Fires continue in the southeast United States

November 14th, 2016

Terra MODIS (1650 UTC), Aqua MODIS (1829 UTC) and Suomi NPP VIIRS (1913 UTC) true-color images [click to enlarge]

Terra MODIS (1650 UTC), Aqua MODIS (1829 UTC) and Suomi NPP VIIRS (1913 UTC) true-color images [click to enlarge]

Fires (as seen on 07 and 10 November) continued to burn in parts of the southeast US on 14 November 2016. A sequence of 3 consecutive true-color Red/Green/Blue (RGB) images from Terra MODIS (1650 UTC), Aqua MODIS (1829 UTC) and Suomi NPP VIIRS (1913 UTC) viewed using RealEarth, above, showed the aerial extent of the dense smoke that was most concentrated over Tennessee, Georgia, North Carolina and South Carolina. With the aid of some of the 16 spectral bands on the ABI instrument aboard GOES-R, true-color images like these will be available at least once every 5 minutes over the Lower 48 states and adjacent areas.

GOES-13 (GOES-East) Visible (0.63 µm) images with plots of surface weather and visibility (below; also available as an MP4 animation) revealed that visibility was restricted to 3 miles or less at one or more sites in all of the aforementioned states. A pair of pilot reports in eastern Tennessee indicated that he top of the smoke layer was at 6000 feet above ground level.

GOES-13 Visible (0.63 µm) images, with hourly plots of surface weather (yellow) and visibility (statute miles, in cyan) [click to animate]

GOES-13 Visible (0.63 µm) images, with hourly plots of surface weather (yellow) and visibility (statute miles, in cyan) [click to animate]

High loading of particulate matter (PM) due to smoke led to AIRNow Air Quality Index ratings of Unhealthy (red)  to Very Unhealthy (purple) over much of that 4-state region (below).

Hourly AIRNow Particulate Matter (PM) Air Quality Index (AQI)

Hourly AIRNow Particulate Matter (PM) Air Quality Index (AQI)

===== 15 November Update =====

Suomi NPP VIIRS Shortwave Infrared (3.74 um) and Day/Night Band (0.7 um) images, plus METAR surface reports [click to enlarge]

Suomi NPP VIIRS Shortwave Infrared (3.74 um) and Day/Night Band (0.7 um) images, plus METAR surface reports [click to enlarge]

A toggle between Suomi NPP VIIRS Shortwave Infrared (3.74 um) and Day/Night Band (0.7 um) images (with and without METAR surface reports) at 0735 UTC or 3:35 am local time on 15 November (above) showed the “hot spot” signatures and bright glow from the larger fires that were burning in northern Georgia and western North Carolina. With ample illumination from the Moon — which was in the Waning Gibbous phase, at 99% of Full — smoke plumes from some of these fires could be seen drifting southward or southeastward,  thanks to the “visible image at night” capability of the Day/Night Band.

During the subsequent daytime hours, Terra MODIS and Suomi NPP VIIRS true-color RGB images (below) again revealed the vast coverage of the thick smoke — and VIIRS Aerosol Optical Depth values were quite high over South Carolina. Unhealthy AQI values persisted during much of the day across parts of Tennessee, Georgia and South Carolina.

Terra MODIS and Suomi NPP VIIRS true-color images, with VIIRS Aerosol Optical Depth (click to enlarge]

Terra MODIS and Suomi NPP VIIRS true-color images, with VIIRS Aerosol Optical Depth (click to enlarge]

A sampling of pilot reports (PIREPS) showed some of the impacts that the smoke was having on aviation (below).

Suomi NPP VIIRS Visible (0.64 µm) image with a PIREP over South Carolina [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm) image with a PIREP over South Carolina [click to enlarge]

Aqua MODIS Visible (0.65 µm) image with a PIREP over Georgia [click to enlarge]

Aqua MODIS Visible (0.65 µm) image with a PIREP over Georgia [click to enlarge]

GOES-13 Visible (0.63 µm) image with a PIREP over North Carolina [click to enlarge]

GOES-13 Visible (0.63 µm) image with a PIREP over North Carolina [click to enlarge]

===== 16 November Update =====

Terra/Aqua MODIS and Suomi NPP VIIRS true- color images [click to enlarge]

Terra/Aqua MODIS and Suomi NPP VIIRS true- color images [click to enlarge]

Terra/Aqua MODIS and Suomi NPP VIIRS true-color images (above) showed that much of the smoke had moved over the adjacent offshore waters of the Atlantic Ocean on 16 November.

 

Fires in the southeast United States

November 7th, 2016
terramodis_truecolor_7nov2016

Terra MODIS True-Color Imagery over the Smoky Mountains, 7 November 2016 (Click to enlarge)

Persistent moderate to severe drought (shown here, from this site) over the southeastern United States has supported the development of fires in and around the Great Smoky Mountains on 7 November 2016. True-color imagery from Terra MODIS, above, (source: MODIS Today) showed the active fires and plumes of smoke spreading northward into the Ohio River Valley.

Suomi NPP VIIRS true-color imagery also captured the smoke emanating from the active fires, and the Aerosol Optical Depth product, toggled below (data sources: RealEarth) showed the extent of the thickest smoke layer (click here for an animation that does not include the RealEarth framing).

Suomi NPP VIIRS true-color image with fire detection locations (red dots), and VIIRS Aerosol Optical Depth product [click to enlarge]

Suomi NPP VIIRS true-color image with fire detection locations (red dots), and VIIRS Aerosol Optical Depth product [click to enlarge]

A sequence of true-color Red/Green/Blue (RGB) images from Terra MODIS (1643 UTC), Suomi NPP VIIRS (1809 UTC) and Aqua MODIS (1824 UTC) is shown below.

Terra MODIS, Suomi NPP VIIRS and Aqua MODIS true-color images [click to enlarge]

Terra MODIS, Suomi NPP VIIRS and Aqua MODIS true-color images [click to enlarge]

The temporal evolution of the smoke was captured on GOES-13 Visible (0.63 µm) images (below; also available as an MP4 animation). Smoke reduced the surface visibility to 2.5 – 3.0 miles at some locations in Kentucky (KJKL | KLOZ) and Tennessee (KOQT), leading to EPA Air Quality Index values in the “Unhealthy” category.

GOES-13 Visible (0.63 µm) images; hourly surface weather symbols are plotted in yellow, with surface visibility (statute miles) plotted in cyan [click to play animation]

GOES-13 Visible (0.63 µm) images; hourly surface weather symbols are plotted in yellow, with surface visibility (statute miles) plotted in cyan [click to play animation]

===== 10 November Update =====

GOES-13 Visible (0.63 µm) images; hourly surface weather symbols are plotted in yellow, with surface visibility (statute miles) plotted in cyan [click to play animation]

GOES-13 Visible (0.63 µm) images; hourly surface weather symbols are plotted in yellow, with surface visibility (statute miles) plotted in cyan [click to play animation]

In the wake of a cold frontal passage on 09 November, northerly to northeasterly winds were transporting the smoke south-southwestward as the fires continued to burn on 10 November. GOES-13 Visible (0.63 µm) images, above, showed the dense smoke plumes — some of which were briefly reducing the surface visibility to less than 1 statute mile in far western North Carolina (Andrews | Franklin). In Georgia, smoke restricted the visibility to 2.5 miles as far south as Columbus.

A Pilot Report (PIREP) in northern Georgia at 1530 UTC, below, indicated that the top of the smoke layer was around 3500 feet (where the Flight Visibility was 4 miles).  Surface reports in the vicinity of that PIREP indicated a ceiling of 1500 to 1700 feet, suggesting that the dense smoke layer aloft was about 1800-2000 feet thick over northern Georgia.

GOES-13 Visible (0.63 µm) image, with cloud ceiling (hundreds of feet above ground level) and visibility (statute miles) plotted in cyan and a Pilot Report in yellow [click to enlarge]

GOES-13 Visible (0.63 µm) image, with cloud ceiling (hundreds of feet above ground level) and visibility (statute miles) plotted in cyan and a Pilot Report in yellow [click to enlarge]

The smoke plumes showed up very well on an Aqua MODIS true-color RGB image from the MODIS Today site, below.

Aqua MODIS true-color image [click to enlarge]

Aqua MODIS true-color image [click to enlarge]

The 1858 UTC Suomi NPP VIIRS true-color image (with fire detections) and the Aerosol Optical Depth product, below, depicted the aerial coverage of the smoke.

Suomi NPP VIIRS true-color image (with fire detection locations in red) and Aerosol Optical Depth product [click to enlarge]

Suomi NPP VIIRS true-color image (with fire detection locations in red) and Aerosol Optical Depth product [click to enlarge]

3-day transport of airborne Copper River Valley glacial silt/sand over the Gulf of Alaska

October 25th, 2016

GOES-15 Visible (0.63 µm) images, 23 through 25 October 2016, with hourly surface observations [click to play animation]

GOES-15 Visible (0.63 µm) images, 23 through 25 October 2016, with hourly surface observations [click to play animation]

GOES-15 (GOES-West) Visible (0.63 µm) images during the daylight hours on 23, 24 and 25 October 2016 (above) revealed the hazy signature of large amounts of airborne glacial silt and sand from the Copper River Valley being transported southward over the adjacent offshore waters of the Gulf of Alaska. The fine glacial silt and sand particles were being lofted by strong katabatic gap winds being channeled southward down the Copper River Valley — these winds were the result of a strong pressure gradient between arctic high pressure that was moving from the Interior of Alaska to the Yukon Territory of Canada (surface analyses) and a large occluded low centered off the coast of British Columbia and the US Pacific Northwest (24 October visible imagery).

Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images on 24 October 2016 [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images on 24 October 2016 [click to enlarge]

Comparisons between Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images on 24 October (above) and 25 October (below) showed that the small airborne glacial silt/sand particles were very reflective to solar radiation, and exhibited a warmer (darker gray to black enhancement) signature in the Shortwave Infrared images (similar to the warmer signature seen due to spherical water droplets at the tops of supercooled stratiform clouds). On 25 October a large aerosol plume was also emerging from Yakutat Bay, moving southwestward.

Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images on 25 October 2016 [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images on 25 October 2016 [click to enlarge]

Time series of surface observations at Middleton Island in the Gulf of Alaska [click to enlarge]

Time series of surface observations at Middleton Island in the Gulf of Alaska [click to enlarge]

A time series plot of surface observations from Middleton Island (PAMD) in the northern Gulf of Alaska (above) showed that the surface visibility was reduced to 3 miles on 24 October and 5 miles on 25 October as the Copper River plume periodically passed over the island. The ceiling height on 24 October was reported to be as low as 1400 feet as the surface visibility began to decrease. Along the southern coast of Alaska just west of the Copper River Delta, the visibility at Cordova (PACV) dropped to 5 miles with haze reported late in the day on 25 October as the western edge of the plume drifted over that area (below).

Time series of surface observations at Cordova, Alaska [click to enlarge]

Time series of surface observations at Cordova, Alaska [click to enlarge]

A zoom-in of the 2246 UTC Suomi NPP VIIRS true-color Red/Green/Blue (RGB) image on 24 October (using RealEarth) showed the gray to light tan color of the glacial silt/sand plume.

Suomi NPP VIIRS true-color RGB images [click to enlarge]

Suomi NPP VIIRS true-color RGB images [click to enlarge]

Shown below are toggles between Suomi NPP VIIRS true-color RGB and Aerosol Optical Thickness (AOT) images (from the eIDEA site) for 23, 24 and 25 October. Very high values of AOT (in the 0.8 to 1.0 range) were associated with the Copper River plumes.

Suomi NPP VIIRS true-color RGB and Aerosol Optical Depth images for 23 October [click to enlarge]

Suomi NPP VIIRS true-color RGB and Aerosol Optical Depth images for 23 October [click to enlarge]

Suomi NPP VIIRS true-color RGB and Aerosol Optical Thickness images for 24 October [click to enlarge]

Suomi NPP VIIRS true-color RGB and Aerosol Optical Thickness images for 24 October [click to enlarge]

Suomi NPP VIIRS true-color RGB and Aerosol Optical Thickness images for 25 October [click to enlarge]

Suomi NPP VIIRS true-color RGB and Aerosol Optical Thickness images for 25 October [click to enlarge]

A toggle between Terra MODIS Visible (0.64 µm) and Infrared (11-12 µm, commonly referred to as the “split window difference”) Brightness Temperature Difference (BTD) images on 25 October (below) revealed that there was a very subtle Copper River plume signature in the BTD image (note: the default 11-12 µm BTD color enhancement was modified to better highlight the plume in this example).

Terra MODIS Visible (0.64 µm) and Infrared (11.0-12.0 µm) Brightness Temperature Difference images [click to enlarge]

Terra MODIS Visible (0.64 µm) and Infrared (11.0-12.0 µm) Brightness Temperature Difference images [click to enlarge]

In that respect, the MODIS Infrared “split window” BTD images could be used to help locate the Copper River plume during nighttime as well as daytime, as seen in the image comparison below. The ABI instrument on GOES-R will have similar 11 µm and 12 µm Infrared bands, and will have the capability to provide this type of BTD imagery at 5 minute intervals over the entire Full Disk scan.

Nighttime (0706 UTC) and daytime (2031 UTC) Terra MODIS Infrared (11-12 µm) Brightness Temperature Difference images [click to enlarge]

Nighttime (0706 UTC) and daytime (2031 UTC) Terra MODIS Infrared (11-12 µm) Brightness Temperature Difference images [click to enlarge]

Previous cases of similar airborne Copper River plumes have been documented on this blog: Oct 2014 | Nov 2013 | Oct 2012.

Fort McMurray, Alberta wildfire

May 3rd, 2016

GOES-15 0.63 um Visible (top) and 3.9 um Shortwave Infrared (bottom) images [click to play animation]

GOES-15 0.63 µm Visible (top) and 3.9 µm Shortwave Infrared (bottom) images [click to play animation]

GOES-15 (GOES-West) Visible (0.63 µm) and Shortwave Infrared (3.9 µm) images (above) showed the hot spot (dark black to yellow to red pixels) and the development of pulses of pyrocumulonimbus (pyroCb) clouds associated with a large wildfire located just to the west of Fort McMurray, Alberta (station identifier CYMM) on 03 May 2016. The fire — which started on 01 May (Wikipedia) — caused a mandatory evacuation of the nearly 90,00 residents of the city (the largest fire-related evacuation in Alberta history). Note that the hourly surface plots indicated a temperature of 90º F (32.2º C) at 22-23 UTC — in fact, a new daily record high temperature of 32.6º C was set for Fort McMurray (time series plot of surface data).

The corresponding GOES-15 Visible (0.63 µm) and Infrared Window (10.7 µm) images (below) revealed cloud-top infrared brightness temperature values as cold as -58º C (darker red color enhancement) at 0030 and 0100 UTC on 04 May.

GOES-15 0.63 um Visible (top) and 10.7 um Infrared Window (bottom) images [click to play animation]

GOES-15 0.63 µm Visible (top) and 10.7 µm Infrared Window (bottom) images [click to play animation]

Suomi NPP VIIRS False-color RGB, Visible (0.64 um), Shortwave Infrared (3.74 um), and Infrared Window (11.45 um) images at 1834 UTC [click to enlarge]

Suomi NPP VIIRS False-color RGB, Visible (0.64 µm), Shortwave Infrared (3.74 µm), and Infrared Window (11.45 µm) images at 1834 UTC [click to enlarge]

A comparison of Suomi NPP VIIRS false-color “Snow vs cloud discrimination” Red/Green/Blue (RGB), Visible (0.64 µm), Shortwave Infrared (3.74 µm), and Infrared Window (11.45 µm) images at 1834 UTC (above) showed that while a large fire hot spot was apparent on the Shortwave Infrared image, there was no clear indication of any pyrocumulus cloud development at that time. However, a similar image comparison at 2018 UTC (below) revealed that a well-defined pyroCb cloud had formed (with a cloud-top infrared brightness temperature as cold as -60º C, dark red color enhancement) which was drifting just to the north of the Fort McMurray airport (whose cyan surface report is plotted near the center of the images). A 2104 UTC NOAA-19 AVHRR image provided by René Servranckx showed a minimum IR brightness temperature of -59.6º C.

Suomi NPP VIIRS false-color RGB, Visible (0.64 um), Shortwave Infrared (3.74 um), and Infrared Window (11.45 um) images at 2018 UTC [click to enlarge]

Suomi NPP VIIRS false-color RGB, Visible (0.64 µm), Shortwave Infrared (3.74 µm), and Infrared Window (11.45 µm) images at 2018 UTC [click to enlarge]

A closer look using Suomi NPP VIIRS true-color RGB and Shortwave Infrared (3.74 µm) images from the SSEC RealEarth site (below) showed the initial pyroCb cloud as it had drifted just east of Fort McMurray, with the early stages of a second pyroCb cloud just south of the city.

Suomi NPP VIIRS true-color RGB and Shortwave Infrared (3.74 um) images [click to enlarge]


Suomi NPP VIIRS true-color RGB and Shortwave Infrared (3.74 µm) images [click to enlarge]

A nighttime comparison of Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images at 1015 UTC or 3:15 am local time (below; courtesy of William Straka, SSEC) showed the bright glow of the large Fort McMurray wildfire, as well as the lights associated with the nearby oil shale mining activity.

Suomi NPP VIIRS Day/Night Band (0.7 um) and Shortwave Infrared (3.74 um) images at 1014 UTC [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images at 1014 UTC [click to enlarge]

A sequence of Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images covering the 02 April – 04 April period (below) showed the diurnal changes as well as the overall growth of the fire hot spot (darker black pixels).

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

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

===== 05 May Update =====

The GOES-14 satellite was operating in Super Rapid Scan Operations for GOES-R (SRSOR) mode, providing images at 1-minute intervals — and the scan sector was positioned to monitor the Fort McMurray wildfire on 05 May. GOES-14 Visible (0.63 µm) and Shortwave Infrared (3.9 µm) images (below; also available as a large 133 Mbyte animated GIF) showed the growth of the smoke plume and fire hot spot signature (black to yellow to red pixels).

GOES-14 0.63 µm Visible (top) and 3.9 µm Shortwave Infrared (bottom) images [click to play MP4 animation]

GOES-14 0.63 µm Visible (top) and 3.9 µm Shortwave Infrared (bottom) images [click to play MP4 animation]


A 30-meter resolution Landsat-8 false-color Red/Green/Blue (RGB) image (below) showed the size of part of the fire burn scar (darker brown) as well as the active fires (bright pink) along the perimeter of the burn scar.

Landsat-8 false-color image [click to enlarge]

Landsat-8 false-color image [click to enlarge]

===== 06 May Update =====

The Fort McMurray fire continued to produce a great deal of smoke on 06 May, and the coverage and intensity of fire hot spots increased during the afternoon hours as seen on 1-minute GOES-14 Visible (0.63 µm) and Shortwave Infrared (3.9 µm) images (below; also available as a large 180 Mbyte animated GIF).

GOES-14 0.63 µm (top) and 3.9 µm Shortwave Infrared (bottom) images [click to play MP4 animation]

GOES-14 0.63 µm (top) and 3.9 µm Shortwave Infrared (bottom) images [click to play MP4 animation]

===== 13 May Update =====

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

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

A comparison of Suomi NPP VIIRS Shortwave Infrared (3.74 µm) and Day/Night Band (0.7 µm) images at 0906 UTC or 3:06 am local time (above) showed the fire hot spots (dark gray to yellow to red pixels) and their nighttime glow.

A time series of VIIRS Shortwave Infrared (3.74 µm) images covering the 04-13 May period (below) revealed the rapid early growth of the fire, and the continued slow spread of the fire periphery toward the Alberta/Saskatchewan border. On 13 May the total size of the area burned by the Fort McMurray fire was estimated to be 241,000 hectares or 595,524 acres.

Time series of Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images, covering the 04-13 May period [click to enlarge]

Time series of Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images, covering the 04-13 May period [click to enlarge]

===== 16 May Update =====

GOES-15 0.63 µm Visible (left) and 3.9 µm shortwave Infrared (right images [click to play animation]

GOES-15 0.63 µm Visible (left) and 3.9 µm shortwave Infrared (right images [click to play animation]

Strong southerly winds ahead of an approaching trough axis (surface analyses) created favorable conditions for rapid fire growth on 16 May — GOES-15 Visible (0.63 µm) and Shortwave Infrared (3.74 µm) images (above) showed the development of pyrocumulus clouds (first on the far western flank of the fire around 1930 UTC, then later in the eastern portion of the fire area). This new flare-up of fire activity prompted additional evacuations of some oil sands work camps and facilities north of Fort McMurray.

A comparison of Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images at 1932 UTC (below) showed that a small pyroCb had developed, which exhibited a cloud-top IR brightness temperature of -41.48 C.

Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm), and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm), and Infrared Window (11.45 µm) images [click to enlarge]

A toggle between the corresponding VIIRS true-color RGB image and Shortwave Infrared images is shown below.

Suomi NPP VIIRS true-color RGB and Shortwave Infrared (3.74 µm) images [click to enlarge]

Suomi NPP VIIRS true-color RGB and Shortwave Infrared (3.74 µm) images [click to enlarge]

A time series plot of surface weather conditions for Fort McMurray (below) shows that during prolonged periods of light winds, the surface visibility dropped below 1 mile at times. The air quality at Fort McMurray was rated as “extreme“, and deemed unsafe for residents to return to the city.

Time series of weather conditions at Fort McMurray on 16 May [click to enlarge]

Time series of weather conditions at Fort McMurray on 16 May [click to enlarge]

===== 17 May Update =====

GOES-15 0.63 µm Visible (left) and 3.9 µm Shortwave Infrared (right) images [click to play animation]

GOES-15 0.63 µm Visible (left) and 3.9 µm Shortwave Infrared (right) images [click to play animation]

A shift to westerly winds followed the passage of a surface trough axis on 17 May (surface analyses), which slowed the northward progress of the fire. GOES-15 Visible (0.63 µm) and Shortwave Infrared (3.9 µm) images (above; also available as an MP4 animation) continued to show a great deal of thick smoke over the region, with hot spots from active fires.

However, during the afternoon hours multiple pyroCb clouds were seen to develop along the eastern flank of the fire. A comparison of Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images at 2054 UTC (below) revealed the pyroCb clouds, which exhibited cloud-top IR Window brightness temperatures as cold as -57º C (darker orange color enhancement).

Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 m) and Infrared Window (11.45 ) images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 m) and Infrared Window (11.45 ) images [click to enlarge]

A comparison of GOES-15 Shortwave Infrared (3.9 µm) and Infrared Window (10.7 µm) images (below; also available as an MP4 animation) showed the development of the pyroCb clouds around 2000 UTC, whose anvil debris moved rapidly southeastward; these pyroCb clouds exhibited a darker gray appearance on the shortwave IR images, along with cloud-top IR Window brightness temperatures as cold as -52º C (light orange color enhancement). Lightning strikes were detected during the early stages of pyroCb growth.

GOES-15 3.9 µm Shortwave Infrared (left) and 10.7 µm Infrared Window (right) images [click to play animation]

GOES-15 3.9 µm Shortwave Infrared (left) and 10.7 µm Infrared Window (right) images [click to play animation]

===== 18 May Update =====

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images covering the 04-18 May 2016 period [click to enlarge]

Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images covering the 04-18 May 2016 period [click to enlarge]

Daily Suomi NPP VIIRS Shortwave Infrared (3.74 µm) images covering the period 04 May to 18 May 2016 are shown above. The rapid growth of the perimeter of fire hot spots (yellow to red color enhancement) is quite evident during the first few days; patches of thick cloud cover tended to mask the fire hot spots during the middle of the period, but then another increase in hot spot growth is seen beginning on 16 May.