GOES-15 0.63 µm visible channel images (click image to play animation)

Numerous wildfires continued to burn across much of the western US into late June, due to a combination of moderate to extreme drought, high temperatures, and strong winds. McIDAS images of 1-km resolution GOES-15 0.63 µm visible channel data (above; click image to play animation) showed large smoke plumes from the more significant fires that were burning in Montana and Wyoming on 27 June 2012. The GOES-15 satellite had been placed into Super Rapid Scan Operations (SRSO) mode, providing bursts of imagery at 1-minute intervals. The smoke plume from the fire burning in southwestern Wyoming was remarkably long, and was lofted high enough to easily pass over the Wind River Range of mountains (which has a number of peaks over 13,000 feet or 1362 meters). A pilot report mentioned that the top of the smoke layer extended to 34,000 feet.

250-meter resolution MODIS true-color and false-color Red/Green/Blue (RGB) images from the SSEC MODIS Today site (below) showed greater detail of the thick smoke plume passing over the Wind River Range, as well as the large “hot spots” (pink color enhancement on the false-color image) associated with the actively burning fires.

MODIS true-color and false-color RGB images

AWIPS images of 4-km resolution GOES-13 3.9 µm shortwave IR data (below; click image to play animation) showed the hot spots associated with some of the larger fires in Utah, Wyoming, and Montana as they burned through the following night.

GOES-13 3.9 µm shortwave IR channel images (click image to play animation)

A comparison of a 4-km resolution GOES-13 3.9 µm shortwave IR image with the corresponding 1-km resolution MODIS 3.7 µm shortwave IR image (below) demonstrated the advantage of higher spatial resolution for detecting the heat signatures from the smaller fires, as well as more accurately locating the boundaries of the larger fire complexes. On the MODIS image, some of the pixel IR brightness temperatures were so hot that they “wrapped around” to the cold end of the temperature scale, and appeared white.

MODIS 3.7 µm vs GOES-13 3.9 µm shortwave IR images

On the following morning of 28 June, GOES-15 0.63 µm visible channel images (below; click image to play animation) showed the large areal coverage of the smoke, which had moved as far east as the Great Lakes region. An HD version of this GOES-15 visible image animation is available here, along with a close-up version centered on the western Wyoming fire which showed filaments of smoke (which had settled into the valleys overnight) becoming mixed and ventilated upward into the boundary layer as daytime heating and surface winds increased during the morning hours.

GOES-15 0.63 µm visible channel images (click image to play animation)

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Suomi NPP VIIRS 3.74 µm shortwave IR and 0.7 µm Day/Night Band images

Hat tip to Tom Lee (Naval Research Laboratory, Monterey, California) for alerting us to another region of the US where a pronounced satellite signature of extensive drilling operations can be seen using Suomi NPP VIIRS Day/Night Band imagery. A comparison of AWIPS images of 375-meter resolution (projected onto a 1-km AWIPS grid) 3.74 µm shortwave IR data and the corresponding 0.7 µm Day/Night Band data (above) revealed the bright night-time illumination of widespread drilling activity across the Eagle Ford oil shale formation in southeastern Texas at 08:49 UTC (3:49 AM local time) on 25 June 2012. On the shortwave IR image, a number of small “hot spots” (pixels with a darker red color enhancement) could be seen, which were associated with natural gas flares at some of the larger drilling rig sites.

A similar signature of night-time drilling activity had been previously noted on VIIRS Day/Night Band imagery across the Bakken oil shale formation in western North Dakota — and a comparison with the color-enhanced shortwave IR image (below) at 08:30 UTC (2:30 or 3:30 AM local time, depending on the exact location) on 26 June 2012 again showed a number of natural gas flare “hot spots” at some of the larger illuminated drilling rig sites.

Suomi NPP VIIRS 3.74 µm shortwave IR and 0.7µm Day/Night Band images

Note that there is some striping seen in the Day/Night Band (DNB) image over North Dakota — a view of the entire VIIRS DNB swath (below) shows that North Dakota was located within the “stray light zone” of the Suomi NPP satellite orbit, where some sunlight was reachng the DNB detectors. Farther to the south over Texas, there was no stray ligt contamination evident on the DNB image.

Suomi NPP VIIRS 0.7 µm Day/Night Band image

A May 2011 map of the Lower 48 state natural gas and oil shale “plays” (below) suggested that there are likely other regions of the US where similar VIIRS DNB and shortwave IR satellite signatures might be seen.

Map of Lower 48 states natural gas and shale oil plays

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GOES-13 10.7 µm IR images + OSCAT surface scatterometer winds

Tropical Storm Debby formed in the eastern Gulf of Mexico on 23 June 2012 — Debby was the earliest “D”-named (4th storm of the season) Atlantic Basin tropical cyclone on record. GOES-13 10.7 µm IR channel images with an overlay of Oceansat-2 OSCAT surface scatterometer winds from the CIMSS Tropical Cyclones site (above) showed that Debby was embedded within a very broad cyclonic circulation that was present over the Gulf of Mexico — and Debby also formed over an area of high ocean heat content.

The low-level circulation center of Debby was generally exposed, but a large area of deep convection persisted within the eastern semi-circle of the storm. A number of Tropical Overshooting Tops were also seen associated with this deep convection (below).

GOES-13 10.7 µm IR images + Tropical Overshooting Tops

A comparison of AWIPS images of Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR chnanel data (below) showed a detailed view of the low-level circulation center and the cold IR cloud tops of the deep convection.

Suomi NPP VIIRS 0.64 µm visible channel + 11.45 µm IR channel images

Abundant moisture was present over the entire Gulf of Mexico, as revealed by the MIMIC Total Prcipitable Water (TPW) product (below; click image to play animation). TPW values in excess of 60 mm (2.4 inches) were common.

MIMIC Total Precipitable Water product (click image to play animation)

During the following overnight hours, a comparison of Suomi NPP VIIRS 0.7 µm Day/Night Band and 11.45 µm IR channel data (below) showed cloud top IR brightness temperatures as cold as -90º C (dark violet color enhancement), while the Day/Night Band image revealed a few bright white pixels indicating cloud illumination due to concentrated lightning activity. The bright lightning illumination pixels appeared to be “smeared” along the scanning direction of the VIIRS instrument. Also evident in the northwestern Gulf of Mexico were numerous small lights associated with extensive offshore drilling operations.

Suomi NPP VIIRS 0.7 µm Day/Night Band image + 11.45 µm IR image

During the afternoon hours of 24 June, another comparison of Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel data (below) showed that some areas of deep convection had begun to develop into the northern semi-circle of the storm.

Suomi NPP VIIRS 0.64 µm visible channel + 11.45 µm IR channel images

===== 25 June Update =====

MODIS 11.0 µm IR, VIIRS 11.45 µm IR, and AVHRR 10.8 µm IR images

Even though the center of Tropical Storm Debby remained offshore, a large convective burst developed over the Florida Panhandle region on 25 June 2012. In the sequence of three 1-km resolution IR images (from the MODIS, VIIRS, and AVHRR instruments) shown above, the coldest cloud top IR brightness temperature was -91 C on the 16:21 UTC MODIS image.

The corresponding animation of 4-km resolution GOES-13 10.7 µm IR images is shown below .

GOES-13 10.7 µm IR images (click image to play animation)

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MODIS true-color image, Sea Surface Temperature product, and 0.65 µm visible channel image

AWIPS comparisons of a 250-meter resolution MODIS true-color Red/Green/Blue (RGB) image at 16:46 UTC on 21 June 2012 with the corresponding 1-km resolution MODIS Sea Surface Temperature product and 0.65 µm visible channel image (above) revealed the vivid signature of iron and/or copper rich runoff sediment in the near-shore waters of western Lake Superior following the historic heavy rainfall event of 19 June – 20 June 2012 (for more details on this event, see the Duluth National Weather Service).

A “before” (21 May 2012) and “after” (21 June 2012) true color image from the SSEC MODIS Today site (below) showed the dramatic change in appearance of the western Lake Superior near-shore waters.

MODIS true-color images (21 May 2012 and 21 June 2012)

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7-day total precipitation, percent of normal, and departure from normal

Maps of the total 7-day precipitation, percent of normal precipitation, and precipitation departure from normal (above) highlighted the extreme nature of the event in the Duluth region, but also showed the large amount of variability in precipitation across other portions of the Upper Midwest states during this period.

In particular, note the large southwest-to-northeast oriented swath across northeastern Nebraska, northwestern Iowa, southeastern South Dakota, and southwestern Minnesota (below): in this highly agricultural area, the stress on the crops within this rain-free swath was apparent on MODIS 0.65 µm visible imagery (lighter gray where the vegetation was less healthy), the MODIS Land Surface Temperature (LST) product (LST values in the upper 80s to mid 90s F, surrounded by LST values in the 70s F), and the Normalized Difference Vegetation Index (NDVI values as low as 0.43 in southwestern Minnesota, surrounded by NDVI values of 0.7 to 0.8 to the north and to the south where ample rainfall had been occurring).

MODIS 0.65 µm visible image, Land Surface Temperature product, and Normalized Difference Vegetation Index product

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