* GOES-18 images shown in this blog post are preliminary and non-operational *

Following its initial Post-Launch Test (PLT) period at 89.5°W longitude, GOES-18 reached a near-operational PLT position over the Pacific Ocean at 136.8°W longitude — and began transmitting images again at 0120 UTC on 07 June 2022. Although the first few images were contaminated with striping, a 24-hour period of Full Disk GOES-18 Mid-level Water Vapor (6.9 µm) images is shown above. A “Earth from Orbit” video (GOES-18 Goes West) was produced (with image contributions from CIRA and CIMSS), as well as this Satellite Liaison Blog post. Two sources of near-realtime GOES-18 imagery include Geostationary Satellite Images and 16-panel displays.

A sequence of GOES-18 daytime CIMSS True Color RGB and nighttime Infrared Window images — created using Geo2Grid — is shown below. A similar animation using daytime Rayleigh-corrected True Color RGB images is available here.

Taking a closer look at the northern Bering Sea region, GOES-18 “Red” Visible (0.64 µm) images (below) revealed a strong southerly surge of thin stratus clouds flowing through the Bering Strait — which impinged upon Saint Lawrence Island, Alaska. Note that numerous ice floes could be seen through the semi-transparent stratus layer. Other patches of drift ice were apparent to the southwest of Saint Lawrence Island, and also near the coastlines of Russia and Alaska. In addition, a hazy plume of wildfire smoke could be seen swirling clockwise off the southwest coast of Alaska.

In the southwestern portion of Interior Alaska, 1-minute Mesoscale Domain Sector GOES-18 Visible and Shortwave Infrared (3.9 µm) images (below) depicted the smoke plume and thermal signature associated with the ongoing Hog Butte Fire (which was started by lightning on 05 June). Over the fire point source, intermittent pyrocumulus jumps could be seen penetrating the top of the expanding smoke plume.

Farther to the south, in a comparison of Visible images from GOES-17 (GOES-West), GOES-18 and GOES-16 (GOES-East) (below) a well-defined eddy circulation was evident off the coast of southern California. The images are displayed in the native projection of each satellite.

GOES-18 Visible images (below) showed widespread thunderstorms that developed over the High Plains, which then moved eastward.

===== 08 June Update =====

GOES-18 Water Vapor images (below) included plots of hourly surface wind barbs and gusts — and displayed a well-defined undular bore associated with a lee-side cold frontal gravity wave that was propagating southward through westward across Texas  and New Mexico on 08 June.

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IFR (Instrument Flight Rules) Probability estimates the likelihood that IFR conditions are occurring by fusing GOES-17 satellite data with model output. The satellite-derived products give output of low IFR, (LIFR), IFR, and Marginal Visual Flight Rules (MVFR). In aviation, the difference between these classifications is generally:

Low Instrument Flight Rules (LIFR): Ceilings are less than 500 feet above ground level and/or visibility is less than 1 mile.

Instrument Flight Rules (IFR): Ceilings are 500 to 1,000 feet and/or visibility 1 to 3 miles.

Marginal VFR (MVFR): Ceilings are 1,000 to 3,000 feet and/or visibility is 3 to 5 miles.

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Color-enhanced wind speeds observed from Synthetic Aperture Radar (SAR) data on the second RADARSAT Constellation Mission satellite (RCM-2), shown above in AWIPS (Click here for a similar image online at this website) show parallel lines of enhanced wind speeds, a wind structure suggestive of a bore (click here for many previous blog posts on this phenomena), over southern Lake Michigan. Peak wind values (in yellow over the water) are near 14 m/s, with minima in between the lines showing winds around 5-6 m/s. (Note that SAR wind information over land is invalid). When this kind of event happens under mostly clear skies, parallel lines of clouds (that are perpendicular to the observed wind) develop. In this case, widespread clouds prevented satellite detection of cloud bands. The toggles below show Visible (Band 2, 0.64 µm) and Infrared (Band 13, 10.3 µm) at the time of the SAR observations.

Modest convection (cloud tops are only around -48^oC) over central Lake Michigan likely generated the bore. For a bore to propagate, a strong inversion is required. Soundings at Green Bay WI and Gaylord MI likely are unrepresentative of the environment over southern Lake Michigan. The sounding at White Lake Michigan — near Detroit — (from this website) does show a surface inversion, as does the sounding at Davenport IA. The cool late-Spring waters of Lake Michigan will serve to anchor a similar low-level inversion over the Lake; bore features travel along those inversions.

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) and “Red” Visible (0.64 µm) images (above) showed Tropical Storm Alex after it reached tropical storm intensity at 0900 UTC on 05 June 2022. Overshooting tops within the deep convection exhibited infrared brightness temperatures of -80ºC or colder (shades of violet).

GOES-16 Infrared Window (11.2 µm) images from the CIMSS Tropical Cyclones site (below) include contours of deep-layer wind shear at 17 UTC  — which displayed the high shear that was displacing the convection associated with Alex well northeast of the storm center.

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The MIMIC Total Precipitable Water (available at this website) animation below tracks Pacific Hurricane Agatha as it makes landfall, and then the accumulation of moisture that is incorporated into Alex.

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