An AWIPS image of the GOES 10.7µm InfraRed (IR) channel (above) shows Tropical Depression Alvin (left) and Tropical Storm Barbara (right) on 30 May 2007 — both disturbances were located near the Intertropical Convergence Zone (ITCZ) over the Eastern Pacific Ocean. The morning NHC discussion pointed out that only twice before (in 1956 and 1984) have there been two named Eastern Pacific basin storms in the month of May. An animation of GOES-12 IR imagery with a different color enhancement (below) indicates that the cold cloud top temperatures (red to white enhancement) associated with Tropical Storm Barbara were increasing in areal coverage during the morning hours.

The NHC discussion also made reference to the CIMSS Advanced Dvorak Technique or ADT (below) in their decision to upgrade Tropical Depression Barbara to a Tropical Storm.

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GOES-11 10.7µm InfraRed (IR) images (above; Java animation) showed an area of strong thunderstorms (exhibiting cold brightness temperatures of -70 to -80º C, black to white enhancement) expanding eastward toward the islands of American Samoa in the South Pacific Ocean on 28-29 May 2007. The motion of these storms on satellite imagery prompted the issuance of a Flash Flood Warning for the islands of Tutuila, Aunuu, and Manua at 02:54 UTC on 29 May (3:54 PM on 28 May, local time). It is important to note that there is no radar in that particular region, making satellite imagery the only forecasting tool for such hazards — however, GOES-11 Southern Hemisphere sector imagery (below) is only available over that region 2-3 times per hour.

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The moon was observed adjacent to the Earth’s limb on the GOES-12 imagery at 11:15 UTC on 24 May 2007. Some of the large-scale features of the moon’s surface could be seen in the GOES-12 visible channel image (above), while the other 4 InfraRed (IR) channels (below) revealed a “banded” pattern of brightness temperatures resulting from the large thermal gradient between the very hot sunlit portion of the moon (where temperatures can reach +110º C / +230º F) and the very cold “dark” side of the moon (where temperatures can fall to -180º C / -292º F).

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An AWIPS image of MODIS sea surface temperature (SST) on 21 May 2007 (above) shows an intricate pattern of Atlantic Ocean eddies along either side of the axis of the Gulf Stream. SST values in the 70-78º F / 21-26º C range (orange enhancement) marked the Gulf Stream axis as it meandered northeastward across the western Atlantic. Some of the eddies were offset a considerable distance from the Gulf Stream axis, most notably the pronounced cool eddy (SST values around 64º F / 18º C, dark green enhancement) located well to the southeast. The black areas over water on the image are regions where the MODIS cloud mask product indicated that clouds were present — no SST data is generated for such “cloudy” pixels. Although some cloud patches were indeed present, the strong thermal gradients associated with the Gulf Stream sometimes cause the MODIS cloud mask product to falsely indicate “cloud” over fairly large regions that in reality are not cloudy.

Note how the Real-Time Global SST model analysis (below) does a poor job resolving the details of these particular eddy features.

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