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Typhoon Bopha (Western North Pacific Ocean)
12.10.12
 

Bopha Updates

NASA Satellites See Typhoon Bopha Fizzle Over Weekend

Infrared data from NASA's Aqua satellite have watched the strong thunderstorms in Typhoon Bopha fizzle and shrink in area over the weekend as wind shear increased. Bopha has now dissipated in the South China Sea, just west of Luzon, Philippines.

NASA's Aqua satellite has been providing data on Bopha since the day it formed on Nov. 26. In the storm's last days, Aqua's Atmospheric Infrared Sounder (AIRS) instrument captured infrared data of the storm and showed that cloud top temperatures warmed from Dec. 8 through Dec. 9 as cloud heights fell and thunderstorms lost their punch.

AIRS infrared data reveals where the coldest, highest cloud tops are located in a tropical cyclone. The coldest cloud tops indicate the strongest storms with the heaviest rain. On Dec. 8, AIRS data revealed a large area of strong thunderstorms surrounded the center of circulation as the storm skirted the west coast of Luzon, the northern Philippines. That same day, Bopha triggered more warnings for the Philippines.

MODIS captured this image of Bopha on Dec. 8 at 02:45 UTC after it had regained typhoon status› View larger image
The MODIS instrument aboard NASA's Terra satellite captured this image of Bopha on Dec. 8 at 02:45 UTC (Dec. 7 at 9:45 p.m. EST/U.S.) after it had regained typhoon status and was headed toward Luzon, Philippines.
Credit: NASA Goddard MODIS Rapid Response Team
This side-by-side image shows Typhoon Bopha on Dec. 8 (left) and Dec. 9 (right).› View larger image
This side-by-side image shows Typhoon Bopha on Dec. 8 (left) and Dec. 9 (right). NASA AIRS infrared data revealed the strongest thunderstorms (purple) within Typhoon Bopha surrounded the center of circulation on Dec. 8. On Dec. 9 the strongest thunderstorms were located just northwest of Luzon, and had almost disappeared.
Credit: NASA JPL, Ed Olsen
Just one day before, Typhoon Bopha's maximum sustained winds were up to 110 knots (126 mph/203.7 kph), but increased wind shear started taking a toll on the storm. As Bopha moved closer to Luzon (northern Philippines), warnings were posted on Dec. 8. Public storm warning signal #2 was in effect in the Luzon provinces of Ilocos Norte & Sur and La Union; and Public storm warning signal #1 was in effect in the Luzon provinces of Cagayan, Calayan group of islands, Babuyan group of islands, Batanes group of islands, Abra, Apayao, Kalinga, Mt. Province, Benguet, Pangasinan. At 2100 UTC (4 p.m. EST/U.S.), Bopha's maximum sustained winds were near 45 knots (51.7 mph/83.3 kph), so it was still a tropical storm. Overnight on Dec. 8 into Dec. 9, wind shear increased and Bopha weakened into a tropical depression.

By Dec. 9 at 0300 UTC (Dec. 8 at 10 p.m. EST/U.S.) the Joint Typhoon Warning Center issued its final advisory on Bopha. At that time it was a tropical depression located near 18.3 north latitude and 119.2 east longitude, about 240 miles north-northwest of Manila, Philippines. The depression was moving slowly at 3 knots (3.4 mph/5.5 kph) to the northeast and dissipating under adverse atmospheric conditions just west of Luzon. On Dec. 9, AIRS data showed quite a different picture as the strongest thunderstorms no longer surrounded the center of circulation and were blown away from the center because of wind shear. The area of strong thunderstorms had also diminished greatly, indicating a weakening storm. Wind shear had taken its toll on this once deadly storm and had blown it apart.

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


















Dec. 7, 2012

NASA Infrared Data Shows Typhoon Bopha Re-Strengthened in South China Sea

The deadly typhoon that caused almost 300 deaths in the southern Philippines is making a loop in the South China Sea, and infrared NASA satellite data indicated that Bopha re-intensified.

NASA's Aqua satellite passed over Bopha on Dec. 6 at 1811 UTC (1:11 p.m. EST, U.S.) and the Atmospheric Infrared Sounder (AIRS) instrument aboard captured an infrared look at the storm. The infrared data revealed where the coldest, highest cloud tops were. The coldest cloud tops indicate the strongest storms with the heaviest rain, and AIRS data revealed they surrounded the center of circulation and were in bands of thunderstorms north and northeast of the center, just skirting the west coast of Luzon, the northern Philippines. Cloud top temperatures in those areas were colder than -63 Fahrenheit (-52 Celsius). Satellite data showed the Bopha's eye on Dec. 7 was about 11 nautical miles in diameter.

AIRS data revealed the strongest thunderstorms within Typhoon Bopha surrounded the center of circulation.› View larger image
On Dec. 6 at 1:11 p.m. EST/U.S., NASA AIRS infrared data revealed the strongest thunderstorms (purple)within Typhoon Bopha surrounded the center of circulation and were in bands of thunderstorms north and northeast of the center, just skirting the west coast of Luzon, the northern Philippines.
Credit: NASA JPL, Ed Olsen
On Dec. 7 at 1500 UTC (10 a.m. EST, U.S.), Typhoon Bopha's maximum sustained winds were back up to 110 knots (126 mph/203.7 kph). Bopha was in the South China Sea near 15.7 north latitude and 116.3 east longitude about 280 nautical miles (322.2 miles/518.6 km) west of Manila, the Philippines. Bopha was moving to the north-northeast at 9 knots (10.3 mph/16/6 kph), but is expected to make a cyclonic loop over the weekend of Dec. 8 and 9, with its center staying at sea. The west coast of Luzon may experience rough surf over the next several days as Bopha makes its circle.

After Bopha loops over open ocean, it is expected to weaken and turn southwest after the weekend.

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










Dec. 6, 2012

NASA Compiles Typhoon Bopha's Philippines Rainfall Totals from Space

NASA's Tropical Rainfall Measuring Mission, or TRMM satellite can estimate rainfall rates from its orbit in space, and its data is also used to compile estimated rainfall totals. NASA just released an image showing those rainfall totals over the Philippines, where severe flooding killed several hundred people. Bopha is now a tropical storm in the South China Sea.

High winds, flooding and landslides from heavy rains with Typhoon Bopha have caused close to 300 deaths in the southern Philippines.

The TRMM satellite's primary mission is the measurement of rainfall in the tropics. A near-real time Multi-satellite Precipitation Analysis (MPA) using TRMM satellite data was created at the NASA's Goddard Space Flight Center in Greenbelt, Md. the MPA monitors rainfall over the global Tropics. MPA rainfall totals from Typhoon Bopha were compiled for the period from November 28 to December 5, 2012 when typhoon Bopha was moving through the southern Philippines.

TRMM rainfall totals are shown here from Nov. 28 to Dec. 5, 2012 when typhoon Bopha was moving through the southern Philippines.› View larger image
TRMM rainfall totals are shown here from Nov. 28 to Dec. 5, 2012 when typhoon Bopha was moving through the southern Philippines. Typhoon Bopha's track is shown overlaid in white. The heaviest rain, estimated at over 240 mm(~9.4 inches), was located near the coast of eastern Mindanao where the typhoon first hit the island. Rainfall totals of over 100mm (~3.9 inches) were normal over a large area of eastern Mindanao.
Credit: NASA/SSAI, Hal Pierce
MODIS satellite captured this visible image of Typhoon Bopha moving through the South China Sea on Dec. 6› View larger image
The MODIS instrument aboard NASA's Aqua satellite captured this visible image of Typhoon Bopha moving through the South China Sea on Dec. 6 at 03:00 UTC (10 p.m. EST, U.S, Dec. 5).
Credit: NASA Goddard MODIS Rapid Response Team
The MPA analysis shows that the heaviest rain, estimated at over 240 mm (~9.4 inches), was located near the coast of eastern Mindanao where the typhoon first hit the island. Rainfall totals of over 100mm (~3.9 inches) covered a large area of eastern Mindanao. Because Bopha was moving relatively fast, it kept rainfall totals down.

On Thursday, Dec. 6 at 1500 UTC (10 a.m. EST, U.S.), Bopha had weakened to a tropical storm with maximum sustained winds near 55 knots (63 mph/102 kph). At that time, Bopha's center was located near 13.0 north latitude and 116.2 east longitude, about 295 nautical miles west-southwest of Manila, Philippines. Bopha was moving to the north-northwest at 4 knots (4.6 mph/7.4 kph) and is expected to continue in that general direction over open waters for the next couple of days.

Infrared satellite imagery has shown that the strongest convection (rising air that condenses and creates the thunderstorms that make up the tropical cyclone) around the center was weakening, and the center was elongating. Bopha is in an area of moderate vertical wind shear which is helping to elongate and weaken the storm. Cooler waters and a northeasterly monsoon surge will help to weaken Bopha over the next couple of days.

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






















NASA Satellites Analyze Typhoon Bopha Inside and Out

Typhoon Bopha proved deadly to residents in the Mindanao region of the Philippines after ravaging islands in Micronesia. NASA's Aqua and TRMM satellites peered at the storm inside and out, providing forecasters with valuable data as the storm moved into the South China Sea.

On Dec. 5, 2012, Bopha crossed over Palawan and entered the South China Sea after crossing over the southern Philippines' Mindanao region, leaving death and destruction in its wake. According to Reuters news reports on Dec. 5, at least at total of 283 people were killed and hundreds remain missing in the Philippines. The hardest-hit province in Mindanao was Compostela, where flood waters and mudslides swept through the town and killed at least 150 people. Homes were destroyed, roads were flooded and washed out, and it was estimated that as much as 80 percent of plantations were destroyed.

satellite image of Bopha
The MODIS instrument aboard NASA's Aqua satellite captured this visible image of Typhoon Bopha moving over Palawan and entering the South China Sea on Dec. 5 at 05:20 UTC (12:20 a.m. EST, U.S.).
Credit: NASA Goddard's MODIS Rapid Response Team
› Larger image

TRMM representation of Bopha rain intensity and cloud height

This 3-D image of Super Typhoon Bopha was created using data from NASA's Tropical Rainfall Measuring Mission (TRMM) satellite on Dec. 2, 2012. TRMM 3-D data showed that the inner eyewall was being replaced by an outer eyewall, something that typically happens in major typhoons. There was also a "hot tower" thunderstorm reaching 12 kilometers (7.4 miles) high, located north of the center of circulation. NASA research indicates that whenever a "hot tower" is spotted in a tropical cyclone, the storm usually intensifies within 6 hours. The graphic also indicates where the highest, most powerful thunderstorms were around the center by the rounded area indicating cloud top temperatures of -90 Celsius.
Credit: NASA/SSAI, Hal Pierce
› Larger image


infrared image of Bopha

NASA's Aqua satellite's AIRS instrument captured this infrared view of Typhoon Bopha's cloud-top temperatures on Dec. 5 at 0517 UTC (12:17 a.m. EST) as it was exiting Palawan and moving into the South China Sea. The purple areas indicate bitterly cold cloud-top temperatures of 210 kelvin (-63C/-81F) and are areas of the strongest thunderstorms, with highest cloud tops, and heaviest rainfall.
Credit: NASA JPL, Ed Olsen
› Larger image

On Dec. 2, 2012, NASA and the Japanese Space Agency's Tropical Rainfall Measuring Mission (TRMM) satellite passed over Super Typhoon Bopha. Data from the overpass was used to create a 3-D image that showed that the inner eyewall was being replaced by an outer eyewall, something that typically happens in major typhoons. There was also a "hot tower" thunderstorm reaching 12 kilometers (7.4 miles) high, located north of the center of circulation. NASA research indicates that whenever a "hot tower" is spotted in a tropical cyclone, the storm usually intensifies within 6 hours. The data also indicated the highest, most powerful thunderstorms were around the center where cloud top temperatures were as cold as -90 Celsius (-130F).

On Dec. 5 at 0517 UTC (12:17 a.m. EST), the Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA's Aqua satellite captured an infrared view of Typhoon Bopha's cloud-top temperatures as it was exiting Palawan and moving into the South China Sea. The AIRS data identified areas of bitterly cold cloud-top temperatures of 210 kelvin (-63C/-81F) where the strongest thunderstorms, with highest cloud tops, and heaviest rainfall were found. One area was located over the South China Sea and the other over northern Palawan at the time of the image.

Three minutes later, another instrument aboard Aqua captured a visible image of Typhoon Bopha. The image revealed that Bopha's clouds covered the entire island of Palawan, and where the AIRS instrument revealed the coldest cloud top temperatures, those areas of clouds appeared the brightest white in the visible image, because they were higher than the surrounding clouds, and cast shadows on the lower clouds. The strongest thunderstorms have waned around the center of circulation during the early part of Dec. 5, although a tightly curved band of thunderstorms remained along the western and northern quadrants.

On Dec. 5 at 1500 UTC (10 a.m. EST) Bopha's maximum sustained winds were near 75 knots (86 mph/139 kph). It was located near 11.5 north latitude and 117.4 east longitude, about 270 nautical miles southwest of Manila, Philippines. Bopha is moving to the northwest near 11 knots (12.6 mph/20 kph) and is expected to slow down in the South China Sea.

Bopha is expected to continue tracking generally west-northwest into the South China Sea and become quasi-stationary over the next couple of days.

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















Dec. 5, 2012, first update

NASA TRMM satellite visualized Typhoon Bopha in 3-D as it moved through the western North Pacific Ocean.› View larger image
NASA TRMM satellite visualized Typhoon Bopha in 3-D as it moved through the western North Pacific Ocean.› View larger image
Caption: NASA TRMM satellite visualized Typhoon Bopha in 3-D as it moved through the western North Pacific Ocean. TRMM radar saw a double eyewall, two concentric rings of intensity storm cells exceeding a 12 km (7.4 miles) altitude. Yellows and greens indicate locations inside of the typhoon's clouds where updrafts were lifting precipitation-size ice between 9 and 12 km (5.5 and 7.4 miles) above the ocean.
Credit: NASA/Owen Kelley
NASA's TRMM Satellite Provides 3-D Analyzation of Super-typhoon Bopha: "Full Catastrophe"

NASA's Tropical Rainfall Measuring Mission (TRMM) satellite observed the eyewall of Super-typhoon Bopha in 3-D shortly before noon on Monday, Dec. 3, 2012 (Philippines local time). At that time, Bopha was at category 3 and had begun rapidly intensifying to category 5 prior to landfall in the pre-dawn hours the next morning. Bopha made landfall in the Philippines, on the island of Mindanao.

"This close to landfall, the TRMM satellite saw what could only be described as the 'full catastrophe' in terms of the eyewall indicators of a potentially destructive tropical cyclone," said Owen Kelley of the TRMM science team at NASA's Goddard Space Flight Center, Greenbelt, Md.

For starters, the TRMM radar saw two hot towers simultaneously reaching a 15.5 km (9.6 mile) altitude on the northeast side of the eyewall where the storm's forward motion is added to the counter-clockwise winds circling under the eyewall. TRMM studies have suggested that even a single hot tower exceeding a 14.5 km (9 mile) height may be sufficient to indicate intensification is on-going. At the base of the hot towers, radar reflectivity exceeded 45 dBZ indicating heavy rainfall (as shown in deep red in the image).

Second, the TRMM radar saw a double eyewall, two concentric rings of intensity storm cells exceeding a 12 km (7.4 miles) altitude. Yellows and greens indicate locations inside of the typhoon's clouds where updrafts were lifting precipitation-size ice between 9 and 12 km (5.5 and 7.4 miles) above the ocean. Concentric eyewalls are generally evidence of an eyewall replacement cycle, which can be associated rapid intensification.

While most of the best tropical-cyclone-observing instruments are passive microwave instruments which give altitude-integrated images with somewhat "fuzzy" horizontal resolution, the TRMM radar is even better. The TRMM radar is like a high-definition camera with a flash that reveals vertical structure. The TRMM radar has 5 km (3.1 mile) horizontal resolution and 250 meter(820 foot) vertical resolution, which clearly resolved the structure within the storm clouds that contains raindrops and ice large enough to fall out of clouds. In this case, the TRMM radar revealed that the inner eyewall had only a ~20 km (12.4 mile) radius, which is smaller than the average tropical cyclone.

The small inner radius of the inner eyewall is the third feature that indicates Super-typhoon Bopha's fearsome potential. A compact eyewall means that the typhoon's eye contains only a relatively small volume of air that would need to be heated in order to lower the storm's ocean-surface central pressure, which in turn, would make is easier to increase the speed of the circling surface winds that determine the storm's "headline" intensity.

Fourth, the TRMM Lightning Imaging Sensor (LIS) saw two lightning flashes in the inner edge of one of the eyewall hot towers. Lightning flashes are relatively rare in eyewalls, even in the eyewalls of intensifying tropical cyclones. Lightning tends to occur where updrafts are strong enough to suspend in mid-air a mix of supercooled water and grauple or hail-sized chunks of ice. Such large chunks of ice can only form when updrafts repeatedly "bob" ice particles up and down through a lower cloud layer with liquid water droplets and then a higher cloud layer cold enough to promote freezing.

In addition to lightning, radar, and passive microwave observations, the TRMM satellite also simultaneously observes cloud-top temperatures, which provide a fifth indicator that the inner-core energy-conversion machinery of Super-typhoon Bopha was working in overdrive. Specifically, the coldest cloud tops were observed with extremely cold temperatures below -90C (-130F), which indicates Bopha was extracting a great deal of energy from the ocean surface and converting it into kinetic energy of strong updrafts that where punching through the troposphere (the bottom layer of the atmosphere that usually contains weather) and into the transition zone between troposphere and stratosphere.

As a bonus, the TRMM-observed cloud-top temperatures clearly illustrate how the circling winds of the tropical cyclone can act as a "containment vessel" preventing at least some of the energy released in hot towers from rapidly dissipating harmlessly far from the cyclone's inner core. Specifically, the cloud-top temperatures show gravity waves propagating around the eyewall instead of spreading away from the inner core like ripples in a pond. The observed gravity waves have their wave crests perpendicular to their direction of motion and the wave crests are seen to be oriented radially, i.e., perpendicular to the wind circling the eye. The gravity waves are seen in the upper left of the image as alternating bands of gray and pink.

For a reason other than the details revealed by TRMM, Super-typhoon Bopha is impressive. Conventional wisdom has it that tropical cyclones can only form at least 5 or 8 degrees of latitude away from the Equator, while some studies suggest that this rule of thumb is dangerous oversimplification (Brunt, 1969, Australian Meteorological Magazine). Tropical Cyclone Bopha has just broken this rule, with the TRMM satellite radar catching Bopha in the act of rapidly intensifying from category 3 to category 5 when approximately 6 degrees north of the Equator. At the time of this writing, the scope of the damage and the total number of fatalities from Bopha are unknown.

In recent years, a few tropical storms have made landfall this close to the Equator. An unofficial list of such recent near-Equator storms could include tropical storm Washi that hit the Philippines last December (Dec. 16, 2011), tropical storm Agni that hit Somalia on Dec. 5 2004, and tropical storm Vamie that struck near Singapore on Dec. 27, 2001. In the past half century, the two tropical storms with the most similar landfall locations in the southern Philippines may be Kate (1970) that made landfall at category 4 and caused over 600 deaths and Washy (2011) that make landfall as a tropical storm and caused over 1,000 deaths.

Bopha is designated a super-typhoon because it formed in the West Pacific (hence the "typhoon" nickname) and because it reached major cyclone status, or category 4 on the Saffir-Simpson scale (hence the "super" designation).

A joint mission between the United States and Japan, the TRMM satellite has just passed the 15th anniversary of its launch. An advantage of an extended mission such as this one is that it increases the chances of observing rare and poorly understood events, such Bopha, a category 5 tropical cyclone close to the Equator. The physical mechanisms contributing to such an event will take scientists time to unravel.

Text credit: Owen Kelley
NASA's Goddard Space Flight Center, Greenbelt, Md.




Dec. 4, 2012

TRMM passed over Bopha on Dec. 4 and revealed the heaviest rainfall was falling from northeast to southeast of the center› View larger image
The TRMM satellite passed over Bopha on Dec. 4 at 1420 UTC (9:20 a.m. EST) and revealed the heaviest rainfall was falling from northeast to southeast of the center, occurring at a rate of 2 inches/50 millimeters per hour (in red).
Credit: SSAI/NASA, Hal Pierce
Typhoon Bopha Brings Heavy Rains to the Philippines

Typhoon Bopha left heavy rainfall in its wake as it moved across the Philippines. NASA's TRMM satellite measured heavy rainfall along the eastern side of the storm as it made landfall. That rainfall caused flooding and mudslides as Bopha, known locally as "Pablo," tracked from southeast to northwest before moving into the Sulu Sea today, Dec. 4.

NASA's Tropical Rainfall Measuring Mission (TRMM) satellite captured rainfall rates, identified areas of heavy rainfall, and measured cloud heights. The TRMM satellite passed over Bopha on Dec. 4 at 1420 UTC (9:20 a.m. EST) and revealed the heaviest rainfall was falling from northeast to southeast of the center, occurring at a rate of 2 inches/50 millimeters per hour. By 12 p.m. EST/U.S. satellite imagery showed that the strongest thunderstorms and heaviest rainfall were over the Sulu Sea. The storm's center was still well-defined, and there were still bands of thunderstorms feeding into the center, but the banding decreased on the eastern side of the storm.

According to the Philippine Atmospheric, Geophysical and Astronomical Services Administration known as PAGASA, Bopha's center was located at 9.9 degrees north latitude and 121.4 east longitude, or about 90 miles/145 km southwest of Iloilo City at 9 a.m. EST, U.S./10 p.m. Philippines local time on Dec. 4. Bopha's maximum sustained winds at that time were near 87 mph (140 kph) as it tracked to the northwest at 14.9 mph (24 kph). According to the Joint Typhoon Warning Center, one hour later the center of Bopha was about 160 nautical miles (184 miles/296 km) north of Zamboanga, Philippines, near 9.6 north and 122.3 east. Bopha was moving west-northwestward at 20 knots (23 mph/37 kph).

Many Public Storm warning signals remain in effect as Bopha moves away from the Philippines today, Dec. 4, 2012. In Luzon, Signal 3 (101 to 185 kph/63 to 115 mph winds) is in effect for Northern Palawan, including the Calamian Group of islands; and in Visayas for: Antique, Iloilo, Guimaras, Bohol, Siquijor, Southern Cebu, Negros Oriental and Negros Occidenta. Signal 2 (61-100 kph/56 to 91 mph winds) is in effect in Luzon for the rest of Palawan (not covered by Signal 3); in Visayas, it includes: Aklan, Capiz and the rest of Cebu; and in Mindanao: Lanao del Norte, Misamis Occidental, Zamboanga del Norte and Camiguin. Signal 1 (30-60 kph winds) covers more territory and includes in Luzon: Occidental Mindoro including Lubang Island, Oriental Mindoro and Romblon. In Visayas it includes: Leyte including Biliran, Southern Leyte and Camotes Island. In Mindanao, Signal 1 is in effect for Zamboanga del Sur including Sibugay, Surigao del Norte, Surigao del Sur, Dinagat, Agusan del Sur, Agusan del Norte, Bukidnon, Misamis Oriental and Lanao del Sur.

PAGASA advises that "Fishing boats and other sea vessels are advised not to venture out into the Seaboards of Southern Luzon, Visayas and Mindanao." According to the Associated Press, Bopha caused 40 deaths in the Philippines.

Bopha is expected to move over the northern part of Palawan and move into the South China Sea. Once in the China Sea, forecasters at the Joint Typhoon Warning Center expect Bopha to weaken as it curves in a more northerly direction over cooler waters and into an area of stronger wind shear.

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








Dec. 3, 2012

3-D image from TRMM's Precipitation Radar showed some strong convective thunderstorms on the eastern side of Bopha's eye› View larger image
At 0347 UTC on Dec. 3, NASA's TRMM satellite flew above a dangerous typhoon Bopha. Joint Typhoon Warning Center (JTWC) to hit the island of Mindinao in the Philippines with winds of 135 kts (155 mph) later today. This 3-D image from TRMM's Precipitation Radar showed some strong convective thunderstorms on the eastern side of Bopha's eye were reaching heights of over 16 km (~9.94 miles). A TRMM analysis showed that Bopha had a well-defined eye with very heavy rain falling at a rate of over 80mm/hr (~3.1 inches) falling in the eye and in intense rain bands spiraling around the eye.
Credit: NASA/SSAI, Hal Pierce
MODIS captured this visible image of Super Typhoon Bopha approaching the Philippines on Dec. 2, 2012› View larger image
The MODIS instrument on NASA's Terra satellite captured this visible image of Super Typhoon Bopha approaching the Philippines on Dec. 2, 2012 at 0145 UTC (Dec. 1 at 7:45 p.m. EST).
Credit: NASA/MODIS Rapid Response Team
On Dec. 2, TRMM captured rainfall data on Bopha showing heavy rainfall from the northeast to the southern quadrant of the eye.› View larger image
NASA's TRMM satellite captured rainfall data on Supertyphoon Bopha on Dec. 2 at 1435 UTC (9:35 a.m. EST) and showed areas of heavy rainfall (red) spanned from the northeast to the southern quadrant of the eye. Rain was falling at a rate of more than 2 inches (50 mm) per hour in the red areas.
Credit: NASA/SSAI, Hal Pierce
This photo of Bopha was taken on Sunday, Dec. 2 from the International Space Station, by Astronaut Ford.› View larger image
This astronaut photo of Super Typhoon Bopha was taken on Sunday, Dec. 2 from the International Space Station, by Astronaut Ford as the Category 4 storm bore down on the Philippines with winds of 135 mph.
Credit: NASA ISS/JSC
NASA Satellites See Super-Typhoon Bopha Closing in on the Philippines

Two NASA satellites gathered data as the passed over Bopha when it was a Super Typhoon on Dec. 2, gathering valuable data for forecasters. Since Dec. 2, Bopha's maximum sustained winds have fluctuated up and down from its previous high of 155 mph and today, Dec. 3, the storm has reached its strongest point so far as a Category 5 typhoon on the Saffir-Simpson scale with sustained winds of 161 mph. Warnings are up for the Philippines as Bopha approaches.

NASA's Terra satellite captured a visible image of Bopha as a Super Typhoon showing the extent of the storm and revealing the eye of the storm. NASA's Tropical Rainfall Measuring Mission (TRMM) satellite captured rainfall rates, identified areas of heavy rainfall, and measured cloud heights.


Tracking Typhoon Bopha Over Time

On Dec. 1 at 1000 p.m. CHST (1200z/7 a.m. EST/U.S.) the center of Typhoon Bopha was located near latitude 5.4 degrees north and longitude 140.1 degrees east. That placed Bopha's center about 270 miles southeast of Ngulu and about 315 miles south-southeast of Yap. Maximum sustained winds were up to 130 mph. When NASA's TRMM satellite passed over Typhoon Bopha at 0402 UTC on Dec. 1 (Nov. 30 at 11:02 p.m. EST/U.S.) it captured an image of the storm that clearly revealed an eye. It also showed tight circulation and an expanded area of very heavy rainfall located from southwest to southeast of the center of circulation where rain was falling at a rate of 2 inches/50 mm per hour.

The next day, Dec. 2, 2012 at 0145 UTC (Dec. 1 at 7:45 p.m. EST), the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Terra satellite captured a visible image of Super Typhoon Bopha approaching the Philippines. The visible image showed a tightly wound center of circulation, with the eye obscured by high clouds. At the time of this image, Bopha's maximum sustained winds were near 155 mph, a powerful Category 4 super typhoon on the Saffir-Simpson scale.

NASA's TRMM satellite captured rainfall data on Super typhoon Bopha on Dec. 2 at 1435 UTC (9:35 a.m. EST) and showed areas of heavy rainfall spanned from the northeast to the southern quadrant of the eye. The heaviest rain was falling at a rate of more than 2 inches (50 mm) per hour.

On Dec. 3 at 1 p.m. CHST local time, (0300 UTC/10 p.m. EST/U.S., Dec. 2) the eye of Typhoon Bopha was located near latitude 6.9 degrees north and longitude 130.9 degrees east. This is about 140 miles northwest of Sonsorol and 240 miles west of Koror. At that time, maximum sustained winds had dropped to 120 mph.

Six hours later, Bopha had again intensified as its maximum sustained winds were up to 130 mph. Bopha's typhoon-force-winds extend outward up to 35 miles from the center, or 70 miles in diameter. Tropical-storm-force winds have a much greater reach and extend outward up to120 miles from the center, making tropical-storm force winds reach over 240 miles in diameter.

At 7 p.m. CHST local time (0900 UTC/4 a.m. EST, U.S.) on Dec. 3, the National Weather Service in Guam reported that "the eye of Typhoon Bopha was located near latitude 7.0 degrees north and longitude 129.7 degrees east. That put the center about 210 miles northwest of Sonsorol, 325 miles west of Koror and 350 miles west-southwest of Kayangel. Typhoon Bopha was moving west at 14 mph and expected to turn to the west-northwest. The National Weather Service in Guam issued their final advisory on the storm with this position, and forecasting for the storm will be covered by the Joint Typhoon Warning Center and the Philippine Atmospheric, Geophysical and Astronomical Services Administration known as PAGASA.


Bopha Now a Category 5 on the Saffir-Simpson Scale

Bopha reached Category 5 status on the Saffir-Simpson Scale for the first time today, Dec. 3. Over the last several days it peaked at a powerful Category 4 typhoon. On Dec. 3 at 1500 UTC (10 a.m. EST, U.S.), Bopha had regained Super Typhoon status as maximum sustained winds increased to 140 knots (161 mph/259 kph). Bopha was located near 7.6 north latitude and 128.2 east longitude, about 630 nautical miles (725 miles/1,167 km) southeast of Manila, Philippines. Bopha is moving to the west-northwest at 16 knots (18.4 mph/29.6 kph). Infrared satellite imagery shows a well-developed, intense system that has a 9 nautical-mile (10.3 mile/16.6 km) wide eye.


Current warnings in the Philippines

All regional warnings for the Federated States of Micronesia have been canceled and replaced by warnings for the Philippines. In the Philippines, Bopha has been given the name "Pablo," and local updates from PAGASA can be found at: http://www.pagasa.dost.gov.ph/wb/tcupdate.shtml.

PAGASA posted Public Storm Warning signal #3 over the Mindanao provinces of Surigao del Norte and Sur, Siargao, Dinagat Province, Agusan del Norte and Sur, Misamis Oriental, Camiguin, Bukidnon, Davao Oriental, Compostela Valley, Davao del Norte and Samal Island. In addition, Public Storm Warning Signal #2 is effect in the Mindanao provinces of Misamis Occidental, Lanao del Norte and Sur, North Cotabato, Davao del Sur and Zamboanga del Norte; and in the Visayas provinces of Southern Leyte, Bohol, Southern Cebu, Negros Oriental and Siquijor. Public storm warning signal #1 is in effect for the Mindanao provinces of Zamboanga del Sur, Maguindanao, Sultan Kudarat, Sarangani and South Cotabato; the Visayas provinces of Eastern and Western Samar, Leyte, Biliran, Aklan, Capiz, Antique, Iloilo, Guimaras, Negros Occidental, Rest of Cebu and Camotes Island; the Luzon provinces of Northern Palawan, Calamian group of islands and Cuyo Island.

The Joint Typhoon Warning Center expects Bopha to make landfall in the Visayas region of the Philippines around 2300 UTC on Dec. 3 (6 p.m. EST, U.S.) and weaken as it moves on a west-northwest to northwesterly track through central Mindanao before exiting into the South China Sea.

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




Dec. 2, 2012

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Credit: NASA/TRMM, Owen Kelly
Typhoon Bopha Satellite View on December 2 Was Tame Compared to the Next Day

Compared with the rapidly intensifying storm seen on December 3, the Tropical Rainfall Measuring Mission (TRMM) overflight of Typhoon Bopha one day earlier appeared tame.

On December 2, Bopha was a category 4 storm on the Saffir-Simpson scale, but Bopha was not intensifying as it did on Dec. 3, and that is what made the difference. The TRMM satellite sees not only evidence of a tropical cyclone's strength but TRMM can also reveals clues about whether or not a tropical cyclone is growing stronger.

Just about the only impressive feature that TRMM saw in Typhoon Bopha on December 2 was that the cyclone did have a large and cold area of "exhaust clouds" indicated by the large orange area in the image. The large cold-cloud area is upper-level exhaust from the convective storm cells in the eyewall that were evidently transporting a large volume of moist ocean-surface air to the upper reaches of the troposphere, condensing water and liberating latent heat in the process. Latent heat is the fuel of hurricanes. At the ocean surface, the friction that a tropical cyclone experiences increases rapidly with wind speed as the seas become rougher. To a first approximation, friction increases with the cube of wind speed. To merely sustain its intensity, a category 4 tropical cyclone must extract a considerable amount of heat from the ocean surface in the form of evaporated seawater that condenses into cloud droplets in the eyewall.

In other respects, the December 2 overflight of Bopha lacked many of the indicators of vigorous energy transformations that were present when the storm was rapidly intensifying on December 3.

On December 2, the eyewall lacked heavy precipitation cores-- virtually no 45 dBZ radar reflectivity signals were seen in the eyewall. The few heavy precipitation cores that were seen (small dark red objects at the lower right of the image) were over 100 km (62.1 mile) away from the cyclone's eye, and therefore, any energy released in them could not help warm the eye and intensify the cyclone.

Second, The light precipitation inside the eyewall only reached a 12 km (7.4 mile) altitude (yellow in the image) on December 2, suggesting that the eyewall updrafts were too weak to reach the 14 to 15 km (8.7 to 9.3 mile) to top of the troposphere. Last, there were no lightning flashes observed in the eyewall on December 2, or elsewhere in the inner core during the approximately 90 seconds that the TRMM Lightning Imaging Sensor observed the cyclone.

Text credit: Owen Kelley
NASA TRMM Team
NASA's Goddard Space Flight Center, Greenbelt, Md.




Nov. 30, 2012

TRMM passed over Bopha on Nov. 29 and revealed the heaviest rainfall was falling south of the center.› View larger image
The TRMM satellite passed over Bopha on Nov. 29 and revealed the heaviest rainfall was falling south of the center, occurring at a rate of 2 inches/50 millimeters per hour (in red).
Credit: SSAI/NASA, Hal Pierce
NASA Sees "Hot Towers" in Intensifying Typhoon Bopha

Bopha intensified into a typhoon today, Nov. 30, as it continues to affect the islands in Micronesia in the western North Pacific Ocean. NASA's TRMM satellite captured rainfall data of Bopha and noticed "Hot Tower" thunderstorms as it was intensifying from a tropical storm into a typhoon.

When NASA and the Japanese Space Agency's Tropical Rainfall Measuring Mission (TRMM) satellite passed over Bopha twice on Nov. 29, and the later data showed that the area of heaviest rainfall had expanded and was still south of the center of circulation. The heaviest rainfall was occurring at a rate of 2 inches/50 millimeters per hour.

TRMM data also showed several "hot towers" within Tropical Storm Bopha. 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 Bopha 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. It was after TRMM spotted the hot towers in Bopha that the storm intensified into a typhoon.

On Nov. 30 at 10 a.m. EST (1500 UTC/1 a.m. CHST local time on Dec. 1), the National Weather Service in Guam urged residents in Koror, Kayangel and Sonsorol in the Republic of Palau and Yap Island and Ngulu Atoll in Yap State to prepare for typhoon conditions. A typhoon watch remains in effect for Ngulu in Yap State and Koror and Kayangel in the Republic of Palau. A tropical storm watch remains in effect for Yap Island in Yap State and Sonsorol in the Republic of Palau.

At 1 a.m. CHST local time on Dec. 1, (1500 UTC/10 a.m. EST, U.S. on Nov. 30) the center of Typhoon Bopha was located near latitude 4.4 degrees north and longitude 143.8 degrees east. Bopha's center was about 510 miles east-southeast of Ngulu, about 525 miles southeast of Yap, and 675 miles east-southeast of Koror Palau and Kayangel. Bopha's maximum sustained winds remain at 75 mph (120.7 kph) and the storm is expected to slowly intensify over the next day. Typhoon Bopha is moving west-northwestward at 12 mph and little change is expected in this movement through Saturday, Dec. 1.

According to the National Weather Service in Guam, "Typhoon force winds extend outward up to 20 miles from the center and tropical storm force winds extend outward up to 85 miles from the center."

Typhoon Bopha is expected to continue moving toward west-northwest. The National Weather Service official forecast track takes Bopha south of Ngulu and very close to the islands of Koror and Kayangel in the Republic of Palau. As Bopha draws closer and intensifies, winds could reach typhoon intensity (as high as 74 mph/ 64 knots/119 km/h). Surf will be very rough and rainfall can reach up to 4 inches on Saturday and up to an additional 6 inches on Sunday/Monday. Residents can expect local flooding and mudslides. The most recent National Weather Service updates can be found here: http://www.prh.noaa.gov/koror/kororCyclone.php.

Forecasters at the Joint Typhoon Warning Center forecast Bopha's center to pass close to Palau on its way to the Visayas region of Philippines by Dec. 4. Residents in the Philippines need to prepare for heavy rains, rough surf and strong winds.

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




Nov. 29, 2012

NASA Sees Tropical Storm Bopha Moving Through Southern Yap State

NASA's TRMM and Aqua satellites captured images of Tropical Storm Bopha as it continues to move through Micronesia in the western North Pacific Ocean and trigger warnings and watches throughout.

On Nov. 27, 2012, NASA's TRMM satellite revealed that rain in Tropical Storm Bopha was falling at a rate of over 70mm/hour (about 1.75 inches) in the red areas. TRMM showed that powerful storms in the area of the developing eye wall were reaching to heights of about 17km (~10.6 miles).
Credit: NASA/SSAI, Hal Pierce
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From its orbit in space, NASA's Tropical Rainfall Measuring Mission (TRMM) satellite captured rainfall rates occurring within Tropical Storm Bopha on Nov. 29 at 0417 UTC (Nov. 28 at 11:17 p.m. EST/U.S.), and noticed the heaviest rainfall was occurring south of the center. Rainfall there was occurring at 2 inches (50 mm) per hour. Satellite data also revealed an eye feature forming.

TRMM rainfall image of Bopha

NASA's TRMM satellite captured rainfall rates occurring within Tropical Storm Bopha on Nov. 29 at 0417 UTC, and noticed the heaviest rainfall (red) was occurring south of the center. Rainfall there was occurring at 2 inches (50 mm) per hour.
Credit: NASA/SSAI, Hal Pierce
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Aqua image of Bopha

The MODIS instrument aboard NASA's Aqua satellite captured this visible image of Tropical Storm Bopha moving through Micronesia in the western North Pacific Ocean on Nov. 28 at 0335 UTC. Notice the large "tail" or band of thunderstorms wrapping into the center from the west and south.
Credit: NASA Goddard MODIS Rapid Response Team
› Larger image

On Nov. 29, a typhoon watch was in effect for Woleai in Yap State and a tropical storm watch remained in effect for Faraulep in Yap State.

On Nov. 29 at 10 a.m. EST/U.S. (1 a.m. CHST local time/ 1500 UTC) Bopha's maximum sustained winds were near 60 mph as it was moving through southern Yap State. The center of Tropical Storm Bopha was located near latitude 3.8 degrees north and longitude 147.4 degrees east. This is about 345 miles southeast of Woleai, and about 400 miles southwest of Weno Island, Chuuk. According to the National Weather Service in Tiyan, Guam, Bopha is expected to pass about 180 miles south of Woleai, on Friday night, Nov. 30. Tropical Storm Bopha is moving west-southwest at 10 mph. Bopha is expected to turn toward the west-northwest with a slight increase in forward speed over the next 24 hours. Bopha is expected to slowly intensify over the next 24 hours, possibly becoming a typhoon later today, Nov. 29 EST/Nov. 30 local time, Guam.

Woleai and surrounding islands can expect wind gusts to 40 mph, dangerous surf between 10 and 12 feet along the southern and eastern shores on Friday, and Saturday, Nov. 30 and Dec. 1. The National Weather Service warns of "coastal inundation 1 to 2 feet may also occur around high tide." Bopha is also expected to bring heavy rainfall on those two days, totaling between 3 to 5 inches.

On Nov. 28, the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Aqua satellite captured a visible image of Tropical Storm Bopha at 0335 UTC that showed a large "tail" or band of thunderstorms wrapping into the center from the west and south. On Nov. 27, NASA's TRMM satellite flew above Tropical Storm Bopha. On that day, TRMM showed that tropical storm Bopha had an area of very intense convective storms near the center of circulation. TRMM's Microwave Imager (TMI) and Precipitation Radar (PR) data revealed that rain was falling at a rate of over 70mm/hour (about1.75 inches) in that area. TRMM's Precipitation Radar (PR) also showed that powerful storms in the area of the developing eye wall were reaching to heights of about 17km (~10.6 miles). Bopha went on to intensify the next day.

For detailed information about what Faraulep, Woleai and surrounding islands can expect, visit the National Weather Service Office statement: http://www.prh.noaa.gov/data/GUM/HLSPQ1

The current Joint Typhoon Warning Center forecast track takes Bopha south of Hgulu and through the Republic of Palau. This track is more southerly than previously expected and "has greatly diminished the threat of damaging winds at Faraulep," according to the National Weather Service in Guam. Bopha is expected to continue on a west-northwesterly track, with its center passing very close to the island of Palau on Oct. 2. By Oct. 4, the forecasters at the JTWC expect Bopha to make landfall in Visayas, the central Philippines.

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




Nov. 28, 2012

Infrared NASA Imagery Sees Tropical Storm Bopha Grow a Tail

Infrared images of Tropical Storm Bopha taken by the AIRS instrument on NASA's Aqua satellite on Nov. 27 (left) and 28 (right), 2012. › View larger image
These infrared images of Tropical Storm Bopha were taken by the AIRS instrument on NASA's Aqua satellite. On Nov. 27 at 1505 UTC (left) Bopha had maximum sustained winds near 45 mph. By Nov. 28 at 0329 UTC (right) Bopha's winds increased to 65 mph. Purple indicates highest, coldest, strongest thunderstorms with heavy rainfall.
Credit: NASA JPL/Ed Olsen
Tropical Storm Bopha continues to intensify in the western North Pacific Ocean as it heads toward Yap State, triggering more warnings and watches. Infrared imagery from NASA's Aqua satellite captured over two days revealed that the storm had consolidated, intensified and developed a large band of strong thunderstorms south of the center, that resemble a tail.

Infrared images of Tropical Storm Bopha were taken by the AIRS instrument on NASA's Aqua satellite on Nov. 27 at 1505 UTC when Bopha had maximum sustained winds near 45 mph, and on Nov. 28 at 0329 UTC when Bopha's winds increased to 65 mph. The highest, coldest, strongest thunderstorms with heavy rainfall were tightly wrapped around Bopha's center of circulation, and in a newly developed, more organized band of strong thunderstorms south of the storm's center. That large band of thunderstorms resembles a tail to the storm that drapes from the Bismarck Sea, southwest of the storm's center, east to Nauru.

A tropical storm warning remains in effect for Lukunor and the Southern Mortlocks in Chuuk State, Puluwat in Chuuk State and Satawal in Yap State. Heavy rainfall, tropical-storm-force winds, and ocean swells between 1 and 2 feet can be expected in warning areas. The National Weather Service noted that Bopha is generating 10 to 12 foot swells near the center which will result in hazardous surf of 12 to 14 feet along eastern and southeastern and southern shores of Lukunor and nearby islands today, Nov. 28.

A typhoon watch remains in effect for Woleai in Yap state, and a tropical storm watch remains in effect for Faraulep in Yap state.

On Nov. 28, at 10 p.m. CHST local time (1300 UTC/8 a.m. EDT/U.S.), Tropical Storm Bopha's maximum sustained winds had increased to 65 mph, and the storm is moving west at 10 mph. According to the National Weather Service in Guam, "That general motion is expected to continue over the next 24 hours. Tropical Storm Bopha is expected to continue intensifying and may become a typhoon Thursday afternoon, Nov. 29."

At 7 p.m. CHST (0900 UTC/4 a.m. EDT/U.S.) the center of Tropical Storm Bopha was near latitude 5.0 degrees north and longitude 152.5 degrees east. That put the center about 135 miles west-southwest of Lukunor, 175 miles south of Weno Island, Chuuk, and 255 miles southeast of Puluwat. Tropical storm force winds extend outward up to 50 miles from the center, making the storm over 100 miles in diameter.

For detailed information about what each island can expect, visit the National Weather Service Office statement: http://www.prh.noaa.gov/data/GUM/HLSPQ1

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




Nov. 27, 2012

Tropical Storm Bopha was captured on Nov. 27 by the AIRS instrument that flies aboard NASA's Aqua satellite.› View larger image
This infrared image of the eastern side of Tropical Storm Bopha was captured on Nov. 27 at 0241 UTC by the AIRS instrument that flies aboard NASA's Aqua satellite. The purple areas indicate coldest, highest cloud top temperatures that have the potential for dropping heavy rainfall.
Credit: NASA JPL/Ed Olsen
The National Weather Service in Guam issued this track for Tropical Storm Bopha forecasting its movement through Dec. 2.› View larger image
The National Weather Service in Guam issued this track for Tropical Storm Bopha that shows its forecast movement through Dec. 2.
Credit: NWS
NASA Sees Tropical Storm Bopha Intensifying in Micronesia

Tropical storm warnings are in effect in Micronesia as NASA and other satellite imagery indicates that Tropical Storm Bopha continues to intensify.

The Atmospheric Infrared Sounder (AIRS) instrument that flies aboard NASA's Aqua satellite captured an infrared image of Tropical Storm Bopha on Nov. 27 at 0241 UTC that indicated a lot of power exists in the strengthening tropical storm. The AIRS image captured the eastern half of the tropical storm and showed a large area of very cold, very high cloud tops, where temperatures colder than -63 Fahrenheit (-52 Celsius) have the potential for dropping heavy rainfall.

On Nov. 27, the National Weather Service in Tiyan, Guam noted that "Residents of Satawal in Yap State should closely monitor the progress of Tropical Storm Bopha, as a tropical storm watch could be required Wednesday, Nov. 28." A tropical storm warning remained in effect for Nukuoro in Pohnpei State and Lukunor in Chuuk State. A tropical storm watch remains in effect for Losap, the Chuuk Lagoon Islands and Puluwat in Chuuk State.

At 1500 UTC (10 a.m. EST/1 a.m. CHST local time) the center of Tropical Storm Bopha was located near latitude 4.7 degrees north and longitude 155.2 degrees east, only 55 miles north-northeast of Nukuoro. Bopha was also about105 miles southeast of Lukunor and 225 miles southeast of Losap. Tropical Storm Bopha was nearly stationary but the National Weather Service expects Bopha to start moving westward.

Bopha's maximum sustained winds have increased to 50 mph and Tropical Storm Bopha is expected to continue intensifying. Tropical storm force winds extend outward up to 45 miles from the center, making the storm almost 100 miles in diameter.

For specific information on effects to individual islands, visit the National Weather Service website: http://www.prh.noaa.gov/data/GUM/HLSPQ1.

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




Nov. 26, 2012

NASA's TRMM  satellite passed over Tropical Depression 26W on Nov. 26 at 0526 UTC.› View larger image
NASA's TRMM satellite passed over Tropical Depression 26W on Nov. 26 at 0526 UTC. The data showed that the depression's low-level center was large, and it had some fragmented convective bands of thunderstorms wrapping around it that contained heavy rain (in red), falling at 2 inches/50 mm per hour. TRMM data also revealed tall convective towering thunderstorms about 15 kilometers (9.3 miles) high.
Credit: NASA/SSAI, Hal Pierce
Near-infrared image taken from the AIRS instrument aboard NASA's Aqua satellite on Nov. 26 at 0341 UTC.› View larger image
This near-infrared image taken from the AIRS instrument aboard NASA's Aqua satellite on Nov. 26 at 0341 UTC shows the leading western edge of Tropical Depression 26W as it moves toward the Philippine Sea. New Guinea is seen on the bottom left corner of the image.
Credit: NASA JPL, Ed Olsen
NASA Spots Heavy Rainfall in Tropical Depression 26W Threatening Micronesia

The twenty-sixth tropical cyclone of the western North Pacific Ocean season formed and has some areas of heavy rain, according to data from NASA's TRMM satellite. Tropical Depression 26W is threatening islands within Micronesia and warnings and watches are currently in effect.

Micronesia is a region in the western North Pacific Ocean made up of thousands of small islands. West of the region is the Philippines, while Indonesia is located to the southwest.

NASA's Tropical Rainfall Measuring Mission (TRMM) satellite passed over Tropical Depression 26W on Nov. 26 at 0526 UTC (12:26 a.m. EST). The imagery showed that the depression's low-level center was large, and it had some fragmented convective bands of thunderstorms wrapping around it that contained heavy rain, falling at 2 inches/50 mm per hour. TRMM data also revealed tall convective towering thunderstorms about 15 kilometers (9.3 miles) high. According to previous NASA research, those "hot towers" usually signify that a tropical cyclone will intensify.

According to NOAA's National Weather Service in Tiyan, Guam, a tropical storm warning remains in effect for Nukuoro in Pohnpei State and Lukunor in Chuuk State. A tropical storm watch remains in effect for Losap and for Chuuk Lagoon Islands in Chuuk State.

A tropical storm warning means tropical storm conditions, including damaging winds of 39 to 73 mph are expected within 24 hours while a tropical storm watch means that tropical storm conditions are possible within 48 hours.

At 1500 UTC (10 a.m. EST) on Nov. 26, 2012, Tropical Depression 26W (TD26W) was centered near 4.8 degrees north latitude and 155.1 degrees east longitude. That put TD26W's center about 65 miles north of Nukuoro, 95 miles southeast of Lukunor, and 215 miles southeast of Losap. The National Weather Service noted that TD26W is moving west-northwest at 7 mph and is expected to move in a more westerly direction and slightly speed up over the next day. Maximum sustained winds are near 35 mph, and could become a tropical storm later today, Nov. 26.

Forecasters at the Joint Typhoon Warning Center expect Tropical Depression 26W to track to the west-northwest over the next several days and strengthen to typhoon status as it tracks through the warm waters of the Philippine Sea. TD26W is forecast to pass just south of Chuuk and affect Yap and Palau by the weekend of Dec. 1 and Dec. 2.

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