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Hurricane Season 2012: Tropical Storm Bolaven (North Pacific Ocean)
08.29.12
 
NASA Satellite Sees Remnants of Tropical Storm Bolaven Racing Over China and Russia

NASA’s Terra satellite captured this natural-color image of Tropical Storm Bolaven on August 29 at 0220 UTC. › View larger
NASA’s Terra satellite captured this natural-color image of Tropical Storm Bolaven on August 29 at 0220 UTC. Some clouds still remain over North Korea and extend over the Sea of Japan as Bolaven's remnants continue speeding to the north-northeast. Credit: NASA Goddard MODIS Rapid Response Team
Tropical Storm Bolaven made landfall on Aug. 28 and has been moving quickly over land while undergoing a transition. NASA's Terra satellite captured an image of the remnants of the ex-tropical storm mostly centered over eastern China.

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image of Tropical Storm Bolaven on August 29 at 0220 UTC. Some clouds still remain over North Korea and extend over the Sea of Japan as Bolaven's remnants continue speeding to the north-northeast at 29 knots (33.3 mph/53.7 kmh).

The Joint Typhoon Warning Center issued the final bulletin on Bolaven on Aug. 28 at 2100 UTC (5 p.m. EDT/6 p.m. on Thursday, August 30, 2012 Asia/Pyongyang local time). Bolaven's maximum sustained winds at that time were near 35 knots (40 mph/65 kmh) and have weakened since. It was centered about 350 nautical miles (402.8 miles/648.2 km) north of Seoul, South Korea near 41.6 North and 126.2 East.

According to Associated Press, Bolaven is responsible for the deaths of twelve people, eight of them fishermen. Bolaven left about 200,000 households in South Korea without power, but damages in North Korea are unknown. On Aug. 29, Bolaven's remnants were moving over eastern Siberia toward the Sea of Japan.

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



Aug. 28, 2012

NASA Sees Tropical Storm Bolaven Making Landfall in North Korea

Visible image of Typhoon Bolaven over Korea and China At 12:55 a.m. EDT (4:55 UTC) on Aug. 28, the MODIS instrument on NASA's Aqua satellite captured this visible image of Tropical Storm Bolaven's clouds over North and South Korea and China. Note the large open center of circulation. Credit: NASA Goddard MODIS Rapid Response Team
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Visible image of Typhoon Bolaven with colorful rainfall map overlay TRMM captured rainfall rates in Typhoon Bolaven on Aug. 27 revealing numerous rain bands north of Bolaven's center were dropping precipitation at a rate greater than 75 mm/hr (~2.95 inches). Credit: NASA/SSAI, Hal Pierce
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Tropical Storm Bolaven weakened as it moved north through the cooler waters of the Yellow Sea in the last day, which is good news for North Korea and southeastern China where it is making landfall today, Aug. 28.

On Aug. 27, NASA's Tropical Rainfall Measuring Mission or TRMM satellite monitored the rainfall rates within Tropical Storm Bolaven. At the time TRMM passed over, Bolaven was still a typhoon. TRMM captured rainfall data at 0917 UTC (about 5:17 p.m. Korea local time/5:17 a.m. EDT) and at 12:33 UTC (8:33 p.m. Korea local time/8:33 a.m. EDT). Bolaven has been generating heavy rainfall and that has been falling over both South and North Korea. Data from TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) instruments showed that numerous rain bands north of Bolaven's center were dropping precipitation at a rate greater than 75 mm/hr (~2.95 inches). That heavy rainfall is cause for concern of flooding as Bolaven makes landfall and moves inland over North Korea and southeastern China.

At 12:55 a.m. EDT (4:55 UTC/12:55 p.m. Korea local time) on Aug. 28, the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Aqua satellite captured a high-resolution visible image of Tropical Storm Bolaven centered in the Yellow Sea. Its center of circulation was cloud-free and appeared very large on satellite imagery. Bolaven's cloud cover was extensive and blanketed North and South Korea, southeastern China and southern Japan.

Both the TRMM and the MODIS imagery were created at NASA's Goddard Space Flight Center in Greenbelt, Md. The data from both satellites is shared with the forecasters at the Joint Typhoon Warning Center who use it to make their forecasts.

On Aug. 28 at 0900 UTC (5 a.m. EDT/5 p.m. local time, North Korea), Tropical Storm Bolaven had maximum sustained winds near 55 knots (63.2 mph/102 kmh). It was located about 115 nautical miles (132.3 miles/213 km) west of Seoul, South Korea near 38.1 North latitude and 124.9 East longitude. Bolaven was moving to the north-northeastward at 23 knots (26.4 mph/42.6 kmh) and generating very rough waters in the Yellow Sea, with wave heights to 34 feet (10.3 meters).

Forecasters at the Joint Typhoon Warning Center (JTWC) noted that multi-spectral satellite imagery is showing today, Aug. 28, that the low-level circulation center is expanding and deteriorating as stratocumulus clouds surround the system. Wind shear from the south-southeast has been pushing the bulk of clouds and showers to the north and northeast of the center of circulation, over North and South Korea.

The JTWC forecast calls for Bolaven to continue moving to the north-northeast into Northern Korea later on Aug. 28 and become extra-tropical over land in the next day.

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



Aug. 27, 2012

NASA Sees Typhoon Bolaven Dwarf Typhoon Tembin

AIRS image of Tembin and Bolaven› Larger image
The AIRS instrument onboard NASA's Aqua satellite captured this infrared image of Typhoon Tembin southwest of Taiwan and Typhoon Bolaven entering the Yellow Sea on Aug. 26. AIRS has been providing infrared data about cloud temperatures, and sea surface temperatures around the storm. The purple areas indicate the highest, coldest cloud top temperatures. Credit: NASA JPL, Ed Olsen

MODIS image of Tembin and Bolaven› Large image
NASA's MODIS instrument that flies onboard the Terra satellite captured this remarkable image of Typhoon Tembin (lower left) being dwarfed by giant Typhoon Bolaven (top right)in the Philippine Sea at 0240 UTC on Aug. 27, 2012. Credit: NASA Goddard MODIS Rapid Response Team
NASA satellites are providing imagery and data on Typhoon Tembin southwest of Taiwan, and Typhoon Bolaven is it barrels northwest through the Yellow Sea. In a stunning image from NASA's Aqua satellite, Bolaven appears twice as large as Tembin.

NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instrument that flies onboard the Terra satellite captured a remarkable image of Typhoon Tembin being dwarfed by giant Typhoon Bolaven at 0240 UTC on Aug. 27, 2012. The visible image shows that the island of Taiwan appears to be squeezed between the two typhoons, while the northeastern arm of Typhoon Tembin's clouds extend over the southern half of Taiwan and sweep over Luzon, the Philippines, where it is better known as Typhoon Igme. Bolaven appears to be twice as large as Typhoon Tembin and has a visible eye. Tembin's eye appears obscured by high clouds in satellite imagery.

Typhoon Bolaven recently passed over Kadena Air Base in Okinawa, Japan as it moves northwestward into the Yellow Sea for a final landfall later this week in North Korea. Clouds from Bolaven's northeastern quadrant were blanketing Japan's island of Kyushu, which is the southwestern most island of the four main islands of Japan. The Yellow Sea is an arm of the North Pacific of the East China Sea, and it is situated between China and Korea.

On Aug. 26, NASA's Aqua satellite captured both storms in one infrared image. The Atmospheric Infrared Sounder (AIRS) instrument captured an infrared image of Typhoon Tembin southwest of Taiwan and Typhoon Bolaven entering the Yellow Sea. AIRS has been providing infrared data about cloud temperatures, and sea surface temperatures around the storm. Both storms had large areas of very cold clout top temperatures that exceeded -63F/-52C) indicating strong uplift in each storm. At the time of the image, Bolaven was moving over the Ryukyu Islands. They are a chain of islands owned by Japan that stretch southwest from Kyushu, Japan to Taiwan.

On Aug. 27, infrared imagery from NASA's Aqua satellite showed that Bolaven maintained tightly-curved banding of thunderstorms that were wrapping into a well-defined and large low-level circulation center. The center of circulation is as large as 550 nautical miles in diameter!

Typhoon Bolaven in the Yellow Sea

On Aug. 27, 2012, Typhoon Bolaven was moving through the Yellow Sea. Its maximum sustained winds were down to 70 knots (80.5 mph/129.6 kmh). Bolaven was located approximately 380 nautical miles (437.3 miles/703.8 km) south-southwest of Seoul, South Korea, near 32.2 North and 125.0 East. The typhoon is moving to the north-northwestward at 16 knots (18.4 mph/29.6 kmh) and creating high seas of 43 feet (13.1 meters).

Bolaven is expected to weaken as it moves into cooler waters in the Yellow Sea. It is also expected to run into stronger wind shear. Bolaven is expected to make landfall in southwestern North Korea on Aug. 28.

Typhoon Tembin Ready to Move North

Typhoon Tembin completed its cyclonic loop south of Taiwan, and is now poised to move northeast and pass Taiwan on its journey behind Bolaven, into the Yellow Sea. On Aug. 27 at 1500 UTC (11 a.m. EDT), Tembin had maximum sustained winds near 65 knots (75 mph/120.4 kmh) making it a minimal typhoon. It was located about 240 nautical (276 miles/444.5 km) miles south-southwest of Taipei, Taiwan near 21.6 North and 120.4 East. It was moving to the east-northeast near 14 knots (16.1 mph/26 kmh). AIRS infrared data showed that Tembin showed an eye covered by central dense overcast, as correlated by the MODIS visible imagery.

Tembin is expected to move north past Taiwan over the next couple of days, and track through the Yellow Sea. Tembin's final resting place will be a landfall in southeastern China, near the North Korea border by the weekend.

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



MODIS image of Bolaven› Larger image
On Aug. 24, 2012 as 0240 UTC NASA's Terra Satellite flew over Typhoon Bolaven and the MODIS instrument captured this visible image of the storm as it continues moving through the Philippine Sea. Credit: NASA Goddard MODIS Rapid Response Team
Typhoon Bolaven Has an Eye on Okinawa

Typhoon Bolaven's eye became apparent on NASA satellite imagery as the storm intensified to a Category Four typhoon, according to the Saffir-Simpson Scale. According to the Joint Typhoon Warning Center, Bolaven's center will be near Okinawa on Sunday, Aug. 26.

On Aug. 24, 2012 at 1500 UTC (11 a.m. EDT) Typhoon Bolaven's maximum sustained winds had increased to 120 knots (138 mph/222 kmh). A Category Four typhoon has maximum sustained winds between 113-136 knots (130-156 mph/209-251 kmh). The Saffir-Simpson Scale explains a Category Four Typhoon as: Catastrophic damage will occur: Well-built framed homes can sustain severe damage with loss of most of the roof structure and/or some exterior walls. Most trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last weeks to possibly months. Most of the area will be uninhabitable for weeks or months.

Bolaven was located 380 nautical miles (437.3 miles/703.8 km) southeast of Kadena Air Base, Okinawa, Japan, near 22.5 North and 132.7 East. It was moving to the north-northwest at 5 knots (5.7 mph/9.2 kmh) and generating very rough and high seas up to 47 feet (14.3 meters). Typhoon-force winds are limited to 40 nautical miles (46 miles/74 km) in diameter around the center, while tropical-storm-force winds make the storm over 360 nautical miles (414 miles/666.7 km) wide.

On Aug. 24, 2012 as 0240 UTC (Aug. 23 at 10:40 p.m. EDT) NASA's Terra Satellite flew over Typhoon Bolaven and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument captured a visible image of the storm that clearly showed an eye. Infrared imagery from the AIRS (Atmospheric Infrared Sounder) instrument that flies onboard NASA's Aqua satellite has also shown a well-defined eye, with a banding of strong thunderstorms wrapping into the low-level center.

Kadena Air Base in Okinawa, Japan is the home to the U.S. Air Force's 18th Wing, and a variety of associate units. Kadena Air Base employed almost 18,000 Americans and more than 4,000 Japanese employees. According to the Kadena Air Base website (www.kadena.af.mil/), the base the tropical cyclone condition of readiness (TCCOR) 3 is in effect. TCCOR 3 means winds of 50 knots (57.5 mph/92.6 kmh) or greater are anticipated within 72 hours. Bolaven's center is expected to be near Okinawa on Sunday, Aug. 26, but because the storm is large, the effects of the storm are expected to begin by Saturday, Aug. 25, as thunderstorms and gusty northeasterly winds are expected, both of which will increase in intensity as the day goes on. Sunday, Aug. 26, Bolaven's center is expected to be close to Okinawa. By Monday, Bolaven will be pulling away to the northeast, and conditions should improve.

Typhoon Bolaven is forecast to move past Okinawa and head north through the Yellow Sea. The Yellow Sea is located north of the East China Sea, between China and the Korean Peninsula. The Yellow Sea got its name from the Gobi Desert sand particles that turn the sea surface a golden yellow color.

Forecasters at the Joint Typhoon Warning Center expect Bolaven to make landfall in either northeastern China or North Korea early next week.

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



Aug. 23, 2012

Twin Typhoons Tembin and Bolaven Appear Same Size on Satellite Imagery

MODIS image of Bolaven and Tembin› Larger image
This visible image was taken at 04:35 UTC (12:35 a.m. EDT) on Aug. 23, 2012 of Typhoons Tembin and Bolaven in the Philippine Sea, by the MODIS instrument onboard NASA's Aqua satellite. Credit: NASA MODIS Rapid Response Team

AIRS image of Bolaven and Tembin› Larger image
The Atmospheric Infrared Sounder (AIRS) instrument onboard NASA's Aqua satellite captured an infrared image of the eastern edge of Typhoon Tembin and most of Typhoon Bolaven on Aug. 23 at 12:29 a.m. EDT in the Philippine Sea. Strong thunderstorms had cloud top temperatures as cold as -63F (-52C) (in purple). Credit: NASA JPL, Ed Olsen
When NASA's Aqua satellite passed over Typhoons Tembin and Bolaven in the Philippine Sea on Aug. 23, satellite data showed that they're about the same size in diameter. That means a wide path of heavy rainfall, gusty winds and rough seas for the Philippine Sea.

NASA's Aqua satellite passed over both storms on Aug. 23 at 12:35 a.m. EDT (04:35 UTC) and the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument captured a visible image of both storms. MODIS imagery indicates that Tembin is about 280 nautical miles (322 miles/518.6 km) in diameter. Bolaven is about the same size. That's about the distance from Boston, Mass. to Philadelphia, Penn.

Typhoon Bolaven Headed for Okinawa Landfall

Typhoon Bolaven's maximum sustained winds were near 100 knots (115 mph/185 kmh) on Aug. 23 at 11 a.m. EDT (1500 UTC) as it continued on its west-northwest track through the Philippine Sea. It is moving at 9 knots (10.3 mph/16.6 kmh) and was about 500 nautical miles (575.4 miles/926 km) southeast of Kadena Air Base, Okinawa, Japan. Bolaven's center was near 20.4 North latitude and 133.6 East longitude. Bolaven is expected to track over or near Kadena Air Base around 1200 UTC on Aug. 25, and the island will experience rough seas and gusty winds over the next day as Bolaven nears.

Another instrument onboard NASA's Aqua satellite measured cloud top temperatures infrared light and showed high, very cold cloud top temperatures which are an indication of strong uplift within the storm. The Atmospheric Infrared Sounder (AIRS) instrument also showed that the central dense overcast has strengthened over the low-level circulation center.

Forecasters at the Joint Typhoon Warning Center expect Bolaven to strengthen and peak at 120 knots (138 mph/222 kmh) by Aug. 25 before making landfall in Okinawa.

Typhoon Tembin Poised for Taiwan Landfall

Typhoon Tembin has regained strength as it heads for landfall in eastern Taiwan. Forecasters at the Joint Typhoon Warning Center expect the storm to make landfall on Aug. 24 around 0000 UTC (Aug. 23 at 8 p.m. EDT) in southeastern Taiwan and then make a cyclonic loop after re-emerging in the Philippine Sea later on Aug. 24. Tembin is known in the Philippines as Typhoon Igme.

Warnings are posted for the following areas in Taiwan: Changhua County, Chiayi County, Chiayi City, Hualien County, Hsinchu City and County, Kaohsiung City, Miaoli County, Nantou County, Pingtung County, Taitung County, Hengchun Peninsula, Penghu County, Taichung City, Tainan City, Yilan County, and Yunlin County.

Warnings are still posted in areas of the Philippines as well. Those warnings include Public storm warning signal #2 for the Batanes group of islands and Public storm warning signal #1 for the Calayan and Babuyan group of islands.

On Aug. 23 at 11 a.m. EDT (1500 UTC), Typhoon Tembin's maximum sustained winds were near 105 knots (121 mph/194.5 kmh). It was located near 22.7 North latitude and 122.0 East longitude, about 150 nautical miles (172.6 miles/277.8 km) south-southeast of Taipei, Taiwan. Tembin is moving to the west at 6 knots (7 mph/11 kmh) and toward a landfall in Taiwan.

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



Aug. 22, 2012

Double Trouble Continues in the Philippine Sea: Tembin and Bolaven

storms Tembin and Bolaven

This is a combination of two images taken from the AIRS instrument that flies onboard NASA's Aqua satellite. It shows Typhoon Tembin near Taiwan and Tropical Storm Bolaven west of the Marianas Islands. The images were taken on Aug. 21 at 04:41 UTC and 16:47 UTC. Credit: NASA JPL, Ed Olsen
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Typhoon Tembin and Typhoon Bolaven continue to churn in the Philippine Sea, and infrared satellite data from NASA showed the power within both storms.

The Atmospheric Infrared Sounder (AIRS) instrument that flies onboard NASA's Aqua satellite captured imagery of both storms on Aug. 21 in two different overpasses. Aqua flies over the same locations during early morning and early afternoon (local time) as it orbits the Earth. Aqua passed over the Philippine Sea on Aug. 21 at 04:41 UTC (12:41 a.m. EDT) and 16:47 UTC (12:47 p.m. EDT). The two satellite passes were combined to show the proximity of the storms from each other. Typhoon Tembin is located east of Taiwan and Typhoon Bolaven west of the Marianas Islands.

The AIRS image of Typhoon Tembin showed a wide area of very high, cold cloud top temperatures, exceeding -63 Fahrenheit (-052 Celsius) surrounding the eye of the storm, which has warmer temperatures (indicating open air). The AIRS data revealed a large area of strong thunderstorms north, east and south of the center of Typhoon Bolaven.

Bolaven has strengthened into a typhoon. It has maximum sustained winds near 80 knots (92 mph/148 kmh) and is expected to continue intensifying. Bolaven is about 270 miles in diameter (310.7 miles/500 km), now larger than Typhoon Tembin. It is located about 685 miles east-southeast of Kadena Air Base, Okinawa, Japan, near 19.3 North latitude and 137.5 East longitude. Bolaven is moving to the west at 9 knots (10.3 mph/16.6 kmh), and is expected to begin moving northwest.

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



Aug. 21, 2012

visible light hurricanes against ocean MODIS images from NASA's Terra and Aqua satellites on August 21, 2012 at 04:45 UTC were combined to provide a complete picture of the two tropical troublemakers in the northwestern Pacific: Typhoon Tembin and Tropical Storm Bolaven. Credit: NASA MODIS Rapid Response Team
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NASA Satellites See Two Intensifying Northwestern Pacific Tropical Cyclones

There's double trouble in the northwestern Pacific Ocean in the form of Typhoon Tembin and Tropical Storm Bolaven. NASA's Terra and Aqua satellites teamed up to provide a look at both storms in one view.

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument flies onboard NASA's Aqua and Terra satellites and the MODIS instrument on each captured a storm when both satellites flew over them on August 21 after midnight (Eastern Daylight Time). The two MODIS images which featured Bolaven and Tembin over the Philippine Sea were combined by NASA's MODIS Rapid Response Team at the NASA Goddard Space Flight Center in Greenbelt, Md. to paint the entire tropical picture in the northwestern Pacific Ocean on August 21.

Tropical Storm Bolaven Poised to Strengthen

Tropical storm Bolaven's maximum sustained winds were near 55 knots (63.2 mph/102 kmh) and the Joint Typhoon Warning Center expects it to strengthen into a typhoon over the next several days. At 0900 UTC (5 a.m. EDT) on Aug. 21, Bolaven was located about 390 nautical miles (449 miles/722 km) south of Iwo To, near 18.4 North latitude and 140.4 West longitude. Bolaven is crawling to the west-northwest at 4 knots (4.6 mph/7.4 kmh).

Bolaven appears on MODIS imagery as a smaller storm than Tembin. While Tembin is over 200 nautical miles (230 miles/370 km) in diameter, Bolaven is just about 100 nautical miles (115 miles/185 km) in diameter.

Bolaven is strengthening and is expected to become a typhoon as it heads northwest. It is currently expected to pass to the north of Taiwan around Aug. 25-26, 2012.

Typhoon Tembin Tracking to Taiwan

Typhoon Tembin is also known as Typhoon Igme in the Philippines, where it is still the cause for active warnings on Aug. 21. Public storm warning signal #1 remains in effect for the Batanes group of islands on Aug. 21. At 0900 UTC (5 a.m. EDT) on Aug. 21, Typhoon Tembin had maximum sustained winds near 110 knots (126.6 mph/203.7 kmh). Typhoon-force winds extended out to 30 nautical miles (34.5 miles/55.5 km) from the center, while tropical-storm-force winds extended out 100 nautical miles (115 miles/185 km) from the center, making Tembin over 200 nautical miles (230 miles/370 km) wide.

Tembin was located about 325 nautical miles (374 miles/602 km) southeast of Taipei, Taiwan, near 21.0 North latitude and 125.4 East longitude. Although Tembin is currently moving to the north-northeast, the Joint Typhoon Warning Center forecasts Tembin to intensify and take a western turn and head across Taiwan on Thursday, Aug. 23. After crossing Taiwan, Tembin is forecast to make a second landfall east of Hong Kong. A Sea Warning and Typhoon Warning is already in effect for Taiwan, as heavy rain and rough seas are expected to affect eastern Taiwan by Wednesday, Aug.22. The Central Weather Bureau indicated that Tembin will likely make landfall in the Yilan, Hualien or Taitung counties on the eastern coast.

For a high resolution image of both storms in one image, visit:
http://lance-modis.eosdis.nasa.gov/cgi-bin/imagery/single.cgi?image=TembinBolaven.A2012234.0445.4km.jpg

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



Aug. 20, 2012

NASA's Aqua satellite has been monitoring Tropical Storm Bolaven in the western North Pacific from Aug 19-20. › View larger image
NASA's Aqua satellite has been monitoring the birth and progress of Tropical Storm Bolaven in the western North Pacific from Aug 19-20. The AIRS instrument has provided infrared satellite imagery that shows the development of colder thunderstorm cloud-top temperatures that were indicative of strengthening storms.
Credit: NASA JPL, Ed Olsen
NASA Watches as Tropical Storm Bolaven Develops

Tropical Storm Bolaven was born over the weekend of August 18-19 in the western North Pacific, and NASA captured infrared satellite imagery of its birth and growth.

NASA's Aqua satellite has been monitoring the birth and progress of Tropical Storm Bolaven in the western North Pacific from Aug 19-20, 2012. The Atmospheric Infrared Sounder (AIRS) instrument has provided infrared satellite imagery that shows the development of colder thunderstorm cloud-top temperatures, that were indicative of strengthening storms. Tropical Storm Bolaven also took more of a rounded shape on August 20 as it continued to organize and intensify.

On August 19 at 03:11 UTC (Aug. 18 at 11:11 p.m. EDT) the AIRS image of Bolaven appeared loosely organized. At that time, the strongest thunderstorms appeared to be east of the center of circulation.

On August 20 at 3:53 UTC (Aug. 19 11:53 p.m. EDT), NASA's AIRS instrument on the Aqua satellite captured another infrared image of Bolaven. The infrared AIRS image showed the storm had a much tighter circulation and Bolaven's strongest thunderstorms were south of the center of circulation, where cloud top temperatures were colder than -63 Fahrenheit (-52 Celsius). Hours later, Bolaven was located about 400 nautical miles (460 miles/741 km) south of Iwo To, Japan, near 18.2 North latitude and 141.2 West longitude. It was moving to the north-northwest at 5 knots (5.7 mph/9.2 kmh) and had maximum sustained winds near 35 knots (40 mph/65 kmh).

Bolaven will continue strengthening as it moves to the west-northwest over the next couple of days in open waters of the western North Pacific Ocean. By August 24 forecasters at the Joint Typhoon Warning Center expect Bolaven to reach typhoon status.

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