Wednesday, February 18, 2009

Here Comes the Sun.....

The 3-day storm has finally ended this morning. Northstar picked up a total of 3 ft. 3 inches over the past 3 days. The storm was more showery with waves of moisture rotating around the main low offshore, instead of a steady jetstream that would have helped to push more moisture over the crest. So snowfall totals varied greatly depending on where the heavier showers set-up & dropped off dramatically as you went East of the Crest. Areas along the crest picked up anywhere from 34 - 56 inches (about 3 - 4.5 feet), & areas east of the lake picked up around 15" or less.

Two week storm cycle finally comes to an end as well. It snowed in some capacity for 14 days straight. Two week totals put a nice dent in the annual snowfall totals. I added up the 24 hour snow totals reported each morning for the past two weeks around Tahoe. Northstar ended up with 96" which is exactly 8 Feet! over the past two weeks on top. Sierra at Tahoe beat us out by 1.5 inches at 97.5! Other areas along the Western Crest reporting 101 - 145 inches (8.5 - 12 Feet). 5 - 6 feet on the Eastern Crest.

We are now ahead of the infamous 06/07 season in which we didn't have this much snow until March 27th and not much more after that. We are also ahead of 05/06 where we didn't have this much snow until March 2nd, but then it dumped 350" in March & April and the crest ended up over 600" on the season! Let's hope we can do that again! We are just about on average now for where we should be for this point in the season at Northstar. If you divide our average of 350" by the 4 snowiest months, Dec. - Apr., we should be at 262.5" by March 1st and we are currently at 259", with 10 days to go. The crest is off by about 3-4 ft.

So what will the next 10 days & beyond bring? Another big storm is right offshore ready to dump on us, but it will stall today just off the coast as there is a quick jam in the progression of storms caused by a big trough in the East that will last a few days. This storm will pump a ridge over us Wed.-Sat. and bring sunshine and temps in the 40's, perfect weather for the Dew Tour finals at Northstar this weekend! Latest models show it so close to the coast that it rains right along the beach.

The storm sitting off the coast will be pumping up some decent moisture from the tropics. It looks like this moisture will finally move in sometime on Sunday now. Meanwhile a storm will be coming down out of Alaska & help to push the storm inland, as well as possibly tap into the moisture from the storm. Models disagreeing on how far south the storm from Alaska comes, but most show it at least far enough to keep snow going until Tuesday. Snow levels could start a little higher with the subtropical moisture but then fall as the cold front approaches from Alaska.

Another storm is ready to come in for the second half of the week & into the weekend to finish February on a snowy note.

The ridge looks to stay stationary just North of Hawaii thru the first week of March. This will leave the storm door wide open with storms continuing to drop down from Alaska. These will be cold storms since they are dropping down from the North. According to Ed Berry's latest discussion, he believes the ridge will possibly hold over Hawaii well into spring. Keep your fingers crossed. BA

10 comments:

Anonymous said...

Good work BA! Looking forward to carving it up Thursday through Sunday. How are conditions at Squaw? Have they seen more or less snow that Northstar over the past week. Great blog.

BA said...

They got about the same amount of snow from this storm but about 5 inches more in the past two weeks.

KranJams said...

wahooo!!! thanks for the great blog.

Anonymous said...

What's the next month or so looking like temperature wise?
I see temps rising to the 40's. Is this a concern in regard to snow vs. rain?

BA said...

Snow levels don't depend on the surface temperature. I have seen it in the 70's here & then a storm rolls in the temperature plummets & it starts to snow. It matters the temperature in the upper atmosphere associated with the storm. Also, if the air is dry, when the snow starts to fall evaporational cooling will drop the temps. Snow levels for this weekend look to start between 6 & 7 thousand feet, regardless of the temps and then fall as colder air moves in aloft.

Brian Dipert said...

BA, this is a great resource, thanks everso for it. One question I've long wondered; what is the phenomenon that so often keeps snow, rain etc from pushing east past the Sierra summit (Donner, etc) and into Truckee-and-beyond region? So often I look at the radar map on weather.com and see that the advancing front has stalled right at the north-to-south summit ridge. Is the impeding factor rising warm air from the Reno valley, or something? Thanks in advance!

Anonymous said...

BA: I look forward to reading your blog every day. Please know that your readers are very appreciative! Dave

BA said...

The cloud deck for storms can be down in the 100's of feet. The clouds have to be pushed up 1000's of feet to go over the mountains. This process is called orographic lift and causes the clouds to get squeezed which is why it dumps on the West side of the mtns as the air is lifted. It takes a lot of energy pushing from the West to push the moisture over the Crest. If the storms are weak or the winds are out of the South the push isn't there and the storm gets stuck on the crest. By the time they do get over Truckee the clouds have been squeezed out some, & by the time they get up and over the second crest on the way to Reno they are really squeezed out.

That is why you will have an average snowfall on Donner Summit of 500", 250" in Truckee, and 18" in Reno. that plus it rains a little more often at the lower elevation.

WeeDiddy said...

any idea about the temp with next weekend's storm? Would suck if we got some rain after all that good snow we've had.

dmourati said...

Thanks for the explanation on orographic lift. I hadn't quite grasped that concept but you painted a clear picture of what happens.