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.

View only this post Read Less

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).

View only this post Read Less

On October 16, 1975, GOES-A was launched from Cape Canaveral in Florida (NESDIS Link). After achieving orbit, it was renamed GOES-1 and it broadcast its first image on October 25 of that year. The animation (mp4) above is from January 1983, when GOES-1 was operating as GOES-West. GOES-1 was in service for 10 years; it was decommissioned in March of 1985.

View only this post Read Less

A 250-meter resolution Terra MODIS true-color Red/Green/Blue (RGB) image from the SSEC MODIS Today site (above) revealed the widespread orange hue of Autumn tree colors over parts of northeastern Minnesota, northern Wisconsin, and the western Upper Peninsula of Michigan on 11 October 2015.

A comparison with the corresponding MODIS false-color RGB image (below) helped to identify 2 features of interest: (1) the large burn scar from the Pagami Creek fire in northeastern Minnesota (12 September 2011), and (2) the long tornado damage scar from the EF3 Langlade tornado in northeastern Wisconsin (07 June 2007). The location of these 2 features appears on this annotated image.

On the following day (12 October), the three MODIS true-color images below showed similar signatures of Autumn tree colors over portions of the Northeast US (SSEC MODIS Today).

The Autumn tree colors across the Northeast US were also evident on Suomi NPP VIIRS true-color imagery, as viewed using the SSEC RealEarth web map server (below).

View only this post Read Less