Tropical Storm Washi kills 632 in the Philippines

The death toll on the Philippine island of Mindanao is at least 632, with hundreds still missing, in the wake of extreme flash flooding from Friday's passage of Tropical Storm Washi. (December 29 update: the death toll has risen to 1249, with 79 still missing.) Washi hit Mindanao as a tropical storm with 45 - 55 mph winds, crossing the island in about eighteen hours. Washi was unusually wet, as the storm was able to tap a large stream of tropical moisture extending far to the east (see the University of Wisconsin CIMSS satellite blog for imagery.) Aiding the heavy rains were sea surface temperatures that were nearly 1°C above average off the east coast of Mindanao, one of the top five warmest values on record. The exceptionally warm waters added about 7% more moisture than is usual for this time of year to the atmosphere. Washi hit a portion of the Philippines that does not see tropical storms and typhoons very often. Mindanao lies between 6°N and 9°N latitude, which is too close to the Equator for the Earth's spin to provide much help for a tropical storm trying to get spinning. Mindanao is thus hit only about once every twelve years by a significant tropical storm or typhoon. Washi's rains were not all that unusual for a Philippine tropical storm, with a peak rainfall amount of 7.44" (189 mm) observed in the city of Hinatuan. However, since the rains fell on regions where the natural forest had been illegally logged or converted to pineapple plantations, the heavy rains were able to run off quickly on the relatively barren soils and create devastating flash floods. Since the storm hit in the middle of the night, and affected an unprepared population that had no flood warning system in place, the death toll was tragically high. Washi is currently a tropical depression near the southern coast of Vietnam, and is dissipating.


Figure 1. MODIS true-color satellite image of Tropical Storm Washi at 01:45 UTC December 16, 2011, as it bore down on the Philippines. At the time, Washi had top sustatined winds of 50 mph. Image credit: NASA.


Figure 2. Track of Tropical Storm Washi. The storm crossed the Philippines unusually far to the south, near 8°N latitude.

Washi the deadliest tropical cyclone of 2011
The death toll from Washi is by far the highest for any tropical cyclone in 2011, surpassing the 215 people that died in Myanmar from Tropical Storm 02B in October. The deadliest storm in the world so far in 2011 occurred on January 11, when torrential rains of approximately 300 mm (12 inches) inundated a heavily populated, steep-sloped area about 40 miles north of Rio de Janeiro. Flash floods and mudslides from the heavy rains claimed 902 lives and caused $1.2 billion in damage. It was Brazil's deadliest storm in history. If we add Washi's toll to a list of deadliest storms of 2011 compiled by insurance broker AON Benfield, the Philippine disaster currently ranks as the third deadliest storm of 2011:



Deadliest natural disaster of 2011: the East Africa drought
While Tropical Storm Washi and the January 11 flash floods in Brazil are the deadliest storms of 2011, there is one weather-related disaster in 2011 that far surpasses these floods for number of people killed: the devastating East Africa drought in Somalia, Ethiopia, and Kenya. On July 20, the United Nations officially declared famine in two regions of southern Somalia--the first time a famine has been declared by the UN in nearly thirty years. Almost 30,000 children under the age of five were believed to have died of malnutrition in Somalia this summer, and the total death toll of this great drought is doubtless much higher. At least thirteen million people in East Africa are in need of food aid. Weather Underground has partnered with the International Rescue Committee (IRC) to help the Horn of Africa region during the ongoing famine. With the help of the Weather Underground community, we hope to raise $10,000 that will go toward helping the refugees survive the crisis. Weather Underground will match the community's donation dollar-for-dollar up to $10,000 for a total donation of $20,000. Please visit the International Rescue Committee donation page to help out. Ninety cents of every dollar donated goes directly to the people in need.

Winter storm Joachim batters Europe
One of the most intense storms in recent years carved a path across Western Europe December 15 - 17th. Named winter-storm ‘Joachim’, the center of the storm passed between France and the United Kingdom, then across the Low Countries and into Northwestern Germany and on to Poland. A peak wind gust of 211 kph (131 mph) was measured at Puy de Dome in Auvergne, France. In Germany, sustained winds of 87 mph were measured at Wendelstein at 8 pm local time on December 16th. The central pressure of Joachim fell as low as 963.8 mb (28.46”) in Braunschweig in western Germany, which may be the lowest pressure ever recorded in Germany. Wunderground's weather historian, Christopher C. Burt, has the details in his latest post.

Wunderground releases its free iPhone app
We are proud to announce that our free Weather Underground iPhone app is now live in the iTunes store. Don't worry Android users, we anticipate that the Android version will be live later today.

I'll have a new post on Tuesday.

Jeff Masters