GOES-17 (GOES-West) “Red” Visible (0.64 µm) images (above) revealed the mesoscale cyclonic circulations of actinoform clouds (or “actinae“) within the marine boundary layer stratocumulus cloud field over the central Pacific Ocean on 30 May 2019.

This type of cloud feature was originally identified in TIROS-V imagery over the Pacific Ocean in 1962 (below), and was featured in the first Monthly Weather Review “Picture of the Month” series in January 1963.

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Due to an overlap of GOES-17 (GOES-West) Mesoscale Domain Sectors, images were available at 30-second intervals — and “Red” Visible (0.64 µm) images (above) showed the development of thunderstorms over southeastern Oregon, southwestern Idaho and northern Nevada on 29 May 2019. Some of these thunderstorms produced heavy rainfall and small hail in southwestern Idaho, and a cold air funnel was spotted in northern Nevada (local storm reports).

A comparison of Visible images from GOES-17 and GOES-15 images (below) helps to underscore some of the improvements in the GOES-R series of satellites over their predecessors — with images every 30 seconds compared to every 4-15 minutes (with gaps of 30 minutes during the Full Disk scans every 3 hours), the short-term convective trends could be better monitored using GOES-17. Also note that the GOES-15 Visible images do not appear as bright as those from GOES-17 — 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.

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) depicted supercell thunderstorms forming along and south of a quasistationary frontal boundary (surface analyses) which produced a variety of severe weather (SPC Storm Reports) across eastern Kansas and far western Missouri late in the day on 28 May 2019 — including the long-track EF-4 tornado that affected Lawrence and Linwood in Kansas (NWS Kansas City), and prompted a Tornado Emergency to be issued for the Kansas City metro area.

The corresponding GOES-16 “Clean” Infrared Window (10.35 µm) images (below) showed that many of the overshooting tops had infrared brightness temperatures in the -70 to -75ºC range.

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) revealed supercell thunderstorms that developed within the warm sector of a midlatitude cyclone approaching from the Upper Midwest (surface analyses) — these thunderstorms produced a variety of severe weather (SPC Storm Reports | NWS Northern Indiana) across Indiana late in the day on 27 May 2019.

Many of these storms exhibited well-defined overshooting tops; the largest hail was 4.0 inches in diameter at 0000 UTC. A comparison of SPC Storm Reports at the time of this large hail (and a nearby wind gust to 72 mph) — plotting the reports at the actual ground location vs a “parallax-corrected” location which shifted them northwestward — showed that the severe report locations closely corresponded to the overshooting top (below).

The corresponding GOES-16 “Clean” Infrared Window (10.35 µm) images (below) showed that many of the overshooting tops had infrared brightness temperatures in the -70 to -75ºC range.

As the thunderstorms moved eastward across Ohio, they continued to produce all modes of severe weather (including EF-3 and EF-4 tornadoes in the Dayton area beginning around 0258 UTC). Additional information on these storms is available from the Hazardous Weather Testbed.

A Terra MODIS Infrared Window (11.0 µm) image at 0243 UTC with plots of SPC Storm Reports within +/- 45 minutes of the image time (below) showed cloud-top infrared brightness temperatures as cold as -73ºC.

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