Super Typhoon Nepartak reached winds of 270 km/h when it was seen by Himawari-8 on 6 July.
By HansPeter Roesli (Switzerland)
When Typhoon Nepartak formed on 3 July, it ended an long-term record storm-free period in the northwest Pacific Ocean. It had been 200 days since a tropical storm or typhoon had formed in that part of the world.
By 6 July it had become a category 5 Super Typhoon, with maximum estimated sustained winds of more than 280 km/h; becoming the strongest typhoon since Super Typhoon Souldelor in August 2015.
The Himawari-8 infrared and visible images of Typhoon Nepartak on 6 July (Figure 1), show Nepartak over the Philippine Sea.
The very distinct eye is shown in more detail on Figure 2. The eye shows fine cellular and radial cloud structures at 500 m spatial resolution. The right-hand image is the same visible image overlaid with the semi-transparent temperature from band IR11.2 in false colours at 2 km resolution.
On the infrared animation, 6 July 03:15–07:22 UTC (MP4, 13 MB) Nepartak was tracked on its west-northwest trajectory with images every 2.5 min at 2 km spatial resolution. During this period a cloud patch showed temperature values were as cold as 180 K, indicating the presence of very high cloud tops.
The full progress of Typhoon Nepartak can be seen on this animated sequence of Himawari-8 infrared images from 5 July 00:00 UTC to 8 July 23:30 UTC (MP4, 16 MB).
Figure 3 is the VIIRS image of the big eye when Nepartak was a Category 5 storm on 7 July, 04:43 UTC. The image is at 375m resolution from band I1 (VIS0.64) overlaid in semi-transparency by I5 (IR11.45). I5's colour scale goes from white/cold to yellow/warm. The enormous eye wall is well exposed on its western side (Suomi-NPP passed over to the east of the eye).
Joint Typhoon Warning Service
CIMSS Tropical Cyclones tracker
Staring into the eye of Nepartak (Dan Lindsey/Twitter)
The Himawari-8 satellite shows Super Typhoon #Nepartak churning through the Pacific Ocean (NOAA Satellites/Twitter)
Category 5 Super Typhoon Nepartak Prompts Typhoon Warning in Taiwan; Heavy Rain Threat in Eastern China (Weather Channel)