NASA - National Aeronautics and Space Administration

Typhoons Lekima, Krosa Menace Western Pacific

There are two active typhoons in the West Pacific region: Lekima and Krosa. Lekima made landfall in central Vietnam as a Category 1 typhoon; Krosa is a Category 4 storm packing 138 mph winds and is expected to affect Taiwan. These images were captured by the Tropical Rainfall Measuring Mission (TRMM) satellite.

Satellite Measurements Show Rain Intensity in Typhoon Lekima


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This image shows Typhoon Lekima just as the center was bearing down on the coast of Vietnam. The image was taken at 3:05 UTC (10:05 am local time) on Oct. 3, 2007, and shows the horizontal pattern of rain intensity within the storm. Rain rates in the center of the swath are from the TRMM PR, and those in the outer swath come from the TRMM Microwave Imager (TMI). The rain rates are overlaid on infrared (IR) data from the TRMM Visible Infrared Scanner (VIRS). TRMM reveals that Lekima still has a closed eye as it nears land although most of the heavy rain (indicated by the dark red areas) is south of the center along the coast. At the time this image was taken, Lekima's sustained winds were estimated at 70 knots (81 mph) by the Joint Typhoon Warning Center. So far, Lekima is being blamed for up to nine deaths in the Philippines and three in Vietnam.

Typhoon Krosa Passes Near Philippines


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This image shows Typhoon Krosa as it passed through the west-central Philippine Sea about 500 miles northeast of the Philippines in the general direction of Taiwan. The image was taken at 01:33 UTC on Oct. 3, 2007. There are some similarities between Krosa and Lekima: Most of the heavy rain is just south of the center (dark reds) and the maximum sustained winds are comparable, about 75 knots (86 mph). Krosa, however, does not yet have a closed eye in the rain field as it did earlier in its development. But, with plenty of warm open water ahead, the storm still had the potential to intensify, which it did. Less than a day after this image was taken, Krosa's maximum sustained winds had increased to an estimated 120 knots (138 mph).

The Tropical Rainfall Measuring Mission (TRMM) satellite was placed into its low-earth orbit in November 1997. Its primary mission is to measure rainfall from space; however, it has also served as a valuable platform for monitoring tropical cyclones, especially over remote parts of the open ocean. TRMM is a joint mission between NASA and the Japanese space agency, JAXA.

Steve Lang
SSAI/NASA Goddard Space Flight Center
Images credit: Hal Pierce, SSAI/NASA Goddard

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NASA's Aqua Satellite Captures Typhoons Lekima and Krosa


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The western Pacific Ocean was a very active place on October 4, 2007. Typhoon Lekima made landfall in Vietnam and was raining on Cambodia, Laos and Thailand. Meanwhile, Typhoon Krosa swirled in the Phillippine Sea with its clouds extending from the Phillippines to Japan's Ryukyu Islands.

This infrared image from Oct. 4 at 4:35 UTC (12:35 a.m. EDT) was created by data from the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite. Lekima is circular blue area on the left side of this satellite image, and Krosa is depicted on the right side.

This AIRS image shows the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the tops of Typhoon Krosa and Lekima. The infrared signal does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the Earth, revealing warmer temperatures (red). This infrared image shows large areas of strong convection surrounding the core of the storm (in purple), particularly seen in Typhoon Krosa. Krosa's eye is also clearly visible in this image as the yellow area in the middle of the purple region.

Powerful Typhoon Krosa in the Open Ocean

On October 4 at 1200 UTC (8:00 a.m. EDT) Krosa was a Category Four Typhoon on the Saffir-Simpson Scale with maximum sustained winds of 120 knots(138 mph), and gusts to 145 knots(166 mph). Krosa was located near 19.9 degrees north latitude and 126.6 degrees east longitude. It's moving to the northwest near 10 knots (11 mph) and is expected to continue moving northwestward. Forecasters noted that the diameter of the eye has increased over the previous six hours from 30 to 35 nautical miles.

Several computer forecast models including those known as the "GFDN, EGRR, ECMWF," and Japanese computer forecast models suggest the storm will make landfall over southeastern China within 4 days.

Lekima Dissipating Over Land

Typhoon Lekima, named after a fruit in Vietnam, landfall late Tuesday in south China's island province of Hainan and made final landfall over north Vietnam in the evening of Oct. 3. It was dissipating as a tropical cyclone over land on Oct. 4.

When Lekima came ashore with sustained winds of 75 mph, it brought heavy rains and flooding. Reports indicated flooded roadways, crop damage and three fatalities. By early morning on Oct. 4, the center of Lekima was located over Laos.

Rob Gutro
Goddard Space Flight Center
Image credit: NASA/JPL

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Typhoon Lekima Poised to Make Landfall in Vietnam


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On Oct. 3, 2007 Category One Typhoon Lekima was bringing winds and rains to central Vietnam. Lekima's center was still off the coast at 6:00 Zulu Time (2:00 a.m. EDT), but on its westward track, the center of Lekima will make landfall later in the day.

At 2:00 a.m. EDT, the center was near 17.6 degrees north latitude and 107.3 degrees east longitude. It was moving west at 8 knots (9 mph) and had maximum sustained winds of 65 knots (74 mph) with higher guests.

Forecasters from the Joint Typhoon Warning Center note that the storm will make landfall along the central coast of Vietnam and dissipate rapidly.

This satellite image, created by data from the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite on Oct. 2 at 6:23 Zulu Time (2:23 a.m. EDT) shows Lekima's clouds and showers (in blue and purple) already reaching central Vietnam, as well as the island of Hainan located near the northern tip of the storm.

This AIRS image shows the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the typhoons. The infrared signal does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the Earth, revealing warmer temperatures (red).

Rob Gutro (From JTWC reports)
Goddard Space Flight Center
Image credit: NASA/JPL

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Three NASA Satellites Investigate Typhoon Lekima Headed to Vietnam

On Monday, Oct. 1, 2007, Typhoon Lekima was headed for Vietnam and is expected to make landfall there by Oct. 3, somewhere between the cities of Vinh to the north and Da Nang in the central part of the country. NASA satellites are keeping an eye on Lekima and include the Aqua satellite, QuikScat and CloudSat, peering into Lekima's clouds, winds and investigating the height and width of the storm.

At 1200 UTC (8:00 a.m. EDT) on Oct. 1, Lekima was located near 16.1 degrees north latitude and 112.1 degrees west longitude, or 220 nautical miles southeast of Hainan Island, which sits off the east coast of Vietnam. It was moving northwest at 8 knots (9 mph) and had maximum sustained winds were near 55 knots (63 mph) with gusts to 70 knots (80 mph).

NASA's Aqua Satellite Looks at Lekima's Clouds


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In this infrared image from Oct. 1 at 5:41 UTC (1:41 a.m. EDT), created by data from the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite, This AIRS image shows the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of Typhoon Lekima. The infrared signal does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the Earth, revealing warmer temperatures (red). This infrared image shows large areas of strong convection surrounding the core of the storm (in purple).

NASA's QuikSCAT Measures Lekima's Winds by Satellite


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This image from NASA's QuikSCAT satellite was taken on Oct. 1, 2007 at 1015 UTC (6:15 a.m. EDT) and depicts the wind speeds in Typhoon Lekima. The center is indicated by the purple color. This image depicts wind speed in color and wind direction with small barbs. White barbs point to areas of heavy rain. The highest wind speeds, around the eye, are shown in purple.

NASA's CloudSat Gives a Clear Look at Lekima's Clouds from Different Angles


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NASA's CloudSat satellite's Cloud Profiling Radar captured a sideways look across Typhoon Lekima on Monday, Sept. 29 at 18:11 UTC (2:11 p.m. EDT).

The top image is from NASA's Aqua satellite, and the image was supplied through the U.S. Naval Research Laboratory. It was created using data from the Moderate Imaging Spectroradiometer (MODIS) instrument.

The image on the bottom is from NASA's CloudSat satellite. The red line through the Aqua satellite image shows the vertical cross section of radar, basically what Lekima's clouds looked like sideways. The colors indicate the intensity of the reflected radar energy. The top of Ingrid's clouds reach to 15 kilometers, or approximately 9.3 miles high. These high cloud tops indicate a strong storm.

The blue areas along the top of the clouds indicates cloud ice, while the wavy blue lines on the bottom center of the image indicate intense rainfall. Notice that the solid line along the bottom of the panel, which is the ground, disappears in this area of intense precipitation. It is likely that in the area the precipitation rate exceeds 30mm/hr (1.18 inches/hour) based on previous studies.

Rob Gutro
Goddard Space Flight Center
Images credit: NASA/JPL; NASA/JPL;NASA/JPL/Colorado State University/Naval Research Laboratory-Monterey