GOES-15 (GOES-West) Infrared (10.7 µm) images (above; also available as an MP4 animation) displayed the formation of a ring of cold eyewall cloud-top IR brightness temperatures (in the -80 to -90º C range, violet colors) during the period of rapid intensification of Hurricane Patricia on 22 October 2015; the storm reached Category 5 intensity around 00 UTC on 23 October. Patricia then continued to intensify, reaching maximum sustained surface winds estimated at 175 knots with a minimum central pressure of 878.4 hPa or 25.94 inches of mercury (making this the strongest tropical cyclone on record for the National Hurricane Center area of responsibility, which is the North Atlantic Ocean and the eastern North Pacific Ocean). The storm weakened somewhat prior to making landfall (although still as a Category 5 hurricane) around 2315 UTC on 23 October.

Multi-day YouTube animations showing the formation of Patricia are available here (0.63 µm visible imagery from GOES-13) and here (10.7 µm infrared imagery from GOES-13). The multi-day location of Patricia’s 850 hPa relative vorticity signature (derived from satellite atmospheric motion vector data) can be seen here.

A plot of the Advanced Dvorak Technique intensity estimate (below) showed the rate of rapid intensification on 22-23 October. At one point Patricia’s central pressure deepened 100 hPa in 24 hours, and 73 hPa in 12 hours, making it the fastest-intensifying tropical cyclone on record in the Western Hemisphere.

GOES-15 Visible (0.63 µm) images (below; also available as an MP4 animation) revealed the small “pinhole” eye of Patricia during rapid intensification on 22 October.

As Patricia was rapidly intensifying from a Category 1 to Category 5 intensity, the tropical cyclone was moving over a region of high Ocean Heat Content (below), and Sea Surface Temperature values were as high as 31º C.

A comparison of Suomi NPP VIIRS Infrared (11.45 µm) and Day/Night Band (0.7 µm) images at 0741 UTC on 23 October is shown below (courtesy of William Straka, SSEC). With ample illumination from the Moon (which was in the Waxing Gibbous phase, at 78% of Full), the “visible image at night” capability of the Day/Night Band provided a detailed view of cloud-top gravity waves surrounding the eye.

A later VIIRS Infrared (11.45 µm) image at 0920 UTC is shown below.

A comparison of GOES-15 (GOES-West) and GOES-13 (GOES-East) Visible (0.63 µm) images (below) showed the eye of Patricia from sunrise on 23 October until landfall along the west coast of Mexico around 2315 UTC. A mesonet station at the Chamela-Cuixmala Biosphere Reserve (located approximately 10 miles northwest of the eye landfall position) reported maximum sustained winds of 185 mph at 2350 UTC, with a peak wind gust of 210.9 mph at 2310 UTC.

MIMIC morphed microwave imagery (below) showed the development and motion of the very compact eye during the 22-23 October period. There was also a signature of the formation of a secondary outer eyewall, suggesting that an eyewall replacement cycle was underway as Patricia was approaching the west coast of Mexico.

View a 23 October weather briefing held at CIMSS to discuss Hurricane Patricia here.

===== 25 October Update =====

Following the landfall of Patricia late in the day on 23 October, and increase in offshore sediment could be seen in Suomi NPP VIIRS true-color Red/Green/Blue (RGB) images (from the RealEarth web map server) on 24 and 25 October (below), a result of runoff from heavy rains inland.

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Himawari-8 viewed Typhoon Champi in the North Pacific on 22 October 2015, as shown above. The storm was near peak intensity during this animation, as indicated by the graphs of satellite maximum wind speed and minimum surface pressure shown below (taken from this website). The eye (abnormally large for a Typhoon!) of Champi passed just to the south of the island of Iwo Jima, where a wind gust of 72 knots (83 mph) occurred at 09 UTC (surface observations). The Himawari-8 AHI instrument has 16 channels, as will the GOES-R ABI when it is launched in October 2016.

The Himawari-8 AHI instrument is also capable of gathering rapid-scan images over specified “Target Areas” every 2.5 minutes; rapid-scan Visible (0.64 µm) images of the eye of Typhoon Champi are shown below (also available as an MP4 animation). The GOES-R ABI will have the capability to scan special mesoscale sectors at 1-minute or even 30-second intervals.

Himawari-8 data — all channels — are routinely available here and here.

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A plot of the Advanced Dvorak Technique (ADT) intensity estimate for Hurricane Olaf (above) showed that the storm went through a period of rapid intensification during the 19-20 October 2015 period, reaching Category 4 strength. The National Hurricane Center noted that Olaf became the 6th major hurricane in the eastern North Pacific during the 2015 season, and that this was is the farthest south (9.9º N latitude) that a major hurricane had formed in that ocean basin since reliable records began in 1971 (discussion archive: NHC | CPHC).

4-km resolution GOES-15 (GOES-West) 10.7 µm Infrared channel images during the period of rapid intensification (below) revealed that cloud-top IR brightness temperatures were quite cold (in the -80º to -90º C range, violet colors) early in the day on 19 October, but then warmed a bit into the -70º to -80º C range (black to white shades) on 20 October as the eye became more well-defined.

A 375-meter resolution Suomi NPP VIIRS Infrared (11.45 µm) image at 10:23 UTC on 20 October (below) hinted at the presence of mesovortices within the eye of Hurricane Olaf.

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Typhoon Koppu hit the northern Philippines island of Luzon on Saturday 18 October. The 4-panel mp4 animation above (Click here for an animated gif) shows the 3 water vapor infrared channels (6.2 µm, 6.9 µm and 7.3 µm) and the window infrared channel (10.35 µm) from the Himawari-8 satellite. There is value in three water vapor channels because the shorter wavelength (6.2 µm) better captures high-level moisture whereas the longer wavelength better captures mid-level moisture. Cirrus is readily apparent in the 6.2 µm channel; tropical cumulus is more readily apparent underneath cirrus in the 7.3 µm channel. Compare the two channels in this animation, for example, or in this one. The three water vapor channels on Himawari-8 (similar to the 3 that will fly on the GOES-R ABI instrument) give a three-dimensional view of atmospheric moisture. All four channels above show the approach of Koppu towards Luzon, with the ragged eye filling rapidly at landfall.

The structure of Koppu’s eyewall is depicted above in a 24-hour morphed animation of microwave data (Source, as referred to from here). The nearly complete eyewall rapidly loses its integrity as the storm moves onshore. Total Precipitable Water (below, taken from the MIMIC Total Precipitable Water Site) shows Koppu on the northern edge of the rich moisture source that is the Intertropical Convergence Zone (Typhoon Champi is to Koppu’s east). Notably, the storm stalled over Luzon after making landfall; flooding rainfalls occurred.

Himawari-8 also captured the evolution of the storm in visible imagery. The full-resolution animation from 0100-0930 UTC on 17 October is shown below (a slower animation is available here). Periodic bursts of deep convection are apparent in the curved bands near the storm center. These convective bursts are better resolved with the 10-minute imagery from Himawari-8 than from 15-minute data from MTSAT-2 (or COMS-1).

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