AWIPS images of the GOES-12 6.5 µm “water vapor” channel (above) showed the development of late-season winter storm that produced heavy snowfall and blizzard conditions (with wind gusts to 64 mph or 29 m s-1 at Rapid City SD) across the Black Hills region and surrounding portions of eastern Wyoming, southeastern Montana, and western South Dakota during the 30 April through 02 May 2008 period. A closer view using GOES-12 10.7 µm IR images reveals that there were a number of cloud-to-ground lightning strikes during various phases of the storm’s development, as large convective elements formed and intensified upwind of the Black Hills.

A MODIS true color image (above, viewed using Google Earth) shows the areal extent of the snow cover on 03 May 2008, as well as the locations of the heaviest total snowfall amounts: 54.5 inches (138 cm) at Lead SD, and 24.0 inches (61 cm) at Sundance WY.

A comparison of MODIS true color and false color images from 03 May (above) demonstrates how the false color imagery (which uses the MODIS 2.1 µm near-IR channel) can differentiate between snow cover (which, along with ice crystal clouds and ice-covered lakes, appear as cyan-colored features) and supercooled water droplet clouds (which appear as shades of white).

Consecutive daily MODIS false color images from 02, 03, and 04 May (below) show that the snow cover was melting rapidly under the influence of the strong May sun. The 54.5 inches of snow that fell at Lead SD had a liquid equivalent of 4.64 inches (12 cm), so the rapid snowmelt led to a quick rise of creeks and streams that caused some flooding problems.

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Category 4 intensity Cyclone Nargis made landfall across southern Myanmar (formerly known as Burma) late in the day on 02 May 2008, packing maximum winds around 135 mph (60 m s-1), producing a storm surge of 12 feet (3.6 meters), and dumping nearly 20 inches (51 cm) of rainfall. According to media reports, the estimated death toll from this powerful tropical cyclone ranges from 22,000 to nearly 100,000. AVHRR false color images from 01 and 02 May (above, viewed using Google Earth) showed Cyclone Nargis in the Bay of Bengal, moving eastward toward Myanmar.

An animation of the Morphed Integrated Microwave Imagery at CIMSS (MIMIC) product (below) revealed evidence of a double eyewall, suggesting that Cyclone Nargis was going through an eyewall replacement cycle just prior to and near the time of landfall.

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GOES-12 RGB composite images (above, using the visible and 3.9 µm shortwave IR channels) revealed a cluster of “hot spots” (red-enhanced pixels) and a large smoke plume drifting east/northeastward from a large grass fire located about 30 miles southeast of Fort Stockton, Texas on 01 May 2008. This fire — known as the Huckabee Fire — started on 30 April (due to a downed power line), and eventually ended up burning over 96,000 acres. This large and very hot fire saturated the 3.9 µm shortwave IR detectors on GOES-12, with the imagery indicating a maximum IR brightness temperature of 337.4º K (64.3º C or 147.7º F).

AWIPS images of the GOES-12 3.9 µm shortwave IR channel (below) showed that the Huckabee fire continued to burn into the morning hours of 02 May, as a cold front moved southward across the region — the cooler air behind the cold frontal boundary was evident as lighter shades of gray surging southward, while warmer, more humid air appeared as darker shades of gray moving slowly northward across eastern Texas into Oklahoma (in advance of the approaching cold front).

An AWIPS 4-panel comparison of MODIS and GOES-12 “shortwave IR” and “IR window” channel data (below) showed the cluster of hot pixels around 09 UTC (4 am local time) on 02 May. This large fire was so hot that a “hot spot” was even apparent on the IR window channel images — surprisingly, the brightness temperature of the hot spot on the GOES-12 IR window image was higher (as indicated by the single yellow-enhanced pixel in the lower right panel) than on the corresponding MODIS IR window image (the cluster of black pixels in the upper right panel).

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A series of mid- to late-April MODIS true color images from the SSEC MODIS Today site (above) reveals that many of the lakes across northern Minnesota were still ice-covered as of 29 April 2008. According to the Minnesota State Climatology Office, the “ice-out” (or melting) of lakes across northern Minnesota this Spring season is delayed by about 2 weeks compared to historical normals, and this is the latest ice-out of many lakes in the region since 1996.

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