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Hurricane Season 2012: Tropical Storm Khanun (Western North Pacific Ocean)
07.20.12
 
AIRS infrared imagery of Khanun from July 18-20. › Click to view a larger image  
of the time series of infrared imagery from the AIRS instrument on NASA's Aqua satellite showing the progress of Tropical Depression Khanun before, during and after landfall on July 18, 19 and 20. Purple areas indicate coldest cloud top temperatures, strongest storms and heaviest rainfall.
Credit: NASA JPL, Ed Olsen
NASA's Aqua Satellite Sees Khanun's Remnants Dissipating Over China

NASA's Aqua satellite has been tracking the remnants of Tropical Depression Khanun, and infrared data revealed that it has moved over northeastern China where it is now dissipating.

NASA's Aqua satellite passed over Khanun on July 18, 19 and 20 and tracked the northeastern progression of the tropical cyclone after it made landfall. On Wednesday, July 18 at 1659 UTC (12:59 p.m. EDT/U.S.), Tropical Depression Khanun's center was still in the Yellow Sea (west of South Korea). At that time, the Atmospheric Infrared Sounder (AIRS) instrument onboard NASA's Aqua satellite saw a band of thunderstorms with cloud top temperatures colder than 220 kelvin (-63.6 F/-53.1C) over western South Korea, bringing heavy rainfall. A larger area of thunderstorms with cloud top temperatures as cold as -63F/-53C were over western North Korea at that time, dropping moderate rainfall.

Tropical Depression Khanun came ashore in western South Korea, bringing heavy rainfall with it on Thursday, July 19 as it moved in a north-northeasterly direction toward North Korea and northeastern China. On July 19 at 0405 UTC (12:05 a.m. EDT/U.S.), the heaviest rainfall and strongest thunderstorms appeared to be over the Kangnam Mountains in northern North Korea that also border eastern China. The Kangnam Mountains lie west of the Rangrim Mountains.

Although the center of Khanun's remnants moved into the Sea of Japan, it was bringing some scattered showers and thunderstorms to a few areas in northeastern China on July 20. NASA's Aqua satellite passed over the region on July 20 at 0447 UTC (12:47 a.m. EDT) and showed some scattered showers moving east into Khabarovsk Krai, Russia, a federal subject of Russia. Khunan's remnants are expected to dissipate today.

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



July 19, 2012
Tropical Depression Khanun over South Korea was captured by the MODIS instrument on July 19, 2012. › View larger image
This true-color image of Tropical Depression Khanun over South Korea was captured by the MODIS instrument onboard NASA's Terra satellite at 0225 UTC, July 19, 2012.
Credit: NASA MODIS Rapid Response Team
Tropical Depression Khanun Blankets South Korea

Tropical Depression Khanun came ashore with some heavy rainfall in the morning hours (local time) on Thursday, July 19. NASA's Terra satellite captured an image of Khanun's clouds on July 19, covering all of South Korea like a blanket.

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument onboard NASA's Terra satellite captured a true-color image of Tropical Depression Khanun over South Korea on July 19, 2012 at 0225 UTC, or 11:25 a.m. local time, Seoul (10:25 p.m. EDT/U.S. on July 18).

The last advisory on Khanun from the Joint Typhoon Warning Center was issued at 0300 UTC (noon local time, Seoul, South Korea) on July 19, when the center was already over land. At that time, Khanun was centered about 15 miles south of Seoul, South Korea, near 37.2 North and 127.1 East. It was moving to the north-northeast at 16 knots (18.4 mph/29.6 kmh) and had maximum sustained winds near 30 knots (34.5 mph/55.5 kph), but was quickly weakening due to its interaction with land.

Khanun caused flooding and power outages, and affected major transportation systems, according to the Korea Herald. One fatality was reported in the North Gyeongsang Province when the wall of a home collapsed. Warnings were dropped in the early afternoon as Khanun continued to weaken and move inland.

Jeju Island, which felt the effects of Khanun first as it approached from the south and the South Jeolla Province both experienced heavy rainfall and power outages from the storm, according to the Korea Herald. The Korean Meteorological Administration reported that 2.1 inches (53.4 millimeters) or rain fell in Jeju, while as much as 3.8 (97 millimeters) fell on Suncheon, located in the South Jeolla Province.

The Korean Meteorological Administration noted that the center of Khanun's remnants had moved over the Sea of Japan by 11 a.m. EDT on July 19, 2012.

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



July 18, 2012
AIRS instrument showed the strongest rainfall south of Khanun's center of circulation. › View larger image
When NASA's Aqua satellite passed over Tropical Storm Khanun on July 18 at 0459 UTC (12:59 a.m. EDT) and infrared imagery from the AIRS instrument showed the strongest rainfall south of the center of circulation.
Credit: NASA JPL, Ed Olsen
NASA Sees Tropical Storm Khanun Weakening For South Korea Landfall

Infrared imagery of Tropical Storm Khanun shows that the storm is weakening as it heads toward a landfall in the Chungcheongnam-do province of western South Korea. Khanun is already bringing rainfall and stirring up seas around southwestern South Korea.

When NASA's Aqua satellite passed over Tropical Storm Khanun on July 18 at 0459 UTC (12:59 a.m. EDT), the Atmospheric Infrared Sounder (AIRS) instrument captured temperature data on cloud tops. Infrared imagery from the AIRS instrument showed that convection (rising air that forms thunderstorms that make up a tropical cyclone) was weakening around the center of the storm. The highest, coldest, thunderstorm cloud tops were south of the center of circulation, that's where temperatures were as cold as -63 Fahrenheit (-52 Celsius), and that's where the heaviest rain was falling.

At 1500 UTC (11 a.m. EDT) on July 18, Khanun's center had already passed the Cheju Island, South Korea, and is headed for the mainland. It is center near 33.9 North and 126.2 East, which is 30 miles northwest of Cheju Island. It is moving to the north at 15 knots and has maximum sustained winds near 45 knots. Khanun is creating 15-foot high seas in the East China Sea as it moves to a landfall.

Khanun is expected to make landfall in South Korea, just south of the North Korean border. After landfall the Joint Typhoon Warning Center expects it to weaken rapidly.

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



July 17, 2012
TRMM's 3-D view of Khanun's rainfall structure showed convective storms near Khanun's center. › View larger image
TRMM's Precipitation Radar (PR) data were used to give a 3-D view of Khanun's rainfall structure of Khanun on July 17, 2012 at 0439 UTC. The 3-D view showed that powerful convective storms near Khanun's center were pushing to heights of about 17 km (~10.6 miles).
Credit: SSAI/NASA, Hal Pierce
NASA's TRMM satellite captured rainfall data on Tropical Storm Khanun on July 17, 2012. › View larger image
NASA's TRMM satellite captured rainfall data on Tropical Storm Khanun on July 17, 2012. Light to moderate rainfall is seen in the yellow, green and blue areas, where rain was falling between 20 and 40 millimeters (.78 to 1.57 inches) per hour. Heavy rainfall (red) is falling at 50 millimeters (~2 inches) per hour.
Credit: SSAI/NASA, Hal Pierce
Animation showing a blend between an infrared/visible image from TRMM's Visible and InfraRed Scanner (VIRS) › Click here to see an animation  showing a blend between an infrared/visible image from TRMM's Visible and InfraRed Scanner (VIRS) and the same image with TRMM rainfall overlaid.
Credit: SSAI/NASA, Hal Pierce
NASA's TRMM Satellite Eyeing Tropical Storm Khanun's Rainfall

The Tropical Rainfall Measuring Mission (TRMM) is keeping an eye on the rainfall being generated by Tropical Storm Khanun as it moves past Kadena Air Base, Okinawa, Japan.

The TRMM satellite had an excellent daytime look at Tropical Storm Khanun near Okinawa in the northwestern Pacific Ocean on July 17, 2012 at 0439 UTC (12:39 a.m. EDT/1:39 p.m. Japan). Khanun had estimated wind speeds of over 40 knots (~46 mph) at the time TRMM passed overhead. The storm was compact but well organized and shows possible eye wall formation. The bulk of the strongest precipitation was occurring in the western semi-circle of the storm.

TRMM's Precipitation Radar (PR) data were used to give a 3-D view of Khanun's rainfall structure. The 3-D view showed that powerful convective storms near Khanun's center were pushing to heights of about 17 kilometers (~10.6 miles).

At 1500 UTC (11 a.m. EDT) on July 17, Khanun's maximum sustained winds had increased to 50 knots (57.5 mph/92.6 kmh). It was located about 95 nautical miles (109 miles/176 km) north-northeast of Kadena Air Base, Okinawa, Japan, near 27.8 North and 128.2 East. Khanun was moving to the northwest near 15 knots (17.2 mph/27.7 kmh). Tropical-storm-force winds extend out to 60 nautical miles (69 miles/111 km) from the center of circulation, so Kadena Air Base was not yet experiencing susatained tropical storm force winds at that time.

Khanun is predicted to slightly increase in power today. It is expected to affect both South and North Korea as it moves northward through the western side of the Yellow Sea over the next couple days.

Text Credit: Hal Pierce / Rob Gutro
SSAI / NASA Goddard Space Flight Center, Greenbelt, Md.

























July 16, 2012
NASA's Aqua satellite saw Kahnun's cloud top temperatures on July 15, 2012 when it was a tropical depression. › View larger image
NASA's Aqua satellite captured a look at Khanun's cloud top temperatures on July 15, 2012 at 1635 UTC (12:35 p.m. EDT) when it was a tropical depression. Coldest cloud top temperatures (purple) were as cold as or colder than -63 Fahrenheit (-52 Celsius), indicating strong thunderstorms. That was a clue to forecasters that Khanun would become a tropical storm, which it did the next day.
Credit: NASA JPL, Ed Olsen
NASA Satellite Sees Strengthening in Tropical Cyclone Khanun

When NASA's Aqua satellite passed over Tropical Depression Khanun on July 15, infrared data revealed some high, strong thunderstorms that hinted the cyclone would intensify. On July 16 Kahnun had indeed become a tropical storm.

NASA's Aqua satellite flew over Khanun on July 15, 2012 at 1635 UTC (12:35 p.m. EDT) when it was a tropical depression. At that time the Atmospheric Infrared Sounder (AIRS) instrument onboard measured Khanun's cloud top temperatures. The storm's coldest cloud top temperatures were as cold as or colder than -63 Fahrenheit (-52 Celsius), indicating strong thunderstorms with the potential for heavy rainfall. AIRS data also revealed that the area of strongest thunderstorms were becoming more organized, indicating that the tropical depression could strengthen into a tropical storm.

On July 16 at 1500 UTC (11 a.m. EDT), Khanun had become a tropical storm when maximum sustained winds reached 35 knots (40 mph/64.8 kmh). At that time Khanun was centered about 370 nautical miles (425.8 miles/685.2 km) east of Kadena Air Base, Okinawa, Japan, near 25.4 North and 133.6 East. Khanun is moving to the west-northwest near 17 knots (19.5 mph/31.4 kmh).

Infrared data on July 16 showed the Khanun continued to consolidate and had a larger area of stronger central convection (rising air that forms the thunderstorms that make up the tropical cyclone), so the system is getting more organized and stronger. Khanun is currently in an area where wind shear is weak allowing for more strengthening.

The Joint Typhoon Warning Center expects Khanun to begin curving to the northwest and passing north of Kadena Air Base on its way to a landfall in South Korea later this week. Khanun is following the periphery of a north-south oriented sub-tropical ridge (elongated area) of high pressure building up south of Honshu. Khanun is expected to make landfall as a tropical storm in South Korea in a few days.

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