Severe convection « CIMSS Satellite Blog

Exploring the effect of parallax

January 10th, 2020 | Scott Bachmeier

GOES-16 “Red” Visible (0.64 µm) images, including plot of SPC Storm Reports (with and without parallax correction) [click to play animation]

Overlapping 1-minute GOES-16 (GOES-East) Mesoscale Domain Sectors provided images at 30-second intervals over the Kansas/Missouri/Oklahoma/Arkansas area on 10 January 2019 — and “Red” Visible (0.64 µm) images (above) included plots of SPC Storm Reports (with and without parallax correction) during the time period which produced the first 2 tornadoes (1 in southwestern Missouri, and 1 in northeastern Oklahoma) of a large-scale severe weather outbreak that continued into the subsequent nighttime hours and the following day.

The GOES-16 Visible images for the times corresponding to the 2 tornado reports (below) include “parallax-corrected” — shifted upward to match a 13 km cloud top, the Maximum Parcel Level calculated from the 18 UTC Springfield, Missouri sounding — and actual surface locations for each report. For the Oklahoma tornado report, the parallax-corrected location more closely matches the location of overshooting tops; for the Missouri tornado report, the parallax-corrected location more closely matches the location where a cluster of overshooting tops had passed several minutes earlier.

GOES-16 "Red" Visible (0.64 µm) image at 2030 UTC, including plot of SPC Storm Reports (with and without parallax correction) [click to enlarge]

GOES-16 “Red” Visible (0.64 µm) image at 2030 UTC, including a Tornado report in Missouri (with and without parallax correction) [click to enlarge]

GOES-16 "Red" Visible (0.64 µm) image at 2051 UTC, including plot of Tornado report (with and without parallax correction) [click to enlarge]

GOES-16 “Red” Visible (0.64 µm) image at 2051 UTC, including a Tornado report in Oklahoma (with and without parallax correction) [click to enlarge]

GOES-16 parallax direction vectors and magnitude (km) for a cloud top feature at 50,000 feet (or 15.2 km) are shown below for select locations across the GOES-16 CONUS domain — a webapp that displays a current infrared image with user-selectable cloud heights is available here. Circled is a vector and magnitude in an area close to that shown in the images above. Note: the length of the vectors does not correspond to the actual distance of parallax correction.

GOES-16 parallax direction vectors and magnitude (km) for a cloud top feature at 15 km [click to enlarge]

GOES-16 parallax direction vectors and magnitude (km) for a cloud top feature at 50,000 feet (15.2 km) [click to enlarge]

Similar webapps are available for the GOES-16 Full Disk, GOES-17 CONUS and GOES-17 Full Disk sectors.

GOES-17 parallax correction direction vectors and magnitude (km) for a cloud top feature at 50,000 feet (15.2 km) [click to enlarge]

GOES-17 parallax direction vectors and magnitude (km) for a cloud top feature at 50,000 feet (15.2 km) [click to enlarge]

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Severe weather across the Deep South

December 16th, 2019 | Scott Bachmeier

GOES-16 “Red” Visible (0.64 µm), with SPC Storm Reports plotted in red [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed thunderstorms that produced a variety of severe weather (SPC Storm Reports) across the Deep South on 16 December 2019. Numerous overshooting tops could be seen with these storms.

GOES-16 “Clean” Infrared Window (10.35 µm) images (below) indicated that many of the overshooting tops exhibited brightness temperatures as cold as -70ºC (darker black pixels) — which closely corresponded to the Most Unstable air parcel Maximum Parcel Level (MU MPL) calculated from 21 UTC rawinsonde data from Jackson, Mississippi.

GOES-16 "Clean" Infrared Window (10.35 um), with SPC Storm Reports plotted in cyan [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm), with SPC Storm Reports plotted in cyan [click to play animation | MP4]

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Severe thunderstorms in the southern US

October 20th, 2019 | Scott Bachmeier

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images (above) showed thunderstorms that produced tornadoes, large hail and damaging winds (SPC storm reports) in the Dallas/Fort Worth, Texas area after sunset on 20 October 2019. One of the tornadoes produced EF-3 damage in North Dallas.

In a larger-scale view of GOES-16 Infrared images (below), other thunderstorms were seen that produced a variety of severe weather in other parts of Texas, Louisiana, Oklahoma, Arkansas and Missouri — including winds of 82 mph in Oklahoma and 80 mph in Arkansas. The rapidly-pulsing behavior of overshooting tops was well captured by the 1-minute imagery.

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in white [click to play animation | MP4]

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Severe thunderstorms in Idaho

October 19th, 2019 | Scott Bachmeier

GOES-17 “Red” Visible (0.64 µm, left) and “Clean” Infrared Window (10.35 µm, right) images, with SPC Storm Reports plotted in red [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed thunderstorms that developed along a fast-moving cold front, producing a swath of damaging winds (SPC storm reports) across southern Idaho on 19 October 2019.

5-minute GOES-17 Mid-level Water Vapor (6.9 µm) images (below) displayed signatures of a jet stream and shortwave trough that were moving across the region that day.