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)

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.

View only this post Read Less

JMA Himawari-8 Visible (0.64 µm) images [click to play animated GIF | MP4]

JMA Himawari-8 Visible (0.64 µm) images (above) showed Tropical Cyclone Tiffany as it made landfall along the eastern coast of the Cape York Peninsula in Queensland, Australia on 09 January 2022. [UPDATE: just prior to making landfall around 0130 UTC on 10 January, Tiffany intensified to a Category 1 typhoon (JTWC discussion)].

A longer animation of Himawari-8 Infrared (10.4 µm) images (below) revealed pulses of overshooting tops which exhibited cloud-top infrared brightness temperatures in the -90 to -95°C range.

JMA Himawari-8 Infrared (10.4 µm) images [click to play animated GIF | MP4]

A stepped sequence of zoomed-in Suomi-NPP VIIRS Infrared (11.45 µm) images at 1517 UTC, viewed using RealEarth (below) showed a few red pixels — which highlighted cloud-top infrared brightness temperatures of -100°C or colder.   

Suomi-NPP VIIRS Infrared (11.45 µm) image at 1517 UTC [click to enlarge]

DMSP-16 SSMIS Microwave (85 GHz) imagery from the CIMSS Tropical Cyclones site (below) showed convection wrapping around a very small eye feature at 1905 UTC.

DMSP-16 SSMIS Microwave (85 GHz) image [click to enlarge]

Himawari-8 Infrared images with contours of deep-layer wind shear (below) indicated that Tiffany was moving through an environment of light to moderate shear. 

JMA Himawari-8 Infrared images, with contours of deep-layer wind shear [click to enlarge]

View only this post Read Less

GOES-16 Ash RGB images [click to play animated GIF | MP4]

GOES-16 Ash RGB images created using Geo2Grid (above) displayed the expansion of 2 volcanic clouds following the eruption of Wolf in the Galápagos Islands on 07 January 2022 — one moving northeastward and dissipating, and the other moving westward. The green shades of the volcanic cloud suggested that it contained fairly high concentrations of SO2 (in contrast to volcanic ash, would would appear as shades of pink/magenta). The cluster of dark blue pixels represented the hot thermal anomaly at the summit of the volcano, which persisted during the entire day.

This persistent thermal anomaly was also apparent in Shortwave Infrared (3.9 µm) images from GOES-17 (GOES-West) and GOES-16 (GOES-East) (below), shown in the native projection of each satellite.

Shortwave Infrared (3.9 µm) images from GOES-17 (left) and GOES-16 (right) [click to play animated GIF | MP4]

View only this post Read Less

GOES-17 ABI and GLM imagery (from this NOAA STAR website), above, over the southern Pacific Ocean show a region of potential tropical cyclogenesis to the west of Fiji, near the western boundary of this mapping. This Invest Area has been percolating for much of the week. Despite low values of shear (shown below, from this website) and warm sea-surface temperatures, intensification to a tropical depression has not yet occurred (see this discussion from the Joint Typhoon Warning Center). However, GLM observations of Flash Extent Density (FED) do show occasional lightning events within the developing system.

Upper-level water vapor imagery (GOES-17 Band 8, at 6.19 µm), below, from 1940 UTC, shows a distinct cirrus overcast at about 17 S, 172 E. Substantial dry air is not indicated in the water vapor imagery, nor in a MIMIC TPW mapping from 1200 UTC (downloaded from here), shown below.

Scatterometry over this system on 7 January (downloaded from this website), show an increase in symmetry to the storm between the HY-2B overpass at 0630 UTC and the HY-2C overpass at 1330 UTC. For more information on this system over the weekend, refer to the SSEC/CIMSS Tropical Website, the Joint Typhoon Warning Center, and the Fiji Meteorological Service.

View only this post Read Less