Interesting timing with the TV show "Southland" that aired last night on TBS. In the morning in their unit one detective told his partner about a low snow level for a storm that was to hit the L.A. area that night. In the ending scene that detective was talking with his wife on the porch of his home and it began to snow. I think the location was somewhere in the SF Valley.
I remember 1983 quite well. It was my second winter in Bridgeport, California. Lots of interesting things occurred that winter as far as low snow levels and problems with roads, especially in Mammoth. I listened to the scanner a lot while I looked outside at snow falling heavily. The point of closure for Conway Summit on U.S. 395 was visible from one of my windows. I would watch long lineups of cars and big rigs on the highway. It happened many times that year.
I remember two transmissions on the Mono County SO dispatch frequency quite well. Mammoth Lakes had not incorporated yet so the SO had primary jurisdiction in town. One night as some of us in the high country like to say: "it's snowing like a big dog," or very heavily. On this night it was snowing at the rate of about 3-4" inches per hour. 395 was closed in several locations and there was just a bit of wind making visibility even more challenging than the snowfall rate was making it. Now Mammoth is known for having some interesting characters, both visitors and residents. I often say that sometimes we don't have that much snow in Mammoth, but there is never a shortage of flakes. Anyway, in the middle of this heavy storm a deputy transmits "would you believe a cowboy hat, sunglasses, no shirt, boxer shorts and cowboy boots walking down Main Street?!" He wasn't calling anyone, he just had to make this announcement and no one had to question the location.
That same year, on a weekend day with a very low snow level and a storm of a similar rate, a deputy asked for the road conditions on SR 14 and U.S. 395. The dispatcher took a minute or two and then came back with "R2 from Sand Canyon to Canada." R2 indicates that all vehicles except 4 wheel drives with snow tires must have chains on. I turned to my wife and said "well that about covers it!" Later a CHP officer inquired of the Bishop dispatcher the conditions of 395 from San Bernardino to the SR 14 junction. The answer was that the 15 was closed from University Parkway (now on 215 before the 15 was constructed to the west) to 395, and 395 from that point north was R2.
Chain restrictions in California are labeled R1, R2 and R3 for internal use by the CHP and Caltrans and they are heard on the air constantly during storms. R1 indicates that chains are required, but autos and pickups with snow tires are exempt. Almost every radial tire made now is a snow tire and the lettering M+S, M/S or just M S will be printed on the sidewall. In effect this level of restriction requires big rigs to chain up and lowers the speed limit to 35 or 25 depending on the highway. R2 indicates that the only vehicles exempt are four wheel drives with snow tires on all four wheels. R3 means that there are no chain requirement exemptions. The road is usually closed before R3 restrictions are posted. I often joke that R3 means "go find a motel!" because if it is that slippery, I don't want to be driving. All vehicles must carry chains when any level of restriction is posted, whether or not they are exempt. During heavy traffic, usually on weekends when Mammoth and June ski areas are open and R1 or R2 is posted, the CHP and Caltrans will set up checkpoints north of Bishop and check every car for chains. Those exempt vehicles without chains in possession are not allowed through. I know some people with 4WDs who carry old chains that don't fit the vehicle. Personnel at the checkpoint don't make you put them on, they just check that your chain box or bag have chains in them. Bad idea as you may need them to get unstuck if you have to steer off the pavement due to an accident or a spin out occurring in front of you.
In February 1989 I attended a training course in San Diego for several days and it began to rain quite heavily the last two days. It continued as I left to return to Mammoth. My 4WD pickup had a higher mileage rate than the Ranger District's new station wagon so I drove it. It was equipped with front wheel drive, a rear window defroster, and rear window wiper. I was styling as I had never driven a vehicle with these features. As I drove up the 15 near March AFB I was listening to my BC-200 handheld and heard that the highway was closed at University Parkway. The exit was a mess with cars lined up to reenter the freeway north on ramp. They were all in the left lane of the exit, so I went down the off ramp in the right lane, then found a side street of University Parkway to wait. The Caltrans frequencies were quite active and I heard a discussion of the road conditions on Cajon Pass and when they might open, 30 minutes, then 20 minutes, then finally 5 minutes. I timed my left turn back onto University Parkway so that I would reach the on ramp about the time they reopened and when I arrived there. I put on my right turn signal and was waved onto the freeway as the first car on with the mile or more backup waved on next. The road, from just north of Devore, had snow pack/icy patches with about 50% of the road being wet. When I reached the 395 off ramp it was snowing heavily and I drove all the way back to Mammoth in R1 conditions. The front wheel drive was awesome and the rear window features essential.
So snow in the high desert is not unusual, but not common. I've noticed over the last 15 years of many chain requirement signs in various locations down there have not been replaced after road construction or were removed rather than being maintained so these types of events have become less frequent, which matches my memory quite well. The weather is changing. I just saw a film on the PBS series "Nova" that presented information that the average temperature there has risen some 7-9 degrees Fahrenheit since 1971. The poles drive much of the earth's weather and the rise in temperature there is more than twice that of the rest of the world. Sit back and hold onto your hats, this is going to get interesting.
, 2008 was not a snow event at all, most of Santa Clarita Valley is only 1,200'-1400' MSL and we don't get snow here at all like the high desert does on occasion, what happened Sunday was a real oddity, and extremely uncommon.