By Dr. Jeff Masters From Weather Underground 3:50 PM GMT on November 08, 2013

After spending 48 hours at Category 5 strength, the strongest landfalling tropical cyclone in world history, Super Typhoon Haiyan, has finally weakened to a Category 4 storm. With top sustained winds of 155 mph, Haiyan is still an incredibly powerful super typhoon, but has now finished its rampage through the Central Philippine Islands, and is headed across the South China Sea towards Vietnam. Satellite loops show that Haiyan no longer has a well-defined eye, but the typhoon still has a huge area of intense thunderstorms which are bringing heavy rains to the Central Philippines. I’ve never witnessed a Category 5 storm that made landfall and stayed at Category 5 strength after spending so many hours over land, and there are very few storms that have stayed at Category 5 strength for so long.

Figure 2. Damage from Super Typhoon Haiyan in Legazpi city, Albay province, Nov. 8, 2013, about 325 miles south of Manila, Philippines. (Twitter/Ritchel M. Deleon)

Massive damage in the Philippines
Wind damage on the south shore of Samar Island in Guiuan (population 47,000) must have been catastrophic, perhaps the greatest wind damage any place on Earth has endured from a tropical cyclone in the past century. A massive storm surge must have also caused great destruction along a 20-mile swath to the north of where the eye hit, where Project NOAH was predicting a 17’ (5.3 meter) storm tide. Wind and storm surge damage were heavy in Tacloban, population 221,000, the capital of the province of Leyte, according to preliminary media reports. Much of Tacloban is at elevations less than ten feet, and several videos posted on YouTube showed a storm surge of at least ten feet moving through the city. The northern (strong) part of Haiyan’s eyewall made a direct hit on the city. Storm Chaser Jim Edds was in Tacloban, and reported that at least ten crewed boats were in the harbor, attempting to ride out the storm. Haiyan’s winds, rains, and storm surge have caused widespread devastation throughout the Central Philippines, though we do not yet have reports from the worst-hit portions of the disaster zone, including the south shore of Samar Island. Fortunately, the storm’s fast forward speed of 25 mph cut down the amount of rain the storm dumped, compared to typical typhoons that affect the Philippines. Hopefully, this will keep the death toll due to flash flooding relatively low. Flash floods are usually the biggest killer in Philippine typhoons.

Figure 3. Predicted rainfall from the 06Z November 8, 2013 run of the HWRF model, for the 96-hour period ending at 06Z November 12, 2013. A 100-mile wide swath of 8 – 16 inches of rain (medium dark red colors) as well as a 30-mile wide swath of 16 – 24″ (dark red colors) is predicted to affect Vietnam and Laos. Rains of this magnitude are likely to cause a top-five most expensive natural disaster in both nations. Image credit: NOAA/NCEP/EMC.

Haiyan an extremely dangerous storm for Vietnam and Laos
Haiyan will steadily decay over the next two days, due to colder waters and higher wind shear. However, it will still likely be a formidable Category 1 or 2 typhoon when it makes landfall in Vietnam near 06 UTC Sunday. Haiyan is expected to begin recurving to the northwest as it makes landfall, which means that a long 100+ mile stretch of the Vietnam coast will receiving the punishing winds and peak storm surge of the strong northern portion of the typhoon. With part of its circulation still over water, Haiyan will be able to pull in a huge amount of moisture that will create prodigious rains over Vietnam and Laos. I expect that the 12+ inches of rain that the storm will dump on those nations will make it a top-five most expensive natural disaster in their history.

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Original story posted Nov 8 2013 at 7:00am Est.

Philippines: thousands excavated as Typhoon Haiyan strikes

By Kate Hodal, south-east Asia correspondent From theguardian.com

Enormous storm predicted to be largest ever recorded, topping hurricane Camille in 1969, hits north Pacific

Typhoon Haiyan has hit the Philippines with winds of 195mph, with experts saying “catastrophic damage” will result from what is predicted to be the strongest tropical cyclone to make landfall in recorded history.

Thousands of people have been evacuated and thousands more have fled their homes as the category five storm sent waves as high as 5m (15ft) ashore on the islands of Leyte and Samar in the central Philippines, overturning powerlines and leaving streets knee-deep in water.

Haiyan – the Philippines’ 25th typhoon so far this year – is expected to barrel through the archipelago close to Cebu, the nation’s second-largest city and home to around 2.5 million people.

With speeds at landfall of 195mph and gusts of up to 235mph, Haiyan is believed to be stronger than the world’s last strongest tropical cyclone, hurricane Camille, which was recorded in the US at 190mph in 1969.

Although schools and offices have been closed and roughly a million people are in shelters scattered around 20 provinces, Haiyan’s powerful winds could potentially blow off the roofs of storm-proof buildings and suck out their walls due to the sheer force of its energy, experts have said.

“There aren’t too many buildings constructed that can withstand that kind of wind,” meteorology expert Jeff Masters told the Associated Press of Haiyan’s 195mph landfall. “The wind damage should be the most extreme in Philippines history.”

The storm – which is dubbed Yolanda in the Philippines – ripped iron roofs off buildings and threw trees across roads, cutting out power to entire provinces, particularly around the storm’s centre in Eastern Samar province.

“We’ve been hearing from my colleagues in [the city of] Tacloban that they’ve seen galvanised iron sheets flying just like kites,” Mai Zamora, of the charity World Vision, told the BBC. “It’s actually all around the roads now. The roads are flooded in Tacloban.”

Haiyan is expected to miss Manila, although the capital may get heavy rain and winds and has been put on low-level alert.

President Benigno Aquino III said three cargo planes, 20 navy ships and 32 military planes and helicopters were on standby for rescue operations and to provide relief. “No typhoon can bring Filipinos to their knees if we’ll be united,” he said in a televised address.

Typhoon Bopha in 2013 destroyed much of the southern islands, killing about 1,100 people and causing over $1bn worth of damage.

Haiyan is expected to lessen by Saturday as it moves towards the South China Sea, where Vietnam, Laos and China are in its potential path.

Link to video: Typhoon Haiyan brings destruction and displacement to Philippines at: http://www.theguardian.com/world/video/2013/nov/08/typhoon-haiyan-destruction-displacement-philippines-video

PHOTOS: Super Typhoon Haiyan hits the Philippines Image from Japan Meteorological Agency’s MTSAT of Haiyan over the Leyte Gulf. Photograph: Zuma/rex

Map of path of typhoon Haiyan Path of typhoon Haiyan

Super typhoon Haiyan approaches Manila Dark clouds loom over the skyscrapers of Manila. Photograph: Rouelle Umali/REX

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