Super Typhoon Meranti

September 12th, 2016

Himawari-8 0.64 µm Visible (top) and 10.4 µm Infrared Window (bottom) images [click to play MP4 animation]

Himawari-8 0.64 µm Visible (top) and 10.4 µm Infrared Window (bottom) images [click to play MP4 animation]

Rapid-scan (2.5-minute interval) Himawari-8 AHI Visible (0.64 µm) and Infrared Window (10.4 µm) images (above; also avialable as a 33 Mbyte animated GIF) showed the pin-hole eye and cold cloud-top IR brightness temperatures (-80º C and colder, violet color enhancement) associated with Super Typhoon Meranti (16W) in the Philippine Sea on 11-12 September 2016. Note that the ABI instrument on GOES-R will provide similar 0.5-km resolution Visible and 2-km resolution Infrared imagery.

Himawari-8 Infrared Window (10.4 µm) image at 1230 UTC on 12 September, with 11 September images of Sea Surface Temperature and Ocean Heat Content [click to enlarge]

Himawari-8 Infrared Window (10.4 µm) image at 1230 UTC on 12 September, with 11 September images of Sea Surface Temperature and Ocean Heat Content [click to enlarge]

As Meranti was intensifying from a Category 4 to a Category 5 storm, it was passing over waters that exhibited both warm Sea Surface Temperatures and high Ocean Heat Content as seen on images from the CIMSS Tropical Cyclones site (above), and was also moving through an environment of very low deep-layer wind shear (below) — all factors that are favorable for tropical cyclone intensification.

Himawari-8 Infrared Window (10.4 µm) images, with satellite-derived 850-200 hPa deep layer wind shear [click to play animation]

Himawari-8 Infrared Window (10.4 µm) images, with satellite-derived 850-200 hPa deep layer wind shear [click to play animation]

Himawari-8 Infrared Window (10.4 µm) images (below; also available as an 89 Mbyte animated GIF) showed Meranti as a Category 5 storm during the nighttime hours on 12 September.

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

A comparison of a Himawari-8 Infrared Window (10.4 µm) image at 1830 UTC and a DMSP-15 SSMIS Microwave (85 GHz) image at 1847 UTC (below) again displayed the very small eye.

Himawari-8 Infrared Window (10.4 µm) and DMSP-15 SSMIS Microwave (85 GHz) images [click to enlarge]

Himawari-8 Infrared Window (10.4 µm) and DMSP-15 SSMIS Microwave (85 GHz) images [click to enlarge]

During the subsequent daytime hours (local time) on 12 September, another comparison of rapid-scan (2.5-minute interval) Himawari-8 Visible (0.64 µm) and Infrared Window (10.4 µm) images (below; also available as a 24 Mbyte animated GIF) continued to show a well-defined eye as Meranti maintained Category 5 intensity (ADT plot). Mesovortices could be seen spinning within the eye on the visible imagery during this time.

Himawari-8 0.64 µm Visible (top) and 10.4 µm Infrared Window (bottom) images [click to play MP4 animation]

Himawari-8 0.64 µm Visible (top) and 10.4 µm Infrared Window (bottom) images [click to play MP4 animation]

===== 13 September Update =====

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

Super Typhoon Meranti went through a secondary round of intensification on 13 September (ADT plot) , with the JTWC estimating maximum sustained winds of 165 knots with gusts to 200 knots at 21 UTC. CIMSS Satellite Consensus (SATCON) plots of wind and pressure indicated that Meranti reached peak intensity near the middle of the day. Himawari-8 Infrared Window (10.4 µm) images (above; also available as a 114 Mbyte animated GIF) continued to display a well-defined eye with an annular storm structure during this period. A faster version of the animated GIF better showed the pronounced trochoidal motion exhibited by the eye of Meranti, as it moved just south of the island of Taiwan.

Himawari-8 Infrared Window (11.45 µm) images [click to enlarge]

Himawari-8 Infrared Window (11.45 µm) images [click to enlarge]

The eye of Meranti passed directly over the small Philippine island of Itbayat, as seen on Himawari-8 Infrared Window (11.45 µm) images viewed using RealEarth (above).

Suomi NPP overflew Meranti around 1730 UTC, just as the eye of the storm was passing over Itbayat. In a toggle between VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images (below; courtesy of William Straka, SSEC) ample lunar illumination provided a very good “visible image at night” which also included a bright lightning streak emanating from the eastern eyewall of the Category 5 storm. The image pair also shows a good example of the “stadium effect” eye geometry (where the eye diameter at the surface is smaller, and opens to a wider distance with increasing height). A larger-scale view of the entire storm from the Day/Night Band is available here; the corresponding 11.45 µm Infrared image is available here.

Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band visible (0.70 µm) imagery of Meranti, 1735 UTC on 13 September 2016 [click to enlarge]

Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band visible (0.70 µm) imagery of Meranti, 1735 UTC on 13 September 2016 [click to enlarge]

DMSP-15 SSMI Microwave (85 GHz) and Himawari-8 Infrared Window (11.45 µm) images [click to enlarge]


DMSP-15 SSMI Microwave (85 GHz) and Himawari-8 Infrared Window (11.45 µm) images [click to enlarge]

In a comparison of DMSP-15 SSMI Microwave (85 GHz) and Himawari-8 Infrared Window (11.45 µm) images around 1830 UTC (above), the appearance of concentric eyewalls on the microwave data suggested that Meranti was preparing to go through an eyewalll replacement cycle, which also signaled that the storm was perhaps near maximum intensity.

This formation of concentric eyewalls was nicely depicted by the MIMIC-TC product (below).

MIMIC-TC product [click to play animation]

MIMIC-TC product [click to play animation]

=====14 September Update =====

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]


Less than 2 hours prior to landfall (which was around 1905 UTC on 14 September, over Xiamen City in the Fujian Province of China), a toggle between Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1716 UTC (above) still showed well-defined curved banding structures around the center of of the Category 2 typhoon.

Himawari-8 Infrared Window (10.4 µm) images from pre-landfall at 0600 UTC on 14 September to post-landfall at 0600 UTC on 15 September (below; also available as a 47 Mbyte animated GIF) showed that Meranti quickly dissipated as it moved inland over mainland China. The images are centered on Xiamen (station identifier ZSAM); alternate animation versions with the BD grayscale enhancement are available in MP4 and animated GIF format.

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

Himawari-8 Infrared Window (10.4 µm) images [click to play MP4 animation]

About 4 hours after landfall, good curved banding structure was still observed in DMSP-18 SSMIS Microwave (85 GHz) imagery at 2314 UTC, while the overall presentation of the storm on Himawari-8 Infrared Window (11.45 µm) imagery began to deteriorate (below).

DMSP-18 SSMIS Microwave (85 GHz) and Himawari-8 Infrared Window (11.45 µm) images [click to enlarge]

DMSP-18 SSMIS Microwave (85 GHz) and Himawari-8 Infrared Window (11.45 µm) images [click to enlarge]

GOES-14 SRSO-R: pyrocumulus clouds over the Rey Fire in California

August 22nd, 2016

GOES-14 0.63 µm Visible (top), 3.9 µm Shortwave Infrared (middle) and 10.7 µm Infrared Window (bottom) images [click to play MP4 animation]

GOES-14 0.63 µm Visible (top), 3.9 µm Shortwave Infrared (middle) and 10.7 µm Infrared Window (bottom) images [click to play MP4 animation]

The GOES-14 satellite was in SRSO-R mode on 22 August 2016, providing images at 1-minute intervals over the western United States. A 3-panel comparison of Visible (0.63 µm), Shortwave Infrared (3.9 µm) and Infrared Window (10.7 µm) images (above; also available as a large 110 Mbyte animated GIF) showed that there were multiple bursts of pyrocumulus (pyroCu) clouds over the Rey Fire in southern California — while the bulk of the smoke was being transported westward over the offshore waters of the Pacific Ocean, smoke that was ejected to higher altitudes by the pyroCu clouds sent a plume of smoke drifting to the southeast.

The nearby Vandenberg rawinsonde data profile (below) suggests that the pyroCu clouds vertically lofted smoke to an altitude of at least 6.7 km (the 449 mb pressure level), where winds shifted to a northwesterly direction. However, since the pyroCu cloud-top IR brightness temperatures never even made it to -20º C (cyan color enhancement on the bottom panels), the smoke probably wasn’t much higher than the 6.7 km altitude (sounding data).

Vandenberg Air Force Base rawinsonde report [click to enlarge]

Vandenberg Air Force Base rawinsonde report [click to enlarge]

A comparison of Suomi NPP VIIRS true-color and false-color Red/Green/Blue (RGB) images displayed using RealEarth (below) showed the dense plume of smoke drifting westward away from the active fire area (brighter shades of pink on the false-color image), along with a pyroCu cloud over the fire and the early stage of the southeastward-moving smoke plume aloft.

Suomi NPP VIIRS true-color and false-color images [click to enlarge]

Suomi NPP VIIRS true-color and false-color images [click to enlarge]

GOES-14 SRSO-R: coastal fog/stratus and wildfire activity in the western US

August 17th, 2016

GOES-14 Visible (0.63 µm) images, with hourly surface weather symbols plotted in yellow [click to play MP4 animation]

GOES-14 Visible (0.63 µm) images, with hourly surface weather symbols plotted in yellow [click to play MP4 animation]

GOES-14 remained in SRSO-R mode on 17 August 2016, providing imagery at 1-minute intervals over the western US. Some interesting phenomena observed included the evolution of coastal fog/stratus in areas such as Vancouver Island and Washington/Oregon (above; also available as a large 134 Mbyte animated GIF) and also the Bay Area of California (below; also available as a large 202 Mbyte animated GIF). In the example above, note the diurnal ebb and flow of fog/stratus as it first moved westward out of, and then eastward back into the Strait of Juan de Fuca.; in the example below, it is interesting to note that as the majority of the coastal fog/stratus dissipated as morning heating/mixing progressed, but a narrow finger of fog/stratus remained in the Golden Gate and protruded into San Francisco Bay.

GOES-14 Visible (0.63 µm) images, with hourly plots of surface reports in yellow [click to play MP4 animation]

GOES-14 Visible (0.63 µm) images, with hourly plots of surface reports in yellow [click to play MP4 animation]

In Southern California, one of the larger wildfires burning at the time was the Blue Cut Fire northeast of Los Angeles. During the early morning hours, GOES-14 Visible (0.63 µm) and Shortwave Infrared (3.9 µm) images (below; also available as a large 70 Mbyte animated GIF) revealed the long and narrow smoke plume streaming northeastward; a marked increase in wildfire hot spots (red pixels in the 3.9 µm imagery) was seen after about 17 UTC (10am local time).

GOES-14 0.63 µm Visible (left) and 3.9 µm Shortwave Infrared (right) images, with hourly plots of surface reports in cyan/yellow [click to play MP4 animation]

GOES-14 0.63 µm Visible (left) and 3.9 µm Shortwave Infrared (right) images, with hourly plots of surface reports in cyan/yellow [click to play MP4 animation]

A closer view of GOES-14 Visible (0.63 µm) images (below; also available as a large 127 Mbyte animated GIF) after 18 UTC (11am local time) showed a more well-defined smoke plume re-develop as the wildfire continued to burn with very little perimeter containment. The smoke plume drifted over Victorville, California (KVCV), where the surface visibility briefly dropped to 7 miles at 22 UTC (surface observation plot).

GOES-14 Visible (0.63 µm) images, with county outlines and 4-character airport identifiers [click to play MP4 animation]

GOES-14 Visible (0.63 µm) images, with county outlines and 4-character airport identifiers [click to play MP4 animation]

GOES-14 SRSO-R: severe thunderstorms over North Dakota, South Dakota and Minnesota

August 10th, 2016

GOES-14 Visible (0.63 µm) images, with hourly surface reports and SPC storm reports of hail (yellow) and damaging winds (cyan) [click to play MP4 animation]

GOES-14 Visible (0.63 µm) images, with hourly surface reports and SPC storm reports of hail (yellow) and damaging winds (cyan) [click to play MP4 animation]

1-minute SRSO-R GOES-14 Visible (0.63 µm) images (above; also available as a 265 Mbyte animated GIF) showed the development of severe thunderstorms which produced large hail and damaging winds (SPC storm reports) in southeastern North Dakota, northeastern South Dakota and far western Minnesota on 10 August 2016. SPC noted a region of enhanced instability centered over southeastern North Dakota around 16 UTC (MCD); it is interesting to note that an orphan anvil was seen to form around 13 UTC between Valley City (KBAC) and Gwinner (KGWR) — near the northern edge of the pocket of instability — before the main convection began to develop just north of the North Dakota/South Dakota border around 1515 UTC.