GOES-18 (GOES-West) Upper-level Water Vapor (6.2 µm), Mid-level Water Vapor (6.9 µm), Lower-level Water Vapor (7.3 µm) and “Clean” Infrared Window (10.3 µm) images (above) revealed the diurnal cycle of nighttime cooling and daytime warming at the summits of Mauna Kea and Mauna Loa on the Big Island of Hawai’i on 10 January 2023. In addition, a hot thermal signature (darker red to black pixels) was evident in the 10.3 µm imagery due to ongoing volcanic activity at Kilauea. This case is another example which helps to underscore the fact that Water Vapor spectral bands are essentially Infrared bands, which — in the absence of clouds — essentially sense the mean temperature of a layer (or layers) of moisture within the troposphere.

The presence of very dry air within most of the middle/upper troposphere over Hawai’i on 10 January had the effect of shifting the water vapor weighting functions to lower altitudes, as seen on plots for the 3 ABI Water Vapor bands calculated using 12 UTC rawinsonde data from Hilo PHTO (below). This allowed thermal radiation from the higher terrain to pass upward — with minimal attenuation — through what little high-altitude moisture was present and reach the 7.3 µm / 6.9 µm / 6.2 µm detectors on GOES-18.

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A sequence of GOES-16 (GOES-East) “Red” Visible (0.64 µm), Day Cloud Phase Distinction RGB and Day Snow-Fog RGB images (above) showed widespread fog/stratus across parts of Montana, North/South Dakota and Minnesota during the day on 06 January 2023. With a quasi-stationary area of high pressure located over that area (surface analyses), winds remained light and the fog/stratus layer was slow to dissipate over much of the region (where snow cover was generally in the 10-20 inch range). The surface visibility was near zero at some sites, with scattered reports of freezing fog and/or light snow.

Plots of rawinsonde data from Bismarck ND (KBIS) and Aberdeen SD (KABR) are shown below — both sites indicated that a strong and moist boundary layer temperature inversion remained in place during the day, which also helped the fog/stratus layer to persist or dissipate rather slowly. Judging from the pressure level of sharp dew point decreases, these fog/stratus features were confined to altitudes of 1200-1400 meters (3900-5000 feet) or lower.

GOES-16 Day Snow-Fog RGB images at 1901 UTC — with an overlay of the corresponding CLAVR-x and Operational versions of the Cloud Top Height (CTH) derived product — include cursor-sampled those two Cloud Top Height values at Bismarck ND (above) and Aberdeen SD (below). It would appear that the 10-km resolution Operational CTH values were unrealistically high — which can often occur over areas with snow cover — compared to the 2-km resolution CLAVR-x CTH values (the full-resolution CLAVR-x products are produced at CIMSS).

A comparison of GOES-16 Day Snow-Fog RGB image, CLAVRx Cloud Top Height and Operational Cloud Top Height derived products at 1901 UTC is shown below.

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From GOES-A (1) in 1975, to GOES-T (18) launched in 2022! On January 4, 2023 GOES-18 is operational as GOES-West, here’s a look-back at all the GOES. Note that the GOES-R series imagers support the generation of a true color image, given they have the blue (or 0.47 micrometer) band. Continuity is critical for operational satellites and this shows the case, as well as these GOES satellite timeline from this CIMSS Satellite Blog post. A glimpse into a bit of what the GOES ABI observed in 2022.

The GOES-18 thumbnail is when the satellite was at its initial check-out location.

More on the “high noon” geostationary imager composite from UW/SSEC, which now includes the GOES-18 ABI.

All the NOAA GOES data for the thumbnails have been accessed via the University of Wisconsin – Madison SSEC Satellite Data Services. The Full Disk images were made using McIDAS-X software, and combined with a series of ImageMagik commands.

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Heavy rains have finally hit California, which declared a state of emergency on Wednesday January 4 due to extreme rainfall amounts. The GOES-West enhanced Band 9 imagery (6.9 µm, mid-level water vapor) illustrates how moisture associated with the recent similar Trans-Pacific atmospheric river generated heavy rainfall for much of California, Oregon, and Washington. Overlayed with NEXRAD radar reflectivity, the animation below paints a good picture of the rainfall that accumulated within the 21 hours shown.

The California Nevada River Forecast Center reports that some areas in northern California have already accumulated up to five inches of rain in the past 24 hours. Flooding has already created dangerous situations for the residents of California.  

Readers can recreate the above animation and explore other GOES data using RealEarth, a free web-based visualization tool for satellite and other remote sensing weather products.

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