Showing posts from December, 2011

Changes Still Coming, But Ever So Slow

Changes should be coming to the Sierra in about a week to 10 days. However with all the cold air still trapped in the arctic, the storms headed our way are weak. In fact the Pacific born storms are all weak. We are about to conclude our driest December in the last 130+ years, with no measurable precipitation in the Central and Northern Sierra. Having said all of that, the changes that I have been forecasting are still en route, but ever so slow. GFS has a fairly weak system coming ashore around the 5th of January, however this system will die as it attempts to rise above the Sierra. Here is a forecast look for the 5th along with the total forecasted precip through the 10th of January. 1/5/2011 Total Precip through the 10th Again, without the cold air, we are not seeing storms of any significance. Right now we need about 6-10 feet of snow just to open most ski areas completely. Right now I do not see that happening any time soon. Having said that, many of the long range mo

Conditions For Snow Becoming More Favorable

As I wrote in my last post, high pressure has been blocking anything from getting down to our area. However that ridge is showing signs of weakening and because of that it is being shoved south and west. This is allowing small storms to come down the coast and have at least a minor impact on Tahoe. Moving forward, these storms will gradually pick up in intensity. It looks like the first big storm of the season will arrive here sometime between Christmas and New Years. Both the EC and GFS long range models are showing signs of enhanced storm intensity. These storms are also moving much further south. EC has a small system coming our way in a little over a week. (Figure 1) Figure 1 - 12/24 Notice how this storm is still off the coast as it heads south. This is much more typical of an El Nino year than a La Nina year. Pretty much means you can throw the Nino/Ninas out the window this year. A series of larger storms start to make their way into our area starting around the 28th.

Change Coming But Not Until December 20th

The stubborn high pressure ridge that has blocked all storms from sniffing our area is showing signs of moving south. That will open a large corridor for major storms to hit our area. However those storms will probably not start until around the Christmas Eve or Christmas Day at the earliest. I have displayed two images below, the first is where the blocking high pressure ridge has been and is now. The second is the GFS forecast for where it will be around the 20th of December.  Notice that the high pressure ridge is much smaller and about 1,000 miles south. The next challenge is for that ridge to move a bit west and the storm corridor will be open, big time. Current Conditions December 20th Conditions I said this in my last post and I believe it is worth repeating. A typical La Nina year will not have as many storms but should produce an average amount of precipitation. This weather pattern, if it holds true, is setting up for some giant storms to slam the Tahoe area around C