Carr Fire in northern California

August 11th, 2018 |
GOES-15, GOES-14, GOES-17 and GOES-16 Shortwave Infrared (3.9 µm) images [click to play MP4 animation]

GOES-15, GOES-14, GOES-17 and GOES-16 Shortwave Infrared (3.9 µm) images [click to play MP4 animation]

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

A comparison of GOES-15 (GOES-West), GOES-14, GOES-17 and GOES-16 (GOES-East) Shortwave Infrared (3.9 µm) images (above) showed the thermal anomaly or “hot spot” (dark black to red pixels) associated with the Carr Fire in northern California on 11 August 2018. A GOES-16 Mesoscale Domain Sector was providing images at 1-minute intervals. This comparison demonstrates how fire detection can be affected by both satellite viewing angle and shortwave infrared detector spatial resolution (4 km at satellite sub-point for the GOES-14/15 Imager, vs 2 km for the GOES-16/17 ABI).

A toggle between 30-meter resolution Landsat-8 False Color and Thermal Infrared (10.9 µm) imagery viewed using RealEarth (below) showed new fire activity (clusters of red pixels) along the northeastern edge of the Carr Fire burn scar on the False Color image, as well as smoke plumes drifting northeastward; the heat signatures (brighter white pixels) of smaller fires hidden by the smoke were more clearly ssen on the Thermal Infrared image. As of this date the Carr Fire was the 8th largest and 6th most destructive fire on record in California, and was responsible for 8 fatalities.

Landsat-8 False Color and Thermal Infrared (10.9 µm) images [click to enlarge]

Landsat-8 False Color and Thermal Infrared (10.9 µm) images [click to enlarge]

Holy Fire in southern California, as viewed by 4 GOES

August 9th, 2018 |
Shortwave Infrared (3.9 µm) images from GOES-15, GOES-14, GOES-17 and GOES-16 [click to play MP4 animation]

Shortwave Infrared (3.9 µm) images from GOES-15, GOES-14, GOES-17 and GOES-16 [click to play MP4 animation]

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

GOES-15 (GOES-West), GOES-14, GOES-17 and GOES-16 (GOES-East) Shortwave Infrared (3.9 µm) images (above) showed the thermal anomaly or “hot spot” (black to yellow to red pixels) associated with the Holy Fire that was burning in southern California on 09 August 2018. This comparison demonstrates how fire detection can be affected by both satellite viewing angle and shortwave infrared detector spatial resolution (4 km at satellite sub-point for the GOES-14/15 Imager, vs 2 km for the GOES-16/17 ABI).

On the previous day, a 30-meter resolution Landsat-8 False Color Red-Green-Blue (RGB) image visualized using RealEarth (below) provided a more detailed view of the Holy Fire, showing active fires (brighter red) around the northern and eastern perimeter of the burn scar and the smoke plume that was drifting to the north and northwest.

Landsat-8 False Color image [click to enlarge]

Landsat-8 False Color RGB image [click to enlarge]

Hurricane John

August 7th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector “Red” Visible (0.64 µm) images from the AOS site (above) showed the circulation of Hurricane John as it was intensifying from a Category 1 to a Category 2 storm off the west coast of Mexico on 07 August 2018. Several tropical overshooting tops could be seen in the animation.

GOES-16 Upper-level Water Vapor (6.2 µm), Mid-level Water Vapor (6.9 µm), Low-level Water Vapor (7.3 µm) and “Clean” Infrared Window (10.3 µm) images (below) revealed an interesting gravity wave that was propagating northward away from the center of John. This wave appeared to perturb the cloud tops — perhaps via vertical mixing — leading to a slight warming of the colder cloud-top infrared brightness temperatures as the wave passed. The appearance and behavior of this wave was very similar to another observed in Nebraska, Colorado and Kansas on 22 July.

GOES-16 Upper-level Water Vapor (6.2 µm, top left), Mid-level Water Vapor (6.9 µm, top right), Low-level Water Vapor (7.3 µm, bottom left) and

GOES-16 Upper-level Water Vapor (6.2 µm, top left), Mid-level Water Vapor (6.9 µm, top right), Low-level Water Vapor (7.3 µm, bottom left) and “Clean” Infrared Window (10.3 µm, bottom right) images [click to play MP4 animation]

Another item of interest was the circulation of weakening Tropical Storm Ileana being absorbed by the larger circulation of intensifying Hurricane John — this process was illustrated by 3-hourly 850 hPa relative vorticity analyses derived from GOES-15 (GOES-West) satellite winds (below). Similar results were seen at the 700 hPa, 500 hPa and 200 hPa pressure levels.

3-hourly analyses of 850 hPa relative vorticity [click to enlarge]

3-hourly analyses of 850 hPa relative vorticity [click to enlarge]

===== 08 August Update =====

Visible images from GOES-15, GOES-14, GOES-17 and GOES-16 [click to play animation | MP4]

Visible images from GOES-15, GOES-14, GOES-17 and GOES-16 [click to play animation | MP4]

GOES-15 (GOES-West), GOES-14, GOES-17 and GOES-16 (GOES-East) Visible images (above) showed 4 views of Hurricane John after it had diminished to a Category 1 storm on 08 August.

Note that the GOES-15 and GOES-14 Visible images do not appear as bright as those from GOES-17 and 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.

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

Severe thunderstorms, as viewed by 4 GOES

August 2nd, 2017 |
GOES-15, GOES-14, GOES-16 and G0ES-13 Visible images, with SPC storm reports of hail size plotted in red [click to play animation]

GOES-15, GOES-14, GOES-16 and G0ES-13 Visible images, with SPC storm reports of hail size plotted in red [click to play animation]

* GOES-16 data posted on this page are preliminary, non-operational and are undergoing testing *

With a Severe Thunderstorm Watch in place, storms developed over far northeastern Colorado late in the day on 02 August 2017 which produced hail as large as 2.0 inches in diameter (SPC storm reports). Since GOES-14 (which had been placed into on-orbit storage as a spare satellite) was briefly activated for testing and evaluation, it afforded the unusual opportunity to view these storms from 4 different GOES perspectives (above). The Visible images (0.63 µm for the 3 legacy GOES, and 0.64 µm for GOES-16) are displayed in the native projections for each satellite.

A closer look using a higher image zoom factor (below) helps to demonstrate the advantage of higher spatial resolution with the GOES-16 0.64 µm “Red” Visible band (0.5 km at satellite sub-point, vs 1.0 km for the 3 legacy GOES) — especially for clearly identifying features such as thunderstorm overshooting tops. Also note that the 3 legacy GOES visible images do not appear as bright as those from GOES-16; visible imagery from GOES degrades with time, and older GOES Imager instruments do not have on-board calibration to account for this. However, the GOES-16 ABI instrument does have on-board visible detector calibration, so dimming of visible imagery over time should not be as noticeable.

GOES-15, GOES-14, GOES-16 and GOES-13 Visible images, with SPC storm reports of hail size plotted in red [click to play animation]

GOES-15, GOES-14, GOES-16 and GOES-13 Visible images, with SPC storm reports of hail size plotted in red [click to play animation]