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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AVHRR Sea Surface Temperature Estimates

Tropical Storm / Hurricane Leslie moved very slowly over the western tropical Atlantic Ocean between 6 September and 7 September (see, for example, this graphics animation from the National Hurricane Center, and the storm track from the CIMSS Tropical Cyclones site below). Strong winds associated with the cyclonic circulation around a hurricane or tropical storm will cause upwelling, forcing cooler waters to the surface. An AWIPS image of the POES AVHRR Sea Surface Temperature (SST) product above shows the result: SST values as cool as 67.9º F (green color enhancement) occur southeast of Bermuda (TXKF) around 26 N, 63 W, the region through which Leslie had moved very slowly over the course of several days. Such cool water upwelling limits the intensification potential of tropical cyclones that move slowly.

Track of Tropical Storm Leslie

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