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Hurricane Season 2008: Typhoon Hagupit (South China Sea)
 
Sept. 25, 2008

TRMM image of Typhoon Hagupit headed towards China Credit: Hal Pierce, SSAI/NASA GSFC
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NASA's TRMM Satellite Catches Hagupit's Rainfall as it Makes Landfall

Deadly Typhoon Hagupit hit southern China early Wednesday morning, Sept. 24 with wind speeds of about 105 knots (~121 miles per hour). The image on the top right shows typhoon Hagupit on September 23 at 1426 UTC 10:26 a.m. EDT) when it was observed by the Tropical Rainfall Measuring Mission (TRMM) satellite as it headed toward southern China. At the time of this image Hagupit was increasing in intensity from a category three typhoon with wind speeds of 105 knots (~121 miles per hour) to peak later that day as a category four typhoon with winds of 120 knots (138 miles per hour). A very large area of extremely heavy rainfall was revealed in Hagupit's eye wall using data from TRMM's Microwave Imager and Precipitation Radar instruments.

PR perspective view of TRMM image of Typhoon Hagupit Credit: Hal Pierce, SSAI/NASA GSFC
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The image on the bottom right shows a perspective view of Typhoon Hagupit (viewed from the west) using Precipitation Radar data from the same time as the image above. The very well defined eye is an indication of the intensity of the typhoon. Very powerful thunderstorms with heights of over 15 kilometers are shown in Hagupit's eye wall.

Text credit: Hal Pierce, Goddard Space Flight Center







Sept. 24, 2008

Hagupit Makes Landfall in Southeastern China

Satellite image of Typhoon Hagupit Credit: NASA/JPL
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Typhoon Hagupit made landfall in mainland China between Macao and Hainan Island and is now a tropical storm headed toward Vietnam.

Hagupit made landfall on Sept. 23 at 20:30 Zulu Time (4:30 p.m. EDT) about 45 miles southwest of Yangjiang, China. Sustained winds of 54 knots (62 mph) were reported at that time making it a tropical storm at the time of landfall.

As of 1200 Zulu Time (8:00 a.m. EDT) on Sept. 24, Hagupit had sustained winds near 50 knots (57 mph), and was located near 22.2 degrees north and 108.0 degrees east. It was moving west-northwest, and is expected to curve to the west-southwest later in the day on Sept. 25 into northern Vietnam before dissipating.

China's Xinhau news reported that Hagupit had caused five deaths and left two missing in south China. The Ministry of Civil Affairs confirmed these numbers and reported that the storm "destroyed 14,333 houses, caused a direct economic loss of 5.772 billion yuan."

The Joint Typhoon Warning Center, the agency that monitors western Pacific Typhoons issued their final advisory on the storm on Sept. 24 at 8 a.m. EDT.

Aqua Satellite Sees Hagupit's Landfall

This visible image was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. The image was taken on Sept 24 at 5:47 UTC (1:47 a.m. EDT). The visible and infrared 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.

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



Sept. 23, 2008

Hong Kong Experiencing Typhoon Hagupit's Winds and Rains

QuickScat image of Typhoon Hagupit's winds Credit: NASA JPL
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Powerful Category Three Typhoon Hagupit is set to make landfall on Wed. Sept. 24th, but it's already raining and gusting on Hong Kong on its approach to mainland China.

On Tuesday, Sept. 23, Hagupit has sustained winds near 105 knots (120 mph) with higher gusts. Hagupit's eye was located approximately 100 nautical miles south of Hong Kong, near 20.8 degrees north and 113.2 degrees east. Hagupit's eye is estimated to be 21 miles in diameter and the extent of hurricane force winds extended outward from there. Tropical storm force winds extend up to 135 miles from the eye, meaning that Hong Kong is experiencing those winds on Tuesday. Hagupit was moving westward near 14 knots (16 mph).

According to the Hong Kong Weather Service "The tropical cyclone signal no. 8 has been issued." Over the course of one hour, between 10:45 and 11:45 p.m. local time on Sept. 22, the maximum rainfall recorded in various regions of China were: Lantau Island: 12 millimeters (.47 inch); Southern District: 11 mm (.43 inch); and Tuen Mun: 11mm (.43 inch).

QuikSCAT Watching Hagupit's Strong Winds

NASA's Quick Scatterometer satellite (QuikScat) has been watching Hagupit's winds by using microwaves to peer into the clouds. QuikScat can determine the speed of the rotating winds. This image from QuikScat shows Hagupit's wind speeds in different colors and wind direction are indicated by small barbs. White barbs point to areas of heavy rain. The highest wind speeds are normally shown in purple, which indicate winds over 40 knots (46 mph), but as this image shows, the winds are simply not that strong. The strongest winds are represented in the center of circulation, depicted in blue in this image. This image was captured on Sept. 23 at 10:21 UTC (6:21 a.m. EDT).

AIRS image of Typhoon Hagupit's temperatures Credit: NASA JPL
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Aqua Satellite Shows Temperature Difference Between Icy Clouds and Warm Seas

This infrared image was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. The infrared image was taken on Sept 22 at 18:11 UTC (2:11 p.m. EDT). The infrared image shows a huge temperature difference between the tops of the clouds in a tropical cyclone and the warm ocean waters that power it.

The 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 area of low pressure. Those temperatures are as cold as or colder than 220 degrees Kelvin or minus 63 degrees Fahrenheit (F). The blue areas are around 240 degrees Kelvin, or minus 27F.

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 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.

Text credit: Rob Gutro (from NHC discussion) NASA's Goddard Space Flight Center



Sept. 22, 2008

Dangerous Category 3 Typhoon Hagupit In South China Sea

Satellite image of Hagupit Credit: NASA/JPL/Colorado State University/Naval Research Laboratory-Monterey
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The Joint Typhoon Warning Center is the organization responsible for forecasts of typhoons and is keeping a close eye on Typhoon Hagupit in the western Pacific Ocean. Hagupit is a powerful Category 3 storm on the Saffir-Simpson hurricane/typhoon scale.

On Sept. 22 at 15:00 UTC (11:00 a.m. EDT), Hagupit was located 410 nautical miles southeast of Hong Kong, near 196 degrees north and 120.2 degrees east. It was packing sustained winds near 100 knots (115 mph) with higher gusts and is moving west at 11 knots (14 mph). Hagupit will continue to track generally west-northwestward as it transits across the South China Sea. Hagupit is expected to make landfall south of Hong Kong on Wednesday, Sept. 24.

NASA's CloudSat Satellite Slices Hagupit Sideways

NASA's CloudSat satellite's Cloud Profiling Radar captured a sideways look across Hagupit. It was compared with top down satellite image to show where CloudSat took its sideways view.

The top image is from the MTSAT satellite on Sept. 21, 17:13 Zulu Time (1:13 p.m. EDT). The image was supplied through the U.S. Naval Research Laboratory. The Multi-functional Transport Satellite (MTSAT) series fulfills a meteorological function for the Japan Meteorological Agency and an aviation control function for the Civil Aviation Bureau of the Ministry of Land, Infrastructure and Transport.

The image on the bottom is from NASA's CloudSat satellite also taken on Sept. 21. The red line through the MTSAT satellite image shows the vertical cross section of radar, basically what Hagupit's clouds looked like sideways. The colors indicate the intensity of the reflected radar energy. The top of Hagupit's clouds are over 14 kilometers or almost 9 miles high.

The blue areas along the top of the clouds indicate cloud ice. Where the solid line (the ground or sea surface) along the bottom of the panel disappears is an area of heavy precipitation. It is likely that in the area the precipitation rate exceeds 30mm/hr (1.18 inches/hour) based on previous studies.

Aqua Satellite Shows Difference Between Freezing Storm Clouds and Warm Ocean

Satellite image of Hagupit Credit: NASA/JPL
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This infrared image was created by data from the Atmospheric Infrared Sounder (AIRS), an instrument that flies aboard NASA's Aqua satellite. The image was created on Sept. 21, at 5:17 UTC or 1:17 a.m. EDT and shows a huge temperature difference between the tops of the clouds in a tropical cyclone and the warm ocean waters that power it. The east side of the storm is cut off from the image, as it was out of the satellite's view.

The 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 area of low pressure. Those temperatures are as cold as or colder than 220 degrees Kelvin or minus 63 degrees Fahrenheit (F). The blue areas are around 240 degrees Kelvin, or minus 27 F.

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 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.

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