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Hurricane Season 2011: Typhoon Nesat (Western North Pacific Ocean)
10.05.11
 
This image shows average rainfall totals in the Western Pacific from September 26 to October 2, 2011 › View larger image
This image shows average rainfall totals in the Western Pacific from September 26 to October 2, 2011, when Typhoon Nesat and Super Typhoon Nalgae passed through. The heaviest average rainfall—more than 350 millimeters or 14 inches—appears in dark blue. Localized rainfall amounts could be significantly higher. The lightest rainfall—less than 50 millimeters or 2 inches—appears in light green.
Credit: NASA Earth Observatory/TRMM/NASA Goddard/Jesse Allen
Typhoons Nesat and Nalgae Soak The Philippines

In a matter of five days, the Philippines and southeastern Asia were hammered by two intense tropical storms in late September and early October 2011. Several months worth of rain fell within a week—a deluge even by tropical standards—on Luzon in the northern Philippines, as well as in northern Vietnam and the Chinese island of Hainan.

This image shows average rainfall totals in the Western Pacific from September 26 to October 2, 2011, when Typhoon Nesat and Super Typhoon Nalgae passed through. The heaviest average rainfall—more than 350 millimeters or 14 inches—appears in dark blue. Localized rainfall amounts could be significantly higher. The lightest rainfall—less than 50 millimeters or 2 inches—appears in light green.

Superimposed on the rainfall totals are the storm tracks for Nesat and Nalgae, with maroon indicating the strongest storm intensity, and pink indicating the weakest. Typhoon Nesat reached category 3 strength, with winds estimated at 105 knots (120 miles/195 kilometers per hour) late on September 26, 2011, when it crossed into the heavily populated island of Luzon, Philippines. The storm weakened, but still maintained typhoon winds when it reached Hainan on September 29.

Nalgae was a category 4 super typhoon when it made landfall in the Philippines on October 1, with winds approaching 130 knots (150 miles/240 kilometers per hour). The storm was downgraded to tropical storm force, but was still approaching Hainan and Vietnam on October 3.

According to news reports, almost three million Filipinos were affected by the storms. At least 58 people were killed and another 28 were missing as of October 3. More than 300,000 people were being housed in evacuation centers, and damage estimates were approaching 8.8 billion pesos ($200 million U.S.). In southern China, roughly 140,000 people were evacuated, losses approached 1.6 billion yuan ($ 251 million U.S.), and at least four people were killed.

This image is based on data from the Multisatellite Precipitation Analysis (MPA) produced at NASA's Goddard Space Flight Center. The MPA estimates rainfall by combining measurements from many satellites and calibrating them against rainfall measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite.

Text credit: Michael Carlowicz
NASA Earth Observatory
NASA/Goddard Space Flight Center, Greenbelt, Md.



September 29, 2011

This infrared image shows Typhoon Nesat's eye (yellow) over the northeastern edge of Hainan Island, China. › View larger image
This infrared image shows Typhoon Nesat's eye (yellow) over the northeastern edge of Hainan Island, China. The coldest clouds (purple) and strongest thunderstorms were evident where cloud temperatures were coldeIt was captured from the AIRS instrument on NASA's Aqua satellite on Sept. 29 at 2:11 a.m. EDT.
Credit: NASA/JPL, Ed Olsen
NASA Captures Typhoon Nesat's Eye Over Hainan Island, China

An infrared satellite image from NASA's Aqua satellite today revealed Typhoon Nesat's large eye over the northeastern edge of Hainan Island, China.

Infrared imagery from NASA provides a clear look at what's happening under cloud cover in tropical cyclones, by providing temperature data.

The Atmospheric Infrared Sounder (AIRS) instrument captures infrared images of tropical cyclones and passed over Typhoon Nesat earlier today, Sept. 29 at 2:11 a.m. EDT. The infrared data basically shows temperatures and deep convection (rising air that forms thunderstorms that make up a typhoon). The strongest thunderstorms and coldest cloud top temperatures (-63/-52C) were around Nesat's eye as it made landfall on Hainan Island.

Earlier today in Hong Kong financial markets, government offices, schools, and many businesses were closed as Nesat approached, according to the Big News Network. Hong Kong was also under a number eight storm warning.

At 5 a.m. EDT, Typhoon Nesat was a Category one typhoon on the Saffir-Simpson hurricane scale with maximum sustained winds near 65 knots (74 mph). Nesat is a good-sized storm, with tropical storm-force winds covering 300 miles in diameter. It had since moved west from the time of the AIRS image and is now 295 miles east of Hanoi, Vietnam (and still over Hainan Island), near 20.1 North and 111.1 East. It was moving to the west-northwest at 15 knots.

After Nesat crosses Hainan Island it is forecast to travel west through the Gulf of Tonkin and make a third and final landfall north of Hanoi, in Northern Vietnam on Saturday.

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



September 28, 2011

TRMM rainfall analysis for the period from 24-29 September 2011. › View larger image
This TRMM rainfall analysis were for the period from 24-29 September 2011. This analysis indicates that the highest rainfall totals of over 375 mm (~14.8 inches) were centered over Luzon's central eastern coast, south of Nesat's track. This analysis reveals that most of Luzon experienced very heavy rainfall during this period with large areas of Luzon having totals higher than 150 mm (~5.9 inches). Typhoon Nesat's track is shown with white typhoon symbols.
Credit: NASA/SSAI, Hal Pierce
NASA's TRMM Satellite Calculates Typhoon Nesat's Rainfall Over Philippines

Powerful typhoon Nesat came ashore in the Philippines on Tuesday, September 27, 2011 causing the deaths of at least 31 people. Nesat was classified as a category three typhoon on the Saffir-Simpson scale with winds of 105 knots (~121 mph) before hitting the island of Luzon.

The Tropical Rainfall Measuring Mission (TRMM) satellite measures rainfall from space, and data from that satellite was used to create a rainfall analysis of the heavy rains that fell on Luzon, Philippines as a result of Typhoon Nesat. The analysis is the result of a TRMM-calibrated merging of global Multi-satellite rainfall estimates (MPA) performed at NASA's Goddard Space Flight Center in Greenbelt, Md. The MPA rainfall total estimates were for the period from 24-29 September 2011. The analysis indicated that the highest rainfall totals of over 375 mm (~14.8 inches) were centered over Luzon's central eastern coast, south of Nesat's track. This analysis reveals that most of Luzon experienced very heavy rainfall during this period with large areas of Luzon having totals higher than 150 mm (~5.9 inches).

The rainfall analysis showed that Nesat continued to produce heavy rainfall after it entered the South China Sea and headed westward toward southern China.

Text credit: Hal Pierce
SSAI/NASA/Goddard Space Flight Center, Greenbelt, Md.



MODIS captured an image of Typhoon Nesat today, Sept. 28 at 05:35 UTC (1:35 a.m. EDT). › View larger image
The MODIS instrument on NASA's Aqua satellite captured an image of Typhoon Nesat today, Sept. 28 at 05:35 UTC (1:35 a.m. EDT). It was in the South China Sea and its center was between Hainan Island, China (to the west) and Luzon, Philippines.
Credit: NASA Goddard MODIS Rapid Response Team
NASA Image Shows Typhoon Nesat's Edge Near Hainan Island, China

When NASA's Aqua satellite flew over Typhoon Nesat early today, it captured a striking visible image that showed the northwestern edge of the storm's clouds were brushing Hainan Island, China.

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on Aqua captured an image of Typhoon Nesat today, Sept. 28 at 05:35 UTC (1:35 a.m. EDT). It was in the South China Sea and its center was between Hainan Island, China (to the west) and Luzon, Philippines (to the east) where it had just crossed. The MODIS image revealed Nesat's large eye. It also showed the extent of Nesat's huge cloud cover, which stretches from Taiwan in the northeast, to the Philippines in the east and southeast. Its western fringes are already over Vietnam, and northern fringes are skirting the mainland China coastline as it moves west toward a landfall on Hainan Island. By Saturday, after a trip through the Gulf of Tonkin, Nesat is expected to make a final landfall in Vietnam.

At 0900 UTC (5 a.m. EDT) today, Sept. 28, Nesat (also known as Pedring in the Philippines) had maximum sustained winds near 65 knots (64 mph/120 kmh). It is a minimal category one typhoon at this time. Typhoon-force winds cover a small area from the center, about 50 miles in diameter. Tropical-storm-force winds, however, cover a much larger area and stretch out to 360 miles in diameter. Nesat is 600 nautical miles east-southeast of Hanoi, Vietnam near 17.6 North and 115.8 East. It is moving to the west-northwest near 11 knots (13 mph/20 kmh).

Nesat is crossing the South China Sea and intensifying again as it heads for Hainan Island and another landfall. Today at 9 a.m. EDT, Hainan Island had partly cloudy skies with winds from the west-northwest near 9 mph. Hainan Island can expect winds to pick up tonight and rain to develop and intensify. Hainan Island can also expect heavy surf and very rough seas with a storm surge as Nesat moves closer.

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



September 27, 2011

On Sept. 26, 2011, Typhoon Nesat's heaviest rainfall was occurring from southwest to southeast around the storm's center. › View larger image
On Sept. 26, 2011, Typhoon Nesat's heaviest rainfall was occurring from southwest to southeast around the storm's center. In those areas rain was falling at 2 inches (50 mm) per hour (red). Around the rest of the storm was mostly moderate to light rainfall (green and blue) between .78 to 1.57 inches (20 to 40 mm) per hour.
Credit: NASA/SSAI, Hal Pierce
This 3-D image of Typhoon Nesat is looking from the east (bottom) to the west (top). North is to the left. › View larger image
This 3-D image of Typhoon Nesat is looking from the east (bottom) to the west (top). North is to the left. This image showed that the highest cloud tops were about 15 km (9.3 miles), indicating very strong thunderstorms around Nesat's eye. They were also dropping rainfall at 2 inches (50 mm) per hour (red).
Credit: NASA/SSAI, Hal Pierce
TRMM Satellite Sees Heavy Rains That Typhoon Nesat Brought to the Philippines

The TRMM satellite had an excellent early evening view of typhoon Nesat (Pedring in the Philippines) yesterday, before it made landfall in the Philippines. TRMM noticed a large area of heavy rainfall and powerful, high thunderstorms on the southern side of the storm that it brought with it when it made landfall.

According to the Big News Network, Nesat brought the Philippines the heavy rainfall that TRMM saw yesterday, creating flooding. High winds and dangerous surf accompanied Nesat's landfall. The eastern Isabela and Aurora provinces were particularly affected. Nesat made landfall with maximum sustained winds near 105 mph (170 kmh). The Albay province reported over 100,000 people evacuated. The Philippines have already felt the effects of two typhoons and two tropical storms this year.

Typhoon Nesat formed in the Pacific Ocean east of the Philippines September 23, 2011. NASA's Tropical Rainfall Measuring Mission satellite (TRMM) passed over Nesat on September 26, 2011 at 0856 UTC (4:56 a.m. EDT). and its precipitation radar instrument measured rainfall happening throughout the storm from its orbit in space.

At that time, Typhoon Nesat was still east of Luzon, Philippines. Its heaviest rainfall was occurring from southwest to southeast around the storm's center. In those areas rain was falling at 2 inches (50 mm) per hour. Around the rest of the storm was mostly moderate to light rainfall between .78 to 1.57 inches (20 to 40 mm) per hour. Rainfall analyses are derived from TRMM'S Microwave Imager (TMI) and Precipitation Radar (PR). Those data were overlaid on a combination Visible and Infrared image from TRMM's Visible and InfraRed Scanner (VIRS).

The PR data is also used to create a 3-D image to get a view of the typhoon's structure and cloud heights. The 3-D and rainfall images were both created at NASA's Goddard Space Flight Center in Greenbelt, Md. The 3-D image showed that the highest cloud tops were about 15 km (9.3 miles), indicating very strong thunderstorms around Nesat's eye. They were also dropping rainfall at 2 inches (50 mm) per hour.

By 10 a.m. EDT on Sept. 27, Nesat's center had already emerged in the South China Sea. Nesat is located 150 nautical miles north-northwest of Manila near 16.9 North and 119.3 East. Its maximum sustained winds were near 85 knots (97 mph/157 kmh) making Nesat a Category 2 Typhoon on the Saffir-Simpson Scale . It is moving west at 16 knots (18 mph/30 kmh).

Nesat is on its way to a second landfall over Hainan Island, China then a third landfall in northern Vietnam later this week.

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



September 26, 2011

This visible image of Typhoon Nesat was captured by MODIS on Sunday, Sept. 25 at 2:40 UTC. › View larger image
This visible image of Typhoon Nesat was captured by the MODIS instrument on Sunday, Sept. 25 at 2:40 UTC as its western edges began to spread over the Philippines. Nesat's eye is not visible in this image.
Credit: NASA Goddard MODIS Rapid Response Team
Infrared image of Typhoon Nesat (Pedring) was taken by AIRS on Sept. 25 at 1:11 p.m. EDT. › View larger image
This infrared image of Typhoon Nesat (Pedring) was taken by the Atmospheric Infrared Sounder instrument on NASA's Aqua satellite on Sept. 25 at 1:11 p.m. EDT. The purple areas are the strongest thunderstorms and coldest, highest cloud tops, where heavy rainfall is likely occurring. Nesat's western edges had already spread over the northern Philippines and its center continues moving in that direction.
Credit: NASA/JPL, Ed Olsen
NASA Sees Typhoon Nesat Nearing Landfall in Northern Philippines

NASA's Terra satellite saw the western edges of Typhoon Nesat brushing the eastern Philippines yesterday as Luzon prepares for a landfall today. Warning Signals are in effect throughout the northern Philippines as the typhoon nears.

NASA's Terra satellite flew over Typhoon Nesat yesterday. Nesat is known locally in the Philippines as "Pedring." NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) captured a visible image of the large storm on Sunday, Sept. 25 at 2:40 UTC (10:40 a.m. local time/Philippines) as its western edges began to spread over the Philippines. Although the visible image did not reveal an eye because it was cloud-filled, satellite microwave imagery did spot the eye.

Typhoon Nesat has maximum sustained winds near 80 knots (92 mph/148 kmh) on Monday, Sept. 26 as its center approaches northern Luzon, Philippines. It was located only 225 miles east-northwest of Manila, near 15.9 North and 124.2 East. It was moving to the west-northwest near 14 knots (16 mph/26 kmh).

Satellite imagery shows tightly-curved bands of thunderstorms wrapping into the low level center of circulation. That's an indication the storm is well-organized. The strongest convection and thunderstorms are mostly over the western semi-circle of the storm today. Microwave satellite data does reveal Nesat has an eye which helps forecasters pinpoint Nesat's center.

PAGASA, the Philippines' meteorological service expects Nesat (Pedring) will make landfall Tuesday afternoon (local time/Philippines) over Casiguran, Aurora and will be in the vicinity of Baguio City. Coastal areas can expect dangerous surf and high ocean swells, heavy rainfall and gusty winds.

Many watches and warnings are in effect. A Signal 3 (for the strongest winds) has been posted for: Catanduanes, Camarines Sur, Camarines Norte, Northern Quezon, Polillo Island, Aurora, Quirino and Isabela. Signal 2 is in effect for Albay, Burias Island, Sorsogon, Rest of Quezon, Rizal, Bulacan, Nueva Ecija, Nueva Vizcaya, Ifugao, Benguet, Mt. Province, Kalinga, Cagayan and Metro Manila. Signal 1 has been raised for Ticao Island, Masbate, Marinduque, Batangas, Cavite, Bataan, Laguna, Pampanga, Zambales, Tarlac, Pangasinan, La Union, Ilocos Sur, Ilocos Norte, Abra, Apayao, Calayan, and the Babuyan Group of Islands.

The Joint Typhoon Warning Center forecasts Nesat to continue tracking due west over Luzon and make landfall with maximum sustained winds near 90 knots (103 mph/166 kmh). It is forecast to cross Luzon and move into the South China Sea in one day.

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



September 23, 2011

The TRMM satellite passed over System 98W on September 22 at 3:18 p.m. EDT (19:18 UTC) › View larger image
The TRMM satellite passed over System 98W on September 22 at 3:18 p.m. EDT (19:18 UTC) in the western North Pacific Ocean. 98W was showing mostly moderate to light rainfall (green and blue) between .78 to 1.57 inches (20 to 40 mm) per hour. There were some small areas of heavy rain falling at 2 inches (50 mm) per hour (red) south of the center.
Credit: NASA/SSAI, Hal Pierce
TRMM Satellite Sees Heavy Rainfall in a Potential New Tropical Storm: Nesat

The next tropical storm in the western North Pacific appears to be taking shape in rainfall imagery from NASA's Tropical Rainfall Measuring Mission satellite.

On Sept. 23, 2011 the low pressure area called System 98W was located about 175 miles north-northeast of Yap near 12.4 North and 138.9 East. Yap is one of the Caroline Islands located in the western Pacific Ocean and a state of the Federated States of Micronesia. The Joint Typhoon Warning Center noted that System 98W has a high chance of becoming Tropical Storm Nesat over the weekend.

The TRMM satellite passed over System 98W on September 22 at 1918 UTC (3:18 p.m. EDT). TRMM Precipitation Radar (PR) data showed 98W had mostly moderate to light rainfall, falling at a rate between .78 to 1.57 inches (20 to 40 mm) per hour. There were some small areas of heavy rain falling at 2 inches (50 mm) per hour south of the center. Infrared imagery today shows that the circulation center appears to be consolidating and organizing, as the convection (rising air that forms thunderstorms) increases and powerful thunderstorms develop. Satellite data also shows bands of thunderstorms developing around the center, another indication that the storm is organizing and strengthening.

So what's allowing System 98W come together? System 98W is in an area where sea surface temperatures are over 80F (26.6C), which is the temperature needed to allow evaporation and creation of thunderstorms that power a tropical cyclone. System 98W is also in an area of low wind shear.

The Joint Typhoon Warning Center noted today that because of the increased convection and more organized low-level center of circulation, "the potential for the development of a significant tropical cyclone within the next 24 hours is high."

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