A trace of rain was officially recorded in Catalina at this site ending prospects of a rainless October. It fell from high-based Cumulonimbus clouds in a band, partially lining the NW horizon that could be seen as the sun rose yesterday. Some ants were injured by the falling drops, ones that reached millimeter sizes and fell at 5-8 mph, though in some areas, winds of 10-15 mph added to drop impacts. Flying insects, while obliged to avoid the watery missiles, were able to do so with ease due to the appreciable spacing between the drops of several feet.
Due to the short-lived hydrometeor events, many humans were unaware that rain had fallen in Catalina on more than one occasion yesterday. That’s why we blog here. Weather and cloud news you can rely on.
How high were the bases of those precipitating clouds spewing snow virga that melted to rain? Higher than the freezing level! Haha.. The balloon sounding profile started with the Altocumulus perlucidus layer at 18,000 feet above sea level, 15,000 feet above Catalina, bases at -11°C. By evening the lowest moist level had lowered to 14,000 feet ASL (11,000 feet AGL) and -3°C. However, that last moist level had to be a bit lower than those snowy cloud bases IMO–we know that the moist level almost always lowers.
So cloud maven person will make the definitive call that the rainy (well, sprinkly) cloud bases were at 16,000 ASL (13,000 feet AGL) when they passed over, if that makes any sense or is anything you really care about.
Yesterday’s clouds
As rain fell……this sky, 12:30 to 1 PM:
Kind of pathetic really; no shafting whatsoever, much less virga than on the horizon yesterday morning. So our end of that band was so weak it was just barely able to get some drops to the ground.
Looks like this is it for rain in October 2017. However, November 2017 appears to look much brighter for substantial, dust-removing rains in Catalina beginning in the first 10 days!
The End (I missed the sunset due to a social engagement–hope you saw it wherever you were). Probably was pretty nice.