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Hurricane Season 2012: Typhoon Vicente (Western North Pacific Ocean)
07.24.12
 
NASA's TRMM satellite captured rainfall data on Typhoon Vicente on July 23, 2012 › View larger image
NASA's TRMM satellite captured rainfall data on Typhoon Vicente on July 23, 2012. Vicente had mostly light to moderate rainfall – seen in the yellow, green and blue areas, where rain was falling between 20 and 40 millimeters (.78 to 1.57 inches) per hour. However, some heavy rainfall (falling at 2 inches/50 mm per hour) and hot towering clouds (in red) were seen around the center of circulation.
Credit: SSAI/NASA, Hal Pierce
AIRS showed very cold cloud top temperatures in Typhoon Vicente on July 22 › View larger image
The AIRS instrument that flies onboard NASA's Aqua satellite showed very cold cloud top temperatures in Typhoon Vicente on July 22, which coincide with the hot towers seen by NASA's TRMM satellite. AIRS imagery on July 23 showed the eye was expanding.
Credit: NASA JPL, Ed Olsen
NASA's Sighting of Hot Towers Indicated Typhoon Vicente's Rapid Intensification

Rapid intensification of tropical cyclones is still somewhat of a mystery to forecasters, but one marker that NASA scientists confirmed is when "hot towers" appear within a tropical cyclone as they did in Typhoon Vicente before it exploded in strength on July 23. Vicente made landfall in southern China on July 23.

NASA's Tropical Rainfall Measuring Mission (TRMM) satellite spotted hot towers in Typhoon Vicente, and it rapidly intensified again within six hours on July 23. By the afternoon (Eastern Daylight time) Vicente's winds spun up to 120 knots (138 mph/222 kmh). At that time, Vicente was located about 75 nautical miles (86.3 miles/138.9 km) south of Hong Kong and was headed northwest at 8 knots (9 mph/~14 kmh).

A "hot tower" is a tall cumulonimbus cloud that reaches at least to the top of the troposphere, the lowest layer of the atmosphere. It extends approximately nine miles (14.5 km) high in the tropics. The hot towers in Vicente were over 9.3 miles (15 km) high. These towers are called "hot" because they rise to such altitude due to the large amount of latent heat. Water vapor releases this latent heat as it condenses into liquid. NASA research shows that a tropical cyclone with a hot tower in its eyewall was twice as likely to intensify within six or more hours, than a cyclone that lacked a hot tower. Not only did Vicente intensify, but it was almost explosive intensification where sustained winds went from 70 knots (80.5 mph/129.6 kmh) to 120 knots (138 mph/222 kmh) in six hours.

Vicente made landfall near Macao, China around 2100 UTC (5 p.m. EDT) on July 23, 2012, with maximum sustained winds near 115 knots (132.3 mph/213 kmh). It was about 60 nautical miles (69 miles/111 km) southwest of Hong Kong at landfall, near 21.7 North and 113.3 East. When it made landfall it brought with it very rough seas, where waves were topping 30 feet high (9.1 meters), which likely brought coastal erosion and low land flooding. According to Reuters news, business across Hong Kong was disrupted from the gale-force winds and heavy rainfall. Flights were delayed and cancelled, schools closed, and CNN reported that 129 people were injured from the storm but there were no fatalities.

On July 24, Vicente was still holding onto typhoon strength, even over land. At 0300 UTC (11 p.m. EDT/July 23), Typhoon Vicente's maximum sustained winds were still near 100 knots (115 mph/185 kmh). At that time it had moved inland and was 110 miles (177 km) west of Hong Kong, near 22.3 North and 112.2 East.

By 9 a.m. EDT on July 24, the center of Typhoon Vicente appeared to near Guangxi, with a large area strong bands of thunderstorms extending into the South China Sea, and over Macao and Hunan Island, China. The western-most fringe of Vicente was also reaching northern Vietnam. Vicente continues to move west on radar and northern Vietnam and Laos can expect heavy rainfall today. The Joint Typhoon Warning Center expects that Vicente will continue moving west and dissipate slowly in southern China.

Beginning this summer and over the next several years, NASA will be sending unmanned aircraft dubbed "severe storm sentinels" above stormy skies to help researchers and forecasters uncover information about hurricane formation and intensity changes. The mission, called Hurricane and Severe Storm Sentinel (HS3) airborne mission will begin in September from Wallops Island, Va. For more information about the mission, visit: www.nasa.gov/HS3

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, Md.



July 23, 2012

NASA's TRMM satellite captured rainfall data on Typhoon Vicente on July 23, 2012 › View larger image
NASA's TRMM satellite captured rainfall data on Typhoon Vicente on July 23, 2012. Vicente had mostly light to moderate rainfall – seen in the yellow, green and blue areas, where rain was falling between 20 and 40 millimeters (.78 to 1.57 inches) per hour. However, some heavy rainfall (falling at 2 inches/50 mm per hour) and hot towering clouds (in red) were seen around the center of circulation.
Credit: SSAI/NASA, Hal Pierce
AIRS showed very cold cloud top temperatures in Typhoon Vicente on July 22 › View larger image
NASA Sees Hot Tower In Typhoon Vicente's Center

"Hot Towers" are an indication that tropical cyclones are likely to intensify within 6 to 9 hours, and NASA's Tropical Rainfall Measuring Mission (TRMM) satellite spotted some in Tropical Storm Vicente's southern eyewall when it passed overhead on July 22. Vicente later became a typhoon. It is now headed for landfall in China.

A "hot tower" is a tall cumulonimbus cloud that reaches at least to the top of the troposphere, the lowest layer of the atmosphere. It extends approximately nine miles (14.5 km) high in the tropics. The hot tower in Vicente was over 9.3 miles (15 km) high. These towers are called "hot" because they rise to such altitude due to the large amount of latent heat. Water vapor releases this latent heat as it condenses into liquid.

Research by Owen Kelley and John Stout of George Mason University and NASA's Goddard Space Flight Center, Greenbelt, Md., shows that a tropical cyclone with a hot tower in its eyewall was twice as likely to intensify within six or more hours than a cyclone that lacked a tower. Vicente did intensify into a typhoon.

Infrared imagery from the Atmospheric Infrared Sounder (AIRS) instrument that flies onboard NASA's Aqua satellite showed very cold cloud top temperatures that coincided with the hot towers. AIRS imagery on July 23 showed the eye was expanding.

On July 23, 2012 warnings are posted for southeastern China, including Hong Kong as the typhoon is expected to make landfall late in the day. Storm signal 8 is currently in effect for Hong Kong although Vicente is expected to make landfall west of Hong Kong. For Guangdong, the area of landfall, China's Central Meteorological Office issued a yellow category warning for typhoon Vicente. The warning means that heavy rain is expected to affect most of Guangdong and Guangxi, as well as Hainan Island, eastern Fujian, southern Yunnan, southern Jiangxi, and southern Hunan.

At 1500 UTC (11 a.m. EDT/U.S.) Typhoon Vicente's maximum sustained winds were near 70 knots (80.5 mph/129.6 kmh). Tropical-storm-force winds extend out 105 nautical miles (120.8 miles/194.5 km) from the center, so Hong Kong was experiencing them at that time. Vicente was also creating rough seas, with waves topping 21 feet high (6.4 meters), and causing coastal erosion. Vicente's center was located just 80 nautical miles (92 miles/148 km) south of Hong Kong, near 21.2 North and 113.8 East. Vicente was moving northwestward near 7 knots (8.5 mph/12.9 kmh).

Warm sea surface temperatures are allowing Vicente to continue strengthening as it heads toward landfall in Guangdong. For the official update from the China Meteorological Administration, visit: http://www.cma.gov.cn/en/NewsReleases/News/201207/t20120723_179338.html. The Joint Typhoon Warning Center forecasters expect that Vicente will start to weaken as it interacts with land, before its center makes landfall.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, Md.



July 20, 2012

AIRS infrared imagery shows the progress of System 92W from July 18, 19 and 20 › View larger image
This time series of infrared imagery from the AIRS instrument on NASA's Aqua satellite shows the progress of System 92W on July 18, 19 and 20. Purple areas indicate coldest cloud top temperatures, strongest storms and heaviest rainfall.
Credit: NASA JPL, Ed Olsen
NASA Satellite Sees Western North Pacific Tropical Cyclone Strengthening

NASA satellite data has watched cloud temperatures drop in a low pressure system in the western North Pacific Ocean called System 92W, indicating that there's more uplift and power in the storm. That's a sign the storm is strengthening.

Infrared data gathered by NASA's Atmospheric Infrared Sounder (AIRS) instrument indicate cloud top temperatures as well as sea surface temperatures. NASA's Aqua satellite passed over System 92W on July 18, 19 and 20 and watched the low pressure area develop east of the Philippines, organize and move northeast of Luzon, Philippines by July 20.

On Wednesday, July 18 at 1705 UTC (1:05 p.m. EDT/U.S.), System 92W's center east of Luzon, and there were several areas of strong convection (rising air that form thunderstorms that make up a tropical cyclone). They appeared disorganized in satellite imagery at that time, however.

On Thursday, July 19, AIRS data showed a much larger and more concentrated area of strong convection and thunderstorms. AIRS data revealed strong thunderstorms with cloud top temperatures colder than 220 kelvin (-63.6 F/-53.1C) and heavy rainfall over northeastern Luzon stretching east into the Philippine Sea.

On Friday, July 20, at 0441 UTC (12:41 a.m. EDT/U.S.) AIRS data revealed that the area of convection east of Luzon had expanded and strengthened. AIRS data also showed that the low-level circulation center was partially exposed, and that the strongest convection and largest area of showers and thunderstorms were southwest of the center. Northeasterly wind shear is pushing the strongest thunderstorms to that quadrant of the storm. By 0800 UTC (4 a.m. EDT), System 92W had moved to 18.0 North latitude and 124.3 East longitude. That's about 280 nautical miles northeast of Manila, Philippines.

The Joint Typhoon Warning Center forecasts System 92W to move west-northwest past northern Luzon and continue into the South China Sea over the next couple of days into an area with lower vertical wind shear. As System 92W moves over the weekend, northern Luzon can expect heavy rainfall and likely some localized flooding. If System 92W does organize into a tropical storm over the weekend, it would be named Vicente.

Text Credit: Rob Gutro
NASA Goddard Space Flight Center, Greenbelt, Md.