CIMSS Satellite Blog, CIMSS

Hurricane Florence

By Scott Bachmeier • 9 September 2018

After previously weakening from a Category 4 hurricane (on 04 September) to a tropical storm on 07 September (track/intensity), Florence re-intensified to become a Category 1 hurricane at 15 UTC on 09 September 2018. 1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.63 µm) are shown above, with the corresponding “Clean” Infrared Window... Read More

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

After previously weakening from a Category 4 hurricane (on 04 September) to a tropical storm on 07 September (track/intensity), Florence re-intensified to become a Category 1 hurricane at 15 UTC on 09 September 2018. 1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.63 µm) are shown above, with the corresponding “Clean” Infrared Window (10.3 µm) images shown below. An eye structure appeared for brief intervals during the day, but was often masked by cloud debris from a series of convective bursts within the surrounding eyewall.

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

GPM GMI Microwave (85 GHz) image at 1811 UTC [click to enlarge]

GPM GMI (above) and DMSP-16 SSMIS (below) Microwave (85 GHz) images from the CIMSS Tropical Cyclones site revealed that the eye was still partially open at 1811 UTC and 1945 UTC.

DMSP-16 SSMIS Microwave (85 GHz) image at 1845 UTC [click to enlarge]

===== 10 September Update =====

GOES-16 “Red” Visible (0.64 µm) images, with GLM Group lightning [click to enlarge]

GOES-16 GLM lightning Groups (aggregates of GLM lightning Events) are plotted on “Red” Visible (0.64 µm) images (above) and “Clean” Infrared Window (10.3 µm) images (below), courtesy of Dave Santek, SSEC.

GOES-16 “Clean” Infrared Window (10.3 µm) images, with GLM Group lightning [click to enlarge]

Overlapping GOES-16 and GOES-17 Mesoscale Domain Sectors were positioned over Hurricane Florence beginning at 1200 UTC (providing imagery at 30-second intervals) — Visible animations are shown below.

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

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

GOES-17 “Red” Visible (0.64 µm) images [click to play MP4 animation]

Longer animations of 30-second GOES-16 Visible and Infrared images viewed using AWIPS (below) provided a better view of the mesovortices within the eye. Florence rapidly intensified (ADT | SATCON) to a Category 4 hurricane during this period.

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

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

One particularly large mesovortex rotated around the eastern edge of the eye after 2100 UTC, significantly eroding the eyewall (below).

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

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

Later in the early evening hours, GOES-16 Infrared imagery (below) showed an area of pronounced cloud-top warming and a thinning of cloud material just south of the eyewall, as Florence began to undergo an eyewall replacement cycle.

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

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Delta Fire pyroCumulonimbus cloud in California

By Scott Bachmeier • 5 September 2018

GOES-16 (GOES-East) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm), “Clean” Infrared Window (10.3 µm) and Cloud Top Temperature product images displayed using AWIPS (above) showed the formation of a pyroCumulonimbus (pyroCb) cloud generated by the Delta Fire in Northern California late in the day on 05 September 2018. As the pyroCb cloud drifted eastward toward the California/Nevada... Read More

GOES-16 “Red” Visible (0.64 µm, top left), Shortwave Infrared (3.9 µm, top right), “Clean” Infrared Window (10.3 µm, bottom left) and Cloud Top Temperature product (bottom right) [click to play animation | MP4]

GOES-16 (GOES-East) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm), “Clean” Infrared Window (10.3 µm) and Cloud Top Temperature product images displayed using AWIPS (above) showed the formation of a pyroCumulonimbus (pyroCb) cloud generated by the Delta Fire in Northern California late in the day on 05 September 2018. As the pyroCb cloud drifted eastward toward the California/Nevada border, Cloud Top Temperature values cooled to a minimum of -53ºC (lighter green enhancement) at 0300 UTC. Note the pulsing behavior of updrafts over the fire area: 2 distinct updraft pulses were apparent (at 0022 UTC and 0042 UTC), with the later pulse producing the pyroCb.

Massive plume of smoke over the #DeltaFire. ?: Jeff Mandrell pic.twitter.com/2QN66HcwM4

— Active NorCal (@ActiveNorCal) September 6, 2018

A longer animation of GOES-16 “Red” Visible, Shortwave Infrared and “Clean” Infrared Window images displayed using McIDAS (below) showed that the first hot (red) Shortwave Infrared pixels appeared at 2027 UTC. The fire caused a 5-mile section of Interstate 5 to be closed.

GOES-16 "Red" Visible (0.64 µm, top), Shortwave Infrared (3.9 µm, middle), "Clean" Infrared Window (10.3 µm, bottom); Interstate 5 is plotted in cyan [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm, top), Shortwave Infrared (3.9 µm, middle) and “Clean” Infrared Window (10.3 µm, bottom) images; Interstate 5 is plotted in cyan [click to play animation | MP4]

GOES-17 (positioned at 89.5º W longitude during its post-launch checkout phase) had a more direct view of the pyroCb than GOES-16 (positioned over the Atlantic Ocean at 75.2º W longitude) — and GOES-17 “Red” Visible, Shortwave Infrared and “Clean” Infrared Window images are shown below. Unfortunately the default GOES-17 Western US Mesoscale Domain Sector was shifted farther to the south on this day, so 1-minute imagery of the pyroCb event was not available.

GOES-17 "Red" Visible (0.64 µm, top), Shortwave Infrared (3.9 µm, middle), "Clean" Infrared Window (10.3 µm, bottom) images; Interstate 5 is plotted in cyan [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm, top), Shortwave Infrared (3.9 µm, middle) and “Clean” Infrared Window (10.3 µm, bottom) images; Interstate 5 is plotted in cyan [click to play animation | MP4]

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

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Stereoscopic View of Tropical Storm Gordon in the Gulf of Mexico

By Scott Lindstrom • 4 September 2018

GOES-17 Data shown here are preliminary and non-operational! Stereoscopic views (using GOES-16 and — preliminary and non-operational — GOES-17 Visible (0.64 µm) imagery) of strengthening Tropical Storm Gordon are shown above. The stereoscopic view shows an initially sheared storm, with the surface circulation apparent becoming somewhat less sheared as convection redevelops... Read More

GOES-16 (left) and GOES-17 (right) Visible (0.64 µm) imagery on 4 September 2018, starting at 1132 UTC (Click to play mp4 animation)

GOES-17 Data shown here are preliminary and non-operational!

Stereoscopic views (using GOES-16 and — preliminary and non-operational — GOES-17 Visible (0.64 µm) imagery) of strengthening Tropical Storm Gordon are shown above. The stereoscopic view shows an initially sheared storm, with the surface circulation apparent becoming somewhat less sheared as convection redevelops over the surface center. (To view in three dimensions: cross your eyes until 3 equal images are apparent, and focus on the image in the center). This animation will be updated periodically as more GOES-17 data become available. (Click here for animated gif)

For more information on this storm, consult the National Hurricane Center website, or the CIMSS Tropical Weather Website.

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Tropical Storm Gordon

By Scott Bachmeier • 3 September 2018

Potential Tropical Cyclone 7 was located between the Bahamas and Florida during the pre-sunrise hours on 03 September 2018. Toggles between VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images from NOAA-20 at 0636 UTC and Suomi NPP at 0726 UTC are shown above (courtesy of William Straka,... Read More

NOAA-20 Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0636 UTC [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 0726 UTC [click to enlarge]

The storm became better organized and increased in intensity, and was named Tropical Storm Gordon at 1205 UTC. Animations of GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) (below) showed Gordon as it moved across far southern Florida (where heavy rain and flash flooding occurred) and into the Gulf of Mexico during the daytime hours.

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

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

===== 04 September Update =====

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

1-minute Mesoscale Domain Sector GOES-16 “Red” Visible (0.64 µm) images (above) and “Clean” Infrared Window (10.3 µm) images (below) showed a series of widespread deep convective bursts within the northeast quadrant of the storm as it moved northeastward toward the Gulf Coast.

GOES-16 “Clean” Infrared Window (10.3 µm) images [click to play MP4 animation]

The GOES-16 Rainfall Rate/QPE product (below) indicated rainfall rates of 2-3 inches per hour were possible from this convection, peaking in the 3-4 inch per hour range just after 1300 UTC. However, Infrared cloud-top brightness temperatures warmed dramatically as the convection moved onshore after about 22 UTC — and the Rain Rate product responded accordingly, with a significant decrease in hourly intensity.