Buck Fire in North Texas

October 28th, 2021 |

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

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) True Color RGB images created using Geo2Grid (above) showed a distinct smoke plume associated with the Buck Fire in North Texas on 28 October 2021. The fire spread rapidly toward the southeast, driven by strong northwesterly winds gusting in excess of 40 knots. Note that the brighter white smoke plume was embedded within broader plumes of blowing dust (shades tan to light brown).

In a sequence of 1-minute GOES-16 “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images along with 5-minute Fire Temperature and Fire Power derived products — all with an overlay of 5-minute Visible Derived Motion Winds (below), the maximum surface 3.9 µm brightness temperature sensed with this fire was 138.7ºC (which is the saturation temperature for the ABI Band 7 detectors), the peak Fire Temperature exceeded 2900 K and the Fire Power reached 1800 MW (the Fire Temperature and Fire Power derived products are components of the GOES Fire Detection and Characterization Algorithm FDCA). Derived Motion Winds tracked the smoke plume moving southeastward at speeds up to 49 knots.

GOES-16 Visible, Shortwave Infrared, Fire Temperature, and Fire Power with an overlay of Derived Motion Winds [click to play animated GIF | MP4]

===== 29 October Update =====

NOAA-20 VIIRS DayNight Band image at 0816 UTC [click to enlarge]

During the subsequent nighttime hours, the bright glow of the Buck Fire could be seen on a NOAA-20 VIIRS Day/Night Band image at 0816 UTC or 3:16 am CDT, as viewed using RealEarth (above).

The fire continued to burn into the following day — and the burn scar could be seen in NOAA-20 VIIRS True Color and False Color images (below).

NOAA-20 VIIRS True Color and False Color RGB images [click to enlarge]

GOES-16 True Color RGB images (below) again displayed a long smoke plume that was transported southeastward. 

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

Prescribed burn in southern Wisconsin

October 19th, 2021 |

GOES-16 “Red” Visible (0.64 µm, top) and Shortwave Infrared (3.9 µm, bottom) images [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) showed the smoke plume and thermal anomaly or “hot spot” (cluster of darker black pixels) associated with what was likely a prescribed burn at or near the Brooklyn Wildlife Area in south-central Wisconsin on 19 October 2021.

A toggle between the GOES-16 Shortwave Infrared image at 2027 UTC and a background Google Maps image — as viewed using RealEarth (below) — further implicated Brooklyn Wildlife Area as the likely fire source region.

GOES-16 Shortwave Infrared (3.9 µm) image at 2027 UTC, along with a Google Maps background [click to enlarge]

GOES-16 True Color RGB images created using Geo2Grid (below) offered a clearer depiction of the smoke plume, as it eventually moved northeastward over the Madison metro area.

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

As the smoke plume moved over the Space Science and Engineering Center at the University of Wisconsin – Madison, the aerosol layer was detected by a rooftop High Spectral Resolution Lidar — generally within the 2-4 km altitude range (below).

UW-SSEC rooftop lidar images [click to enlarge]

A few miles to the northeast, the ceilometer at Madison Dane County Regional Airport also detected the base of the smoke plume aloft (below)

Plot of surface report data from Madison Dane County Regional Airport [click to enlarge]

Southwesterly surface wind gusts at Monroe (located about 20 miles southwest of the fire source region) were as high as 24 knots (28 mph) just before 19 UTC (below).

Plot of surface data from Monroe [click to enlarge]

Thanks to Kathy Strabala (SSEC) for bringing this case to our attention!

Alisal Fire in Southern California

October 12th, 2021 |

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

GOES-17 (GOES-West) True Color RGB images created using Geo2Grid (above) showed the transport of smoke from the Alisal Fire in Southern California on 12 October 2021. The dashed line in the images is Highway 101 — a portion of which was closed, as the wind-driven fire raced toward the coast. Late in the day some low-altitude smoke began to move eastward along the coast, eventually reducing the surface visibility to 6 miles at Santa Barbara.

During the preceding overnight hours (at 0916 UTC or 2:16 am PDT), a comparison of Suomi-NPP VIIRS Shortwave Infrared and Day/Night Band images (below) revealed the thermal signature and nighttime glow of the fire. The VIIRS imagery was downloaded and processed via the SSEC/CIMSS Direct Broadcast ground station.

Suomi-NPP VIIRS Shortwave Infrared (3.74 µm) and Day/Night Band (0.7 µm) images [click to enlarge]

The Suomi-NPP overpass time of the fire region was actually 0926 UTC — and a time-matched comparison of Shortwave Infrared images from GOES-17 and Suomi-NPP (below) demonstrated that the superior spatial resolution of VIIRS instrument (~375 meters, vs ~2 km for the ABI on GOES-17) provided a more accurate depiction of the areal coverage of the fire.

Shortwave Infrared images from Suomi-NPP (3.74 µm) and GOES-17 (3.9 µm) [click to enlarge]

===== 13 October Update =====

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

On 13 October, GOES-17 True Color RGB images (above) showed that as offshore wind speeds relaxed, a shift to onshore flow recirculated some of the smoke inland — with smoke briefly reducing the surface visibility to 1.5 miles at Santa Barbara airport (below). Farther to the south, residual smoke from the previous day of burning was also evident, with some of it traveling as far as Isla Guadalupe (Guadalupe Island) nearly 400 miles away.

Time series of surface observation data from Santa Barbara Municipal Airport [click to enlarge]

Pyrocumulonimbus clouds spawned by the KNP Complex wildfire in California

October 4th, 2021 |

GOES-17 Visible (0.64 µm, center), Shortwave Infrared (3.9 µm, center) and Infrared Window (10.35 µm, bottom) images [click to play animation | MP4]

The KNP Complex wildfire continued to burn in central California on 04 October 2021, producing a pair of pyrocumulonimbus or pyroCb clouds — one during the atypical late morning hours (beginning around 1530 UTC, or 11:30 am PDT) and the other during the more typical late afternoon hours (beginning around 2130 UTC, or 5:30 PM PDT). 1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed the pyroCB clouds, fire thermal anomalies or “hot spots” (clusters of red pixels) and cold cloud-top infrared brightness temperatures, respectively. The minimum 10.35 µm temperatures were near -60ºC. Note the relatively warm (darker gray) appearance of the pyroCb clouds in the 3.9 µm images — this is a characteristic signature of pyroCb cloud tops, driven by the smoke-induced shift toward smaller ice particles (which act as more efficient reflectors of incoming solar radiation, contributing to the warmer 3.9 µm brightness temperatures). Note: beginning at 1700 UTC, overlapping GOES-17 Mesoscale Sectors provided imagery at 30-second intervals.

1-minute GOES-17 True Color RGB images created using Geo2Grid (below) showed the first pyroCb cloud as it continued to move northeastward across the California/Nevada border, and then the second pyroCb cloud as it moved northwestward. The change in direction of motion was influenced by the approach of an offshore closed low from the west (250 hPa analysis: 12 UTC | 00 UTC). 

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