GOES-17 imagery revealed another explosive eruption of Hunga Tonga-Hunga Ha?apai in the south Pacific Ocean between 1500 and 1530 UTC on 13 January 2022; an eruption in December 2021 is discussed here. The brightness temperatures in this volcanic plume cooled from -9.4^o to -66.7^o between 1520 and 1530 UTC. This 1308 UTC NUCAPS profile from 20.5^oS / 175.5^o W (the profile location is shown here) suggests the plume rose from 445 mb to 188 mb in those 10 minutes (or from 20 thousand to 39 thousand feet).

Imagery at 2100 UTC, below, shows the extent of the plume in the visible.

Computed Ash/Dust Cloud Heights, below, from 1510-1600 UTC on 13 January, available at the CIMSS Volcanic Cloud Monitoring Web Portal (link, search under the Wellington VAAC for Hunga Tonga), shows the rapid increase in height, to above 16 km, as well.

An animation of GOES-17 visible imagery, below, (courtesy Scott Bachmeier, CIMSS) shows the evolution of the pulsing eruption throughout the day on 13 January.

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* You might notice that this AWIPS Full Disk imagery is at full resolution! In NWS Forecast Offices, full-disk imagery in AWIPS is degraded to 6-km resolution, meaning that interesting events outside of GOES-16 CONUS (or GOES-17 PACUS) that do not fall within a mesoscale sector can only be shown such that they’re zoomed out (as in this tweet from WFO Seattle about this event). The full-res imagery herein was created by inputting the full-resolution full-disk imagery (obtained at CIMSS from the GRB datastream) into AWIPS, replacing the subsected data.

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GOES-16 (GOES-East) True Color RGB images created using Geo2Grid (above) displayed the eye-like signature of a potential subtropical cyclone or “neutercane” over the Southeast Pacific Ocean on 12 January 2022. This type of mesoscale “hybrid” system has been observed near decaying cold fronts, or (as in this case) near the centers of aged occluded extratropical cyclones.

VIIRS Infrared Window (11.45 µm) images from NOAA-20 and Suomi-NPP as viewed using RealEarth (below) showed that deep convection — exhibiting cloud-top brightness temperatures of -40°C and colder, shades of green) — existed around the immediate edge of of the small eye.

Surface analyses from the Chile Navy Weather Service (below) depicted the small occluded cyclone as it was moving southeastward off the coast of Chile.

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GOES-16 (GOES-East) Low-level (7.3 µm) and Mid-level (6.9 µm) Water Vapor images (above) showed that portions of the coastline of Lake Superior, Lake Michigan and Lake Huron were apparent during the day on 10 January 2022. When a very cold/dry arctic air mass is present over a particular area, the water vapor “weighting functions” are shifted to lower altitudes — which in this case allowed the strong thermal contrast between (1) the cold, snow-covered land surface across Minnesota, Wisconsin, Michigan and Ontario and (2) the warmer ice-free nearshore waters of the Great Lakes to be sensed by GOES Water Vapor spectral bands. The coldest surface air temperatures that morning across the region included -34ºF at Badoura MN, -27ºF at Grantsburg WI and -15ºF at Ironwood MI.

Plots of GOES-16 Low-level (7.3 µm) and Mid-level (6.9 µm) Water Vapor weighting functions (below) — calculated using 12 UTC rawinsonde data from Green Bay, Wisconsin (KGRB) — showed peak radiation contributions for the 7.3 µm and 6.9 µm spectral bands were at the 853 hPa and 730 hPa pressure levels, respectively, with some contribution coming directly from the surface. This example underscores the fact that “water vapor” spectral bands are essentially infrared bands — and with very little water vapor within the atmospheric column to absorb then re-radiate any upwelling energy (at its colder ambient temperature aloft), the signature of this land vs. water thermal contrast was able to reach the satellite sensors with minimal attenuation. 

According to the Green Bay WI rawinsonde Total Precipitable Water (TPW) climatology (source), the TPW value of 0.04 inch at 12 UTC on 10 January was very close to the record low value (0.03 inch) for that date/time (below).

Other examples of GOES water vapor imagery sensing the surface in a cold/dry air mass: Feb 2020 | Jan 2019 | Dec 2019.

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Data from this site shows SAR observations over the Great Lakes daily around 0000 and 1200 UTC. The image above shows SAR data over Lake Superior just before 1200 UTC on 10 January. The background flow used in processing shows strong northwesterly winds. Note the relative calm in the lee of the Keewenah peninsula, and an interesting boundary in the winds near Michipicoten Island. As noted in this blog post from December, the strongest winds are likely associated with enhanced Lake-Effect bands, as enhanced vertical mixing in those bands will allow stronger upper level winds to mix down to the lake surface.

Does ABI imagery show enhancements in the regions where the SAR data indicates enhanced mixing with convective bands? Consider the 3.9 µm image below (from this NOAA/STAR website) from 1201 UTC. Cold cloud tops northeast of Marquette MI do correlate well with the strong winds in that regions.

Scatterometry can also be used to measure winds on the lake surface. The imagery below (from this website) shows vectors from the Chinese HY-2B scatterometer at 1330 UTC. Spatial resolution for this imagery is much coarser, and observations closer to shore do not occur. Northwest winds of at least 30 knots are indicated however.

A careful observer of the SAR winds above might notice very strong winds in/around Little Bay de Noc, the northeastern part of Green Bay. Care must be taken to differentiate between ice and winds in regions where ice is present, as SAR data can be also used to identify regions of ice. The toggle below of NOAA-20 True and False color imagery over the western Great Lakes (from the VIIRS today website) does show cyan regions — typical of ice — over northeastern Green Bay. (Click here for highest resolution False Color imagery from NOAA-20 on 9 January)

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What kind of wave heights are these strong northwesterly winds generating over Lake Superior? Altimetric data from SMAP, below, (source) shows 6-8 foot waves over western Lake Superior. The longer fetch for the region northeast of Marquette probably means much higher waves there.

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