Tahoe Snow and an Atmospheric River sets up for Washington

Posted April 6, 8:10 am MT 7;10 am PT

Snow Stake Cams

MSLP Surface Chart thru Arp 15

All Snow GFS

Forecast Discussion

Heavy snow is back in the Sierra as a fast-moving system zips through Lake Tahoe. The bulk of the storm will be out of the area by early afternoon, but some spots could see a foot of snow. This system slides to the east, northeast and dries up, while the next Low Pressure system spins in the Gulf of Alaska and produces an Atmospheric River (AR) for Washington that stretches all the way to Hawaii, so an official Pineapple Express!

This is another example of repeating AR’s, as this one originally cam through back in November. They don’t repeat every cycle, but there have been several that have repeated this year. I will break them down in the next couple of months as we analyze this historic season.

These charts look really similar, with a few differences. First, the line of thunderstorms in the Midwest, has not developed yet, in the model projections, and the High off the Atlantic coast is in a different spot. The big storm hitting Greenland is there, as well as the typical tropical moisture in the Gulf of Mexico.

Other than those differences it’s pretty close. The teleconnections are the difference in the placement of the High off the Atlantic coast, so that is a good indication of how the pattern works.

Lake Tahoe

Heavy snow this morning and early afternoon as the intensity of the storm has jumped from yesterday’s model run. We could see up to a foot of snow for resorts along the northern crest, but most resorts will likely be in the 4-8 range.

Temperatures start out the day in the mid 20’s, at base level and increase for a high around the freezing mark. Winds between 25-30 with gusts around 50 mph. Upper mountain winds peaking at 70 mph.

Scattered snow showers likely in the afternoon and evening. Tomorrow will be a great day to ride, with temperatures in the upper 30’s for the high, after beginning the day in the mid 20’s. Light winds between 5-10 mph.

ECMWF Meteogram Long Range for Aspen