Pyrocumulonimbus cloud in eastern Australia

November 22nd, 2019 |

Himawari-8 “Red” Visible (0.64 µm, top), Shortwave Infrared (3.9 µm, middle) and “Clean” Infrared Window (10.4 µm, bottom) [click to play animation | MP4]

Himawari-8 “Red” Visible (0.64 µm, top), Shortwave Infrared (3.9 µm, middle) and “Clean” Infrared Window (10.4 µm, bottom) [click to play animation | MP4]

JMA Himawari-8 AHI “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.4 µm) images (above) showed the development of a pyrocumlonimbus (pyroCb) cloud produced by bush fires northwest of Sydney, Australia (station identifier YSSY) on 22 November 2019 (surface analyses). In the 3.9 µm images, hot thermal signatures of the bush fires (darker black to red pixels) were apparent; in addition, the cloud tops of the pyroCb cloud appeared warmer (darker gray) than surrounding convective cloud tops. The pyroCb exhibited cloud-top 10.4 µm brightness temperatures colder than -40ºC.

VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 as viewed using RealEarth are shown below. Cloud-top 11.45 µm brightness temperatures of the pyroCb were in the -70 to -75ºC range on the later 0407 UTC Suomi NPP image.

VIIRS True Color RGB and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 [click to enlarge]

VIIRS True Color RGB and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 [click to enlarge]

The coldest Himawari-8 10.4 µm brightness temperature (BT) associated with the southernmost thunderstorm was -67.0ºC at 0520 UTC (with the northern pyroCb storm, closer to the fire complex, reaching -66.9ºC at 0500 UTC).  According to 00 UTC rawinsonde data from nearby Williamtown (below), those BTs were 2-3ºC colder than the coded tropopause temp of -64.5ºC at 12.6 km. The VIIRS 11.45 µm BTs were nearly 10ºC colder than the tropopause, suggesting significant penetration of overshooting tops into the lower stratosphere.
Plot of rawinsonde data from Williamtown, New South Wales [click to enlarge]

Plot of rawinsonde data from Williamtown, New South Wales [click to enlarge]

Widespread fires across the Deep South

November 19th, 2019 |

GOES-16 Fire Temperature RGB, Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area products [click to play animation | MP4]

GOES-16 Fire Temperature RGB, Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area products [click to play animation | MP4]

A sequence of GOES-16 (GOES-East) Fire Temperature RGB, Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area products (above) displayed signatures of widespread fires — a combination of prescribed burns and agricultural fires — across parts of the Deep South on 19 November 2019. Fire Temperature, Fire Power and Fire Area products are components of the GOES Fire Detection and Characterization Algorithm (SHyMet | ATBD).

GOES-16 “Red” Visible (0.64 µm) images, with and without plots of surface observations, are shown below. While most of the fires were too small/brief to produce large smoke plumes, a prominent plume was associated with one of the hottest and most long-lived fires — which was likely a prescribed burn — in the Chickasawhay State Wildlife Management Area (located east of Hattiesburg/Laurel Airport KPIB) in southeastern Mississippi.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with and without plots of surface observations [click to play animation | MP4]

There were no surface stations downwind of that Mississippi fire; however, one small smoke plume drifted over Lafayette in southern Louisiana (KLFT) near the end of the day, briefly reducing the visibility to 6 miles at 22 UTC (below).

Time series of surface observation data from Lafayette Regional Airport in Louisiana [click to enlarge]

Time series of surface observation data from Lafayette Regional Airport in Louisiana [click to enlarge]

For the hot fire in southeastern Mississippi, GOES-16 Shortwave Infrared, Fire Temperature, Fire Power and Fire Area values are shown for the same hot fire pixel at 1716, 1731 and 1806 UTC (below). Note that the individual parameter trends can be different for a given fire pixel — for example, even though the hottest 3.9 µm brightness temperature value was 58.8ºC at 1806 UTC, the peak Fire Temperature value was 1373.1 K at 1731 UTC. However, the time of the maximum Fire Power value of 213.6 MW coincided with the time of the hottest 3.9 µm brightness temperature value (1806 UTC).

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1716 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1716 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1731 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1731 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1806 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1806 UTC [click to enlarge]

Easy Fire in Southern California

October 30th, 2019 |

GOES-17 Shortwave Infrared (3.9 µm) and “Red” Visible (0.64 µm) images [click to play animation | MP4]

GOES-17 Shortwave Infrared (3.9 µm) and “Red” Visible (0.64 µm) images [click to play animation | MP4]

As northeast Santa Ana winds began to increase before sunrise on 30 October 2019, 1-minute Mesoscale Domain Sector GOES-17 (GOES-West) Shortwave Infrared (3.9 µm) and “Red” Visible (0.64 µm) images (above) showed the sudden onset of a thermal anomaly (cluster of  hot 3.9 µm pixels) — associated with the Easy Fire northwest of Los Angeles — which occurred at 1308-1309 UTC (6:08-6:09 AM local time). After sunrise, the narrow wind-driven smoke plume was seen in the Visible imagery.

A comparison of 3 consecutive VIIRS Shortwave Infrared (3.74 µm) images from Suomi NPP and NOAA-20 with the corresponding GOES-17 Shortwave Infrared (3.9 µm) images (below) demonstrated the advantage of polar orbiter imagery for providing a more accurate depiction of the size and location of a fire. Note: the color enhancements are different for the Suomi NPP/NOAA-20 vs GOES-17 images, since there are differences between shortwave infrared detectors on the VIIRS and ABI instruments.

3.74 µm Shortwave Infrared images from Suomi NPP and NOAA-20 compared with the corresponding GOES-17 3.9 µm images [click to enlarge]

3.74 µm Shortwave Infrared images from Suomi NPP and NOAA-20 compared with the corresponding GOES-17 3.9 µm images [click to enlarge]

Stereoscopic views of the Kincade Fire in California

October 30th, 2019 |

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery on 24 October 2019, 1500-2350 UTC (Click to animate)

GOES-16 and GOES-17 satellite imagery can be remapped and combined to create stereoscopic imagery. To achieve the 3-dimensional effect, cross your eyes until three scenes are visible, and focus on the middle image.  You can also achieve this by placing a finger halfway between your eyes and the screen, and focusing on your finger, then focusing on the image behind.  (Here’s a website that might help).  The imagery above, from 24 October 2019, shows high clouds rotating anti-cyclonically above the smoke produced from the Kincade Fire (previous blog posts on this fire are here and here). The smoke plume extended far out into the Pacific Ocean. A Full-resolution image animation is shown below.

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery on 24 October 2019, 1500-2350 UTC (Click to animate)

Animations for 25 October, 26 October, 27 October, 28 October and 29 October are shown below, in order.

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery from 1500 UTC on 25 October 2019 to 0050 UTC on 26 October 2019 (Click to animate)

On the 25th and 26th of October, prevailing winds moved smoke into the Bay Area.  On both days, the fire appeared less vigorous in the visible imagery than on the 24th, at top, or on the 27th;  at least, it appeared to be producing less smoke.

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery from 1500 UTC on 26 October 2019 to 0050 UTC on 27 October 2019 (Click to animate)

On the 27th, below, the fire resembled the scene on 24 October, with a large smoke plume extending far southwest into the Pacific Ocean.

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery from 1500 UTC to 2350 UTC on 27 October 2019 (Click to animate)

On the 28th, below, smoke generation has decreased, and the smoke pall appears over the Bay Area again. A full-resolution version is available here.

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery from 1500 UTC to 2350 UTC on 28 October 2019 (Click to animate)

The scene on the 29th, below (Full resolution available here) is shown below. The smoke plume is extensive.

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery from 1500 UTC to on 29 October 2019 to 0050 UTC on 30 October 2019 (Click to animate)

How did the smoke plume change from day to day? The animation below shows data at 2350 UTC on 24-29 October.

GOES-16 (left) and GOES-17 (right) visible (0.64 µm) imagery at 2350 UTC from 24 to 29 October 2019 (Click to enlarge)