Super-cooled Clouds (3 of 3)

As with the night-time "fog product", during the day-time the 3.9 um imagery can be used, in association with the 10.7 um data, to find areas of supercooled cloud. In this example, the 3.9 um image (top left) from 1445 UTC on 10 Jan 1996 is displayed as energy (see the earlier discussion on imagery presentation). The areas covered by water cloud appear bright, due to the addition of the reflected solar component. Water cloud can be seen in the Buffalo vicinity, to the south of Lake Michigan and other areas.

The corresponding visible image (top right) also shows these water cloud areas. An estimate of cloud top temperature from the corresponding 10.7um image (right) determined that for the clouds around Buffalo, typical cloud top temperatures were about -24 C, which, along with the 3.9 um data, indicates a supercooled cloud. The 1200 UTC sounding from BUF on the 10th shows cloud top temperatures to be around -20 C, an important verification. (This is especially true if additional cloud layers exist above the suspected supercooled water cloud, since they would affect the 10.7 um brightness temperatures.)

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