Jane and I plan to be on the sidewalks in Pasadena and Monrovia this
weekend, and it looks like the weather is cooperating -- for the most part!
This week our weather was influenced by a pesky system called a "cutoff
low" over the Pacific -- so-called because it is cut off from the jet
stream, and its motion is difficult to predict. As we saw in last
year's record rainy season, a cutoff low can sit stationary off the
coast for days sucking tropical moisture into the LA basin.
That low has now moved southeast over northern Mexico, which causes our
winds to shift to offshore. That should bring us drier desert air and
clearer skies for several days. Early next week they're forecasting
very warm temperatures with the expected Santa Ana wind conditions.
When that dry air flows down the mountain slopes into the basin, it
heats up and gives us those indian summer conditions in November.
Tonight the conditions are not perfect -- we're still sitting in some
cool moist air from this week's weather system. Here in the San Gabriel
Valley we have some lingering marine layer clouds. We'll be able to see
the Moon and Mars okay, but the early part of the evening we'll be
looking up through layers of air at very different temperatures and
moisture content. Each of those layer boundaries give a slight
refraction to the light passing through, and makes for a shimmery view
obscuring much of the subtle detail on difficult objects like Mars.
So the moral of my rambling story -- the best views for Mars will be
Saturday evening in Monrovia. Join us there at Myrtle & Lime in Library
Park, from 6:00 'til 9:00 p.m.
But even with less than perfect conditions, we'll be in Old Town
Pasadena this evening from about 6:30 'til 9:30, on Colorado Blvd. near
Delacey, somewhere on the two-block stretch from Fair Oaks to Pasadena Ave.
Hope to see you there!
Old Town Astronomers: http://www.otastro.org