Blowing dust off the Alaskan coast

November 6th, 2006 |

GOES-11 visible images (QuickTime animation)
A QuickTime animation of GOES-11 visible channel images (above) revealed multiple plumes of glacial sediment blowing offshore along the coast of Alaska on 06 November 2006. Strong chinook winds in the glacial valleys were lofting dust and carrying it out over the adjacent Gulf of Alaska. This phenomenon had been occurring on other days in early November (as seen on a MODIS true color image 5 days earlier).

A longer (14-hour) animation using the GOES-11 10.7µm – 12.0µm IR difference product (below) shows a subtle blowing dust signal that can be followed during the non-daylight hours as well (when visible channel imagery is not available). The airborne particulate matter associated with the largest dust plume reduced the surface visibility to 2-3 miles at Cordova, Alaska (station identifier PACV) late in the day; also, note the rapid rise in temperature farther to the east at Yakutat, Alaska (station identifier PAYA), as easterly chinook winds arrived and gusted to 18 mph at 20:00 UTC.
GOES-11 IR difference images (QuickTime animation)

Hawaiian island lee cloud line, and cold frontal rope cloud

November 6th, 2006 |

GOES-11 visible image animation
Two interesting semi-linear cloud features were apparent in the vicinity of the Hawaiian Islands on 06 November: (1) a cloud line to the lee of the Big Island of Hawaii, due to easterly “trade winds” within the marine boundary layer converging after flowing around the island (also note the small cyclonic eddy that formed immediately northwest of the Big Island), and (2) a long, narrow “rope cloud” that stretched for a considerable distance across the Pacific Ocean (to the north and northwest of Hawaii), which marked the leading edge of a cold frontal boundary which had become quasi-stationary (large-scale GOES-11 visible image animation).