GOES-16 (GOES-East) Mid-level Water Vapor (6.9 µm) images (above) showed a cutoff low that was moving slowly eastward across eastern New Mexico and the Oklahoma/Texas Panhandle on 28 November – 29 November 2020. This system was helping to produce rain and snow across parts of that region — and some elongated convective elements were evident across the OK/TX Panhandles. Snowfall totals included 2.5 inches in New Mexico and 3.0 inches in Texas, with 4.8 inches at Felt, Oklahoma (NOHRSC).

On the following day, a few north-to-south oriented mesoscale bands of snow cover were evident on GOES-16 “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images (below). Since snow is a strong absorber of radiation at the 1.61 µm wavelength, it appeared as darker shades of black on those images. Swaths of lighter snow cover melted rather quickly during the day.

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JMA Himawari-8 True Color Red-Green-Blue (RGB) images created using Geo2Grid (above) showed the volcanic clouds produced by an eruption of Lewotolok in Indonesia on 29 November 2020 — with one cloud plume moving to the northwest, and another moving more rapidly southeastward. This difference in volcanic cloud propagation was due to directional wind shear, as revealed by rawinsonde data from Kupang on the island of Timor (below), located about 250 km southeast of Lewotolok. A shift to northwesterly winds occurred at an altitude around 9 km (the 322 hPa pressure level).

Himawari-8 Ash RGB images (above) displayed an ash signature for both volcanic plumes, which became more diffuse after about 5 hours. Himawari-8 retrievals of Ash Height from the NOAA/CIMSS Volcanic Cloud Monitoring site (below) showed maximum values in the 16-18 km range for the southeast-moving cloud (the  advisory issued by the Darwin VAAC listed maximum height values of 50,000 feet or 15 km).

Himawari-8 False Color images (below) indicated the presence of both SO2 (shades of yellow to green) and ash in the southeastward-moving volcanic cloud.

Explosive #eruption of #Lewotolo (#Lewotolok) #volcano, E. #Indonesia, at 01:50 UTC on Nov 29. Rapidly identified by the @NOAA/@UWCIMSS VOLCAT system due to strong thermal signal and vertical Cloud Growth Anomaly (#VolcanoCb) in #Himawari imagery. Max ash cloud height >12 km. pic.twitter.com/qoPcTlFJpz

— Simon Carn (@simoncarn) November 29, 2020

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Clear skies over most of the five Great Lakes on 28-29 November allowed the VIIRS instrument on NOAA-20 to gather information for Advanced Clear-Sky Processing for Ocean (ACSPO) Sea Surface Temperatures.  The animation above shows two afternoon images (from 28 November 2020, at 1728 UTC and 1911 UTC) and one morning image (from 29 November 2020 at 0727 UTC).  The color enhancement shows values from 35ºF to 55ºF.

Lake Erie shows the warmest temperatures, just over 50ºF in the eastern part of the Lake. High Pressure over the Ohio River valley on 28 November (2100 UTC analysis) meant light winds over Lake Erie. The lack of wind-induced mixing allowed for warming (a few degrees F between 1728 and 1911 UTC) of the surface skin of the lake. Lake Superior shows temperatures around 40º F (albeit a bit warmer along just off the Upper Peninsula of Michigan); Lakes Michigan and Huron, western Lake Michigan and northwest Lake Ontario show temperatures in the mid-40s. Eastern Lake Ontario shows temperatures in the upper-40s.

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Note: You can compare these observations to previous years here, for Lake Michigan. (Links to comparisons at other lakes are at that link as well). Thanks to the Blog Reader for this link!

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1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm), Mid-level Water Vapor (6.9 µm) and Air Mass Red-Green-Blue (RGB) images (above) showed a Storm Force low (surface analyses) developing in the Gulf of Alaska on 26 November 2020. As the storm intensified, trends of warming//drying on the Water Vapor images and brighter orange/red hues on the Air Mass RGB images near the center of circulation indicated the development of a potential vorticity anomaly that lowered the dynamic tropopause (bringing dry, ozone-rich  air into the upper portion of the atmospheric column).

A toggle between Suomi NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images (below) showed the storm at 2228 UTC.

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