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]

Occluded cyclone in southern Canada

July 15th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, upper left), Low-level Water Vapor (7.3 µm, upper right), Mid-level Water Vapor (6.9 µm, lower left) and Upper-level Water Vapor (6.2 µm, lower right) images [click to play animation]

A 4-panel comparison of GOES-16 (GOES-East) “Red” Visible (0.64 µm), Low-level Water Vapor (7.3 µm), Mid-level Water Vapor (6.9 µm) and Upper-level Water Vapor (6.2 µm) images (above) showed a large occluded cyclone (surface analyses) over northern Saskatchewan and northern Manitoba on 15 July 2018. In the cold sector of the storm, morning temperatures were confined to the 40s F — especially at Churchill, Manitoba where strong easterly winds were blowing off Hudson Bay.

A closer examination of the GOES-16 images (below) revealed the presence of waves over southwestern Manitoba on the Water Vapor imagery — these appeared to vertically-propagating waves which formed due to the interaction of strong boundary layer winds with the topography of that area (some land features rise to 2600 feet). These waves then began breaking and propagating slowly westward late in the animation.

GOES-16 "Red" Visible (0.64 µm, upper left), Low-level Water Vapor (7.3 µm, upper right), Mid-level Water Vapor (6.9 µm, lower left) and Upper-level Water Vapor (6.2 µm, lower right) images [click to play animation]

GOES-16 “Red” Visible (0.64 µm, upper left), Low-level Water Vapor (7.3 µm, upper right), Mid-level Water Vapor (6.9 µm, lower left) and Upper-level Water Vapor (6.2 µm, lower right) images [click to play animation]

A NOAA-20 VIIRS True Color Red-Green-Blue (RGB) image (below) showed numerous smoke plumes from wildfires in southeastern Manitoba and western Ontario, as well as the light cyan color of ice in central and eastern portion of Hudson Bay (ice analysis: northern | southern).

NOAA-20 VIIRS True Color RGB image [click to enlarge]

NOAA-20 VIIRS True Color RGB image [click to enlarge]