Typhoon Soudelor approaches Taiwan

August 7th, 2015 |
COMS-1 10.8 µm Infrared imagery (click to play animation)

COMS-1 10.8µm Infrared imagery (click to play animation)

Imagery from the Korean COMS-1 satellite, above, shows Category 3 Typhoon Soudelor approaching the island of Taiwan. The eye appearance becomes ragged at the end of the animation, suggesting entrainment of dry air into the center of the Typhoon. Although Sea Surface Temperatures are warm (image taken from here), strengthening before landfall is not forecast. Life-threatening flooding is likely as the circulation and moisture associated with Soudelor interact with the high terrain on the island of Taiwan (Total Precipitable Water animation from MIMIC).

Suomi NPP overflew Soudelor during the morning of the 7th (1709 UTC on 6 August), and the half-moon illumination allowed the VIIRS Day/Night Band to show impressive outflow in the northern semi-circle of the storm; the 11.45 µm Infrared image, however, shows few cold cloud tops just to the north of the eye.

Suomi NPP VIIRS Day/Night Band Visible  (0.70 µm) and Infrared (11.45 µm)  images, 1709 UTC 6 August 2015 (click to enlarge)

Suomi NPP VIIRS Day/Night Band Visible (0.70 µm) and Infrared (11.45 µm) images, 1709 UTC 6 August 2015 (click to enlarge)

A closer view of the eye of Typhoon Soudelor is shown below.

Suomi NPP VIIRS 0.7 µm Day/Night Band and 11.45 µm Infrared images (click to enlarge)

Suomi NPP VIIRS 0.7 µm Day/Night Band and 11.45 µm Infrared images (click to enlarge)

The 16-channel animation from Himawari-8 AHI, below, at half-hour time steps from 0000 through 1230 UTC on 7 August, shows plain evidence of dry air at mid-levels increasing with time, first northeast of the storm and later west of the storm (especially in the ‘water vapor’ channels: 6.2 µm, 6.9 µm and 7.3 µm).

All 16 Himawari-8 AHI channels, 0000-1230 UTC on 7 August, wavelengths as indicated (click to animate)

All 16 Himawari-8 AHI channels, 0000-1230 UTC on 7 August, wavelengths as indicated (click to animate)

About 5 hours prior to landfall on Taiwan, a nighttime comparison of Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared (11.45 µm) images at 1653 UTC on 07 August (00:53 AM on 08 August, Taiwan time) is shown below. The images showed a ragged eye structure, but a well-defined spiral band wrapping around the northern semicircle of the typhoon.

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared (11.45 µm) images [click to enlarge]

According to The Weather Channel, the highest reported gust in Taiwan was 64.0 meters per second (143 mph) at 5 a.m. Taiwan time on 08 August at Su-ao, Yilan County. However, the Central Weather Bureau deleted all wind data for this site, so the accuracy may be in question. The next-highest gust was 58.5 meters per second (131 mph) on the island of Pengjiayu, northeast of mainland Taiwan. The highest reported rainfall total was 1329.0 millimeters (52.32 inches) at Taipingshan, Datong Township, Yilan County, Taiwan, during the 72-hour period from 06 August through 08 August.

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