Southwest US monsoon convection: GOES-15 vs GOES-16

July 12th, 2018 |

GOES-15 Visible (0.63 µm, left) and GOES-16 Visible (0.64 µm, right) images [click to play MP4 animation]

GOES-15 Visible (0.63 µm, left) and GOES-16 “Red” Visible (0.64 µm, right) images [click to play MP4 animation]

GOES-15 (GOES-West) Visible (0.63 µm) and GOES-16 (GOES-East) “Red” Visible (0.64 µm) images — displayed in the native projection of each satellite, and centered on Las Vegas, Nevada — are shown above, depicting the development of deep convection across parts of the Desert Southwest on 12 July 2018. While the GOES-15 satellite was in Rapid Scan Operations mode (providing 2 extra images nearly every hour, at :11 and :41), a GOES-16 Mesoscale Sector was providing images at 1-minute intervals. Numerous flash flood watches, warnings and advisories were issued by NWS Las Vegas during the course of the day as some of the storms produced heavy rainfall (with as much as 0.75 inch at Cal Nev Ari and 0.61 inch at Needles, California KEED).

Note that the GOES-15 Visible images do not appear as bright as those from GOES-16 — prior to the GOES-R Series of satellites, the performance of visible detectors degraded over time, leading to imagery that appeared more dim as the Imager instrument aged. Visible detectors on the new ABI instrument benefit from on-orbit calibration to remedy this type of degradation.

The corresponding GOES-15 Infrared Window (10.7 µm) and GOES-16 “Clean” Infrared Window (10.3 µm) images (below) revealed cloud-top infrared brightness temperatures around -70ºC (black enhancement) associated with some the stronger thunderstorms; this was the tropopause temperature at an altitude of 16.7 km / 48,300 feet on 00 UTC Las Vegas rawinsonde data. The improvement in spatial resolution from 4 km (at sub-satellite point) with GOES-15 to 2 km with GOES-16 is very apparent — even though the satellite viewing angle is about 10 degrees higher for GOES-16 than it is for GOES-15.

GOES-15 Infrared Window (10.7 µm, left) and GOES-16 "Clean" Infrared Window (10.3 µm, right) images [click to play MP4 animation]

GOES-15 Infrared Window (10.7 µm, left) and GOES-16 “Clean” Infrared Window (10.3 µm, right) images [click to play MP4 animation]

Higher spatial resolution Infrared Window images from Terra/Aqua MODIS and Suomi NPP VIIRS (below) revealed a cloud-top infrared brightness temperature as cold as -79ºC in far northwestern Arizona on the 2017 UTC VIIRS image.

Infrared Window images from Terra/Aqua MODIS (11.0 µm) and Suomi NPP VIIRS (11.45 µm) [click to enlarge]

Infrared Window images from Terra/Aqua MODIS (11.0 µm) and Suomi NPP VIIRS (11.45 µm) [click to enlarge]

In addition to heavy rainfall, some thunderstorm winds created areas of blowing sand:

The GOES-16 Total Precipitable Water derived product (below) showed that rich moisture was present across the Desert Southwest, fueling the development of the widespread convection. TPW values in the 1.0 to 2.0 inch range were seen over southeastern California, southwestern Arizona and far southern Nevada.

GOES-16 Total Precipitable Water derived product [click to play MP4 animation]

GOES-16 Total Precipitable Water derived product [click to play MP4 animation]

A 4-km resolution Terra/Aqua MODIS Total Precipitable Water product (below) indicated values in the 40-55 mm or 1.6-2.2 inch range.

Terra/Aqua MODIS Total Precipitable Water product [click to enlarge]

Terra/Aqua MODIS Total Precipitable Water product [click to enlarge]

Fires in Saskatchewan

May 15th, 2018 |

GOES-16 ABI Band 1 (“Blue Visible”, 0.47 µm, top), Band 2 (“Red Visible”, 0.64 µm, middle) and Band 7 (“Shortwave Infrared”, 3.9 µm, bottom) from 1345 to 2230 UTC on 15 May 2018 (Click to animate);  Note that the yellow enhancement in the shortwave infrared starts at 305 K.

Fires that developed over the plains of Saskatchewan, near Meadow Lake in west-central Saskatchewan, and near Prince Albert in central Saskatchewan, showed up well in Visible and Infrared imagery, shown above.  A wind shift that occurred as the fires burned changed the direction of the smoke plume.  Prince Albert had visibilities that dropped to 3 statute miles.  Meadow Lake had visibilities down to 4 statute miles.

True-Color imagery (Source: (Link), imagery provided by Paul Ford, ECC Canada), also shows the distinct smoke plumes from the fires.

True-Color imagery over Saskatchewan, 1730-2000 UTC

The Dual-Pol S-band radar at Radisson captured the plume north of Prince Albert at 1900 UTC (See below; click here for the satellite imagery at that time).  Very small Cross-Correlation coefficients are apparent in the smoke plume. The radar at 2010 UTC (link) suggests 3 separate fires, which agrees with the satellite imagery. (Click here for 2015 UTC Satellite Imagery).

Cross-Correlation Scan from the dual pol, S-band at Radisson, Saskatchewan, 1900 UTC on 15 May 2018 (Click to enlarge)

Many Thanks to Paul Ford, ECC Canada, for the radar imagery, and for alerting us to this event. Saskatchewan fires can be tracked at this website. Most of Saskatchewan is currently under a fire ban.


========== ADDED ============
AWIPS imagery of this fire were collected. Click here to see the towns of the region. Full-disk imagery is available from GOES-16 at 15-minute increments. The 3.9 µm imagery is shown from 1200 to 2345 UTC, followed by the Fire RGB Imagery. The Fire RGB image combines the 3.9 µm (Red), 2.2 µm (Green) and 1.6 µm (Blue) imagery. The wavelength of the radiation emitted by the fire decreases as the temperature of the fire increases; a relatively cool fire will emit mostly 3.9 µm energy and will be red in the RGB. A very hot fire will emit all three wavelengths and will appear whiter in the RGB.

GOES-16 ABI Band 7 (“Shortwave Infrared”, 3.9 µm) from 1200 to 2345 UTC on 15 May 2018 (Click to enlarge)

GOES-16 ABI Fire RGB, combining 3.9 µm, 2.2 µm and 1.6 µm imagery, from 1200 to 2345 UTC on 15 May 2018 (Click to enlarge)

The imagery below is zoomed in on the region of the three fires.  (Map).  The 3.9 µm is shown first, then the Fire RGB.

GOES-16 ABI Band 7 (“Shortwave Infrared”, 3.9 µm) from 1200 to 2345 UTC on 15 May 2018 (Click to enlarge)

GOES-16 ABI Fire RGB, combining 3.9 µm, 2.2 µm and 1.6 µm imagery, from 1200 to 2345 UTC on 15 May 2018 (Click to enlarge)

 

The RGB — like many — gives an excellent qualitative estimate of the fire.  Quantitative estimates are available that more define the fire more comprehensively. The 1845 UTC Fire RGB suggests a very hot fire (the 3.9 µm imagery at 1845 UTC suggests the same thing). What do the Baseline fire products show? The Fire Temperature, Fire Power, and Fire Area products for 1845 UTC are shown below.  (Animations are here:  Fire Temperature, Fire Power, Fire Area)   Hotter fire pixels are apparent at 1745 and 2015 UTC.    Click for toggles of Band 7 (3.9 µm), Fire RGB and Baseline Fire Temperature at 1745 UTC, 1845 UTC, and 2015 UTC.  These products might facilitate resource allocation in a way that single channels or RGB combinations cannot.

GOES-16 Baseline Fire Temperature Product 1845 UTC on 15 May 2018 (Click to enlarge)

GOES-16 Fire Power Baseline Product, 1845 UTC on 15 May 2018 (Click to enlarge)

GOES-16 ABI Fire Area Baseline Product at 1845 UTC on 15 May 2018 (Click to enlarge)

Fires and blowing dust across the Upper Midwest and southern Manitoba

April 29th, 2018 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, left) and Shortwave Infrared (3.9 µm, right) images, with surface station identifiers plotted in cyan [click to play MP4 animation]

The combination of strong winds and low relative humidity prompted the SPC to forecast elevated to critical fire weather potential across parts of the Upper Midwest on 29 April 2018. A Mesoscale Domain Sector was positioned over the region, providing data at 1-minute intervals — and “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images (above) revealed the smoke plumes and thermal anomalies or “hot spots” (black to yellow to red pixels) associated with some of these larger fires. The most prominent fires were located in southeastern Manitoba later in the day (including the largest fire EA015, which was listed as Out of Control).

On the Visible images, also note the hazy signature of blowing dust that developed from the northern Red River Valley of North Dakota and Minnesota into southern Manitoba — with winds gusting in excess of 50 knots, the surface visibility dropped to 3 miles at Grafton ND (KGAF) and Winnipeg International Airport (located just northwest of station CXWN in southern Manitoba).

Time series of surface observation data at Grafton, North Dakota [click to enlarge]

Time series of surface observation data at Grafton, North Dakota [click to enlarge]

Time series plot of surface weather data at Winnipeg, Manitoba [click to enlarge]

Time series plot of surface observation data at Winnipeg, Manitoba [click to enlarge]


Refinery Explosion and Fire in Superior WI

April 26th, 2018 |

GOES-16 ABI “Red Visible” (0.64 µm) from 1532-2027 UTC on 26 April 2018 (Click to enlarge)

Explosions at an oil refinery in Superior WI on 26 April 2018 (news link) produced a black plume of smoke visible in the GOES-16 “Red Visible” Band, the highest resolution (0.5 km at nadir) band on GOES-16. The plume is first visible at about 1717 UTC, and it then streams southeastward over northwest Wisconsin. Areas immediately downwind of the refinery were evacuated due to air quality concerns.

The explosion and subsequent fire was not sufficiently hot to be detected by the shortwave infrared 3.9 µm channel on GOES-16. However, the smoke plume is obvious in this animation, cooler than the background by 3-4ºC, and yellow in the enhancement chosen.

GOES-16

GOES-16 “Red” Visible (0.64 µm, left) and Near-Infrared “Vegetation” (0.86 µm, right) images [click to animate]

The dark smoke plume was also evident on Near-Infrared “Vegetation” (0.86 µm) images (above), aided by the additional contrast between the dark plume and the lighter gray appearance of the land surface.

GOES-16 Natural Color images [click to animate]

GOES-16 Natural Color RGB images [click to animate]

The GOES-16 Natural Color Red-Green-Blue (RGB) product (above) was also useful for identifying and tracking the smoke plume.

Aqua MODIS True Color and False Color RGB images [click to enlarge]

Aqua MODIS True Color and False Color RGB images [click to enlarge]

250-meter resolution Aqua MODIS True Color and False Color images from the MODIS Today site (above) provided a detailed view of the smoke plume at 1842 UTC. In the False Color image, snow cover and lake ice appear as shades of cyan.