GOES-18 (GOES-West) SO2 RGB images (above) showed the eastward drift of a volcanic cloud produced by an explosive eruption of Mount Shishaldin that began around 0150 UTC on 16 September 2023. Trace amounts of ash fall were observed at False Pass from 0200-0430 UTC.

GOES-18 True Color RGB images from the CSPP GeoSphere site (below) helped to highlight the ash-laden volcanic cloud (light shades of tan) moving east from the summit of Shishaldin.

GOES-18 “Red” Visible (0.64 µm) images (below) include plots of GLM Group points — which revealed 2 brief periods of satellite-detected volcanic lightning activity near the summit of Shishaldin shortly after the eruption onset. Station PAKF is False Pass, where some light ash fall was observed.

Lots of lightning from the ongoing eruption of Shishaldin Volcano in western Alaska. pic.twitter.com/hYVBEQ0vhA

— Brian Brettschneider (@Climatologist49) September 16, 2023

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Hurricane Lee, moving northward off the east coast of the United States, is generating a large cirrus shield (see the ABI Band 4 image below) at high levels over New England, as also shown in the Air mass RGB shown above. The corrugated features in the cirrus are well-known predictors of aircraft turbulence, and pilot reports of observations are common within the field of cirrus (as shown in these blog posts). Additionally, the CIMSS Turbulence product, a prediction developed using Machine Learning and ABI Channels 8 (Upper-level water vapor, 6.19 µm) and 13 (Clean window infrared, 10.3 µm), along with GFS thermondynamic fields, shows a high probability of turbulence in the region where turbulence is observed. CIMSS turbulence probability fields are also available online here. A training recording (mp4) on the product is here.

For the latest on Hurricane Lee, refer to the National Hurricane Center (USA, Canada). Information is also available at the NWS Forecast Offices in Boston, Portland (Gray Maine), and Caribou.

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Many thanks to Professor Rick DiMaio at Lewis University for focusing our attention on this event!

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed Category 1 Hurricane Lee as it moved northward between Buoy 41048 and Bermuda (station identifier TXKF) on 14 September 2023. As shown in the plot below, the highest wind gust at Buoy 41048 was 41.0 m/s (79.7 knots, or 97.7 mph) at 2010 UTC (data transmission from the buoy ceased after 2310 UTC). The strong winds from Lee produced wave heights to 32 ft — and produced upwelling that cooled the water temperature several degrees.

In 1-minute GOES-16 “Clean” Infrared Window (10.3 µm) images (below), the coldest cloud tops exhibited infrared brightness temperatures around -80ºC (brighter shades of white embedded within darker black regions).

Analyses of deep-layer wind shear from the CIMSS Tropical Cyclones site (below) showed that Lee was moving into an environment of increasingly unfavorable shear as it gained latitude — which was acting to suppress the development of deep convection and the maintenance of a well-defined eye.

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Daytime EUMETSAT Meteosat-10 High Resolution Visible (0.8 µm) images (above) showed Storm Daniel as it developed into a Medicane over the southern Mediterranean Sea on 09 September (with convective bands wrapping around the storm center), then moved inland across northeastern Libya on 10 September 2023.

Hourly MIMIC Total Precipitable Water images from 09 to11 September (below) displayed bands of TPW in the 2.0-3.0 inch range (darker shades of red) wrapping around the center of Storm Daniel as it moved inland — causing heavy rainfall and extensive flooding (see this Climate Connections blog post for more details). Ship reports indicated that water temperatures in the central Mediterranean Sea — where Storm Daniel had meandered for a few days before approaching Libya — were in the 77-79ºF range.

As the center of Storm Daniel was approaching the Libya/Egypt border on 11 September, a MIMIC Total Precipitable Water image with an overlay of Metop-C ASCAT surface scatterometer winds at 0800 UTC showed a long fetch of winds in the 25-33 knot range (red barbs) approaching the coast of Libya — then at 1100 UTC, a ship report within the same region of that ASCAT fetch reported a wind speed of 40 knots (below).

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