Exploring the effect of parallax

January 10th, 2020 |

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

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]