While I was away, we got some exciting monsoon weather. My local rainfall I estimate at 0.09", but local mountains had lots of rain. The LA Times reported that,
A tropical rain storm that caused deadly floods and destructive
mudslides in the San Gabriel Mountains on Sunday was the kind of weather
event seen only once about every 500 years, the National Weather
Starting at about 2:45 p.m., the storm dropped
nearly 4 inches of rain onto Mt. Baldy in a single hour, triggering
mudslides and floods that killed one motorist and severely damaged more
than 30 homes.
The deluge also cut off the community of Forest Falls after mudslides of up to 10-feet high buried the town’s lone road connecting it to California 38. San Bernardino County firefighters were still assessing the damage Monday and Tuesday, but said about 100 buildings had sustained damage.
The storm was the product of an “orographic flow” -- when moisture-saturated air is pushed up by a mountain’s natural
topography and is squeezed like a sponge. A wave of tropical air blown
north from Central America gave the storm extra ammunition,
I drove by Forest Falls on Highway 38 out of Mentone on Monday, and although I saw evidence of rainfall such as small pebbles and sand on the road, I didn't see any evidence that rainfall was present in amounts of concern on the highway (about 1/2 to 1 mile away from the community of Forest Falls). Clearly, the community of Forest Falls didn't have that experience, which is a lesson in how localized weather and weather effects can be, particularly in the mountains.