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.

Cyclone Chapala approaches Yemen

November 2nd, 2015
METOP-B Imagery (0.63 µm Visible and 10.8 µm Infrared) over Chapala, ~0615 UTC on 2 November 2015

METOP-B Imagery (0.63 µm Visible and 10.8 µm Infrared) over Chapala, ~0615 UTC on 2 November 2015 (Click to enlarge)

Cyclone Chapala continued its unusual approach towards Yemen on the southwestern edge of the Arabian Peninsula. Early on 2 November, the storm has passed just north of the Island of Socotra and entered the Gulf of Aden. METOP-B overflew the storm at ~0615 UTC on 2 November; Visible and Infrared data, above, show a still-compact storm with an obvious eye ringed by cold cloud tops (the coldest brightness temperatures are near -75º C) tucked into the mouth of the Gulf of Aden. Wind shear in the region is very low and sea-surface temperatures are warm. The morphed microwave imagery, below (taken from this site), indicates that the eyewall brushed the island of Socotra as it passed (a comparison of Meteosat-7 Infrared and DMSP SSMIS microwave images around 15 UTC on 01 November can be seen here).

Morphed Microwave Imagery ending 1645 UTC 01 November 2015

Morphed Microwave Imagery ending 1645 UTC 01 November 2015 (Click to enlarge)

Subsequent microwave imagery, below, for the 24 hours ending 1200 UTC on 2 November (the image below overlaps the one above) show a decrease in the eyewall structure and intensity.

Morphed Microwave Imagery ending 1200 UTC 02 November 2015

Morphed Microwave Imagery ending 1200 UTC 02 November 2015 (Click to enlarge)

Satellite-based intensity estimates at around 0000 UTC on 2 November (link) suggest a central mean sea-level pressure around 940 mb with sustained winds near 120 knots. The 0000 UTC Meteosat-7 image is shown below.

Meteosat-7 Window Channel Infrared (11.5 µm) 0000 UTC, 2 November 2015

Meteosat-7 Window Channel Infrared (11.5 µm) 0000 UTC, 2 November 2015 (Click to enlarge)

Suomi NPP overflew the region shortly after 2100 UTC on 1 November, and the Day/Night Band imagery from VIIRS is shown below, toggled with the 11.45 µm Infrared imagery. The storm is centered just northwest of Socotra; mesovortices are evident within the eye, as are overshooting tops in the eyewall convection; the bright streak seen on the Day/Night Band image is a region of the western eyewall illuminated by intense lightning activity. Zoomed-out versions of the imagery are available here for Day/Night Band and here for 11.45 µm Infrared. (VIIRS Imagery courtesy William Straka, SSEC/CIMSS).

Suomi NPP VIIRS Day/Night Band Visible Image and 11.45 µm Infrared Image 2149 UTC, 2 November 2015

Suomi NPP VIIRS Day/Night Band Visible Image and 11.45 µm Infrared Image 2149 UTC, 2 November 2015 (Click to enlarge)

A comparison of Meteosat-7 Infrared and DMSP SSMIS Microwave images around 1530 UTC on 2 November, below, showed the northern edge of the eyewall very near to the coast of Yemen.

Meteosat-7 Infrared and DMSP SSMIS Microwave images {click to enlarge)

Meteosat-7 Infrared and DMSP SSMIS Microwave images (click to enlarge)

At landfall, below, as viewed by Suomi NPP’s VIIRS instrument and a timely overpass, the eye of the storm had filled. The change in storm structure prior to landfall was very apparent in this toggle of two METOP Infrared images, at 0558 and 1644 UTC on 2 November. However, Meteosat-7 Infrared images showed that there was a large convective burst that developed as Chapala made landfall. Chapala was the first tropical cyclone on record to make landfall in Yemen while still at hurricane intensity.

Suomi NPP VIIRS I05 (11.45 µm) Infrared Image, 2127 UTC on 2 November [click to enlarge]

Suomi NPP VIIRS I05 (11.45) Infrared Image, 2127 UTC on 2 November (click to enlarge)

A 6-day animation of the storm using VIIRS true-color imagery from RealEarth can be seen here. Cyclone Chapala is also discussed in this blog post.

===== 05 November Update =====

A 14-day animation of UK Met Office OSTIA Sea Surface Temperature, below, reveals the cold wake of upwelling water (yellow color enhancement) following the passage of Hurricane Chapala.

UK Met Office OSTIA Sea Surface Temperature analyses [click to enlarge]

UK Met Office OSTIA Sea Surface Temperature analyses [click to enlarge]

Strong Convection over the Upper Midwest

July 13th, 2015
MODIS 11 µm infrared imagery and GOES Sounder DPI Lifted Index, 0400 UTC (Click to enlarge)

MODIS 11 µm infrared imagery and GOES Sounder DPI Lifted Index, 0400 UTC 13 July 2015 (click to enlarge)

A strong mesoscale convective system (MCS) moving southeastward through the Upper Midwest from late 12 July 2015 into early morning 13 July caused numerous severe wind reports across Minnesota and Wisconsin. This MCS was forecast to drop southeastward and continue to produce severe weather during the day on 13 July 2015 (Storm Prediction Center outlook). The toggle above shows the 0420 UTC Terra MODIS 11.0 µm image and the 0400 UTC GOES-13 Sounder DPI Lifted Index product (which is available in realtime here). As the MCS moved over southern Wisconsin, the coldest cloud-top IR brightness temperature on the 0826 UTC MODIS 11.0 µm IR image was -85º C. The strong system continued to move southeastward as very unstable air as diagnosed by the Sounder fed into it (click here for 850-mb RAOB plots). The 0746 UTC Suomi NPP VIIRS 11.45 µm IR image, below, also toggled with a GOES-13 Sounder Lifted Index product, showed a similar story: very strong convection downwind of a source of strong instability. The GOES Sounder can also diagnose Convective Available Potential Energy (CAPE), with values from 5000-6000 J/kg seen over southern Minnesota and eastern Iowa.

Suomi NPP VIIRS 11.45 µm infrared imagery and GOES Sounder DPI Lifted Index, 0746/0800 UTC (Click to enlarge)

Suomi NPP VIIRS 11.45 µm infrared imagery and GOES Sounder DPI Lifted Index, 0746/0800 UTC 13 July 2015 (click to enlarge)

The Suomi NPP VIIRS Day/Night Band, below, which is a source of visible imagery at night, depicted signatures of the active lightning that accompanied this system: numerous along-scan bright streaks over southern Wisconsin were caused by lightning illuminating the cloud as the VIIRS instruments scanned the cloud top. This toggle showed a comparison of Day/Night Band and 11.45 µm Infrared imagery.

Suomi NPP VIIRS Day/Night Band 0.70 µm visible imagery 0746 UTC (Click to enlarge)

Suomi NPP VIIRS Day/Night Band 0.70 µm visible imagery 0746 UTC 13 July 2015 (click to enlarge)

A closer view comparing the 0746 UTC VIIRS IR and Day/Night Band images, below, includes overlays of METAR reports and both 15-minute and 1-hour cloud-to-ground lightning strikes. The coldest VIIRS cloud-top IR brightness temperature was -78º C.

Suomi NPP VIIRS 11.45 µm IR and 0.7 µm Day/Night Band images, with overlays of METAR surface reports and cloud-to-ground lightning strikes (click to enlarge)

Suomi NPP VIIRS 11.45 µm IR and 0.7 µm Day/Night Band images, with overlays of METAR surface reports and cloud-to-ground lightning strikes (click to enlarge)

At 0805 UTC, the coldest CLAVR-x POES AVHRR Cloud Top Temperature value was -81º C, with maximum Cloud Top Height values of 15 km along the southwestern portion of the MCS.

POES AVHRR Cloud Top Temperature and Cloud Top Height products at 0805 UTC (click to enlarge)

POES AVHRR Cloud Top Temperature and Cloud Top Height products at 0805 UTC (click to enlarge)

This image of Radar Composites of the main line of storms was produced by Greg Carbin of SPC and was posted on Facebook on 13 July 2015.

Typhoons Chan-Hom and Nangka in the same Suomi NPP VIIRS Overpass

July 8th, 2015
Suomi NPP Day/Night Band (0.70 µm) and Infrared Window Channel (11.45 µm) images at 1616 UTC 8 July 2015 (Click to animate)

Suomi NPP Day/Night Band (0.70 µm) and Infrared Window Channel (11.45 µm) images at 1616 UTC on 8 July 2015 (click to enlarge)

The toggle above shows Suomi NPP VIIRS 0.7 µm Day/Night Band and the 11.45 µm Infrared images (courtesy of William Straka, SSEC). It is unusual because two strong tropical cyclones (Category 2 Typhoon Chan-Hom on the left, and Category 4 Typhoon Nangka on the right) are captured in one satellite overpass.

The Day/Night Band (DNB) image shows little evidence of lightning (bright white streaks) with either storm; due to ample illumination from a Third Quarter Moon (at 54% of Full),  the DNB was able to provide a “visible image at night”. Both images show Nangka to be the stronger storm: the eye is more pronounced, and is more symmetric. More information on these storms is available here.