Severe weather in southeastern Wyoming and eastern Colorado

July 29th, 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 MP4 animation]

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

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

A comparison of GOES-15 (GOES-West), GOES-17 and GOES-16 (GOES-East) Visible images (above) showed thunderstorms which produced tornadoes, large hail and damaging winds (SPC storm reports) from southeastern Wyoming to eastern Colorado on 29 July 2018. The images are displayed in the native projections of each satellite; images from GOES 16/17 are at 5-minute intervals, while those from GOES-15 are at intervals ranging from 4 to 30 minutes (depending on the operational scan schedule for that GOES-West satellite).

The first infrared images (NOAA/NESDIS News) from GOES-17 (below) also showed the development of these severe thunderstorms. The coldest cloud-top Infrared Window (11.2 µm) brightness temperatures over eastern Colorado were around -70ºC (dark black enhancement) after about 2200 UTC.

GOES-17 Infrared (11.2 µm) images [click to play animation | MP4]

GOES-17 Infrared (11.2 µm) images [click to play animation | MP4]

Images from all 16 spectral bands of the GOES-17 ABI are shown below. Prior to the development of convective storms, mountain waves could be seen over Wyoming and Colorado on Water Vapor bands 8 (6.17 µm), 9 (6.93 µm) and 10 (7.34 µm).

All 16 bands of the GOES-17 ABI [click to play animation | MP4]

Images from all 16 bands of the GOES-17 ABI [click to play animation | MP4]

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 satellite sub-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 satellite sub-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.