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]

Deep cyclone over Hudson Bay

August 11th, 2016

GOES-13 Water Vapor (6.5 µm) images, with hourly surface observations [click to play animation]

GOES-13 Water Vapor (6.5 µm) images, with hourly surface observations [click to play animation]

GOES-13 (GOES-East) Water Vapor (6.5 µm) images (above) showed the intensification of a strong cyclone over Hudson Bay, Canada during the 09 August – 10 August 2016 period; the cyclone deepened to a central pressure of 980 hPa (28.94″ of mercury) at 06 UTC on 10 August.

Daily composites of Suomi NPP VIIRS true-color Red/Green/Blue (RGB) images visualized using RealEarth (below) showed the storm on 08, 09 and 10 August.

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

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

Severe thunderstorms and heavy rainfall/flooding in the Upper Midwest

July 12th, 2016

GOES-13 Infrared Window (10.7 µm) images, with SPC storm reports [click to play animation]

GOES-13 Infrared Window (10.7 µm) images, with SPC storm reports [click to play animation]

GOES-13 Infrared Window (10.7 µm) images (above; also available as an MP4 movie file) showed a series of mesoscale convective systems that moved across northeastern Minnesota, northwestern Wisconsin and the Upper Peninsula of Michigan during the 11 July12 July 2016 period. Some of these storms produced tornadoes, large hail, and damaging winds (SPC storm reports) in addition to heavy rainfall, with as much as 9.00 inches in Minnesota and 9.80 inches in Wisconsin (NWS Duluth storm summary). Several highways were closed due to flooding and/or washout, including a portion of Interstate 35 in Minnesota (interstates and highways are plotted in violet on the images).

A sequence of Infrared images from Terra/Aqua MODIS (11.0 µm) and Suomi NPP VIIRS (11.45 µm) (below) showed greater detail in the storm-top temperature structure at various times during the event.

Infrared images from Terra/Aqua MODIS (11.0 µm) and Suomi NPP VIIRS (11.45 µm) [click to play animation]

Infrared images from Terra/Aqua MODIS (11.0 µm) and Suomi NPP VIIRS (11.45 µm) [click to play animation]

===== 19 July Update =====

Comparison of before (09 July) and after (12 July through 19 July) Suomi NPP VIIRS true-color images [click to enlarge]

Comparison of before (09 July) and after (12 July through 19 July) Suomi NPP VIIRS true-color images [click to enlarge]

A comparison of Suomi NPP VIIRS true-color Red/Green/Blue (RGB) images from before the event (09 July) and after the event (12 through 19 July) (above) revealed the large amounts of sediment flowing offshore into the southwestern portion of Lake Superior.

Another comparison of before (09 July) and after (13 through 19 July) true-color RGB images from Terra and Aqua MODIS is shown below.

Comparison of before (09 July) and after (13 through 19 July) Terra/Aqua MODIS true-color images [click to enlarge]

Comparison of before (09 July) and after (13 July through 19 July) Terra/Aqua MODIS true-color images [click to enlarge]

A toggle between a Terra MODIS Visible (0.65 µm) image and the corresponding MODIS Sea Surface Temperature (SST) product on 16 July (below) showed that the SST values in the sediment-rich nearshore waters were significantly warmer (middle 60s F, red enhancement) than those found closer to the center of Lake Superior (middle 40s F, cyan enhancement).

Terra MODIS Visible (0.65 µm) image and Sea Surface Temperature product [click to enlarge]

Terra MODIS Visible (0.65 µm) image and Sea Surface Temperature product [click to enlarge]

Super Typhoon Nepartak

July 7th, 2016

Track of Super Typhoon Nepartak (03 to 07 July 2016) [click to enlarge]

Track of Super Typhoon Nepartak (03 to 07 July 2016) [click to enlarge]

Super Typhoon Nepartak (02W) formed as a tropical depression in the West Pacific Ocean south of Guam on 02-03 July 2016, and tracked northwestward until making landfall in southern Taiwan on 07 July (above). Nepartak rapidly intensified to a Category 4 storm on 05 July, peaking at Category 5 intensity on 06 July (ADT | SATCON wind | SATCON pressure). Two factors helping the storm to reach and maintain Category 5 intensity for a relatively long period of time were (1) the passage over water having large Ocean Heat Content and Sea Surface Temperature values, and (2) an environment characterized by low deep-layer wind shear (06 July/15 UTC | 07 July/21 UTC).

2.5-minute interval rapid-scan Himawari-8 Infrared Window (10.4 µm) images (below) showed the formation of a well-defined eye with an annular storm structure early in the day on 07 July. The eye became less organized as Nepartak approached the island of Taiwan and made landfall as a Category 4 typhoon around 2150 UTC.

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]

Surface observations (plot | text) from Feng Nin airport (station identifier RCFN) in Taitung City showed sustained winds of 70 knots (81 mph) with a gust to 99 knots (114 mph) from the north-northeast at 21 UTC, and a pressure of 964.0 hPa (27.47″). iCyclone chaser Josh Morgerman recorded a minimum pressure of 957.7 hPa at 2043 UTC (4:43 am local time) in Taitung City:


Shortly before landfall, a comparison of DMSP-18 SSMIS Microwave (85 GHz) and Himawari-8 Infrared Window (10.4 µm) images around 20 UTC (below) showed that the eye was still rather distinct on the microwave image.

DMSP-16 SSMIS Microwave (85 GHz) and Himawari-8 Infrared Window (10.4 µm) images [click to enlarge]

DMSP-16 SSMIS Microwave (85 GHz) and Himawari-8 Infrared Window (10.4 µm) images [click to enlarge]

However, the MIMIC-TC product (below) revealed how quickly the eyewall structure eroded once the circulation of Nepartak encountered the rugged terrain of Taiwan.
MIMIC-TC product [click to enlarge]

MIMIC-TC product [click to enlarge]

Looking back to earlier periods in the storm history, a 2-panel comparison of Himawari-8 Visible (0.64 µm) and Infrared Window (10.4 µm) images from 06-07 July (below) revealed the presence of mesovortices within the eye on the visible imagery. The spatial resolution of these Visible (0.5 km) and Infrared (2 km) AHI images is identical to what will be provided by the ABI instrument on GOES-R.
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]

A Suomi NPP VIIRS true-color Red/Green/Blue (RGB) image from 07 July (viewed using RealEarth) is shown below; the actual satellite overpass time for this image was around 0444 UTC.
Suomi NPP VIIRS true-color image on 07 July [click to enlarge]

Suomi NPP VIIRS true-color image on 07 July [click to enlarge]

During the period of rapid intensification on 06 July, 2.5-minute interval rapid-scan Himawari-8 Infrared Window (10.4 µm) images (below) revealed pulses of storm-top gravity waves which were propagating radially outward away from the eye of Nepartak (especially evident during the later half of the animation period).
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]

It is also interesting to note that nighttime mesospheric gravity waves could be seen propagating away from the eye/eyewall region of Nepartak at 1729 UTC or 1:29 am local time on a 06 July Suomi NPP VIIRS Day/Night Band (0.7 µm) image (below, courtesy of William Straka, SSEC). Since very little illumination was provided by the Moon (which was in the Waxing Crescent phase, at only 5% of Full), these waves were being illuminated by airglow.
Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

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

The MIMIC-TC product (below) also showed that Nepartak completed an eyewall replacement cycle on 06 July.
MIMIC-TC product [click to enlarge]

MIMIC-TC product [click to enlarge]

Animations of 10-minute interval Himawari-8 Infrared Window (10.4 µm) images spanning nearly the entire life cycle of Nepartak — from a tropical depression south of Guam on 03 July to landfall over mainland China on 08 July — are available as an MP4 movie (139 Mbytes) or an animated GIF (493 Mbytes).