Major Pacific storm series invading West Coast
6″ to 12″+ of rain expected in northern California in the next few days
100″ of snowfall possible above 8,500 feet in the Sierra & Cascades next 7 days?
Record floods, mudslide & avalanche danger increasing
Storm’s effects reach to Minnesota & Canada
4 day thaw ahead for Minnesota Friday through Monday
+20 degrees vs. average – near record warmth by Monday
Heavy snow 12″ to 18″ possible by Tuesday near Lake Winnipeg?
-It never rains in California
But girl don’t they warn ya
It pours, man it pours
A 2006 heavy rain event drives the Stillaguamish River at Granite Falls, to 9 feet above flood stage
Image: Walter Siegmund
Epic “Mega Storm” slams California
This may be your lead on national newscasts by this weekend.
The opening salvo of the 2012-’13 winter storm season is slamming the West Coast today with torrential rain, fierce wind and prolific mountain snow.
The system will likely deliver some incredible, flood spawning rainfall totals up to 1 foot in some areas in the next 5 days.
In the mountains, heavy snow will fall above 8,500 feet. Since this is a relatively warm early season system, snow levels will remain relatively high. Winter Storm Warnings are flying for the High Sierra.
It’s the first wave in a series of low pressure systems that will ram the West Coast through early next week. The storms are being fueled by the infamous “Pineapple Express” – a plume of tropical moisture that injects copious rainfall enhancing moisture into storms that strike the western USA.
Wide open “fire hose”
NOAA’s “Integrated Water Vapor Loop” forecast into early next week shows the effects of the snake-like moisture plume as it sprays the West Coast with a series of blasts….like and out of control, wide open fire hose.
Each of “Atmospheric River” events will dump several inches of rain in the valleys, and several feet of snow above 8,500 feet. NOAA elbaorates.
Heavy Precipitation Event Developing in Northern California
Heavy precipitation (Fig. 1) is predicted for Northern California over the next 5 days [for official National Weather Service (NWS) weather forecasts, visit: http://www.wrh.noaa.gov/, and for river forecasts, visit: http://www.cnrfc.noaa.gov/]. As with most extreme precipitation events in the region, this one is associated with a strong atmospheric river (AR).
Just a few of these “Atmospheric River” events produce 30% to 50% of California’s average annual precipitation.
The lyrics in the Albert Hammond classic song nailed the meteorology.
Storm will affect Minnesota & southern Canada this weekend:
I wish I could say this system will dump heavy, desperately needed rainfall on Minnesota this weekend. The northerly track will preclude that possibility.
What it will do is pump unseasonably mild air north into the Upper Midwest. I could see 70 in Kansas with this system this weekend, and upper 50s in Minnesota by Monday…a good 20 degrees above average for early December.
Cooler weather will follow by Tuesday, but mild temps in the 40s will liekly return by next Wednesday & Thursday.
Image: ECMWF output for Minneapolis from Norwegian Met Institute
On the colder side of the storm, heavy snow will fall in southern Canada either side of Lake Winnipeg. The storm may dump as much as 12″ to 18″ by Tuesday.
Image: NOAA GFS 120 hour snowfall output via wxcaster.com
The heavy snow cover just north of Minnesota may have implications as we move into early December. Winter storm tracks are notorious for setting up just south of the southern edge of heavy snow cover. I am watching what seems to be a trend toward increasing Minnesota’s chances for significant snow…possibly in the December 10th to 13th time frame.
NOAA’s GFS model keeps hinting at show chances after December 10th
Image: NOAA via College of DuPage
It’s early…but the big storm coming through to the north may be paving the way for future snow in Minnesota.