Wildfires and blowing dust in New Mexico

May 8th, 2022 |

GOES-17 Fire Temperature RGB (top left) and Shortwave Infrared (3.9 µm, top right), with GOES-16 Fire Power (bottom left) and Fire Temperature (bottom right) [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-17 (GOES-West) Fire Temperature RGB and Shortwave Infrared (3.9 µm) along with 5-minute GOES-16 (GOES-East) Fire Power and Fire Temperature (above) displayed thermal signatures of the Calf Canyon Fire and the Cerra Pelado Fire in northern New Mexico on 08 May 2022. The Fire Temperature and Fire Power derived products are components of the GOES Fire Detection and Characterization Algorithm FDCA.

The northern portion of the Calf Canyon Fire exhibited extreme behavior, with rapid intensification and rates of spread that led to evacuation orders being issued for 2 communities just north of Mora. That part of the fire also exhibited maximum 3.9 µm brightness temperatures of 138.71ºC — which is the saturation temperature of ABI Band 7 detectors — beginning around 1900 UTC.

GOES-16 True Color RGB images created using Geo2Grid (below) revealed the dense smoke plumes (pale shades of white) from the the wildfires, in addition to broad plumes of blowing dust (shades of tan) originating in northwestern New Mexico — strong winds across the region aided in the rapid northeastward transport of these aerosols.

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

GOES-16 Split Window Difference (10.3 µm – 12.3 µm) images (below) include plots of  hourly surface visibility — as the plume of blowing dust (shades of yellow to blue) from northwestern New Mexico was transported northeastward across Colorado, it appears to have played a role in reducing the visibility to as little as 2-3 miles at some locations (although local blowing dust sources may have also contributed to these low visibility values).

GOES-16 Split Window Difference (10.3 µm – 12.3 µm) images, with hourly surface visibility (miles) plotted in red [click to play animated GIF | MP4]

Posted in Air quality, Fire detection, GOES-16, GOES-17, Red-Green-Blue (RGB) images | Comments Off on Wildfires and blowing dust in New Mexico

First thunderstorm of the season in the Anchorage, Alaska area

May 4th, 2022 |

GOES-17 “Red” Visible (0.64 µm) images [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) images (above) showed these isolated thunderstorms as they moved north-northwestward up the Susitna Valley (northwest of Anchorage).

In the corresponding 1-minute GOES-17 “Clean” Infrared Window (10.35 µm) images (below), the coldest cloud-top infrared brightness temperatures of the thunderstorms were around -35ºC (darker blue enhancement).

GOES-17 “Clean” Infrared Window (10.35 µm) images [click to play animated GIF | MP4]

A toggle between Suomi-NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images around 2201 UTC (below) included a plot of available NUCAPS sounding points from NOAA-20.

Suomi-NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images and 2201 UTC [click to enlarge]

The NOAA-20 NUCAPS profile for the green (infrared + microwave) sounding point 25 miles WSW of Big Lake (below) diagnosed a surface parcel CAPE value of 616 J/kg, with a Lifted Index of -3.  

NOAA-20 NUCAPS profile for the sounding point 25 miles WSW of Big Lake [click to enlarge]

A later toggle between Suomi-NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images and 2345 UTC is shown below; the coldest cloud-top infrared brightness temperature of the thunderstorms was -38ºC (near Big Lake), which closely corresponded to the altitude of the Equilibrium Level on the NUCAPS profile.

Suomi-NPP VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images and 2345 UTC [click to enlarge]

Posted in GOES-17, NOAA-20, NUCAPS, Suomi NPP, VIIRS | Comments Off on First thunderstorm of the season in the Anchorage, Alaska area

Persistent fog/stratus across eastern Virginia

May 3rd, 2022 |

GOES-16 “Red” Visible (0.64 µm) images [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) images (above) showed abroad arc of fog/stratus that persisted for much of the day across parts of eastern Virginia, Chesapeake Bay and the Delmarva Peninsula on 03 May 2022. Since this fog/stratus deck — which was on the cold side of a quasi-stationary frontal boundary — was slow to dissipate, it held daytime temperatures in the 50s and 60s F (in contrast to the 70s F in cloud-free areas east of the front, and 80s F west of the front). By the end of the day, some of the colder air and stratus had sagged southward across extreme northeastern North Carolina (including the northern end of the Outer Banks).

Afternoon thunderstorms reached strong to severe levels as they approached the frontal boundary, producing 1-inch diameter hail and damaging winds (SPC Storm Reports).

1-minute GOES-16 Visible images with overlays of the 5-minute GOES-16 Fog Depth product (below) provided an estimate of the fog/stratus deck thickness, helping to highlight which portions might be slower to dissipate.

GOES-16 “Red” Visible (0.64 µm) images, with an overlay of the GOES-16 Fog/Stratus Depth product [click to play animated GIF | MP4]

Posted in Fog detection, GOES-16, Severe convection | Comments Off on Persistent fog/stratus across eastern Virginia

Hermits Peak / Calf Canyon Fire in New Mexico generates a pyrocumulonimbus cloud

May 1st, 2022 |

GOES-16 “Red” Visible (0.64 µm, top left), Shortwave Infrared (3.9 µm, top right), Infrared Window (10.35 µm, bottom left) and Fire Temperature (bottom right) [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and Infrared Window (10.35 µm) images along with 5-minute Fire Temperature images (above) showed intensification of 3 portions of the combined Calf Canyon Fire and Hermits Peak Fire in New Mexico on 01 May 2022. Active fire behavior was aided by surface winds gusts in the 45-54 mph range and very dry air within the boundary layer; these large fires also burned very hot, with 3.9 µm Shortwave Infrared brightness temperatures reaching 138.71ºC — the saturation temperature of ABI Band 7 detectors. Coldest 10.35 µm cloud-top brightness temperatures of intermittent pyroCumulus clouds were around -37ºC (darker yellow enhancement). The Fire Temperature derived product is a component of the GOES Fire Detection and Characterization Algorithm FDCA.

However, in a comparison of 375-meter resolution NOAA-20 VIIRS True Color RGB, Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images valid at 2026 UTC — downloaded and processed using the SSEC/CIMSS Direct Broadcast ground station (below), a small cluster of cloud-top 11.45 µm brightness temperatures of -40 to -43.6ºC (red enhancement) indicated that this feature met the criteria for classification as a pyrocumulonimbus cloud.

NOAA-20 VIIRS True Color RGB, Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images at 2026 UTC [click to enlarge]

The Calf Canyon Fire previously generated a pyroCb cloud on 22 April.

Posted in Fire detection, GOES-16, NOAA-20, Red-Green-Blue (RGB) images, VIIRS | Comments Off on Hermits Peak / Calf Canyon Fire in New Mexico generates a pyrocumulonimbus cloud

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