Dangerous Typhoon Wipha Drenching Japan

Large and powerful Category 1 Typhoon Wipha is bearing down on Japan as the storm races northeast at 28 mph. Wipha is likely to be the strongest typhoon to hit Japan since Typhoon Tokage of October 2004, according to the Japan Meteorological Agency. Wipha is merging with a cold front and undergoing the transition to an extratropical storm--the same process Hurricane Sandy underwent as it approached landfall in October 2012. While Typhoon Wipha is not as powerful as Sandy, it does have a huge area of winds in excess of 50 knots (57.5 mph), which extend out 130 miles to the left of the center. Since the center of Wipha is expected to graze the southern coast of Japan today, and the storm will only weaken slightly, a 100-mile-wide swath of Japan will see damaging winds of 50 knots, according to the Japan Meteorological Agency. About a 30 mile-wide swath of Japan will experience winds of 75 mph (hurricane force.) Tokyo will be right at the edge of the hurricane-force wind swath. With many trees still in leaf, these winds will cause widespread tree damage and downed power lines. The counter-clockwise flow of moist, tropical air around the center of Wipha is meeting up with the cold front currently over Japan. This is generating torrential rains over large portions of the country, as the moist air is forced upwards over the cold front, making the air expand and cool, condensing its copious moisture. Radar precipitation estimates show that rainfall rates of 1 - 2" per hour were occurring near Tokyo today. Heavy rains of 4 - 8" capable of causing damaging flooding will be widespread over Japan, including over the Fukushima nuclear site, where rainfall from Typhoon Man-Yi on September 16 complicated clean-up efforts of the reactors damaged by the March 2011 earthquake and tsunami.

Japan may not be all done with typhoons this month, as both the GFS and European models are predicting that an area of disturbed weather (Invest 93W) east of the Philippines will develop into a tropical storm late this week, which will then head northwest and threaten Japan by next Wednesday, October 23.


Figure 1. MODIS satellite image of Typhoon Wipha approaching Japan, taken at approximately 04:25 UTC on October 15, 2013. At the time, Wipha was a Category 1 storm with winds of 90 mph. Image credit: NASA.

Typhoon Nari hits Vietnam
Torrential rains are falling in Southeast Asia due to Typhoon Nari, which made landfall near Da Nang around 03 UTC on Wednesday as a Category 1 typhoon with 80 mph winds. The eye passed 10 miles south of Da Nang, putting the city in the stronger northern semicircle of the storm. Da Nang recorded top sustained winds of 55 mph, gusting to 81 mph, and picked up 4.06" of rain. Damage is heavy in Da Nang, and at least five deaths are being blamed on the storm. Nari battered the Philippines on Friday, killing thirteen people and leaving 2.1 million people without power on the main Philippine island of Luzon.

The Atlantic is quiet
The tropical wave (Invest 98L) a few hundred miles east of the Lesser Antilles Islands that we've been tracking this week has been torn apart by high winds, and is no longer a threat to develop. There are no threat areas in the Atlantic to discuss today, and none of the reliable computer models for forecasting tropical cyclone genesis is predicting development over the next five days.


Figure 2. MODIS satellite image of Tropical Storm Octave (top) and Tropical Storm Priscilla (bottom) taken at approximately 18:30 UTC (2:30 pm EDT) on October 14, 2013. At the time, Octave had top winds of 50 mph, and Priscilla had top winds of 45 mph. Image credit: NASA.

Tropical Depression Octave in the Eastern Pacific bringing needed rain to Texas
In the Eastern Pacific, we have two tropical cyclones: Tropical Storm Priscilla, a minimal-strength tropical storm that is weakening and heading northwest out to sea, and Tropical Depression Octave, which hit Mexico's Baja Peninsula early Wednesday morning. Octave and Priscilla are embedded in a large plume of tropical moisture that is riding up to the northeast over Mexico and Texas. Flood watches and warnings are posted over much of the southern half of Texas, where widespread rains of 2 - 6" have fallen over the past two days. While the heavy rains have caused some minor to moderate flooding, the precipitation is mostly welcome, as it will make a substantial dent in the multi-year drought that has gripped much of Texas.


Video 1. Waterspout observed offshore of Cabo San Lucas, Mexico on October 14, 2013, as rains bands from Tropical Storm Octave moved over the Baja Peninsula.

Jeff Masters