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Category 1 Typhoon Haiyan Hitting Vietnam; Extreme Damage in the Philippines

By: Dr. Jeff Masters, 7:09 PM GMT on November 10, 2013

Typhoon Haiyan is closing in on the northern Vietnam coast near the Chinese border as a much-weakened Category 1 storm with 85 mph winds, after devastating the Philippines on Thursday and Friday as an extreme Category 5 storm with top winds of 195 mph. Satellite loops show that Haiyan no longer has a well-defined eye, but the typhoon still has a large area of intense thunderstorms which are bringing heavy rains of up to 1.5 inches per hour to Vietnam and Southeastern China. Haiyan will weaken and dissipate by Monday as it pushes inland over southern China, but the 8+ inches of rain that the storm will dump on Vietnam and Southeastern China will cause major flooding problems.

Haiyan is the third significant storm to hit Vietnam in the past six weeks. According to reliefweb.int, in the first two weeks of October, Central Vietnam was hit by two Category 1 storms, Typhoons Wutip and Nari, leaving behind significant damages in nine provinces. The total economic loss due to Nari was $71 million. Typhoon Wutip's damages were estimated at $663 million. According to EM-DAT, this makes Wutip the second most expensive natural disaster in Vietnamese history, behind the $785 million in damages caused by 2009's Typhoon Ketsana.

Figure 1. MODIS satellite image of Typhoon Haiyan taken at approximately 4:25 UTC November 10, 2013. At the time, Haiyan was a Category 1 storm with top winds of 90 mph. Image credit: NASA.

Extreme damage in the Philippines
With a preliminary death toll of 1,200, Haiyan already ranks as the 8th deadliest typhoon in Philippines history. The deadliest typhoon in Philippines history was Typhoon Thelma of 1991, which killed between 5101 - 8000 people, reports wunderground's weather historian Christopher C. Burt in his latest post on Philippines typhoon history. Haiyan will become the deadest typhoon in Philippines history if the estimates today of 10,000 dead hold up. Bloomberg Industries is estimating insured damages of $2 billion and total economic damages of $14 billion, making Haiyan the most expensive natural disaster in Philippines history. This is the third time in the past 12 months the Philippines have set a new record for their most expensive natural disaster in history. The record was initially set by Typhoon Bopha of December 2012, with $1.7 billion in damage; that record was beaten by the $2.2 billion in damage done by the August 2013 floods on Luzon caused by moisture associated with Typhoon Trami.

Figure 2. A Filipino boy carries bottled water amongst the damaged houses where a ship was washed ashore in Tacloban city, Leyte province, central Philippines on Sunday, Nov. 10, 2013. (AP Photo/Aaron Favila)

The greatest death toll from Haiyan is likely to be in the capital of Leyte, Tacloban (population 221,000), which received a direct hit from Haiyan's northern eyewall. A stark eyewitness account posted to Facebook of what Tacloban endured, by storm chaser Josh Morgerman of iCyclone.com:

"First off, Tacloban City is devastated. The city is a horrid landscape of smashed buildings and completely defoliated trees, with widespread looting and unclaimed bodies decaying in the open air. The typhoon moved fast and didn't last long--only a few hours--but it struck the city with absolutely terrifying ferocity. At the height of the storm, as the wind rose to a scream, as windows exploded and as our solid-concrete downtown hotel trembled from the impact of flying debris, as pictures blew off the walls and as children became hysterical, a tremendous storm surge swept the entire downtown. Waterfront blocks were reduced to heaps of rubble. In our hotel, trapped first-floor guests smashed the windows of their rooms to keep from drowning and screamed for help, and we had to drop our cameras and pull them out on mattresses and physically carry the elderly and disabled to the second floor. Mark's leg was ripped open by a piece of debris and he'll require surgery. The city has no communication with the outside world. The hospitals are overflowing with the critically injured. The surrounding communities are mowed down. After a bleak night in a hot, pitch-black, trashed hotel, James, Mark, and I managed to get out of the city on a military chopper and get to Cebu via a C-130--sitting next to corpses in body bags. Meteorologically, Super Typhoon HAIYAN was fascinating; from a human-interest standpoint, it was utterly ghastly. It's been difficult to process."

Video 1. Storm chasers James Reynolds, Josh Morgerman and Mark Thomas of iCyclone.com were in the capital of Leyte Province, Tacloban, which received a direct hit from Super Typhoon Haiyan. Video includes the remarkable winds and storm surge of Haiyan, and the rescue of injured people from flood waters.

Extreme damage near the initial landfall location
Rescuers have finally reached the south shore of Samar Island and the city of Guiuan (population 47,000), where Haiyan initially made landfall with winds estimated at 195 mph. Typhoon and hurricane maximum wind speed estimates are only valid for over water exposure, and winds over land are typically reduced by about 15%, due to friction. This would put Haiyan's winds at 165 mph over land areas on the south shore of Guiuan Island. This is equivalent to a high end EF-3 tornado, and damage photos from the town do show tornado-like damage--though much of the worst damage appears to be due to the storm surge. A new Doppler radar that was scheduled to go into operation in 2014 was blown off the tower it was installed on.

Figure 3. Col John Sanchez, Central Command, AFP took these photos from a PAF Nomad aircracft over Guiuan, E. Samar, Sunday morning from 1030H to 1045H: "Guiuan bore the brunt of Super Typhoon Yolanda at its first landfall Friday. One hundred percent of the structures either had their roofs blown away or sustained major damage. Nearly all coconut trees fell. We saw people in the streets, seemingly dazed. Trucks and cars were left in the streets where they were stopped in their tracks as Yolanda struck. We were probably the first outsiders to fly over the area since Friday and obviously, no relief goods have arrived there yet. It was almost lunchtime but there was no smoke from cooking fires. The 2.4 km runway is clear of debris and could still be used by C130 aircraft. Yolanda is probably worse than Pablo and the only reason why we have no reports of casualties up to now is that communications systems in Region 8 are down." Image credit: Col John Sanchez , Central Command, AFP.

Haiyan's place in history
Haiyan hit Guiuan, on the Philippine island of Samar, at 4:40 am local time November 8, 2013 (20:40 UTC November 7.) Three hours before landfall, the Joint Typhoon Warning Center (JTWC) assessed Haiyan’s sustained winds at 195 mph, gusting to 235 mph, making it the 4th strongest tropical cyclone in world history. Satellite loops show that Haiyan weakened only slightly, if at all, in the two hours after JTWC’s advisory, so the super typhoon likely made landfall with winds near 195 mph. The next JTWC intensity estimate, for 00Z UTC November 8, about three hours after landfall, put the top winds at 185 mph. Averaging together these estimates gives a strength of 190 mph an hour after landfall. Thus, Haiyan had winds of 190 - 195 mph at landfall, making it the strongest tropical cyclone on record to make landfall in world history. The previous record was held by the Atlantic's Hurricane Camille of 1969, which made landfall in Mississippi with 190 mph winds.

The Japan Meteorological Agency (JMA), which uses their own techniques to estimate typhoon strength via satellite imagery, put Haiyan's peak strength at 125 knots (145 mph), using a 10-minute averaging time for wind speeds. The Philippines weather agency (PAGASA) also uses a 10-minute averaging time for their typhoon wind advisories, and winds estimated by either JMA or PAGASA for Haiyan have appeared in the media, resulting in some confusion about what the typhoon's winds were at landfall. The averaging time used by JTWC and NHC is 1-minute, resulting in a higher wind estimate. To convert from 10-minute averaged winds to 1-minute average, one conversion factor that is commonly used is to multiply by 1.14--though lower conversion factors are sometimes used. Note that even after correcting for the difference between using 1-minute and 10-minute wind averaging times, the JMA wind estimates are well below what JTWC estimated; JMA consistently estimates weaker winds for high-end typhoons than JTWC. Since we have no actual measurements of the winds or pressure from Haiyan at landfall, we don't know which agency made a more accurate wind estimate.

With Angela Fritz' help, I've put together a list of most intense world tropical cyclones at landfall, using 1-minute averaging times. The list is unofficial and may have omissions; email me at jmasters@wunderground.com if you have suggestions for improvement:

Tropical disturbance 90W will bring more heavy rain to the Philippines
A tropical disturbance located east of the Philippines near 5°N 136°E, (Invest 90W), is steadily organizing, and has the potential to become a tropical depression by Monday. The disturbance has developed an elongated surface circulation and a respectable amount of heavy thunderstorm activity. Wind shear is low, but the disturbance is too close to the Equator intensify quickly, since the storm will not be able to leverage Earth's spin to get itself spinning. The disturbance has a high chance of development, according to Sunday's 17:30 UTC Western Pacific Tropical Weather Discussion by the Joint Typhoon Warning Center. A number of recent runs by the GFS model have predicted that the disturbance will organize into a tropical depression or weak tropical storm by Tuesday, when it will pass through the southern or central Philippines. I expect 90W will be organized enough to bring heavy rains of 2 - 4" to the area devastated by Super Typhoon Haiyan on Tuesday and Wednesday, and give a 70% chance it will be a tropical depression or weak tropical storm by Tuesday. The Japan Meteorological Agency is already classifying 90W as a tropical depression.

The Red Cross is appealing for donations.

Portlight disaster relief charity is reaching out to disability organizations in the Philippines to provide durable medical equipment. and welcomes donations.

Google Person Finder: Typhoon Yolanda - Google.org

Wunderblogger Lee Grenci discusses mesovorticies in the eye of Haiyan in his latest post.
Wunderground's weather historian Christopher C. Burt reviews the Philippine's typhoon history.
The University of Wisconsin CIMSS Satellite Blog has a great collection of satellite images of Haiyan.
NOAA's Michael Folmer has a post showing the unusual burst of lightning that occurred at landfall in Haiyan.
Hurricanes and Climate Change: Huge Dangers, Huge Unknows, my August 2013 blog post.
Storm Chaser James Reynolds on Twitter, from Tacloban, Leyte.
Storm Chaser Jim Edds on Twitter, from Tacloban, Leyte.

Jeff Masters


The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.