North Carolina fertilizer plant fire

January 31st, 2022 |

GOES-16 Near-Infrared (1.61 µm, left and 2.24 µm, center) and Shortwave Infrared (3.9 µm, right) images [click to play animated GIF | MP4]

GOES-16 (GOES-East) Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 µm) images (above) displayed the thermal signature of a fire at the Weaver Fertilizer Plant in Winston-Salem, North Carolina (airport identifier KINT) that began around 2346 UTC or 6:46 pm EST (about an hour after sunset) on 31 January 2022. The highest 3.9 µm infrared brightness temperature was 300.64 K at 0011UTC, 25 minutes after the fire was first detected by GOES-16.

Note that a faint thermal signature of the fire (pixels exhibiting dim shades of white) was also seen in the Near-Infrared (1.61 µm Band 5 and 2.24 µm Band 6) images — this is because those two ABI spectral bands are located close to the peak emitted radiance of very hot features such as large fires (below).

Spectral Response Function (SRF) plots for GOES-16 ABI Bands 5, 6 and 7 (credit: Mat Gunshor, CIMSS) [click to enlarge]

Rapid ice growth in Lake Erie

January 31st, 2022 |

GOES-16 “Red” Visible (0.64 µm) images, with surface wind barbs (knots) plotted in cyan [click to play animated GIF | MP4]

GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed the widespread coverage of ice across Lake Erie on 31 January 2022. Surface winds were generally light across the region, minimizing wind stress on the pack ice. A careful inspection of the imagery revealed some straight pathways cut through the ice by US Coast Guard icebreakers.

An Aqua MODIS True Color RGB image from the MODIS Today site (below) provided a higher-resolution view of the linear icebreaker paths in the western portion of the lake (where the ice was generally thicker).

Aqua MODIS True Color RGB image [click to enlarge]

The entire icebreaker channel was apparently completed sometime before sunrise on 31 January — the western portion was evident in a Sentinel-1A Synthetic Aperture Radar (SAR) Normalized Radar Cross Section (NRCS) image (source) at 2324 UTC on 30 January, and its eastward continuation was seen in a RCM-1 SAR NRCS image at 1136 UTC image on 31 January (below).

SAR NCRS images from Sentinel-1A at 2324 UTC on 30 January and from RCM-1 at 1136 UTC on 31 January [click to enlarge]

A toggle between GOES-16 Visible images at 1801 UTC on 29 January and 31 January (below) showed the marked increase in ice coverage during that 48-hour period.

GOES-16 “Red” Visible (0.64 µm) images at 1801 UTC on 29 January and 31 January 2022 [click to enlarge]

In fact, a GLERL plot of current Lake Erie ice coverage compared to the historical average (below) showed that the percentage of ice cover had recently become well above average for the date.

Plot of current Lake Erie ice coverage (black) compared to the historical average (red) [click to enlarge]

Mid-Atlantic and Northeast US winter storm

January 29th, 2022 |

GOES-16 Mid-level Water Vapor (6.9 µm) images, with hourly surface weather type plotted in yellow [click to play animated GIF | MP4]

GOES-16 (GOES-East) Mid-level Water Vapor (6.9 µm) images (above) showed the widespread precipitation (WPC Storm Summary) produced by a midlatitude cyclone that rapidly intensified off the Northeast US coast on 29 January 2022.

GOES-16 Water Vapor images with hourly plots of wind barbs and gusts (below) showed that the highest wind gusts occurred near the New England coast.

GOES-16 Mid-level Water Vapor (6.9 µm) images, with hourly surface wind barbs plotted in red [click to play animated GIF | MP4]

GOES-16 Air Mass RGB images (below) included contours of RAP40 model PV1.5 pressure — an indicator of the height of the “dynamic tropopause” — which showed that the dynamic tropopause had briefly descended to the 900 hPa pressure level at 20 UTC.

GOES-16 Air Mass RGB images, with contours of RAP40 model PV1.5 pressure plotted in cyan [click to play animated GIF | MP4]

Lake Effect snow over Chicago

January 28th, 2022 |
GOES-16 Nighttime Microphysics with and without radar at 0641 UTC on 28 January 2022 (Click to enlarge)

Lake Effect snow moved over Chicago on 28 January 2022. Along-lake winds, as shown below in scatterometry from this site, produced a single snow band that released on Chicago. The image above shows Nighttime microphysics with and without radar displayed. Once the relationship between the radar and the RGB is established, it is not difficult to monitor the stationarity of the band.

Great Lakes scatterometry at 0000 and 1200 UTC on 28 January 2022 (Click to enlarge)
GOES-16 Nighttime Microphysics with and without radar at 1001 UTC 28 January 2022 (Click to enlarge)

After sunrise, other ABI bands are available to highlight precipitating lake-effect snowbands. RGB combinations that include Band 5 (1.6 µm) are of particular use because they can highlight glaciation in the cloud. Consider the examples below showing two RGBs and visible imagery with and without radar overlain. Which one would you choose and use to highlight the precipitating snow band? Will that choice change with sun angle, do you think?

GOES-16 Day Cloud Phase Distinction RGB with and without radar at 1536 UTC 28 January 2022 (Click to enlarge)
GOES-16 Band 2 Visible (0.64 µm) with and without radar at 1536 UTC 28 January 2022 (Click to enlarge)
GOES-16 Day Cloud Phase Distinction RGB with and without radar at 1536 UTC 28 January

The Day Cloud Phase Distinction RGB, below, animated from 1426 to 1921 UTC (click here to see the animation without observations), highlights the narrow nature of the band as it moves inland over Chicago.

GOES-16 Day Cloud Phase Distinction with hourly surface observations, 1426 – 1921 UTC on 28 January 2022 (Click to enlarge)