Marshall Fire near Boulder, Colorado

December 30th, 2021 |

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

GOES-16 Fire Temperature RGB, Shortwave Infrared (3.9 µm) Fire Power and Fire Temperature derived products (above) showed rapid expansion of the Marshall Fire’s thermal signature in Boulder County, Colorado on 30 December 2021. The earliest unambiguous fire signature appeared on the 1841 UTC image (11:41 am MST); the maximum 3.9 µm infrared brightness temperature was 110.96ºC (at 2021 UTC), the peak Fire Power was 1848.94 MW (at 2031 UTC) and the peak Fire Temperature was 1632.94 K (at 2031 UTC). The fire burned over 6000 acres in less than 24 hours, and destroyed or damaged over 1000 homes and businesses (making it the most destructive wildfire on record for the state of Colorado).

A comparison of Shortwave Infrared images from GOES-17 (GOES-West) and GOES-16 (GOES-East) is shown below. As was the case above, the earliest unambiguous fire thermal signature appeared on the 1841 UTC images from both satellites. Beginning at 2100 UTC, a GOES-17 Mesoscale Domain Sector was positioned over the region to monitor the ongoing fire, which provided images at 1-minute intervals.

Shortwave Infrared (3.9 µm) images from GOES-17 (left) and GOES-16 (right) [click to play animated GIF | MP4]

GOES-17 and GOES-16 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images (below) revealed the rapid development of a band of pronounced warming/drying — indicative of strong mountain wave subsidence — over the Front Range (centered near the Boulder KBOU area), along with additional mountain waves extending to the east. The band of strong mountain wave subsidence helped to transfer the momentum of strong westerly winds aloft (Boulder rawinsondes) downward to the surface; the rapid spread of the fire was driven by very strong surface winds, gusting to speeds over 100 mph.

GOES-17 (left) and GOES-16 (right) Upper-level (6.2 µm, top), Mid-level (6.9 µm, center) and Low-level (7.3 µm, bottom) Water Vapor images [click to play animation | MP4]

GOES-16 True Color RGB images created using Geo2Grid (below) highlighted the smoke plume, which drifted as far eastward as Nebraska and Kansas by sunset. Note the development of Kelvin-Helmholtz waves (particularly along the northern edge) as lee-side mountain waves distorted the smoke plume. Smoke briefly reduced the surface visibility to 1.5 miles at Denver International Airport — and farther to the east, the visibility dropped to 7 miles at Fort Morgan. Several other narrow plumes of blowing dust could be seen moving eastward across the eastern Colorado plains (which was experiencing severe to extreme drought). 

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

1-minute GOES-17 True Color RGB images are shown below.

GOES-17 True Color RGB images [click to play animated GIF | MP4]

VIIRS Fire RGB images from Suomi-NPP and NOAA-20 as viewed using RealEarth (below) showed the coverage of the Marshall Fire (cluster of red pixels) at 3 time periods.

VIIRS Fire RGB images from Suomi-NPP and NOAA-20 [click to enlarge]

===== 31 December Update =====

VIIRS Shortwave Infrared (3.74 µm) from Suomi-NPP [click to enlarge]

During the subsequent nighttime hours, a VIIRS Shortwave Infrared (3.74 µm) from Suomi-NPP (above) displayed thermal anomalies associated with active fire pockets that continued to burn at 0925 UTC or 2:25 am MST. 

Strong jet streak over the Upper Midwest

December 28th, 2021 |

GOES-16 Upper-level Water Vapor images, with plots of Derived Motion Winds [click to play animated GIF | MP4]

An anomalously-strong 250 hPa jet streak (analysis) was moving across the Upper Midwest late in the day on 27 December 2021. The 205 knots at Chanhassen Minnesota was a 250 hPa record maximum speed for all 00 UTC rawinsondes on 28 December at that site, as was the 207 knots at Green Bay, Wisconsin. GOES-16 (GOES-East) Upper-level Water Vapor (6.2 µm) images with plots of Derived Motion Winds (DMW) (above) showed this jet streak as it moved over the Chanhassen (KMPX) and Green Bay (KGRB) areas.

GOES-16 Upper-level Water Vapor images, with plots of Derived Motion Winds and contours of RAP model Maximum Wind Speed isotachs [click to play animated GIF | MP4]

12 hours later, the tail end of the still anomalously-strong 250 hPa jet streak (analysis) was moving across Wisconsin and Michigan on the morning of 28 December. The 187 knots at Green Bay, Wisconsin was a 250 hPa record for 12 UTC rawinsondes on 28 December at that site, as was the 181 knots at Gaylord, Michigan. GOES-16 Upper-level Water Vapor images with plots of Derived Motion Winds and contours of RUC40 model maximum wind speeds (above) showed this jet streak as it moved over the Green Bay (KGRB) and Gaylord (KAPX) areas.

Examples of 3 DMWs over Wisconsin and Michigan having speeds in excess of 180 knots are shown below. The DMW speed values were generally in good agreement with the hourly RAP40 isotachs at the Level of Maximum Winds, demonstrating that DMWs can be useful for model verification.

Satellite signatures of the Webb Space Telescope rocket launch

December 25th, 2021 |

GOES-16 ABI spectral bands 1-16 [click to play animated GIF | MP4]

The Webb Space Telescope was launched from Europe’s Spaceport — located about 40 miles northwest of Kourou, French Guyana (station identifier SOCA) at 1220 UTC on 25 December 2021. A sequence of 1-minute Mesoscale Domain Sector GOES-16 (GOES-East) images from all 16 ABI spectral bands (above) showed one or both of two features: (1) the hot thermal signature of the Ariane 5 solid rocket booster and core engines, moving rapidly eastward, and (2) the reflective and/or colder signature of the rocket engine condensation cloud, most of which moved slowly northward away from the coast. 

At 1221 UTC, a cluster of warm pixels — a signature of the rocket engines — was evident in all Near-Infrared and Infrared ABI spectral bands (below).

GOES-16 ABI spectral bands at 1221 UTC [click to play animated GIF | MP4]

A closer view of GOES-16 “Red” Visible (0.64 µm) images (below) showed the motion and deformation of the rocket condensation cloud in greater detail. Changes in wind direction and speed with height tended to distort the shape of the condensation cloud, moving it in different directions. Another view of this rocket condensation cloud is available here, using CSPP GeoSphere.

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

The Plume RGB (below) is very useful for providing a single product to highlight all of the aforementioned rocket launch features (a shorter-duration animation is available here). Examples of the Plume RGB for other rocket launches can be seen in this blog post .

GOES-16 Plume RGB images (credit: Tim Schmit, NOAA/NESDIS/ASPB) [click to play animated GIF | MP4]

The ascending rocket plume was also seen on the extreme eastern limb of a GOES-17 (GOES-West) Visible image (below). Wind-induced distortion of the ascending rocket plume was evident in that view as well.

Texas oil refinery explosion and fire

December 23rd, 2021 |

GOES-17 (left) and GOES-16 (right) Near-Infrared and Shortwave Infrared images [click to play animated GIF | MP4]

An explosion and fire occurred at the ExxonMobil refinery in Baytown, Texas around 12:50 AM (0650 UTC) on 23 December 2021 — and a comparison of GOES-17 (GOES-West) vs GOES-16 (GOES-East) Near-Infrared (1.61 µm and 2.24µm) and Shortwave Infrared (3.9µm) images (above) displayed the thermal signature of the fire. The maximum 3.9 µm infrared brightness temperature sensed by GOES-16 was 343.02 K (compared to 337.82 K by GOES-17).

GOES-16 Plume RGB images (credit: Tim Schmit, NOAA/NESDIS/ASPB) [click to play animated GIF | MP4]

GOES-16 (above) and GOES-17 (below) Plume RGB images created using Geo2Grid also helped to highlight the thermal signature of the fire (red pixels).

GOES-17 Plume RGB images (credit: Tim Schmit, NOAA/NESDIS/ASPB) [click to play animated GIF | MP4]

In a time-matched comparison of Shortwave Infrared images from GOES-16 and Suomi-NPP about 1.5 hours after the initial refinery explosion (below), the GOES-16 thermal signature was beginning to diminish (exhibiting an infrared brightness temperature of 14.7ºC) while the higher spatial resolution Suomi-NPP VIIRS shortwave infrared brightness temperature was notably warmer at 26.2ºC.

Shortwave Infrared images from GOES-16 and Suomi-NPP [click to enlarge]