A vigorous extra-tropical cyclone moving towards the western Great Lakes on 11 November 2021 generated significant winds and waves over Lake Superior. RADARSAT winds, above, from RCM1, (available at this website) show a large area of southeasterly winds between 30 and 40 knots at 1159 UTC on 11 November. Regions of lighter winds are present to the lee of both Isle Royale and Michicipoten Island. The animation below steps through the low-level water vapor and clean window infrared channels (Band 10 at 7.34 µm and Band 13 at 10.3 µm, respectively) and the airmass RGB. All three ABI products suggest a negatively-tilted trough moving into the western Great Lakes. Click here to see an animation of 3-hour surface plots from 0900 UTC 11 November through 0600 UTC on 12 November (also shown at the bottom of this post).

How do the SAR winds above compare to observations? Open-lake observations are scarce during Gales, and the mid-lake buoys (45028, 45006 and 45001, for example) have been retrieved for the season. However, Stannard Rock Lighthouse observations show sustained east-southeast winds near 40 knots at around 1200 UTC, as shown in the capture below, from this website (accessed from here). (Note that Stannard Rock wind observations are 35 m above the Lake surface)

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At 1636 UTC, JASON-2 overflew eastern Lake Superior, and Altimetry data (from this website) from that satellite was used to compute wave heights, shown below. Peak Significant Wave Heights (defined as the average of the highest 1/3rd of all waves) under the satellite were in the 11-12 foot range. (Click here for a quick brief on JASON Wave Heights). Lake Superior Wave Heights at 1600 UTC (from this website (linked off here) maintained by GLERL) show rough agreement with the JASON observations.

GOES-16 Data at the time of the JASON overpass, below, shows the continued development/amplification of the extratropical cyclone. Note in particular the feature over western Iowa/eastern Nebraska that has dropped down the western side of this developing storm since 1201 UTC imagery, above.

At 2356 UTC on 11 November, RCM2 overflew western Lake Superior, and data at that time shows southwesterly winds between 25 and 30 knots over western Lake Superior. GOES-16 data at the same time, below (and surface data, bottom) show a mature storm to the north of Lake Superior. Data from the Devils Island C-MAN station (link) (see below) show sustained winds at 24 knots with gusts to 34 knots. (Note that the instruments for this reading are 25 m above ground)

Airmass RGB imagery from 1201, 1626 and 2356 UTC, below, the times of the wind and wave observations above, show the piecewise development of this system. Surface analyses for this system, from 0900 UTC on 11 November through 0600 UTC 12 November, are shown at bottom.

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On 10 November 2021, SpaceX and NASA launched the Crew-3 mission to the International Space Station from Kennedy Space Center in Florida at 7:03 pm EDT (0203 UTC on 11 November). GOES-16 (GOES-East) Mesoscale Domain Sector 1 provided images at 1-minute intervals (above) — reflectance and/or thermal signatures of the Falcon-9 rocket booster were seen in 15 of the 16 ABI spectral bands during the initial portion of its northeastward trajectory. The hottest Shortwave Infrared (3.9 µm) brightness temperature was 70.63ºC at 0205 UTC (which was around the time of Second Stage ignition).

A zoomed-in comparison of GOES-16 Visible and Near-Infrared images at 0204 UTC (below) provided a better view of the signatures just off the coast of Florida — an AWIPS cursor sampling indicated that there was even a 0.13% reflectance signal in the 0.47 µm “Blue” Visible image (but this value was not bright enough to be seen using the default enhancement). 

GOES-16 Plume RGB images (below) highlighted a bright thermal signature of the Falcon-9 rocket booster ascent, as well as the darker signature of low-altitude condensation clouds (resulting from the rocket launch) which moved slowly eastward.

A toggle between Plume RGB images from GOES-16 and GOES-17 at 0205 UTC (below) revealed a significant eastward parallax displacement of the yellow/orange thermal anomaly signature on the GOES-17 image. At that time, the rocket was at an altitude of about 70 km.

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A tropical cyclone has developed in the Bay of Bengal and is moving northwest across the Indian subcontinent. The system is forecast to continue bringing heavy rains to Southern India until Thursday. It has already caused damage, flooding, and loss of life in Sri Lanka and India.

Animations showing water vapor data from the Himawari-8 satellite’s Advanced Himawari Imager (AHI) can be found below. The first animation highlights cyclonic structure developing over the past two days every hour. In the final frame, a distinct eye is visible. Similar to the ABI aboard GOES-16/17, AHI collects data every ten minutes. The second animation shows the ten-minute temporal resolution of AHI for a shorter time period, zooming to see the ‘eye’ of the storm.

These animations were made using RealEarth, a free data discovery and visualization platform developed at SSEC/CIMSS at the University of Wisconsin-Madison. It is available to anyone at realearth.ssec.wisc.edu.

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RealEarth also contains CMORPH estimates (hourly, daily and weekly) of precipitation. The daily precipitation from 10 November over the Bay of Bengal is shown below. The highest value in the colorbar is 150 mm — but in reality, the heaviest accumulations over the Bay of Bengal exceeded 300 mm!

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GOES-17 (GOES-West) Mid-level (6.9 µm) Water Vapor images (above) revealed a complex pattern of middle-tropospheric vortices moving slowly west-southwestward over Interior Alaska and the Chukchi / Bering Seas on 09 November 2021. Note that the cold (brighter white) peaks of a few of the higher mountain ranges — including Denali — could be seen.

The presence of a relatively dry air mass across those areas allowed the signature of higher terrain to be evident in Water Vapor images — since a dry air mass has the effect of shifting the peaks of Water Vapor weighting functions to lower altitudes. The weighting function of the 6.9 µm spectral band (calculated from rawinsonde data at 12 UTC on 09 November and 00 UTC on 10 November) is plotted in blue for Fairbanks and Anchorage (below).

GOES-17 water vapor weighting functions for Fairbanks, Alaska [click to enlarge]

Plots of GOES-17 parallax direction and magnitude for objects at altitudes of 15,000 feet (4.5 km) and 30,000 feet (9.1 km) are shown below (source), and help to explain the slight north-northwestward shift of the brighter white (colder) high-terrain signature in the Water Vapor imagery.

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