Overlapping 1-minute Mesoscale Domain Sectors provided 30-second interval GOES-16 (GOES-East) Day Land Cloud Fire RGB images (above) that included an overlay of Fire Power and Fire Mask derived products (2 components of the GOES Fire Detection and Characterization Algorithm FDCA) — which showed the thermal signature and dark black smoke plume associated with a fire at the Sound Resource Solutions chemical plant in Shepherd, Texas on 08 November 2023. The smoke plume was thick enough to significantly reduce incoming solar radiation reaching the surface, which inhibited the subsequent development of boundary layer cumulus clouds (resulting in a pronounced gap in the cumulus field downwind of the fire and smoke plume source after about 1700 UTC).

The FDCA first identified a Processed Fire at 1420 UTC — and the peak Fire Power value of 171.65 MW occurred 6 minutes later (above). The maximum Shortwave Infrared (3.9 µm) brightness temperature of 55.54ºC also occurred at 1426 UTC (below).

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GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed a narrow (2-4 miles in width) plume of smoke+fog — the smoke was from a marsh fire burning near New Orleans East — that was moving to the northwest across Lake Pontchartrain after sunrise on 07 November 2023. This dense smoke+fog plume rapidly reduced visibility along a portion of Interstate 10, resulting in several accidents (media report).

A plot of rawinsonde data from New Orleans at 1200 UTC (below) indicated that there was a pronounced and very shallow temperature inversion just above the surface, which was trapping the dense wildfire smoke+fog near the surface and preventing its vertical dispersion (until a few hours after sunrise, when boundary layer mixing began to increase).

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On the following day, GOES-16 Nighttime Microphysics RGB and daytime Visible images (above) showed another smoke+fog plume, which persisted long enough after sunrise to impact traffic along the Lake Pontchartrain Causeway. Prior to sunrise, Nighttime Microphysics RGB imagery revealed the plume thickening near New Orleans East and beginning to move NW across the lake — and around 1100 UTC, I-10 and I-510 in that vicinity were proactively closed for several hours until visibility improved.

Unlike the previous day — when a veil of high clouds frequently prevented a view of low clouds/fog — a more distinct fog signature was seen in GOES-16 Night Fog Difference images (below).

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Storm Reports for the first two weeks of November 2023 show that the all but one of the reports have occurred over lower Michigan, where large hail (1 to 1.5 inches in diameter) occurred shortly after sunrise on 6 November in Newaygo County (1423 UTC), Montcalm County (1440, 1443 UTC) and Kent County (1448 UTC). What satellite imagery could be used to monitor this out-of-season development? The airmass RGB animation, above, from 0801 – 1501 UTC, shows the orangish shading typical of an airmass with high potential vorticity impinging on western Lower Michigan. Is that orange region really a region where Potential Vorticity is elevated? The image below compares the 1200 UTC (6-h GFS forecast) of pressure on the 2 PVU (taken from this source) to the 1201 UTC Airmass RGB. Strong convection develops over Lake Michigan after 1200 UTC and moves into southwestern lower Michigan where the severe weather occurred around 1400 and 1500 UTC.

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GOES-R provides Derived Stability Indices as one of its Level 2 Products. The clear-sky stability products include the Total Totals Index and the animation below shows the values along with the GOES-16 Clean Window infrared imagery. Values in excess of 45 occasionally appear in clear sky pixels over western lower Michigan as the stronger convection develops. Values are even larger to the west/southwest over Wisconsin where dynamic forcing is presumably less strong (given that convection did not develop there; here is a 6-h forecast of pressure on the 330 K surface along with cyclonic vorticity at 850 mb; note the strongest dynamics at 12 UTC are over northeast WI).

GOES-16 low-level water vapor imagery, below, shows the characteristic red signature sometimes associated with Elevated Mixed Layers (EMLs, features that are conducive to convection) moving towards lower Michigan. The weighting function from 45 N, 95W computed from 1200 UTC 6 November 2023 GFS data (here, taken from this source), shows a peak contribution from near 500 mb. The 1200 UTC Chanhassen Minnesota soundings (here, from this source), shows near dry-adiabatic conditions at 500 mb, i.e, a possible EML; if convection reaches that level, one might expect vigorous ascent.

GOES-16 Visible imagery, below, colored by the L2 cloud height product, shows both the convective texture of the clouds over Newaygo, Montcalm and Kent counties, and the relatively high heights of those clouds.

GOES-16 Cloud Top Heights, below, from 1401-1456 UTC, show the highest clouds tracking across southern Newaygo county and northern Kent and Montcalm counties from 1426 – 1451 UTC.

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The visible imagery colored with the cloud-top height mimics what happens with the Sandwich RGB, shown below. For this RGBs, the default scaling from 0-255 was changed to 0-150 for this early morning/low light event. The cold cloud tops of the strongest convection are apparent, tracking in the same region of Newaygo/Montcalm/Kent counties between 1400 and 1500 UTC, when the severe weather was occurring.

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A GOES-16 Mesoscale Domain Sector provided 1-minute imagery over the area — Visible and Infrared images that included time-matched (+/- 3 minutes) plots of SPC Storm Reports (in Newaygo/Montcalm/Kent counties) are shown below. In the vicinity of the hail reports, overshooting tops were evident in the Visible images and cloud-top 10.3 µm infrared  brightness temperatures were as cold as -60ºC (darker red enhancement).

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Thanks to TJ Turnage, Science and Operations Officer (SOO) at the Grand Rapids MI forecast office, for alerting us to this event.

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GOES-16 (GOES-East) SO2 RGB and Ash RGB images (above) showed a remnant volcanic cloud from the 31 October Klyuchevskaya eruption as it moved over southern Saskatchewan, northern North Dakota and far northwestern Minnesota on 06 November 2023. The volcanic cloud exhibited brighter shades of orange-yellow in the SO2 RGB imagery, and darker shades of blue in the Ash RGB imagery — as seen in RGB comparisons over southern Saskatchewan (north of CWEN-CWVN) at 0301 UTC and northwestern North Dakota at 0801 UTC (below).

The 0301 UTC and 0801 UTC image times corresponded to Volcanic Ash Advisories that were issued by the Montreal VAAC and the Washington VAAC (below).

GOES-16 SO2 RGB and Ash RGB images at 1601 UTC (below) showed the volcanic cloud over far northwestern Minnesota (in the vicinity of KPKD).

The qualitative appearance on SO2 and Ash RGB imagery was suggestive of a volcanic cloud that was a mixture of SO2 and ash (with more SO2 than ash) — and a radiometrically-retrieved Ash Loading product from the NOAA/CIMSS Volcanic Cloud Monitoring site (below) indicated that the ash content of the cloud was relatively low (0.5-1.0 grams per square meter, violet).

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