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Hurricane Season 2011: Typhoon Songda (Northwestern Pacific Ocean)
06.02.11
 
TRMM rainfall analysis indicates that the highest rainfall totals occurred in the Pacific east of the Philippines. › View larger image
TMPA rainfall totals are shown here for the period from May 23 to 31, 2011. The numbers represent the date in May where the storm was located, and the time (Zulu Time) is designated by a "Z."
Credit: NASA/SSAI, Hal Pierce
NASA's TRMM Satellite Confirms that Japan Gets Heaviest Rainfall From Songda

The Tropical Rainfall Measuring Mission (TRMM) satellite measures rainfall from tropical cyclones, and the data on Super Typhoon Sondga shows that Japan received the most rainfall from the storm.

The TRMM-based, near-real time Multi-satellite Precipitation Analysis (TMPA) conducted at the NASA Goddard Space Flight Center in Greenbelt, Md. was used to create an analysis that showed the total rainfall that occurred when super typhoon Songda was active in the western Pacific Ocean. TMPA rainfall totals are shown here for the period from May 23 to 31, 2011. The numbers represent the date in May where the storm was located, and the time (Zulu Time) is designated by a "Z."

This rainfall analysis indicates that the highest rainfall totals of over 300mm (~11.8 inches) occurred in the Pacific east of the Philippines. The highest rainfall totals over land fell in the islands of southern Japan even though Songda had by then weakened to a tropical storm.This analysis indicates that over 150 mm (~5.9 inches) fell on Kyushu and that some areas of the island of Honshu received over 100 mm (~3.9 inches).

For more information about how TRMM looks at rainfall, visit NASA's TRMM website at: http://trmm.gsfc.nasa.gov/. TRMM is a joint mission between NASA and the Japanese space agency JAXA.

Text Credit: Hal Pierce, SSAI/NASA Goddard Space Flight Center



May 31, 2011

Songda captured by NASA's Aqua satellite when it was a super typhoon off shore from the northern Philippines. › View larger image
This visible image of Songda was captured by NASA's Aqua satellite on May 27 at 05:10 UTC when it was a super typhoon off shore from the northern Philippines. It was taken by the MODIS instrument on the Aqua satellite.
Credit: NASA Goddard/MODIS Rapid Response Team
Sondga's rainfall was captured by NASA's TRMM satellite on Saturday, May 28. › View larger image
This image of Typhoon Sondga's rainfall was captured by NASA's TRMM satellite on Saturday, May 28. Notice that the outer fringes of the storm brushed by Taiwan (left). The strongest rainfall (about 2 inches/50 mm per hour) appears in red. The yellow and green areas are moderate rainfall falling at a rate between .78 and 1.57 inches (20 and 40 mm) per hour.
Credit: NASA/SSAI, Hal Pierce
Infrared image of Songda on May 27 when Songda's center was parallel to the southern tip of Taiwan. › View larger image
This infrared image was taken by the AIRS instrument on NASA's Aqua satellite on May 27 at 17:11 UTC as Songda's center was parallel to the southern tip of Taiwan, but far to the east at Sea.. Notice that the eye is no longer visible in this image, indicating that the storm is weakening. Purple areas represent the strongest thunderstorms with coldest cloud top temperatures.
Credit: NASA/JPL, Ed Olsen
Two NASA Satellites See Typhoon Songda Weaken and Move Past Japan

NASA's Tropical Rainfall Measuring Mission and Aqua satellite provided forecasters some insights into the behavior of Super Typhoon Songda over the past weekend. Former Super typhoon Songda brought rainfall to parts of Japan over the weekend and today marine warnings for high surf remain in several Sub-prefecture regions as extra-tropical depression Sondga's remnants push further out to sea.

Sub-prefecture regions of Nemuro Chiho, Kushiro Chiho, and Tokachi Chiho still have high wave advisories in place today, May 31, 2011, from the Japanese Meteorological Agency as Sondga's remnants continue moving into the open waters of the Northwestern Pacific Ocean.

On Sunday, May 30, BBC News reported that as Songda continued its northeasterly journey past Japan, the work at the Fukushima nuclear plant was suspended until the storm had passed.

On Saturday, May 29 at 1500 UTC (11 a.m. EDT) Songda had weakened to a depression with maximum sustained winds near 30 knots (34 mph/55 kmh). It was located 300 miles (482 km) west-southwest of Yokosuka, Japan near 34.4 North and 136.6 East. It was moving to the northeast at 26 knots (30 mph/48 kmh).

Earlier, Songda made landfall over the Wakayama prefecture and weakened. It then reemerged over water and moved east-northeast while transitioning into an extra-tropical storm.

According to Stars and Stripes newspaper, the Kadena Air Base (island) issued an "all clear" on Sunday May 29 at 7:56 a.m. local/Japan time for most areas of Okinawa. Down powerlines were reported at Marine Corps Air Station Futenma due to downed power lines.

On Saturday, May 28, Kadena Air Base experienced strong winds and a lot of rainfall in a short period of time as it Songda moved north-northeast. At 1500 UTC (11 a.m. EDT), Kadena Air Base reported sustained winds of 52 knots (60 mph/96 kmh), gusting to 61 knots (70 mph/113 kmh). Rainfall totals were as much as 21 inches (52 centimeters) in 3 hours!

At that time, Songda's center was just 60 miles (96 km) west of Kadena Air Base, Japan, so its center did not cross the island. At that time its maximum sustained winds around the low-level center were near 75 knots (86 mph/139 kmh) and it was still a Category 1 typhoon. It was generating very rough seas at the time reported wave heights were near 37 feet (~11 meters).

Typhoon Sondga's rainfall was captured by NASA's TRMM satellite on Saturday, May 28 at 0613 UTC (1:13 a.m. EDT). At that time, the outer fringes of the storm brushed by Taiwan. The strongest rainfall (about 2 inches/50 mm per hour) remained at sea and was mostly confined to the northwestern quadrant of the storm. Most of the rainfall in the storm was moderate, falling at a rate between .78 and 1.57 inches (20 and 40 mm) per hour.

Stars and Stripes newspaper reported that before Songda approached Kadena Air Base the "Navy’s 7th Fleet has moved assets out of port at Yokosuka Naval Base. That fleet included a number of ships including flagship USS Blue Ridge and four destroyers: Fitzgerald, McCain, Mustin and Curtis Wilbur." The newspaper reported that two vessels stayed in port for maintenance and others at sea shifted their navigation away from the storm.

On May 27 at 2100 UTC (5 p.m. EDT) Typhoon Songda was 385 miles (619 km) southwest of Kadena Air Base, Japan and its maximum sustained winds were near 115 knots (132 mph/213 kmh).

The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument onboard NASA's Aqua satellite captured a visible image of Songda on May 27 at 05:10 UTC (1:10 a.m. EDT) when it was a super typhoon off shore from the northern Philippines. At that time, Songda still had an eye.

By 17:11 UTC (1:11 p.m. EDT) another satellite image showed a changing story. At that time, an infrared image was taken by the Atmospheric Infrared Sounder (AIRS) instrument onboard NASA's Aqua satellite as Songda's center was parallel to the southern tip of Taiwan, but far to the east at Sea. At that time, the eye was no longer visible in this image, indicating that the storm is weakening. Fortunately increased wind shear kicked up and continued weakening the storm by the time it approached Kadena Air Base.

One aspect of the infrared imagery that was impressive is the extent of the clouds connected to Songda. The infrared imagery shows what looks like a tail of clouds extending to the northeast that stretches from Taiwan into northern Japan.

Text Credit: Rob Gutro, NASA's Goddard Space Flight Center, Greenbelt, MD



May 27, 2011

The purple areas indicate very strong thunderstorms with heavy rainfall that surround the visible eye of Songda. › View larger image
This infrared image of Super Typhoon Songda was captured by the AIRS instrument on NASA's Aqua satellite on May 27, 2011 at 5:05 UTC (1:05 a.m. EDT). At this time, Songda was a Category 4 storm. The purple areas indicate very strong thunderstorms with heavy rainfall and there is a large area of them that surround the visible eye. Taiwan is northwest of the storm.
Credit: NASA/JPL, Ed Olsen
Super Typhoon Songda was seen again by the TRMM satellite on May 27, 2011 at 0710 UTC. › View larger image
Super Typhoon Songda was seen again by the TRMM satellite on May 27, 2011 at 0710 UTC. Super typhoon Songda contained bands of extremely heavy rainfall with numerous powerful thunderstorms. The red areas represent heavy rainfall (falling at about 2 inches/50 mm per hour). The yellow and green areas are moderate rainfall, falling at a rate between .78 to 1.57 inches (20 to 40 mm) per hour.
Credit: NASA/SSAI, Hal Pierce
NASA Sees a 14 Mile-Wide Eye and Powerful Super Typhoon Songda

Typhoon Songda became a Super Typhoon in the evening on May 26, 2011 (Eastern Daylight Time) was it reached a Category 5 status on the Saffir-Simpson Scale. NASA satellite data shows that the monster storm with a 14 mile-wide eye has weakened due to adverse wind conditions today and is still a powerful Category 4 typhoon.

The Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite captured an infrared image of Super Typhoon Songda on May 27, 2011 at 5:05 UTC (1:05 a.m. EDT). At that time Songda was a Category 4 storm. The infrared image showed a large area of very strong thunderstorms with heavy rainfall surrounding the eye of the storm. The eye is almost 14 miles (12 nm/22 km) in diameter and those thunderstorms were dropping rainfall as much as 2 inches (50 mm) per hour.

On May 27 at 1500 UTC (11 a.m. EDT), Typhoon Songda's maximum sustained winds were near 125 knots (143 mph/231 kmh) down from its peak of 140 knots (161 mph/260 kmh) which it reached late on May 26. Sondga has tracked north-northwest but is expected to turn to the north-northeast.

AIRS infrared imagery from today shows that the cloud tops are warming, and convection (rapidly rising air that forms the thunderstorms that power a tropical cyclone) is weakening. The rule with infrared imagery and thunderstorms is: the colder the cloud top, the stronger the convection and stronger the thunderstorm. So, what's making Sondga weaken? Cooler sea surface temperatures (now that its north of 20 degrees north latitude) and increasing southwesterly vertical wind shear.

Taiwan is already feeling the effects from Sondga as the surf has kicked up and is expected to remain rough until Sondga passes this weekend. Songda is currently expected to pass just to the east of Ishigakijima island and to the west of Kadena Air Base, putting the island on the strongest side (the northeastern corner) of the storm. Songda is then forecast by the Joint Typhoon Warning Center to continue moving northeast and curving past the east coast of Japan, while its center remains at sea. By May 30, Songda is expected to have passed Japan.

Text Credit: Rob Gutro, NASA's Goddard Space Flight Center, Greenbelt, MD








May 26, 2011

Super Typhoon Songda › View larger image
Songda had a circular eye with extremely heavy rainfall, particularly in the southeast quadrant. The red areas represent heavy rainfall (falling at about 2 inches/50 mm per hour). The yellow and green areas are moderate rainfall, falling at a rate between .78 to 1.57 inches (20 to 40 mm) per hour.
Credit: NASA/SSAI, Hal Pierce
Songda Becomes a Super Typhoon

As predicted, Typhoon Songda intensified and was a super typhoon with wind speeds estimated at over 130 knots ( ~145 mph) when NASA's TRMM satellite passed directly over head on May 26, 2011 at 0806 UTC (4:06 a.m. EDT).

The Tropical Rainfall Measuring Mission (TRMM) satellite captured the heavy rainfall rates within the super typhoon using TRMM's Visible and InfraRed Scanner (VIRS) instrument. The rainfall analysis from TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) data showed that Songda had a circular eye with extremely heavy rainfall (as much as 2 inches/50 mm per hour) particularly in the southeast quadrant. TRMM's PR instrument data showed the concentric rain bands typical of powerful typhoons.

Warnings are in effect in the Philippines today. Public storm warning signal no 1 is in effect in the following provinces: Luzon: Catanduanes, Camarines Sur & Norte, Quirino, Albay, Aurora, Quezon Provinces, Polilio Island, Cagayan and Isabela.

At 1500 UTC (11 a.m. EDT) on May 26, Super Typhoon Songda (called Chedeng in the Philippines) had maximum sustained winds near 140 knots (161 mph/259 kmh). Typhoon-strength winds extend 45 miles out from the center, while tropical storm-force winds extend 155 miles from the center, making Songda over 300 miles wide.

Super Typhoon Songda
Simulated flyby above Sondga using data from TRMM PR data. Credit: NASA/SSAI, Hal Pierce

Songda's center was 250 miles east-northeast of Manila, near 16.2 North and 125.1 East. It was moving northwest near 8 knots (9 mph/15 kmh). Songda is creating very rough and dangerous seas in Philippine Sea, with wave heights reaching 38 feet (11.5 meters).

Songda has intensified in favorable conditions as the forecasters at the Joint Typhoon Warning Center predicted. Songda may have reached its peak intensity and is forecast to start turning to the northeast and weaken because of increased wind shear.

Songda will then start to veer northeast and weaken due to deteriorating atmospheric conditions.

Taiwan has already posted Marine Warnings for May 27 and 28, forecasting wave heights to increase from 2 meters (~6.5 feet) to as much as 6 meters (~20 feet) on east-facing shorelines as Super Typhoon Sondga moves past (it will stay off-shore and track to the east of Taiwan). The current track from the Joint Typhoon Warning Center takes Songda over the island of Kadena on May 28, and then skirting the east coast of Japan as it continues on a northeasterly track over the weekend.

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



May 25, 2011

Typhoon Songda on May 25, 2011 was an intensifying category 3 typhoon with winds near 105 kts at that time. › View larger image
NASA's TRMM satellite captured this image of rainfall happening within Typhoon Songda on May 25, 2011 at 0903 UTC. The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches (20 to 40 mm) per hour. Songda was an intensifying category 3 typhoon with winds near 105 kts at that time.
Credit: >NASA/SSAI, Hal Pierce
NASA's TRMM Satellite Sees a Well-Organized, Major Typhoon Songda

Typhoon Songda was east of the Philippines when the Tropical Rainfall Measuring Mission (TRMM) satellite had an early evening view on May 25, 2011 at 0903 UTC (05:03 EDT) and saw good organization within the storm and heavy rainfall. Songda has intensified into a major typhoon as it tracks parallel to the east coast of the northern Philippines, spawning warnings.

Both TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) instruments were used to provide the rainfall analysis. TRMM's TMI had the best coverage of rainfall with Songda and showed well organized bands of moderate to heavy rainfall converging into the typhoon. TRMM is managed by both NASA and the Japanese Space Agency, JAXA.

Infrared imagery from the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite showed an eye about 12 nautical miles wide and strong convection surrounding the eye on all sides. Songda intensified over the over the last 12 hours because of very warm sea surface temperatures between 30 and 31 Celsius, and low wind shear.

At 1500 UTC (11 a.m. EDT) on May 25, Songda's maximum sustained winds were near 105 knots (120 mph/194 kmh) making it a Category Three Typhoon on the Saffir-Simpson scale. Sondga was located about 385 nautical miles east-southeast of Manila, Philippines and is now moving northwestward near 5 knots (6 mph/9 kmh). Yesterday it was moving to the west-northwest, so the curving northward has already begun.

Songda is predicted to become a very powerful category 4 super typhoon with wind speeds peaking at 125 knots (143 mph/231 kmh) as it passes to the northeast of the Philippines. By Friday, the current forecast track takes Songda's center very close to the island with Kadena Air Base in the Northwestern Pacific Ocean.

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



Songda sports a discernible eye, and its clouds span hundreds of kilometers, covering parts of the Philippines. › View larger image
The MODIS instrument on NASA’s Aqua satellite captured this natural-color image of Songda on May 25, 2011. Songda sports a discernible eye, and its clouds span hundreds of kilometers, covering parts of the Philippines.
Credit: >NASA image courtesy MODIS Rapid Response Team at NASA GSFC
NASA's Aqua Satellite Sees a Stronger Typhoon Songda

Typhoon Songda strengthened between May 24 and 25, 2011. At 11:00 p.m. Manila time (15:00 UTC) on May 25, the U.S. Navy’s Joint Typhoon Warning Center (JTWC) reported that Songda had maximum sustained winds of 105 knots (195 kilometers per hour) with gusts up to 130 knots (240 kilometers per hour). These wind speeds were up from 65 knots and gusts up to 80 knots the previous day. The storm was located roughly 385 nautical miles (730 kilometers) east-southeast of Manila, Philippines.

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this natural-color image of Songda on May 25, 2011. Songda sports a discernible eye, and its clouds span hundreds of kilometers, covering parts of the Philippines.

According to the JTWC warning issued May 25, Songda was expected to travel toward the north-northwest along the northern Philippines before turning northeast roughly east of Taiwan. As of May 25, Songda’s wind speeds were expected to increase over the next 48 hours.

Text Credit: Michon Scott
NASA's Earth Observatory/NASA Goddard Space Flight Center



May 24, 2011

Aqua passed over Typhoon Songda on May 24 and revealed stronger thunderstorms (purple) near its low-level center. › View larger image
NASA's Aqua satellite passed over Typhoon Songda earlier today, May 24 at 04:29 UTC and revealed stronger thunderstorms (purple) near its low-level center.
Credit: >NASA/JPL, Ed Olsen
NASA's Infrared Satellite Imagery Shows a Stronger Typhoon Songda

Songda is now a typhoon in the Northwestern Pacific Ocean as it continues tracking parallel to the eastern coast of Luzon, Philippines. Infrared satellite imagery from NASA's Aqua satellite revealed that the storm has a much tighter low-level circulation center than it did yesterday.

NASA's Aqua satellite passed over Typhoon Songda earlier today, May 24 at 04:29 UTC (12:49 a.m. EDT) and the Atmospheric Infrared Sounder (AIRS) instrument captured an infrared look at the storm's cloud top temperatures and warm waters surrounding it.

AIRS infrared imagery shows that the thunderstorm cloud tops around the low-level center are cooling and consolidating. The rule in infrared imagery with thunderstorms is that the colder the cloud top temperature, the higher the thunderstorm and the stronger it is. Cloud-top temperatures in today's imagery are as cold as -63 Fahrenheit/-52 Celsius indicating strong storms that are heavy rainmakers. The AIRS imagery also showed that the convection (rapidly rising air that forms thunderstorms) was not symmetrical as the strongest thunderstorms were mostly over the southern part of the semicircle.

At 1500 UTC (11 a.m. EDT) on May 24, Songda (known as Chedeng in the Philippines) was about 500 nautical miles (575 miles/926 kilometers) east-southeast of Manila, Philippines near 12.6 North and 129.3 East. It was moving west-northwest near 9 knots (10 mph/17 kmh) and its maximum sustained winds had increased to 65 knots (75 mph/120 knh). Tropical-storm force winds extend out to 105 miles (169 km) from the center, so the storm has expanded a little since yesterday. As Songda has strengthened so has its generation of rough surf. Songda is now generating waves up to 26 feet (8 meters) high.

Two warnings are in effect in the Philippines, Public storm warning signal no 2 is in effect for the Luzon province of Catanduanes. Public storm warning signal no 1 is in effect for the following provinces: in Luzon for: Sorsogon, Burias island, Ticao island, Albay, Camarines Sur & Norte, and in Visayas for the Samar provinces

The sea surface temperatures in the vicinity of the typhoon are warm and wind shear is low, both of which will enable Songda to strengthen further as it curves to the north.

Text Credit: Rob Gutro, NASA's Goddard Space Flight Center, Greenbelt, MD



The MODIS instrument on NASA�s Aqua satellite captured this natural-color image of Songda on May 24, 2011. › View larger image
The MODIS instrument on NASA’s Aqua satellite captured this natural-color image of Songda on May 24, 2011. Although the storm does not show a clear eye, it bears the coiled shape typical of powerful storms. Songda’s clouds pass over the eastern Philippines (image lower left).
Credit: >NASA image courtesy MODIS Rapid Response Team at NASA GSFC.
NASA's Aqua Satellite Captures Typhoon Songda

Songda formed as a tropical depression on May 20, 2011, and strengthened into a tropical storm the same day. On May 24, the storm strengthened into a typhoon. At 11:00 p.m. Manila time (15:00 UTC) on May 24, 2011, the U.S. Navy’s Joint Typhoon Warning Center (JTWC) reported that Songda was located about 500 nautical miles (900 kilometers) east-southeast of Manila, Philippines. The typhoon had maximum sustained winds of 65 knots (120 kilometers per hour) with gusts up to 80 knots (150 kilometers per hour).

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured a natural-color image of Songda on May 24, 2011. Although the storm does not show a clear eye, it bears the coiled shape typical of powerful storms. Songda’s clouds pass over the eastern Philippines.

A warning graphic issued by the JTWC forecast Songda remaining strong as it followed a roughly northward track along the Philippines. The storm had traveled toward the west-northwest in the hours leading up to the 15:00 UTC May 24 bulletin.

Text Credit: Michon Scott
NASA's Earth Observatory/NASA Goddard Space Flight Center



May 23, 2011

Three infrared images show the strengthening of Tropical Storm Songda over the period of May 19-22, 2011. › View larger image
This series of three infrared images shows the strengthening of Tropical Storm Songda over the period of May 19-22, 2011. Notice that the area with strongest convection (purple) has expanded over that time. That area has the coldest, highest thunderstorm cloud tops near -63 F/-52C, and heaviest rainfall. Over those four days, Songda took on a more rounded shape.
Credit: >NASA/JPL, Ed Olsen
NASA Sees Tropical Storm Songda Singing of Rain and Gusty Winds for the Philippines

"Rainy days and Mondays" is the song that the residents of the northern Philippines do not want to hear if it involves the approaching Tropical Storm Songda. The Carpenters song was a hit, but a hit from Songda is making residents of the Philippines nervous as NASA's Aqua satellite has been watching the progression and intensification of the storm over the last several days.

In a series of three infrared images from the period of May 19-22, 2011, NASA's Atmospheric Infrared Sounder (AIRS) instrument revealed the strengthening of Tropical Storm Songda. The area with strongest convection has expanded and organized over that time. That area of strongest convection has the coldest, highest thunderstorm cloud tops near -63 F/-52C, and heaviest rainfall. The time series of imagery over those four days also shows that Songda took on a more rounded shape as it continued to strengthen from a tropical depression to a tropical storm. Today, May 23, satellite imagery shows a strong band of deep convection is persisting along the southern edge of Songda.

On May 21, Tropical Storm 04W still had maximum sustained winds near 40 mph (35 knots/64 kmh). On Sunday, May 22, the maximum sustained winds increased to 52 mph (45 knots/83 kmh) and the storm was renamed "Tropical Storm Songda." At that time the center of the storm was near 10.0 N and 136.4 E, or 190 miles north-northeast of Palau. By 2100 UTC on May 22, Songda's winds again increased to 55 knots as it continued moving north-northwest.

On May 23, Songda's maximum sustained winds have again increased and are now clocked at 69 mph (60 knots/111 kmh). Tropical storm-force winds extend out 100 miles (161 km) from the center. Further strengthening is expected by the forecasters at the Joint Typhoon Warning Center. Songda's center was located about 295 miles (475 km) northwest of Palau, near 11.5 North and 131.8 East, and it was moving west-northwest near 12 mph (10 knots/~18 kmh). Songda is kicking up high waves in the Northwestern Pacific, up to 22 feet (6/7 meters) high.

Songda is expected to continue intensifying over the next couple of days, but its center is forecast stay offshore from Luzon, Philippines and track east of land. However, the western side of the storm is expected to bring gusty winds, heavy rainfall and rough surf to Luzon over the next couple of days as it approaches and sweeps north toward Taiwan.

Text Credit: Rob Gutro, NASA's Goddard Space Flight Center, Greenbelt, MD



May 20, 2011

TRMM 3-D image showing thunderstorm towers punching heights of over 16 km (~9.9 miles) above the ocean's surface. › View larger image
This TRMM satellite 3-D image shows that some thunderstorm towers near TSO4W's center of circulation were punching up to heights of over 16 km (~9.9 miles) above the ocean's surface.
Credit: NASA/SSAI, Hal Pierce
TRMM saw several areas of heavy thunderstorms dropping rain (red) at over 50 mm/hour (~2 inches/hour). › View larger image
The TRMM satellite flew over rapidly forming Tropical Storm 04W in the western Pacific on May 20, 2011 at 0037 UTC (~10:37 a.m. Local time). TRMM saw several areas of heavy thunderstorms dropping rain (red) at over 50 mm/hour (~2 inches/hour).
Credit: >NASA/SSAI, Hal Pierce
NASA Sees Tropical Storm 04W's Thunderstorms Grow Quickly

Tropical Storm 04W formed from the low pressure System 98W this morning in the northwestern Pacific. NASA's Tropical Rainfall Measuring Mission (TRMM) satellite watched the towering thunderstorms in the center of the tropical storm grow to almost 10 miles (16 km) high as it powered up quickly.

At 1500 UTC (11 a.m. EDT) on May 20, Tropical Storm 04W (TS04W) was located 180 miles (290 km) east-southeast of Yap near 8.3 North and 141.9 East. It had maximum sustained winds near 35 knots (40 mph/65 kmh). On its west-northwest track it is already generating rough seas, with waves up to 12 feet (~3.6 meters) high.

The TRMM satellite flew over rapidly forming Tropical Storm 04W in the western Pacific on May 20, 2011 at 0037 UTC (~10:37 a.m. Local time). This daylight TRMM pass showed that TS04W was becoming much better organized. The TRMM data showed that TSO4W now contained several areas of heavy thunderstorms dropping rain at over ~2 inches/hour (50 mm/hour).

Using TRMM data, Hal Pierce of NASA's TRMM satellite team created a 3-D image of Tropical Storm 04W at NASA's Goddard Space Flight Center in Greenbelt, Md. The 3-D perspective image helps forecasters see the cloud heights within tropical cyclones, giving indications of the storm's strength. The higher the thunderstorms go into the atmosphere, the stronger they are.

The 3-D image was created using data from TRMM's Precipitation Radar (PR). It showed that some thunderstorm towers near TSO4W's center of circulation were punching up to heights of over 9.9 miles (16 km) above the ocean's surface.

Regional warnings have been posted for TS04W. A tropical storm warning is in force for Fais and Ulithi in Yap State. That means that winds of 40 mph (65 kmh) or higher are expected within 24 hours in the warning area. In addition, a tropical storm watch is in force for Yap and Ngulu in Yap State. The watch means that in 48 hours, those areas could experience winds of 40 mph (65 kmh) or higher.

Now, Tropical Storm 04W is on a west-northwesterly track and residents of the northern Philippines should be on guard as it heads in that direction. The current forecast track from the Joint Typhoon Warning Center extends to May 25 and it is not yet expected to be close enough to land at that time. However, in the days after May 25 residents of Luzon, the Philippines may experience the effects of the approaching tropical storm (which is expected to strengthen by that time).

This storm is predicted to become a category 2 typhoon with wind speeds of 90 knots (~103 mph/166 kmh) within five days as it moves toward the west-northwest.

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



May 19, 2011

This TRMM image from May 19 shows that System 98W does have some heavy rainfall. › View larger image
This image of rainfall from NASA's TRMM satellite on May 19 at 1124 UTC (7:24 a.m. EDT) shows that System 98W does have some heavy rainfall occurring within (falling at ~2 inches/50 mm/hr). The small yellow and green areas are moderate rainfall, falling at a rate between .78 to 1.57 inches (20 to 40 mm) per hour.
Credit: NASA/SSAI/Hal Pierce
TRMM 3-D image from May 19 showing powerful thunderstorms with heights of almost 17 km (~10.6 miles). › View larger image
This 3-D image from TRMM satellite data on May 19 showed that some powerful thunderstorms were penetrating to heights of almost 17 km (~10.6 miles).
Credit: >NASA/SSAI, Hal Pierce
NASA's TRMM Satellite Sees Heavy Rainfall in System 98W

The low pressure area called System 98W in the northwestern Pacific Ocean has some potential for development, at least when you look at the rainfall rates through the eyes of NASA's Tropical Rainfall Measuring Mission (TRMM) satellite.

The TRMM satellite flew over an area of disturbed tropical weather south-southwest of Guam in the western Pacific Ocean on May 19, 2011 at 1124 UTC (7:24 a.m. EDT). TRMM data captured the rainfall rates occurring within the low pressure area. A rainfall analysis from TRMM's Microwave Imager and Precipitation Radar data showed that heavy thunderstorms within were dropping rainfall at a rate of over 50 mm/hour (~2 inches hour).

At NASA's Goddard Space Flight Center in Greenbelt, Md., meteorologist Hal Pierce created a 3-D perspective image using data that was derived from TRMM's Precipitation Radar instrument, The 3-D image gives perspective of cloud heights and showed that some powerful thunderstorms were penetrating to heights of almost 17 km (~10.6 miles).Towering thunderstorms releasing energy near the center can be a sign of an intensifying storm.

The TRMM satellite is managed by both NASA and the Japanese Space Agency, JAXA.

On May 19, System 98W was centered near 7.7 North and 142.8 East. That's about 280 nautical miles east-southeast of Yap. Yap is an island in the Caroline Islands of the western Pacific Ocean. Yap is a state of the Federated States of Micronesia. System 98W's maximum sustained winds were near 15 knots, and it had a minimum central pressure of 1009 millibars.

TRMM will continue to monitor the progress of this storm over the next couple of days.

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