Pacific Hurricane Norman, a potent storm with sustained winds of 150 mph, exists outside of GOES-16’s CONUS (Contiguous United States) domain. In fact, on 30 August 2018, both GOES-16 Meso sectors were placed over the tropics to provide 1-minute imagery of tropical systems, both Norman over the Pacific, and a strong tropical easterly wave over the Atlantic and Caribbean. The toggle above shows the two positions (using visible imagery at 0.64 µm) along with the CONUS domain (using the clean window, band 13 at 10.3 µm).

The Mesoscale Sector allows 1-minute imagery over Norman. Otherwise, full-disk imagery with a time cadence of every 15 minutes would be used. The hour-long animation, below, shows the evolution of the storm and its environment.

A closer view of the eye, below, (Click to play animated gif), shows a well-developed eye with embedded low clouds. Because Norman is near 120 W, the view angle is oblique and only the western edge of the eyewall can be viewed.

Norman appears to be at the northern edge of deep tropical moisture, based on the toggle below of GOES-16 Clear Sky Total Precipitable Water and the GOES-16 infrared Low-Level Water Vapor image (7.34 µm). The projected path of Norman is mostly Westward so the storm will remain within deep tropical moisture for the next several days. It is forecast to remain a strong hurricane.

For more information on Norman, please consult the website of the National Hurricane Center or the SSEC/CIMSS Tropical Weather Website.

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

A comparison of Visible images from GOES-15 (GOES-West), GOES-17 and GOES-16 (GOES-East) (above) showed an isolated thunderstorm that developed in the Nebraska Panhandle late in the day on 29 August 2018. The storm produced hail (SPC storm reports), and also exhibited an Above Anvil Cirrus Plume. The images are displayed in the native projection of each satellite, with no re-mapping.

One other feature that was seen north of the thunderstorm was smoke which was being transported eastward from the Britania Mountain Fire in southeastern Wyoming. The smoke was more apparent on the GOES-17 and GOES-16 images as forward scattering increased toward sunset.

Shortwave Infrared imagery from the 3 satellites revealed important differences affecting fire detection: namely spatial resolution and viewing angle. The 3.9 µm detector on the GOES-15 Imager has a spatial resolution of 4 km (at satellite sub-point), compared to 2 km for the GOES-16/17 ABI. Given that the fire was burning in rugged mountain terrain, the view angle from each satellite had an impact on the resulting bire brightness temperature values. For example, the first indication of very hot (red-enhanced) pixels was at 1527 UTC from GOES-16/17, vs 1715 UTC from GOES-15; at the end of the day, the very hot fire pixels were no longer seen with GOES-15 after 2300 UTC, but continued to show up in GOES-17 imagery until 0042 UTC and in GOES-16 imagery until 0122 UTC.

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

The presence of GOES-17 data means that 4 mesoscale sectors, each taking 1-minute imagery, are over the United States. In the example above, from 1616 UTC on 29 August 2018, there is no overlap. (Note: Three of the Four are in their default locations; the Mesoscale sector over the northeast United States has been shifted north to monitor convection over New England).

On 28 August 2018, however, two mesoscale sectors overlapped over the central United States, and sampled convection developing over Oklahoma (that subsequently caused wind damage in Roger Mills County in western Oklahoma). The Stereoscopic View of that convection is shown below. To view the convection in three dimensions, cross your eyes until you see 3 images, and focus on the image in the center. An animated gif (215 Megabytes!!) is available here.

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Thunderstorms produced a variety of severe weather (SPC storm reports) as they moved eastward across the Upper Midwest on 28 August 2018. 1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) and “Clean” Infrared Window (10.3 µm) images (below) showed the development and progression of the severe convection across central Wisconsin.

Toggles beween Visible and Infrared images from Terra MODIS (1715 UTC), Aqua MODIS (1855 UTC) and Suomi NPP VIIRS (1945 UTC) are shown below.

These storms also brought heavy rain, which resulted in flooding that closed Interstate 90/94 near Mauston (about halfway between Madison and Fort McCoy) — that area received about 10 inches of rainfall in a 48-hour period (below). Amtrack trains were also forced to stop overnight near that same area, due to flooded tracks.

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