by OntarioWeatherService » Mon Sep 17, 2007 2:52 pm
"What I saw looked like hail/snow. It could very well have been hail, but it could have been snow as well from the photos. Soundings indicated a 15,500 Foot Freezing level, with 60% RH. This would mean true snow would fall a bit lower due to drier air at that level. More like 13,000 Feet, barely missing the mountains.
Now what about if we had a major storm over the area. The storm was 65,000 Feet Tall. A massive storm for Southern California. This storm probably developed it's own environment around it. A tropical system does much of the same thing, and sense the lower levels were moist, and the air was hot, it would make it more tropical in the storm itself. This would make the updraft explode. Now take that major updraft to 65,000 Feet, and force air down from there in the massive downdraft. -120 degrees at that level or colder.
Pressure differences were 1016mb on the top of the Mountain with even higher, maybe 1025-1030mb pressure above the storm. Much like a hurricane. 9mb-14mb pressure difference would drive winds from the Highest pressure, to the lowest pressure. Cold air advection probably played a great role and the temp on the top of the mountain went below freezing in that downdraft.
As for snow? I'm not quite sure. The updraft was huge in that storm. This means that the result would be the super-cooled temps and forming SOLID ICE. This then would fall down as hail. This hail is probably colder than normal hail being how cold the atmosphere was they came from, hence the reason they are still there today.
If it was snow, the cloud would have to not be as convective to form solid ice. It would result in snow, but my final answer is HAIL, and LOTS OF IT. Someone should go up there and get a sample. It's probably different from the plains, being in a supercooled environment."
Kevin
www.ontarioweatherservice.com
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