Here's a curiosity. At this hour, the National Weather Service Bay Area radar is showing the accompanying image, with the note:
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
441 PM PDT FRI APR 16 2004
NOW ... THE LONG STREAMERS OF HIGH REFLECTIVITY APPARENT ON DOPPLER RADAR ACROSS THE BAY AREA ARE BEING CAUSED BY CHAFF...SMALL PARTICLES RELEASED DURING A MILITARY EXERCISE. PLEASE DISREGARD THESE RADAR RETURNS.
Anyone out there have a clue why there's chaffing going on in an area with three active commercial airports?
Update: A reader informs me that since both weather and military fire control radars operate at significantly higher frequencies than air traffic control radar, chaff cut to resonate in one frequency band shouldn't interfere with the other. (Thanks, Chris.) I'm still curious why such an exercise gets run here, rather than out in the Nevada desert.