McKinney Fire in California produces multiple pyrocumulonimbus clouds

July 30th, 2022 |

GOES-17 “Red” Visible (0.64 µm, top left), Fire Temperature RGB (top right), “Clean” Infrared Window (10.35 µm, bottom left) and Cloud Top Temperature derived product (bottom right) images [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm), Fire Temperature RGB, “Clean” Infrared Window (10.35 µm) and Cloud Top Temperature derived product images (above) showed that the rapidly-growing McKinney Fire in far northern California produced multiple (5 or 6) pulses of pyrocumulonimbus (pyroCb) clouds late in the day on 30 July 2022. The coldest pyroCb cloud-top 10.35 µm infrared brightness temperatures were around -55ºC, while the coldest pyroCb Cloud Top Temperature value was -59ºC.

This wildfire burned very hot — the peak 3.9 µm infrared brightness temperature was 138.71ºC, which is the saturation temperature of ABI Band 7 detectors.

During the subsequent overnight hours, a toggle between NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images valid at 1039 UTC or 3:39 AM PDT (below) showed the bright nighttime glow and hot thermal signature of active fires around the perimeter of the large McKinney Fire burn scar.  Evacuation orders were in effect for portions of Yreta west of Interstate 5.

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images valid at 1039 UTC [click to enlarge]

“Barcode Artifact” in GOES-18 Band 07 (Shortwave Infrared) imagery

July 29th, 2022 |

GOES-18 Shortwave Infrared (3.9 µm) images [click to play animated GIF | MP4]

GOES-18 images shown in this blog post are preliminary and non-operational

During its Post-Launch Testing (PLT) period, once GOES-18 drifted to a position close to its final “Operational GOES-West” longitude of 137º W, a “Barcode Artifact” of vertical striping was occasionally seen in colder scenes of Band 07 Shortwave Infrared (3.9 µm) imagery — primarily centered around “spacecraft midnight” times, from 06-12 UTC . One example, using 1-minute Mesoscale Domain Sector images over the Alaska region on 20 July 2022, is shown above. Note that the vertical striping is more obvious over the colder (brighter white) clouds.

GOES-18 Shortwave Infrared (3.9 µm) images [click to play animated GIF | MP4]

Another example on the same date is shown above, centered over the East Pacific Ocean off the coast of California and Mexico. Using the default grayscale enhancement, the Barcode Artifact is rather subtle and more difficult to notice. However, once a special “stretched” enhancement is applied to the images below, the Barcode Artifact becomes very notable across the extensive stratocumulus cloud deck over the ocean.

GOES-18 Shortwave Infrared (3.9 µm) images [click to play animated GIF |

MP4]

The vertical striping of the Barcode Artifact will also appear in many multispectral products that use 3.9 µm imagery — for example, GOES-18 Nighttime Microphysics RGB images (created using Geo2Grid) over that same region are shown below.

GOES-18 Nighttime Microphysics RGB images [click to play animated GIF | MP4]

It is important to note that the Barcode Artifact is not related to the Loop Heat Pipe cooling issue that has affected GOES-17 — plots of 2-day and 10-day Focal Plane Module temperatures for GOES-17 and GOES-18 (ending on 26 July 2022) are displayed below.

2-day and 10-day plots of Focal Plane Module temperatures for GOES-17 (top) and GOES-18 (bottom), ending on 26 July 2022 [click to enlarge]

It also bears mentioning that this Barcode Artifact is also occurring with GOES-17 (GOES-West) imagery — but to a lesser extent compared to GOES-18. A plot of Band07-Band13 Difference values for GOES-17 vs. GOES-18 on 27 July 2022 is shown below.

Plot of Band07-Band13 Difference values for GOES-17 and GOES-18 on 27 July 2022 (credit: Mat Gunshor, CIMSS) [click to enlarge]

A subtle example of GOES-17 Barcode Artifact can be seen toward the end of an animation of Night Fog BTD (11.2 µm – 3.9 µm) images on 26 July, shown below,

GOES-17 Night Fog BTD (11.2 µm – 3.9 µm) images [click to play animated GIF | MP4]

H/T to Jim Nelson (CIMSS) and Tim Schmit (NOAA/NESDIS/ASPB) for providing many of the GOES-18 animations. Additional information and examples of GOES-18 Barcode Artifact can be found at the Satellite Liaison Blog.

Heavy rainfall and flooding in eastern Kentucky

July 28th, 2022 |

GOES-16 “Clean” Infrared Window (10.35 µm) images, with hourly surface plots; Interstates are plotted in gray [click to play animated GIF | MP4]

GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images (above) showed the development of multiple clusters of thunderstorms that were responsible for producing heavy rainfall and flash flooding across parts of eastern Kentucky during the nighttime hours leading up to sunrise on 28 July 2022. The coldest GOES-16 cloud-top infrared brightness temperature associated with these thunderstorms was -82.7ºC at 0431 UTC (within the small cluster of violet pixels over Jackson, Kentucky KJKL).

In a toggle between NOAA-20 VIIRS Infrared Window (11.45 µm) images valid at 0634 UTC and 0814 UTC (below) the coldest cloud-top infrared brightness temperature was -83ºC (just northeast of Hazard, Kentucky at 0814 UTC). These NOAA-20 images were downloaded and processed using the SSEC/CIMSS Direct Broadcast ground station, before being displayed n AWIPS.

NOAA-20 VIIRS Infrared Window (11.45 µm) images valid at 0634 UTC and 0814 UTC [click to enlarge]

Record rainfall and flash flooding in the St. Louis area

July 26th, 2022 |

GOES-16 “Clean” Infrared Window (10.35 µm) images, with hourly precipitation type symbols plotted yellow and Interstates plotted in gray [click to play animated GIF | MP4]

GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images (above) showed the development of an elongated band of training thunderstorms that was responsible for producing record rainfall and flash flooding in the St. Louis, Missouri area during the nighttime hours leading up to sunrise on 26 July 2022. The coldest GOES-16 cloud-top infrared brightness temperatures were around -75ºC.

A Suomi-NPP VIIRS Infrared Window (11.45 µm) image valid at 0802 UTC (below) displayed the large Mesoscale Convective System as it was just beginning to move away from the St. Louis (KSTL) area. The coldest cloud-top infrared brightness temperature in the VIIRS image was -83ºC (within the interior shades of violet). These thunderstorms developed as a southwesterly low-level jet began to increase isentropic upglide across and north of a stationary front that was located just south of the deep convection (surface analyses | WPC Mesoscale Precipitation Discussion).

Suomi-NPP VIIRS Infrared Window (11.45 µm) image valid at 0802 UTC [click to enlarge]