Comparisons of GOES-15, GOES-16 and GOES-17

July 17th, 2018 |
Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) [click to play animation | MP4]

Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) [click to play animation | MP4]

* GOES-17 imagery shown here are preliminary and non-operational *

A 3-panel comparison of Visible images from GOES-15 (GOES-West), GOES-17 and GOES-16 (GOES-East) shown above highlights the dissipation of fog in the Strait of Juan de Fuca during the morning hours on 17 July 2018. The three sets of images are displayed in the native projection of each satellite (with no re-mapping) — GOES-17 was at its post-launch checkout location of 89.5ºW longitude.  Images from GOES-16/17 were at 5-minute intervals, while images from GOES-15 were every 5-15 minutes depending on the operational scan schedule of that GOES-West satellite.

A similar 3-satellite comparison shown below focuses on the development of showers and thunderstorms across western Montana, between Missoula KMSO and Butte KBTM. The improved spatial resolution (0.5 km at sub-satellite point for GOES-16/17, vs 1.0 km for GOES-15) and more frequent images allowed small-scale features of the storms to be more easily identified and followed.

Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) [click to play animation | MP4]

Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) [click to play animation | MP4]

One final comparison, shown below, depicts thunderstorms over western Colorado — outflow boundaries south of these storms produced strong surface winds in the Grand Junction area (SPC storm reports).

Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) [click to play animation | MP4]

Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) — SPC storm reports of wind are plotted in red [click to play animation | MP4]


Ferguson Fire in California forms a pyrocumulonimbus cloud

July 15th, 2018 |
GOES-16

GOES-16 “Red” Visible (0.64 µm, left), Shortwave Infrared (3.9 µm, center) and “Clean” Infrared Window (10.3 µm, right) images [click to play MP4 animation]

* GOES-17 images shown here are preliminary and non-operational *

The Ferguson Fire in central California produced a pyrocumulonimbus (pyroCb) cloud during the afternoon hours on 15 July 2018. GOES-16 (GOES-East) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.3 µm) images (above) showed that the high-altitude portion of the pyroCb cloud then drifted northeastward toward the California/Nevada border, where cloud-top infrared brightness temperatures cooled to near -55ºC (orange enhancement) as it crossed the border around 0005 UTC on 16 July.

A comparison of Visible images from GOES-15 (0.63 µm), GOES-17 (0.64 µm) and GOES-16 (0.64 µm) is shown below — with the imagery displayed in the native projection of each satellite. Images from GOES-16/17 are at 5-minute intervals, while images from GOES-15 are every 5-15 minutes depending on the operational scan schedule of that GOES-West satellite. GOES-17 was at its post-launch checkout position of 89.5ºW longitude, so it offered a more direct view of the pyroCb cloud.

Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) [click to play animation]

Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) [click to play animation]

A toggle between NOAA-19 Visible (0.63 µm), Shortwave Infrared (3.7 µm) and Infrared Window (10.8 µm) images (below) showed the pyroCb cloud southwest of the California/Nevada border (between Bridgeport KBAN and Mammoth KMMH) at 2327 UTC. In spite of a minimum cloud-top 10.8 µm infrared brightness temperature of -59ºC (red enhancement), note the darker (warmer) appearance of the cloud on the 3.7 µm image — this is due to reflection of solar radiation off the smaller ice particles of the pyroCb anvil. The -59ºC temperature roughly corresponded to an altitude of 13 km or 42.6 kft on the 00 UTC Reno, Nevada rawinsonde report (plot | data)

NOAA-19 Visible (0.63 µm), Shortwave Infrared (3.7 µm) and Infrared Window (10.8 µm) images [click to enlarge]

NOAA-19 Visible (0.63 µm), Shortwave Infrared (3.7 µm) and Infrared Window (10.8 µm) images [click to enlarge]

A time lapse of the pyroCb was created by Sierra Fire Watch (below).

Time lapse [click to play YouTube video]

Time lapse [click to play YouTube video]

Ferguson Fire in central California

July 14th, 2018 |
Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) [click to play animation | MP4]

Visible images from GOES-15 (0.63 µm, left), GOES-17 (0.64 µm, center) and GOES-16 (0.64 µm, right) [click to play animation | MP4]

* GOES-17 imagery shown here are preliminary and non-operational *

A comparison of Visible images from GOES-15 (GOES-West), GOES-17 and GOES-16 (GOES-East)  on 14 July 2018 is shown above — in addition to thunderstorms over the high terrain of the Sierra Nevada, the development of a pyrocumulus cloud (with a small overshooting top) can be seen over the Ferguson Fire that had been burning for nearly a day near Yosemite National Park in central California.

Images from GOES-16/17 are at 5-minute intervals, while image intervals from the older GOES-15 satellite range from 5-30 minutes. The improved spatial resolution of the GOES-16/17 0.64 µm visible imagery (0.5 km at sub-satellite point, compared to 1.0 km for GOES-15) allowed finer details of the overshooting top to be seen — and the improved image-to-image navigation of the new GOES-16/17 satellites was also apparent (note the significant navigation errors in a few of the GOES-15 images).

A photo from the ground (below) showed a large pyrocumulus cloud towering over the top of the dense smoke.

Southwest US monsoon convection: GOES-15 vs GOES-16

July 12th, 2018 |

GOES-15 Visible (0.63 µm, left) and GOES-16 Visible (0.64 µm, right) images [click to play MP4 animation]

GOES-15 Visible (0.63 µm, left) and GOES-16 “Red” Visible (0.64 µm, right) images [click to play MP4 animation]

GOES-15 (GOES-West) Visible (0.63 µm) and GOES-16 (GOES-East) “Red” Visible (0.64 µm) images — displayed in the native projection of each satellite, and centered on Las Vegas, Nevada — are shown above, depicting the development of deep convection across parts of the Desert Southwest on 12 July 2018. While the GOES-15 satellite was in Rapid Scan Operations mode (providing 2 extra images nearly every hour, at :11 and :41), a GOES-16 Mesoscale Sector was providing images at 1-minute intervals. Numerous flash flood watches, warnings and advisories were issued by NWS Las Vegas during the course of the day as some of the storms produced heavy rainfall (with as much as 0.75 inch at Cal Nev Ari and 0.61 inch at Needles, California KEED).

Note that the GOES-15 Visible images do not appear as bright as those from GOES-16 — prior to the GOES-R Series of satellites, the performance of visible detectors degraded over time, leading to imagery that appeared more dim as the Imager instrument aged. Visible detectors on the new ABI instrument benefit from on-orbit calibration to remedy this type of degradation.

The corresponding GOES-15 Infrared Window (10.7 µm) and GOES-16 “Clean” Infrared Window (10.3 µm) images (below) revealed cloud-top infrared brightness temperatures around -70ºC (black enhancement) associated with some the stronger thunderstorms; this was the tropopause temperature at an altitude of 16.7 km / 48,300 feet on 00 UTC Las Vegas rawinsonde data. The improvement in spatial resolution from 4 km (at sub-satellite point) with GOES-15 to 2 km with GOES-16 is very apparent — even though the satellite viewing angle is about 10 degrees higher for GOES-16 than it is for GOES-15.

GOES-15 Infrared Window (10.7 µm, left) and GOES-16 "Clean" Infrared Window (10.3 µm, right) images [click to play MP4 animation]

GOES-15 Infrared Window (10.7 µm, left) and GOES-16 “Clean” Infrared Window (10.3 µm, right) images [click to play MP4 animation]

Higher spatial resolution Infrared Window images from Terra/Aqua MODIS and Suomi NPP VIIRS (below) revealed a cloud-top infrared brightness temperature as cold as -79ºC in far northwestern Arizona on the 2017 UTC VIIRS image.

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

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

In addition to heavy rainfall, some thunderstorm winds created areas of blowing sand:

The GOES-16 Total Precipitable Water derived product (below) showed that rich moisture was present across the Desert Southwest, fueling the development of the widespread convection. TPW values in the 1.0 to 2.0 inch range were seen over southeastern California, southwestern Arizona and far southern Nevada.

GOES-16 Total Precipitable Water derived product [click to play MP4 animation]

GOES-16 Total Precipitable Water derived product [click to play MP4 animation]

A 4-km resolution Terra/Aqua MODIS Total Precipitable Water product (below) indicated values in the 40-55 mm or 1.6-2.2 inch range.

Terra/Aqua MODIS Total Precipitable Water product [click to enlarge]

Terra/Aqua MODIS Total Precipitable Water product [click to enlarge]