Cyclone Maila rapidly intensifies to a Category 4 storm near the Solomon Islands
10-minute Himawari-9 Infrared (10.4 µm) images, from 0000 UTC on 07 April to 0000 UTC on 08 April [click to play animated GIF]
A Himawari-9 Target Sector was positioned over Maila until 1449 UTC, providing images every 2.5 minutes — which gave a smoother depiction of the evolution of Maila’s eye during rapid intensification (below). The coldest cloud-top infrared brightness temperatures were -90ºC and colder (yellow pixels embedded within dark purple areas) — for example, at 0107 UTC and 0912 UTC. No -90ºC pixels were seen in the 10-minute Full Disk scan Infrared images, highlighting the value of 2.5-minute Target Sector imagery for capturing subtle details.
2.5-minute Himawari-9 Infrared (10.4 µm) images, from 0002-1449 UTC on 07 April [click to play animated GIF]
Himawari-9 Infrared (11.2 µm) images with an overlay of streamlines and contours of deep-layer wind shear at 2100 UTC on 07 April
Another factor favoring intensification was the warm water that was present in the portion of the Solomon Sea where Maila had been slowly meandering for several days (below).
Sea Surface Temperature and Ocean Heat Content on 08 April, with a plot of Maila’s track
Microwave imagery from DMSP-18 (below) displayed the eyewall structure of Maila at 1749 UTC — which was partially eroded along its eastern edge at that time.
DMSP-18 SSMIS Microwave (85 GHz) image at 1749 UTC on 07 April
A Synthetic Aperture Radar (SAR) image from RCM-3 (below) sampled wind speeds as high as 118 kts in the NW quadrant of Maila at 1914 UTC.
RCM-3 SAR wind image at 1914 UTC on 07 April [click to enlarge]
VIIRS Day/Night Band (0.7 µm) images from NOAA-20 and NOAA-21 (mislabeled by AWIPS as NPP) [click to enlarge]