GOES-16 (GOES-East) Dust RGB and Split Cloud Top Phase (11.2-8.4 µm) images (above) showed signatures of blowing dust — brighter shades of magenta/pink on the Dust RGB and darker shades of blue on the Split Cloud Top Phase images — moving southward across southwestern Texas on 05 March 2021. Winds were not particularly strong on this day (with peak gusts only in the 30-40 knot range), so the dust signatures were not as vivid as was seen in similar recent events such as 15 Jan 2021 and 30 Jan 2021. The blowing dust did restrict surface visibility to 2.5 miles at Midland, Texas (KMAF).

GOES-16 True Color RGB images created using Geo2Grid (below) did not reveal a distinct blowing dust signature until later in the day, when a more favorable forward scattering geometry helped to highlight the feature.

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GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed the wind-driven consolidation of ice within Green Bay during the 03 March – 04 March 2021 period. Northerly winds in the wake of a cold frontal passage on 03 March led to the fracturing of land-fast ice in the far northern portion of Green Bay — this ice then began drifting south-southwestward.

By sunrise on 04 March, GOES-16 Visible images indicated that the fractured ice had continued to drift farther southward overnight, eventually merging with the land-fast ice that had been covering the southern half of Green Bay; overnight low temperatures in the upper teens to low 20s F likely aided this merger process. Note that some filaments of ice had also migrated through gaps between islands, drifting southward across far western Lake Michigan (just off the coast of Wisconsin).

A toggle between 250-meter resolution Aqua MODIS True Color RGB images (source) on the 2 days is shown below.

As an aside, farther inland the tornado damage path from an EF3 tornado in northeastern Wisconsin was still evident, 13.5 years later (below).

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NOAA-Unique Combined Atmospheric Processing System (NUCAPS) data from CrIS and ATMS on NOAA-20 can give temperature and moisture information in regions otherwise lacking data. How well do those fields estimate the actual distribution of temperature and moisture? The toggle above compared visible imagery with gridded fields of temperature and moisture from NUCAPS from late in the day on 2 March 2021.

The thermal fields depict the frontal zone far to the south of Hawaii;  cooler air where shallow cumulus convection is occurring is farther north.  Of particular note is the excellent spatial correspondence between diagnosed dry air around and just to the northeast of Hawaii and an obvious lack of cloudiness there!  (Here is the 0000 UTC 3 March 2021 sounding from Hilo; a strong inversion is just below 700 mb.)

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1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) images (above) showed the hazy signature of a plume of re-suspended ash from the 1912 Katmai volcanic eruption. Strong surface winds gusting to 50-55 knots — caused by a strong pressure gradient along the western periphery of a Storm Force low in the Gulf of Alaska (surface analyses) — lofted some of the thick layer of ash that has remained on the ground in the vicinity of the volcano. The most dense portion of the aerosol plume was  moving across the Barren Islands (between Kodiak Island to the south and the Kenai Peninsula to the north); near the northern edge of the aerosol plume, surface visibility was reduced to 5 miles at Homer and 7 miles at Seldovia.

A sequence of Suomi NPP VIIRS Day/Night Band (0.7 µm) images (below) showed that the plume had formed before sunrise — ample illumination from a Full Moon provided vivid “visible mages at night” (at 1131 UTC and 1311 UTC).

ASCAT winds from Metop-C at 0743 UTC and 2124 UTC (source) are shown below — they indicated a dramatic increase in surface wind speeds  of 50 knots or greater emerging from the Barren Islands into the Gulf of Alaska later in the day.

GOES-17 True Color RGB images created using Geo2Grid (below) provided a clearer view of the re-suspended ash plume. North of the plume, note the tidal ebb and flow of ice within Cook Inlet and Turnagain Arm leading into the Anchorage area.

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