Typhoon Haiyan

Post Landfall 1 | Summary
Posting Date: November 11, 2013, 5:00:00 AM

 In the three days since Super Typhoon Haiyan roared through the central Philippines, the scale of the devastation revealed in its wake continues to escalate. Preliminary analyses suggest that Haiyan (named Yolanda in the Philippines) may have been the strongest storm to make landfall anywhere in the world in recorded history. With sustained winds estimated at 315 km/h (196 mph) at its first landfall, according to the Joint Typhoon Warning Center (JTWC), the storm maintained impressive wind speeds as it traversed the Philippines. The national meteorological agency, PAGASA, reports that Haiyan made a total of six landfalls through the Visayas region before exiting into the South China Sea.

The catastrophic destruction wrought by the storm’s winds and massive storm surge are becoming clearer, but the full extent of the damage will not be known for some time. Power, communications, and water supplies remain down throughout the affected region, and officials have yet to reach remote areas cut off by blocked roads, landslides, and floods. The preliminary death toll surpasses 1,000 people, but thousands more are missing and feared dead.

 Wind, Storm Surge, and Precipitation Intensity

Super Typhoon Haiyan made landfall on the southern tip of Samar Island early morning local time on November 8. As there are no wind speed or central pressure measurements yet available, there is still a significant amount of uncertainty regarding the storm’s actual intensity at landfall. Estimates from leading agencies, including the JTWC, the Japan Meteorological Agency (JMA), and PAGASA, are all derived based on satellite imagery and are summarized in the table below.

 *Converted from 10-min average winds.

If the wind speed at landfall estimate from the JTWC holds true, Haiyan would be the strongest recorded cyclone to make landfall anywhere in the world. The previous storm to hold that record was Hurricane Camille, which made landfall on the Gulf Coast of the United States in 1969 with winds of 305 km/h (190 mph). The strongest storm to make landfall in the Northwest Pacific before Haiyan was Super Typhoon Megi, which struck the Luzon region of the Philippines in 2010 with winds of 290 km/h (180 mph).

Ahead of the storm, PAGASA’s storm surge prediction project, named NOAH, forecast maximum storm tides (normal tide level plus storm surge) of more than 15 feet near the region of landfall.

Precipitation totals of 350 mm were observed by NASA’s TRMM satellite, although higher amounts may ultimately be recorded by rain gauges as communication and power come back online. Haiyan’s rapid forward motion kept totals from being even higher, but some inland flooding has likely occurred.

Reported Impact

The storm made its initial landfall in the city of Guiuan (population of 47,000) in Eastern Samar province. Preliminary reports from a Philippines Air Force reconnaissance flight indicate that all structures in the city were either destroyed or sustained significant damage, including a newly installed PAGASA Doppler radar. Trees were uprooted, cars overturned, and debris strewn about the devastated city.

 

Guiuan, Eastern Samar (Source: Philippines Air Force via https://www.facebook.com/media/set/?set=a.356701284467306.1073741835.323973651073403)

 Tacloban City, the capital and biggest city (population of 220,000) of Leyte province, also bore the brunt of the storm’s ravages, as it was located just north of the storm’s track, where the highest winds and surge are expected. Fierce winds lasted for several hours and were comparable to those of an EF-3/EF-4 tornado. Eyewitness and video accounts indicate that a storm tide of at least 10 feet inundated the downtown area.

Leaves were stripped from trees, power lines were snapped, and buildings were flattened over a widespread area. According to some reports, not a single building in the city appears to have survived intact. More than 1,000 people are believed to have died in Tacloban, although the mayor of the city said that the final death toll could be much higher. The storm surge is believed to be the most significant cause of damage and casualties.

According to official government reports, more than 2 million families (nearly 10 million people) have been affected by the storm in the Philippines, with more than 650,000 people displaced. The islands of Leyte, Samar, and northern Cebu are the worst affected. Relief efforts from both national and international agencies are under way, but damage to infrastructure, including to roads and airports, is hindering operations. The economic cost of the typhoon is expected to be the highest from a natural disaster in the Philippines’ history, although only a small portion of it is expected to be insured.

 Vietnam and China

 After leaving the Philippines, Haiyan entered the cooler waters of the South China Sea where it gradually weakened. As of the JMA’s 21:00 UTC advisory on November 10, Haiyan is making landfall in northern Vietnam with maximum 10-minute sustained winds of 108 km/h (67 mph). It is expected to dissipate on Monday as it moves inland into southern China. While its much reduced wind speeds are not expected to cause significant structural damage, heavy precipitation poses a major threat of flooding and landslides in both Vietnam and China.

In advance of the storm, more than 600,000 people were evacuated form coastal regions in Vietnam, although many have been allowed to return home as the storm is expected to come ashore farther north, near the Chinese border, than previously forecast. China has issued a typhoon alert for Hainan Island and the provinces of Guangdong and Guangxi.

AIR is continuing to collect data on Haiyan’s parameters to model the event using the AIR Typhoon Model for Southeast Asia. AIR plans to issue an industry loss estimate later this week.

Post Landfall 1 | Downloads
Posting Date: November 11, 2013, 5:00:00 AM