GOES-15 (left) and GOES-13 (right) 0.63 µm visible images (click image to play animation)

McIDAS images of GOES-15 (GOES-West) and GOES-13 (GOES-East) 0.63 µm visible channel data (above; click image to play animation) revealed smoke plumes and pyrocumulus clouds associated with a pair of large wildfires that were burning in western Wyoming on 15 September 2012. Because of difference in viewing angle between the two satellites, the pyrocumulus clouds appeared brighter white on the GOES-15 images (due to more direct reflection of sunlight off the western edges of the clouds), while on the GOES-13 images the “overshooting” clouds cast more well-defined shadows on top of the smoke layer below.

A comparison of AWIPS images of Suomi NPP VIIRS 0.64 µm visible channel and 11.45 µm IR channel data at 19:36 UTC or 1:36 PM local time (below) showed that the southernmost fire burning along the eastern slopes of the Wind River Range had already developed a pronounced pyrocumulus cloud, which exhibited an IR brightness temperature as cold as -40º C (green color enhancement).

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

According to 12 UTC rawinsonde data from nearby Riverton, Wyoming (station identifier KRIW), the -40 C IR cloud top brightness temperature roughly corresponded to an altitude just over 31,000 feet or 9.6 km (below).

Riverton, Wyoming rawinsonde data at 12 UTC

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GOES-14 6.5 µm water vapor channel images (click image to play animation)

As a part of the GOES-14 Super Rapid Scan Operations for GOES-R (SRSOR) testing, the satellite provided full-disk images at 30-minute intervals during the day on 14 September 2012. For current GOES satellites, the operational full-disk image interval is 3 hours; the ABI instrument on GOES-R will provide a full-disk image every 5 minutes. GOES-14 0.65 µm water vapor channel images are shown above (click image to play animation).

The corresponding GOES-14 0.63 µm visible channel images (below; click image to play animation) revealed two features of interest over the eastern portion of the full disk which were more obvious due to the large forward scattering geometry: (1) a large pall of smoke over the Amazon basin and much of interior South America, a result of widespread biomass burning (magnified view), and (2) Saharan Air Layer dust located to the north, east, and southeast of Tropical Storm Nadine in the North Atlantic Ocean (magnified view).

GOES-14 0.63 µm visible channel images (click image to play animation)

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MTSAT-2 10.8 µm IR channel images (click image to play animation)

McIDAS images of MTSAT-2 10.8 µm IR channel images (above; click image to play animation) showed the formation of a large and well-defined eye as Super Typhoon 17W (Sanba) intensified over the West Pacific Ocean on 13 September 2012.

A plot of the CIMSS Advanced Dvorak Technique intensity estimate (below) showed the trend of rapid intensification.

CIMSS ADT plot for Storm 17W (Sanba)

Sanba was in an environment characterized by relatively low values of Deep Layer Wind Shear (below), which favored intensification.

MTSAT-2 IR images + Deep layer wind shear

Sanba had also been moving over a region with very warm Sea Surface Temperatures and a very high Ocean Heat Content values (below).

Track of Sanba overlaid on Sea Surface Temperature + Ocean Heat Content products

The first daylight MTSAT-2 0.7 µm visible channel images (below) showed nice eye and eyewall structure.

MTSAT-2 0.7 µm visible channel images

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POES AVHRR 0.86 µm visible channel + 12.0 µm IR channel images at 20:23 UTC

A daily record of 1.18 inches of rainfall was recorded at McCarran International Airport in Las Vegas, Nevada on 11 September 2012 — this was also the highest daily rainfall total on record for any day in the month of September. Some locations in the Las Vegas metro area received as much as 2.09 inches (Public Information Statement), with 3.35 inches falling in the higher elevations (7450 feet) to the west of the city at Mt. Charleston. AWIPS images of 1-km resolution POES AVHRR 0.86 µm visible channel and 12.0 µm IR channel images at 20:32 UTC (above) and 21:26 UTC (below) showed evidence of overshooting tops and cloud top IR brightness temperatues as cold as -65º C (darker red color enhanement).

POES AVHRR 0.86 µm visible channel + 12.0 µm IR channel images at 21:26 UTC

10-km resolution GOES Sounder Total Precipitable Water (TPW) derived product images (below) showed the TPW values were as high as 45 mm (1.78 inches) across parts of Clark County in southern Nevada during the hours leading up to the development of the thunderstorms.

GOES Sounder Total Precipitavble Water derived product imagery

The Blended Total Precipitable Water (TPW) Percent of Normal product (below) indicated that TPW values across the region were in excess of 200% of normal (yellow color enhancement).

Blended Total Precipitable Water Percent of Normal product

With afternoon heating, GOES Sounder Convective Available Potential Energy (CAPE) values (below) exceeded 2600 J kg-1 (darker yellow color enhancement) in the pre-convective environment.

GOES Sounder Convective Available Potential Energy (CAPE) product

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