1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) depicted smoke plumes and thermal anomalies (clusters of hot pixels) associated with widespread prescribed burns across parts of Oklahoma, Arkansas and Missouri on 07 March 2021.

For one of the largest fires in far southern Oklahoma (located about 15 miles north-northwest of Ardmore), a 4-panel comparison of 5-minute GOES-16 Shortwave Infrared images with components of the Fire/Hot Spot Characterization algorithm — Fire Temperature, Fire Power and Fire Area — is shown below. The highest 3.9 µm infrared brightness temperature (114.8ºC or 387.95 K) and Fire Power (1555 MW) values were seen at 2036 UTC, while the highest Fire Temperature value (924.5 K) occurred at 2056 UTC.

With a broad ridge of high pressure centered over the Lower Mississippi River Valley (surface analyses), its anticyclonic flow could be seen via smoke plumes from multiple prescribed burns across the Deep South — as highlighted by GOES-16 True Color RGB images created using Geo2Grid (below).

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Accumulating hail fell in Daytona Beach FL (Link) on 6 March 2021 in association with a front over the Florida peninsula.  Preliminary storm reports from SPC (link) show reports of 1″ to 1.75″ hail. (The region was under a general thunderstorm outlook from SPC: link). The animation above shows the Convection RGB from 1431 through 1701 UTC on 6 March, bracketing the hail event over Daytona Beach near 1600 UTC. A strong white/yellow signal develops in a cell over Volusia County (Dayton Beach is within Volusia County) around 1545 UTC. This is the cell that deposits the hail.

ProbHail values for this event (from this website) were small, at less than 10%. The value of ProbSevere here could be in identifying the cell responsible for the Hail, and showing values for the radar object that exceed others nearby; that is, providing guidance as to which radar cell to interrogate most often. The image above shows ProbSevere at 1535, just before a Severe Thunderstorm Warning was issued. The image below shows ProbSevere at 1600 UTC, just after the Special Marine Warning was issued (and while the Severe Thunderstorm warning was still in effect).

The time series plot for the radar object that produced the hail is shown below. Note that ProbHail (and lightning) increased (marginally) before the hail events (reported between 1535 and 1615 UTC) before collapsing.

There are several features in the visible imagery, below, that might be affecting the thunderstorm producing the hail. An east-west boundary is moving down the Atlantic coastline, passing through Daytona Beach around 1551 UTC. A very strong reflective signal becomes apparent after 1541 UTC as well (link): the convective cell has penetrated through the cirrus shield in the region.

This was a challenging forecast in a marginal environment.

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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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