Satellite-based Flash Flood Warning
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.