1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) displayed the well-defined eye of Category 4 Hurricane Genevieve in the East Pacific Ocean (off the west coast of Mexico) on 18 August 2020. Genevieve underwent a period of rapid intensification during the pre-dawn hours that day (ADT plot).

A GOES-16 Visible image at 1617 UTC (below) includes plots of Metop-A ASCAT scatterometer surface winds — the highest wind was 69 knots just northeast of the storm center.

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GOES-16 (GOES-East) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed 2 pulses of pyro-convection emanating from the Williams Fork Fire that was burning between between Kremmling (K20V) and Berthoud Pass (K0CO) in Colorado on 14 August 2020. The cloud of the second pulse, originating around 2300 UTC, exhibited infrared brightness temperatures of -40ºC and colder  (shades of blue in the 10.35 µm images) — assuring the heterogeneous nucleation of all supercooled water droplets to form ice crystals, and thereby meeting the criteria of a pyrocumulonimbus (pyroCb). The pyroCb then drifted east-southeastward across Colorado.

The coldest pyroCb infrared brightness temperature was -46ºC, which corresponded to an altitude near 11 km according to rawinsonde data from Denver (below).

===== 15 August Update =====

On the following day, 1-minute Mesoscale Domain Sector GOES-16 (GOES-East) Visible, Shortwave Infrared and Infrared images (above) showed another pyroCb that developed around 2240 UTC. This pyroCb moved southeastward, exhibiting cloud-top infrared brightness temperatures as cold as -55ºC — which, according to rawinsonde data from Denver (below) represented an altitude near 12 km.

Farther to the west, the Loyalton Fire was burning in northern California, near the border with Nevada. 1-minute Mesoscale Domain Sector GOES-17 (GOES-West) Visible, Shortwave Infrared, Infrared Window and Fire Temperature Red-Green-Blue (RGB) images (below) showed that this fire produced a pyroCb cloud around 2100 UTC, which then drifted northeastward across the California/Nevada border.

This event exhibited extreme fire behavior, producing fire whirls and prompting NWS Reno to issue a Tornado Warning for the source region of the pyroCb at 2135 UTC. The cloud-top infrared brightness temperatures of the pyroCb were around -55ºC; rawinsonde data from Reno (below) indicated that this corresponded to an altitude near 12 km.

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On 13 August 2020, Visible images from GOES-17 (GOES-West, positioned at 137.2ºW), GOES-15 (GOES-West backup, positioned at 128ºW), GOES-14 (on-orbit spare, positioned at 104.5ºW) and GOES-16 (GOES-East, positioned at 75.2ºW) (above) showed the morning dispersion of smoke from the Red Salmon Complex that had been burning in northern California. The images are displayed in the native projection of each satellite.

In southern California, Shortwave Infrared images from all 4 satellites (below) displayed thermal signatures (dark black to red pixels) from wildfires burning near Los Angeles. Thermal signatures varied between the 4 satellites, based upon differences in spatial resolution, viewing angle, and intermittent fire thermal signal attenuation by high clouds moving over the area. In the GOES-15 images, the occasional appearance of white pixels was due to a “roll-over” issue  — where extremely hot temperatures get displayed as cold (white).

GOES-15 was providing supplemental operations for GOES-17 during a period of maximum ABI Loop Heat Pipe thermal anomaly; GOES-14 had been brought out of storage for its annual 10-day test checkout.

The raw GOES data was acquired and processed by SSEC Satellite Data Services.

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed the eastward progression of a Mesoscale Convective System (MCS) that produced a long swath of damaging winds (SPC Storm Reports) or derecho from eastern Nebraska to Indiana on 10 August 2020. The highest measured wind gust was 112 mph in eastern Iowa at 1755 UTC.

The corresponding GOES-16 “Clean” Infrared Window (10.35 µm) images are shown below.

In a comparison of Infrared Window images from Suomi NPP (11.45 µm) and GOES-16 (10.35 µm) at 1931 UTC (below), the higher spatial resolution of the VIIRS instrument detected infrared brightness temperatures as cold as -84ºC, compared to -76ºC with GOES-16 (the same color enhancement is applied to both images). The northwest parallax offset associated with GOES-16 imagery at this location was also evident.

GOES-16 Visible/Infrared Sandwich Red-Green-Blue (RGB) and “Clean” Infrared Window (10.35 µm) images, with “probability of intense convection” contours and SPC Storm Reports, is shown below. The probability contours are produced from a deep-learning algorithm used to identify patterns in ABI and GLM imagery that correspond to intense convection. It is trained to highlight strong convection as humans would identify it. Work is ongoing to incorporate this storm-top information into NOAA/CIMSS ProbSevere.

A comparison of Terra MODIS True Color RGB images (source) from before (28 July) and after (11 August) the derecho (below) revealed very large swaths of wind-damaged crops (lighter shades of green) across Iowa. It is estimated that around 10 million acres of corn and soybean crops were flattened by the strong winds.

A toggle between VIIRS True Color RGB images from Suomi NPP and NOAA-20 visualized using RealEarth (below) also displayed the crop damage swath.

Shown below is a before/after (28 July/11 August) comparison of VIIRS Day/Night Band (DNB) imagery (source), where many of the areas across Iowa that suffered significant power outages — appearing darker (due to a lack of city lights) on the nighttime DNB images — corresponded to the large swaths of crop damage seen on the 11 August MODIS True Color image. Around 550,000 households lost power across the state.

Even 2 days later (on 12 August), many customers remained without power across Iowa (below), especially in Marshall County (where peak winds of 106 mph were recorded), Tama County (where peak winds of 90 mph were recorded) and Linn County (where peak winds of 112 mph were recorded).

Updated estimated wind speed map for the #derecho2020. #iawx #IowaDerecho pic.twitter.com/XMaAgc6oHT

— NWS Des Moines (@NWSDesMoines) August 20, 2020

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