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Hurricane Season 2009: Typhoon Nida (Western Pacific)
12.03.09
 
December 3, 2009

Tropical Depression Nida (top left) on December 3 at 1:35 UTC and System 97W (bottom right). > View larger image
The MODIS instrument on NASA's Terra satellite captured an image of Tropical Depression Nida (top left) on December 3 at 1:35 UTC and System 97W (bottom right).
Credit: NASA MODIS Rapid Response
Nida fading top left (in purple and blue) on Dec. 2 at 16:11 UTC (11:11 a.m. ET) and System 97W developing (bottom right). > View larger image
This infrared image from AIRS shows Nida fading top left (in purple and blue) on Dec. 2 at 16:11 UTC (11:11 a.m. ET) and System 97W developing (bottom right). The highest, coldest, thunderstorm cloud tops are in purple (as cold as -63F).
Credit: NASA JPL, Ed Olsen
NASA's Terra and Aqua Satellites See Nida Fading, and 97W Getting Organized

NASA's Terra and Aqua satellites flew over Tropical Depression Nida and System 97W in the Western Pacific Ocean and noticed that one is fading while the other is powering up.

The Moderate Imaging Spectroradiometer or MODIS instrument that flies on NASA's Terra satellite captured a visible image of the two storms in one satellite pass. Nida still had a swirl to its clouds although the system has continued to weaken. On the visible imagery, System 97W currently appears as a rounded area of clouds with no established center.

The Atmospheric Infrared Sounder or AIRS instrument captured an infrared snapshot of both storm's cold cloud tops in one image. That provided more detail about the storms, showing Nida as elongated from southwest to northeast, indicating that the storm is coming apart. The infrared imagery also showed System 97W as a rounded area, indicating a strengthening circulation.

On December 3 at 0300 UTC, the Joint Typhoon Warning Center issued its final advisory on Tropical Depression Nida. Nida had maximum sustained winds down to 28 mph (25 knots), and was still crawling along at 4 mph to the northwest. It was located about 450 miles southeast of Kadena, near 21.6 North latitude and 134.2 East longitude.

Animated multispectral satellite imagery indicated that the low level circulation center, the storm's core, was fully exposed, and didn't show any strong convection. Convection is important because it's rapidly rising air that promotes the development of thunderstorms that power a tropical cyclone. It's like a car without gasoline, it's not going anywhere. Another thing that's leading to Nida's demise is cool, dry air moving into the edges of the storm. Because of dry air, wind shear and an open center, Nida is expected to last only another 24 hours.

As Nida fades, System 97W is getting organized. Earlier today, December 3, System 97W's center was located about 110 nautical miles west of Guam, near 13.6 North latitude and 142.9 East longitude. Currently, its maximum sustained winds are around 28 mph, and it is moving away from Guam in a west-northwesterly direction near 10 mph. Current estimated minimum central pressure from the system is around 1002 millibars. The storm is also moving into a better atmospheric environment, which will allow it to strengthen.

The Joint Typhoon Warning Center noted that the "Likelihood of tropical cyclone formation is good."

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



December 2, 2009

This NASA infrared AIRS satellite image shows Nidastill has some stronger thunderstorms around its center. > View larger image
This NASA infrared AIRS satellite image shows Nida (top left) still has some stronger thunderstorms around its center (higher, stronger storms are depicted in purple). Meanwhile System 97W (bottom right) is also showing some strong thunderstorms in the southeastern side (purple).
Credit: NASA JPL, Ed Olsen
This NASA visible AIRS satellite image shows Nida (top left) looking elongated, almost like a cocoon. > View larger image
This NASA visible AIRS satellite image shows Nida (top left) looking elongated, almost like a cocoon.
Credit: NASA JPL, Ed Olsen
Nida Getting Knocked By Winds, and 97W Piquing Interest

Nida is now a tropical storm, and is being knocked around by wind shear in the Western Pacific. Satellite imagery has confirmed Nida's center of circulation is exposed and the storm is losing its circular shape. Meanwhile, System 97W located to Nida's southeast looks ominous on NASA satellite imagery.

Tropical Storm Nida's winds are around 57 mph (50 knots) today, December 2. Nida is moving west-northwest near 9 mph. At 10 a.m. ET, Nida was located about 505 nautical miles southeast of the island of Kadena, near 21.3 North and 134.8 East.

Kadena is a United States Air Force (USAF) base located in the towns of Kadena and Chatan and the city of Okinawa, in Okinawa Prefecture, Japan. Kadena Air Base is the hub of U.S. airpower in the Pacific, and home to the USAF's 18th Wing and a variety of associate units.

NASA satellite data has helped forecasters see that the storm is elongating. Visible data from NASA's Aqua satellite, using the Atmospheric Infrared Sounder (AIRS) instrument showed the storm stretching in a northeast to southwest direction.

In addition, the Joint Typhoon Warning Center (JTWC) noted "Animated multispectral satellite imagery showed a fully exposed low level circulation center (LLCC) nearly one degree to the southwest of increasingly sheared convection." The convection (thunderstorms) near the LLCC is making the center difficult to locate on satellite imagery. The JWTC also notes that "the latest microwave imagery (like that from AIRS and NASA's Advanced Microwave Sounding Unit (AMSU) instruments both on NASA's Aqua satellite) indicates a weakened low level signature as well."

The AMSU instrument on NASA's Aqua satellite also showed that Nida's warm core has contracted and has become increasingly asymmetric. In addition, the core has dropped several thousand feet into the mid to lower troposphere. That's an indication of a weakening storm.

Because wind shear has increased to over 34 mph (30 knots), Lida isn't expected to continue weakening and dissipate over open water in the next three days. In addition, Lida is no longer expected to swing north and track to the west of Iwo To, but will likely keep zigzagging to the west-northwest until it fades.

System 97W, however, looks interesting on NASA satellite imagery. In the latest AIRS imagery 97W can be seen to the east of Tropical Storm Nida. It is centered about 235 miles southeast of Guam, near 10.4 North and 147.1 East. The JTWC has upgraded the likelihood of tropical cyclone formation for this system to "fair."

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



December 1, 2009

Typhoon Nida on November 30 shows the eye is now cloud-filled, one sign of a weakening storm. > View larger image
NASA's Aqua satellite's MODIS instrument captured an image of Typhoon Nida on November 30 at 4:15 UTC. The image showed the eye is now cloud-filled, one sign of a weakening storm.
Credit: NASA, MODIS Rapid Response
NASA's CloudSat satellite captured a side look at Nida on Nov. 30, and  saw cloud tops dropped to near 8 miles high. > View larger image
NASA's CloudSat satellite captured a side look at Nida on Nov. 30, and saw cloud tops dropped to near 8 miles high. There were still some areas of cloud ice (blue top), but the areas of heavy precipitation have diminished (blue areas at the bottom).
Credit: NASA/JPL/Colorado State Univ./NRL-Monterey
Typhoon Nida's Cloud Tops Dropping as it Zigzags in Wind Shear

Nida is battling to keep its typhoon strength in the Western Pacific Ocean as wind shear continues to tear at the storm and weaken it. NASA's CloudSat satellite noticed that Nida's cloud tops are not as high as they were over the weekend, and lower cloud tops mean less powerful thunderstorms.

Over the last few days, satellites have shown forecasters that Nida has zigzagged between 18 and 20 degrees North Latitude on its somewhat erratic northern track. It has moved west, then east, and now back in a westward direction on its general track north.

After a westward movement, Nida is expected to now travel to the west of the islands of Iwo To and Chichi Jima over the next several days.

On December 1 at 4 a.m. ET (0900 UTC), Nida was now a Category One typhoon, with maximum sustained winds near 86 mph (75 knots). Winds are still gusting near 100 mph near the center of the storm. The range for typhoon storm-force winds now extend to 45 miles from the center, while tropical storm-force winds extend up to 135 miles from the center.

Nida is located about 335 miles southwest of the island of Iwo To (formerly known as Iwo Jima), near 20.6 North and 137.3 East. Nida is still trudging along at a slow rate near 5 mph in a west-northwesterly direction, but is expected to move in a more westerly direction over the next couple of days before turning north.

NASA's Aqua satellite's Moderate Imaging Spectroradiometer (MODIS) instrument captured an image of Typhoon Nida on November 30 at 4:15 UTC. The image showed the eye is now cloud-filled, one sign of a weakening storm, and since that image, Nida had weakened from a Category Two Typhoon to a Category One storm.

Forecasters at the Joint Typhoon Warning Center noted that infrared imagery like that from NASA's Atmospheric Infrared Sounder on NASA's Aqua satellite, has shown that Nida's eye has degenerated. Satellite imagery also has shown that Nida is elongating in a southwest to northeast direction, a sign that the storm can't maintain its shape and strength. Satellite imagery has also shown that dry air is entering the system, and it will wick up moisture and weaken the storm further.

NASA's CloudSat satellite gives forecasters a unique look at tropical cyclones because its Cloud Profiling Radar basically "cuts a storm in half" and looks at it from the side. What CloudSat saw in the latest imagery was that Nida's cloud tops have dropped from over 9 miles high (15 kilometers) to around 8 miles (13 kilometers) high. Those dropping cloud heights indicate that Nida doesn't have the uplift, or strong convection that it had earlier, and that's also reflected in its slowing sustained winds. There were still some areas of cloud ice (indicating highest thunderstorm tops with strongest uplift), but the areas of heavy precipitation have diminished.

Nida is expected to re-curve northeast and become an extra-tropical low within 2 to 3 days.

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



November 30, 2009

AIRS image of Nida > View larger image
NASA's AIRS instrument captured an image of Super Typhoon Nida on Nov. 28 that clearly showed Nida's eye, and surrounding it, very strong, cold, thunderstorm cloud tops (purple) near -63F. The blue areas are around -27F.
Credit: NASA JPL, Ed Olsen
Cloudsat image of Nida > View larger image
NASA's CloudSat satellite's Cloud Profiling Radar captured a side look (bottom image) across Nida on Nov. 28. Nida's clouds are over 15 kilometers or 9 miles high. The top image is from the METSAT satellite to show where CloudSat took its side view.
Credit: NASA/JPL/Colorado State Univ./NRL-Monterey
NASA Captures Typhoon Nida's Clouds from Two Angles

NASA satellites capture amazing views of tropical cyclones, and the Aqua and CloudSat satellites captured a top-down look at temperatures in Typhoon Nida's clouds, and an image of what they look like from the side.

On Monday, November 30, by 4 a.m. ET, Nida had lost her "Super Typhoon" status as a result of wind shear, and is now a typhoon. Nida's maximum sustained winds are near 115 mph (100 knots). The storm was over open ocean in the Western Pacific, about 330 miles south-southwest of the island of Iwo To (formerly Iwo Jima), near 19.6 North and 139.1 East. It was crawling to the west-northwest near 3 mph (2 knots), so the forecast track has become more difficult to predict.

Tropical storm force winds extend 150 miles from the center, so the storm is about 300 miles in diameter. Typhoon-force winds extend out to 55 miles from the center. Nida is kicking up 35-foot high waves in the open ocean.

NASA's CloudSat satellite's Cloud Profiling Radar captured a side look across Nida on Nov. 28. Nida's clouds are over 15 kilometers or 9 miles high. CloudSat also noticed ice in throughout all of Nida's cloud tops, indicating strong, high, thunderstorms. CloudSat also noted heavy rainfall over some of the areas where Nida meets the ocean's surface, more than 30mm/hr (1.18 inches/hour). CloudSat also provided an estimate of winds and atmospheric pressure at the time of the overpass on November 28 and clocked the wind around 140 knots and the minimum central pressure around 918 millibars.

NASA's Aqua satellite also passed over Nida on November 28 and captured infrared and microwave imagery using its Atmospheric Infrared Sounder (AIRS). The data from AIRS is also used to create an accurate 3-D map of atmospheric temperature, water vapor and clouds, all of which are helpful to forecasters. The AIRS image clearly showed Nida's eye, and strong, cold thunderstorm cloud tops, colder than -63 Fahrenheit (220 degrees Kelvin) circling the eye.

The infrared signal of the AIRS instrument does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the ocean and land surfaces, revealing warmer temperatures in orange and red. The orange temperatures are 80F (300 degrees Kelvin) or greater (the darker they are, the warmer they are), and tropical cyclones need sea surface temperatures of 80F to strengthen and maintain their strength.

The Joint Typhoon Warning Center is the organization responsible for forecasts of typhoons in that region, and their latest discussion noted that Nida is weakening as it continues to crawl in a northerly direction.

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



November 27, 2009

TRMM captured a satellite image of Super Typhoon Nida's rainfall on November 26. > View larger image
TRMM captured a satellite image of Super Typhoon Nida's rainfall on November 26 and captured moderate rainfall around the storm's center between .78 to 1.57 inches per hour (yellow and green), with some heavy rainfall, as much as 2 inches of rain per hour (red), in a rain band southeast of the storm's center.
Credit: NASA/SSAI, Hal Pierce
Super Typhoon Nida to Pass East of Iwo To and Chichi Jima

Nida is still holding on to Super Typhoon status in the Western Pacific Ocean, and over the weekend, is forecast to pass east of both Iwo To and Chichi Jima islands. Although the center of Nida will remain at sea, both islands will face heavy surf, gusty winds and heavy rainfall.

On Friday, November 27, at 0900 UTC (4 a.m. ET or 6 p.m. local Asia/Toyko time) Nida had maximum sustained winds near 149 mph (130 knots) with gusts to 184 mph (160 knots)! That makes Nida a Category 4 Typhoon. The range of sustained winds for a Category 4 typhoon (or hurricane) range from 131 to 155 mph (114-135 knots or 210-249 kilometers/hour).The National Hurricane Center says of a Category 4 Typhoon/hurricane: "Extremely dangerous winds causing devastating damage are expected."

Nida is about 300 miles in diameter, so tropical storm force winds extend as far as 150 miles from the center of the storm. Typhoon/hurricane-force winds extend 70 miles from Nida's center. Nida's eye is estimated to be about 25 nautical miles in diameter. Nida's center was located 415 nautical miles northwest of Guam, near 17.8 degrees North latitude and 139.2 degrees East longitude. Nida was moving north near 10 mph.

NASA and the Japanese Space Agency's Tropical Rainfall Measuring Mission (TRMM) satellite flew over the center of Super Typhoon Nida on November 26 and captured moderate rainfall around the storm's center between 20 and 40 millimeters (.78 to 1.57 inches) per hour, with some heavy rainfall, as much as 2 inches of rain per hour, in a rain band southeast of the storm's center.

The Joint Typhoon Warning Center noted that "Animated multispectral imagery shows a well-defined eye that is beginning to fill and become ragged. The same animation shows elongation on the northeast quadrant." Both of those factors indicate that the storm's strength is waning.

Nida was generating dangerously high waves, up to 39 feet high. As its center sweeps past Iwo To and Chichi Jima this weekend, those islands can expect very high surf with dangerous battering waves.

Nida is moving north, but will start heading northeast in the next day or two. It will also transition into an extra-tropical storm and continue weakening on its northern journey into cooler waters and areas of stronger wind shear.

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



November 25, 2009

Super Typhoon Nida with a perfectly symmetrical storm and a clear eye, both hallmarks of a powerful typhoon. > View larger image
The MODIS instrument on NASA's Aqua satellite captured a visible image of Super Typhoon Nida early on Nov. 25 that shows a perfectly symmetrical storm and a clear eye, both hallmarks of a powerful typhoon.
Credit: NASA MODIS Rapid Response Team
NASA's Aqua satellite captured a clear eye and cold, powerful thunderstorm cloud tops (colder than -63F) in Nida. > View larger image
NASA's Aqua satellite captured a clear eye and cold, powerful thunderstorm cloud tops (colder than -63F) in Nida in this infrared image Nov. 25 at 0347 UTC. Nida is a Category 5 storm with sustained winds near 172 mph.
Credit: NASA JPL, Ed Olsen
NASA's Aqua Satellite Sees Nida Explode into a Category 5 Super Typhoon!

Typhoon Nida is in a favorable environment that has enabled it to intensify faster and stronger than previously forecast, and has now exploded into a Super typhoon. NASA's Aqua satellite passed over Nida and captured a visible image of the storm revealing a clear eye, which indicates a strong typhoon.

The Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Aqua satellite captured a visible image of Super Typhoon Nida on November 25 at 0355 UTC (November 24 at 10:55 p.m. ET). The image clearly revealed an eye that showed the surface of the northwestern Pacific Ocean! The MODIS image showed a tightly circulating symmetrical hurricane form.

At 10 a.m. ET on November 25, Super Typhoon Nida had maximum sustained winds near 172 mph (150 knots) with gusts as high as 207 mph! A category five typhoon on the Saffir-Simpson scale has sustained winds greater than 155 mph. Typhoon-force winds extend as far as 45 miles from Nida's center, while tropical storm-force winds extend out as far as 105 miles from Nida's center.

Nida was about 155 miles west-southwest of Guam, near 12.6 North latitude and 142.2 East longitude. It was moving to the northwest near 15 mph, and its powerful winds were kicking up dangerously high waves up to 44 feet high!

Fortunately, no landmasses are directly threatened by Nida, although today, Nida is passing between the island of Yap and Andersen Air Force Base. Those islands will experience heavy surf to their northeastern and southwestern sides, respectively. The Joint Typhoon Warning Center noted that Nida can strengthen even further as it is going to track over very warm sea surface temperatures in the next day.

Nida is forecast to remain in open waters over the next 5 days and is expected to pass far to the southwest of the island of Iwo Two on Monday, November 30.

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





November 24, 2009

The TRMM satellite measured Nida's rains on Nov. 24 at 1052 UTC. > View larger image
The TRMM satellite measured Nida's rains on Nov. 24 at 1052 UTC. Some of the hot towers around Nida's center of circulation are around 8.6 miles high and contain heavy rain (red areas) falling at almost 2 inches per hour. The yellow and green areas are moderate rainfall between .78 to 1.57 inches per hour.
Credit: NASA/SSAI, Hal Pierce
Typhoon Nida Lashing Yap State in the Western Pacific

Typhoon Nida grew out of the 26th tropical depression in the western Pacific Ocean, and is now lashing Yap State. NASA and the Japanese Space Agency's Tropical Rainfall Measuring Mission (TRMM) satellite captured an image of heavy rainfall and towering thunderstorms in Nida's center today, November 24.

TRMM rainfall data indicated the majority of Nida's rainfall was between 20 and 40 millimeters (.78 to 1.57 inches) per hour, with areas near Nida's center falling at as much as 2 inches of rain per hour, which is considered heavy rainfall. That area of rainfall was the same area where TRMM saw some "hot towers." A hot tower is a tropical cumulonimbus cloud that extends outside of the troposphere and into the tropopause. TRMM noticed a couple of hot towers in Nida with cloud tops as high as 8.6 miles high. These towers are called "hot" because they rise high because of the large amount of latent heat released as water vapor condenses into liquid.

Nida had maximum sustained winds near 74 mph, making it a Category One typhoon. It was located about 265 miles south of Guam, near 8.9 North latitude and 145.0 East longitude. Nida was moving west-northwest near 6 mph and generating 18-foot high waves.

There's a Typhoon warning posted today for Faraulep. That means typhoon conditions of sustained winds 64 knots (74 mph or 119 km/hr) or higher associated with a typhoon are expected in a specified coastal area in 24 hours or less. Faraulep is a small atoll in the western Caroline Islands, located within Yap State, in the Federated States of Micronesia. A tropical storm watch is now posted for Ulithi and Fais in the Western Pacific Island. That means tropical storm conditions can be expected in the next 36 hours. Ulithi is an atoll in the Caroline Islands, located about 103 nautical miles east of Yap. It consists of 40 islets totaling 1.7 square miles. Fais Island is one of the outer islands of the State of Yap.

Nida is forecast to move in a northwesterly direction and continue to strengthen over the next several days.

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