reported that the surge has displaced as many as 45% of Tuvalu’s residents, according to Tuvalu’s Prime Minister.

Pam's storm surge inflicted severe impacts on Tuvalu, located at least 700 miles (1126 km) from the storm's path.
Image: @unisdr

As we look to the future, Pam’s surge raises many important research questions. How often have tropical cyclones inundated islands with salt water from 700 miles (1126 km) away? What role does sea level rise play in an event like this? Should we expect more far-reaching surges in the future, as global climate warms and sea levels rise, and, if so, what is the best course of action to minimize losses?

Media Links:

Friday, March 13, 2015

Severe Tropical Cyclone Pam Generates Deadly Waves and Surge in Vanuatu

Severe Tropical Cyclone Pam is generating deadly waves and storm surge in Vanuatu. Pam tracked just east of Efate and Vanuatu's capital city, Port-Vila, as a large category-5 tropical cyclone. Although marine observations throughout Vanuatu are sparse, Pam is certainly generating massive waves and considerable storm surge during this horrific night.

Intense tropical cyclones generate localized storm surge and wave conditions along island chains. This graphic highlights some of the most vulnerable areas to storm surge.

 Severe Tropical Cyclone Pam is generating phenomenal waves and large storm surge. This graphic highlights some of the most vulnerable areas. Image: NOAA RGB Channel, Graphic: Hal Needham

Winds on Efate should have shifted from east to south, blowing sudden storm surge and massive waves onto the southern coastline, including the Port-Vila area. It appears that Pam may have tracked far enough east to keep Port-Vila out of the eyewall, but still expect sudden surge rises on the south coast of Efate.

 Winds on Efate shifted from east to south as Pam tracked close to the island. This wind shift increased surge levels on the southern coast of the Island. Image: www.siliconrepublic.com

Pam will next approach Erromango and Tanna, making landfall or passing just east of these islands. The wind setup on these islands is different, because they have experienced prolonged northeast winds for much of this storm. As Pam approaches these islands, winds from the northeast should increase dramatically, generating massive surges and waves along the northeast coasts. Expect "chaotic" seas on the back sides of these islands, as large waves approach from various directions.

Thursday, March 12, 2015

High Storm Surge Potential as Four Active Tropical Cyclones Spin in the Pacific and Indian Oceans

The tropics continue to threaten high storm surge potential as four active tropical cyclones spin in the Pacific and Indian Oceans.  The cyclones are Severe Tropical Cyclone Pam, which is approaching the Island Nation of Vanuatu, Severe Tropical Cyclone Olwyn, which made landfall in Western Australia and is currently tracking from north to south along the coastline, TC Nathan, which is nearly stationary off the coast of Queensland, and Tropical Storm Bavi, which is in the Northern Hemisphere, and forecast to track on the north side of Micronesia.

Four active tropical cyclones are visible in this atmospheric circulation map provided by the Earth Wind Map project.
Link: http://earth.nullschool.net/.

Severe Tropical Cyclone Pam threatens to inflict the most severe damage, as this category-5 tropical cyclone bears down on Vanuatu. On Mar 12 at 1800Z, the Joint Typhoon Warning Center (JTWC) estimated Pam’s intensity at 140 kts (259 kph, 161mph), which essentially classifies Pam as a category-5 cyclone in any rating system around the world. Pam is also a large cyclone, which gives greater potential for damaging winds and storm surge generation. Unfortunately, Pam continues to track slightly west of south, and has not yet begun a curve to the south and southeast, which means Pam is tracking perilously close to Vanuatu’s southern islands, and may make a direct landfall.

 NOAA’s visible satellite image shows TC Pam approaching Vanuatu. 
Source: http://www.ssd.noaa.gov/PS/TROP/floaters/17P/flash-vis-long.html

The JTWC estimates Pam’s maximum significant wave height at 13 m (44 ft). Significant wave height is the mean height of the highest one-third of the waves. NOAA’s WAVEWATCH 3 (WW3) ocean modeling predicts similar significant wave heights, with heights building to at least 15 m (50 ft) after Pam passes south of Vanuatu.

 NOAA’s WAVEWATCH3 forecasts significant wave heights, swell heights, wave periods, wind speed and direction.

Storm surge forecasts are not provided for Vanuatu or Fiji, however, Vanuatu Meteorological Services forecasts “phenomenal seas” exceeding 10 m (33 ft) through Sunday. In my previous post, I uploaded photos of storm surge flooding in Tuvalu, approximately 700 miles (1125 km) northeast of Pam. As this storm surge was generated when Pam was less developed, we can only imagine the terrific waves and surge that will pound the coasts of Vanuatu and Fiji during the next 24 hours.

Severe Tropical Cyclone Olwyn made landfall near Exmouth, Western Australia, as a category-3 tropical cyclone, and then took a sight seeing tour as it tracked along the coastline, maintaining category-3 status. As of 11:00AM WST, Olwyn’s maximum sustained winds were 150 kph (93 mph). This intensity would be a strong category-1 hurricane in the Atlantic.

 Severe TC Olywn made landfall in W. Australia near Exmouth, then tracked south along the coast towards Carnarvon.
Source: http://www.bom.gov.au/products/IDW60281.shtml

Tide gauge data from Western Australia's Department of Transport indicated a 1.75-m (5.7 ft) storm surge at Exmouth, and a storm tide level (tide + storm surge) of nearly 3.5 m (11.5). Higher water levels may be observed near Shark Bay, where the bay should trap the surge and enhance water levels.

 Tide gauge data from Exmouth reveals a 1.75-m storm surge (green line) and a storm tide level (storm surge + tide) of nearly 3.5 m (yellow line). Source: http://www.transport.wa.gov.au/imarine/exmouth-storm-surge.asp

As Olwyn tracks south along the coast, it may generate a 0.5- 1.0 m (1.6-3.3 ft) shelf wave along the entire southwest coast, according to Andrew Burton, Regional Forecasting Centre Operations Manager at the Australia Bureau of Meteorology, Western Australia Region. Shelf waves tend to form when cyclones travel parallel to a coastline and trap high water near the coast, such as during Hurricane Dennis when it tracked along Florida's West Coast in 2005. Olwyn's shelf wave may help elevate water levels at many locations above the level of Highest Astronomical Tide (HAT). 

Tropical Cyclone Nathan decided to pay Queensland a visit, but then got a bit indecisive north of Cape Flattery, as it made a sharp turn to the north before reaching the coast. Nathan is a category-2 tropical cyclone, but is forecast to intensify to a category-3 cyclone as it moves back to the east. Australia’s Bureau of Meteorology predicts that abnormally high tides could develop between Coen and Cape Flattery today, possibly leading to minor coastal flooding along the foreshore.

 Tropical Cyclone Nathan approached the Queensland Coast, north of Cape Flattery, before making an abrupt turn towards the north. Source: http://www.bom.gov.au/products/IDQ65002.shtml. 

I'm sure Tropical Storm Bavi is up to something interesting too, but I'll have to save that for another day. It's not very often that four active tropical cyclones are spinning at the same time! Take care, everyone, and stay safe!

TC Pam Generates Surge Flooding on Tuvalu from ~700 Miles (1125 km) away!

On Thursday, March 12, Severe Tropical Cyclone Pam generated storm surge flooding on Vaitupu Island, Tuvalu, from approximately 700 miles (1125 km) away! This large, powerful tropical cyclone is obviously displacing some serious water, and will likely generate life-threatening storm surges in the island nations of Vanuatu and Fiji.

 Severe Tropical Cyclone Pam generated storm surge and waves that flooded portions of Vaitupu Island, Tavalu, on Thursday, March 12th. At the time of this flooding, Pam was centered approximately 700 miles (1125 km) to the southwest. Image: @Niuslady

 Severe Tropical Cyclone Pam generated storm surge and waves that flooded portions of Vaitupu Island, Tavalu, on Thursday, March 12th. At the time of this flooding, Pam was centered approximately 700 miles (1125 km) to the southwest. Image: @Niuslady

Storm surge will be highest where the most intense winds blow onshore. Surges along island chains are often quite localized, as one location experiences a strong onshore wind and high surge, while locations nearby may experience strong offshore winds and low/modest surges. A lot depends on the direction the coastline faces, as well as the presence of bays and inlets, which tend to enhance surge during onshore winds.

This map provides georeferenced storm surge photos and videos, as well as Pam's storm track. It will be updated regularly though this storm. Stay safe, everybody!

This map provides georeferenced storm surge photos and videos, as well as Pam's storm track

Monday, December 15, 2014

Texas A&M Galveston Hosts Houston/Galveston Flood Protection Workshop

Texas A&M Galveston is hosting a workshop on storm surge flooding for the Houston/ Galveston area. The workshop is bringing together engineers, planners, coastal scientists, surge modelers and geographers. Organizations represented include Texas A&M Galveston, SSPEED Center, Rice University, Texas A&M College Station, UT Austin, Jackson State University, SCIPP and LSU.

Dr. William Merrell, of Texas A&M Galveston, addresses the audience at a coastal flood workshop this morning in Galveston. Photo: Hal Needham

These organizations are dialoguing about critical flood protection that are essential to protect the region from storm surge. The Houston Ship Channel, one if the largest petrochemical complexes in the world, is located in this region, but has little protection against a massive storm surge. The workshop wraps up tomorrow.

Thursday, December 11, 2014

Despite Quiet Atlantic Hurricane Season, We're Still Emerging from the "Decade of Destruction"

Well another chapter in the Atlantic Hurricane Seasons book has closed, and this year was another quiet one. This year the basin observed eight named storms, six hurricanes and two major hurricanes, which is less than the 1981-2010 climatological average of 12 named storms, six hurricanes and three major hurricanes.

2014 Atlantic Hurricane Season                         1981-2010 Climatological Average
Named Storms: 8                                               Named Storms: 12
Hurricanes: 6                                                     Hurricanes: 6
Major Hurricanes: 2                                            Major Hurricanes: 3

 Hurricane Arthur had the biggest impact on the U.S. during the 2014 Atlantic Hurricane Season. The category-2 hurricane impacted the Carolinas on July 3-4, pushing storm surge into towns like Manteo, NC.

This season was the ninth consecutive year without a major hurricane landfall in the United States, which is the longest stretch since record keeping began in 1851 (Masters 2014). It was also the ninth consecutive year in which Florida did not observe a landfalling hurricane, which is the longest period for that state (Solomon 2014). And, interestingly enough, this year also ended with a powerful typhoon striking the Philippines near the end of the Atlantic Hurricane Season

 The UNC School of Government's Public Administration program created an infographic that summarizes severe hurricane impacts in the U.S. from 2004-2013.

However, before we let our guard down, we must remember that we are just coming off a very destructive decade of hurricane activity in the Atlantic. The University of North Carolina (UNC) School of Government's Public Administration program posted a fascinating infographic, called, "Decade of Destruction: The High Cost of Hurricanes," that captures climatological statistics and human impacts of this hazardous period, which they define as 2004-2013. The infographic can be found at this link:  https://onlinempa.unc.edu/decade-destruction-high-cost-hurricanes-infographic/.

 UNC's "Decade of Destruction" Infographic provides fascinating information related to the impact of hurricanes in the United States from 2004-2013.

This infographic contains many interesting factoids about hurricane impacts during the past decade. For example, did you know that hurricanes inflicted $310 billion in losses and claimed 2,334 deaths between 2004-2013? Did you know that 77 hurricanes and 35 major hurricanes formed in the Atlantic during this period? Or that the federal government only spends $1 on disaster reduction for every $6 it spends on disaster recovery?

These are just a few examples of hurricane impacts you'll find at this site. This is an excellent resource, as it's always important to step back and look at the bigger picture. Otherwise, it's easy to let our guard down after a few quiet seasons on the home front.

           The Infographic contains a mind-boggling graphic that summarizes financial losses of recent U.S. hurricanes. Yes, those numbers are BILLIONS of dollars!

Masters, J., 2014: The 2014 Atlantic Hurricane Season Ends with Below-Average Activity. Dr. Jeff Masters Wunderblog. Available on the Web at: http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2870.

Solomon, J., 2014: For ninth year, Florida avoids hurricanes. Tampa Bay Times, November 30, 2014. Available on the Web at: http://www.tampabay.com/news/weather/for-ninth-year-florida-avoids-hurricanes/2208414.