A cold frontal gravity wave along the East Coast?
Lee-side frontal gravity waves are occasionally seen to the east of the Rocky Mountains, moving southward across the High Plains of the central US (for example, see 03 April 2007, 07 April 2000, and 12 January 1998). However, a satellite signature of what appeared to be a similar type of feature was observed along the US East Coast on 02 April 2008. AWIPS images of the GOES-12 6.5 µm “water vapor channel” (above) showed the positions of a cold frontal boundary at 3 hour intervals on that day, while more frequent GOES-12 water vapor images viewed using McIDAS (below) revealed the subtle “gravity wave” feature as it propagated southward off the coast of Virginia and North Carolina during the day. Several coastal stations in Virginia and North Carolina reported northerly to northeasterly surface winds of 30 mph (13 meters per second) or greater after the passage of the gravity wave, with offshore buoy and ship reports as high as 38 mph (17 meters per second).