Last Friday, my posting was about about a cold storm coming Tuesday and what I thought the details of this storm was going to be for California and Arizona, places most hard-hit by this storm. Saturday, I issued a small update basically saying that little had changed in my thinking despite the models not having as much precipitation.
Today, I continue to like what I issued last Friday far more than what the details of the models have. It seems they just may not be catching the amount of precipitation that will fall, especially in Southern California and Arizona.
For that reason, I am going to pretty much copy below what I issued on Friday. There are some minor changes in snow levels and accumulations but really they are pretty minor considering the time frames involved. The major impacts of this storm will be the cold and the thunderstorm threat, especially central and Southern California, with hail likely and the very, very low snow levels.
Expect snow accumulations even in portions of the upper deserts and foothills of the mountains. Several of the high sections of I-15 from Victorville to outside of Primm will receive snow and even accumulating snow that can cause icy travel. There is a decent chance of snow being seen in Las Vegas late Tuesday night and Wednesday morning. The mountain passes from the Central Valley to the coast will have snow that can accumulate as well and could cause at the least icy travel. Expect major problems through the Grapevine, Soledad Canyon and Cajon Pass with shutdowns of these roads a good possibility.
In Arizona, the worst weather will be Wednesday into Wednesday night. Snow levels here are likely to fall to impressively low levels to 3,000 feet or so. Heavy snow is likely above 5,000 feet with 8 to 16 inches and possibly more above 7,000 feet, but snow is also likely to fall in much of the Rim Country and accumulate too with 3 to 6 inches down to at least 3,500 feet. Therefore expect rough travel anywhere from the higher foothill and upper deserts and Rim Country through the mountains.
PORTIONS OF THE ORIGINAL POST:
-Rainfall northern to central California averages one-third to two-thirds of an inch.
-Snow levels plummet Tuesday reaching 2,500 feet in the north to 3,000 feet in the southern Sierra and coastal range by Tuesday afternoon and drop another 500 feet Tuesday night into Wednesday for central California.
-Resort levels pick up 8-16 inches of snow but several inches of snow could accumulate down to 3,000 feet.
-A little light rain and drizzle can occur at any time west of the mountains Southern California, but the heaviest rain will come in the afternoon into part of Tuesday night before becoming showery later Tuesday night with a few showers lingering into Wednesday. Rainfall amounts of one-half to 1 inch seem likely with locally higher amounts in the lower foothills of the coastal slopes.
-Snow levels start out at 4,000 feet Los Angeles County mountains and east and 4,500 to 5,000 feet San Diego but fall to 3,000 feet late in the day and down to 2,500 feet everywhere Tuesday night and Wednesday. Resorts could pick up 1-2 feet of snow with 4 to 8 inches down to pass level (Grapevine/Cajon/Highway 14) and maybe a couple inches down to 3,000 feet. If this happens, major travel problems are likely through all the passes.
-Expect temperatures to be 25-30 degrees colder than they are today and will be tomorrow for Tuesday and Wednesday.
-Precipitation develops from west to east later Tuesday night and Wednesday with the heaviest precipitation Wednesday.
-Deserts pick up one-quarter to one-half of an inch of rain with locally higher amounts possible and there may be thunder and lightning.
-Snow levels also become very low dropping to 4,000 feet Wednesday. This can bring substantial accumulation to Rim Country with 3-8 inches possible down to 5,000 feet. Mountains above 6,500 and 7,000 feet could pick up 12 to 18 inches with chances of up to 2 feet.
-There will likely be travel problems across the state as well, especially the major road, I40, across the northern part of the state.
This is some serious and dangerous heat. Outdoor activity is just not at all recommended during the daytime.
A strong ridge of high pressure in the West brings the highest heat of the season so far to a large area.
Combine the cold with the wind and some precipitation and there is a real danger of hypothermia.
Any shower and thunderstorm can contain heavy downpours, heavy enough to cause temporary, low-lying ponding.
According to all long-range models, the warmest area in North America compared to average will be over the Northwest.
No matter where you are, the sunshine gets more intense and causes quicker burning