2.5-minute JMA Himawari-9 Red Visible (0.64 µm, top) and Clean Infrared Window (10.4 µm, bottom) images, from 2002 UTC on 12 December to 0822 UTC on 13 December [click to play animated GIF | MP4]

Target Sector (2.5-minute interval) JMA Himawari-9 AHI Red Visible (0.64 µm) and Clean Infrared Window (10.4 µm) images (above) showed the brief development of a ragged eye with Cyclone Jasper as the storm approached the coast of Far North Queensland, Australia — prior to it making landfall north of Cairns around 1200 UTC on 13 December 2023.

In Synthetic Aperture Radar (SAR) wind speed images from RCM-3 at 1956 UTC on 12 December and 0854 UTC on 13 December (source), a swath of higher speeds (having maxima of 65.78 knots and 49.62 knots, respectively) was seen within the southern semicircle of the eyewall (below).

RCM-3 SAR wind speed at 1956 UTC on 12 December [click to enlarge]

RCM-1 SAR wind speed at 0854 UTC on 13 December [click to enlarge]

A GCOM-W1 AMSR2 Microwave (85 GHz) image at 1554 UTC on 13 December (below) also displayed higher reflectivity within the southern eyewall, moving inland near and just north of Cairn surface observation site.

GCOM-W1 AMSR2 Microwave (85 GHz) image at 1554 UTC on 13 December [click to enlarge]

Himawari-9 Infrared Window (11.2 µm) images from the CIMSS Tropical Cyclones site (below) showed that Jasper was moving through an environment of low deep-layer wind shear — which, in addition to its motion across modestly-warm water (SST | OHC) favored some intensification. In fact, Jasper did intensify to 60 knots at 0600 UTC on 13 December (SATCON), about 6 hours prior to landfall,

JMA Himawari-9 Infrared Window (11.2 µm) images, with contours and streamlines of deep-layer wind shear at 0000 UTC on 13 December [click to enlarge]

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