Thursday, September 3, 2009

August Re-Cap....

Boring weather right now so we'll have to settle for the August re-cap. Most forecasters right now are caught up in the Hurricanes & wildfires, so not much chatter on the upcoming winter at the moment. September will usually bring us our first dusting of snow, but I don't see anything hopeful for the next couple of weeks. Should stay warm & dry after a slight cooling from the storm to our North this weekend.

August was another dry month this summer. The average precip in summer months is low & is mostly from thunderstorms. The Tahoe Basin was 49% of avg. bringing the water year total to 79% of avg. on the year. The standout spot was Ward Creek which must have had a rogue thunderstorm sit over it & put it at 109% of avg. on the month. The Truckee River Basin was only 35% of avg. bringing the water year total to 86% of avg. Squaw Valley was a standout spot with 87% of avg. September is the last month of the 08/09 water year.

August was 4.1 degrees below avg. in Truckee. That makes 22 of the last 25 months below avg. That means Truckee has been averaging 2.6 degrees below avg. the past 2 years. Now, 9 of the 10 months prior to this period were above avg., but the past 2 years Truckee has been really cold compared to the avg. This may be contributed to the La Nina & the overall cooling of the Pacific which has begun.

La Nina typically pushes the storm track to our North by pumping a ridge off the coast. A cooler ocean & cooler temps usually promotes less precip overall. Storms feed on the upward motion of warm air that cools as it rises forming clouds & precip. It can be cold air encountering warm air forcing it up or warm air over-riding cold air, the bigger the temp difference the better. For us most storms are cold fronts coming across the Pacific during the winter. This process will occur less or be weaker when the cold front is encountering cold water & cooler air already in place over us limiting the amount of warm air that can rise to form clouds. This explanation would make a lot more scientific sense as to how dry it's been the last few years & why there are ripe condtions for forest fires, not Global Warming as I've seen on the news. In a warming climate, & with El Nino's & a Southward shifted storm track, CA should see an increase in precip not a decrease. Our hope this winter is that El Nino causes a shift in the storm track causing storms to hit CA instead of the PacNW. Hopefully the track isn't too far South.

I started a Twitter account which people can follow this season if they wish. I will not be tweeting about eating lunch & taking naps, this will be strictly a real-time storm info tool. Like if I wake up to 2 ft. of powder at 5 a.m. I will send out a tweet, or if I'm on the mtn. & the snow level drops unexpectedly & snow is suddenly piling up on the slopes I will send out a tweet. My account name is TahoeWeather, but I am following a good one that I suggest called Tahoe_Weather. They send out a tweet everytime the NWS sends out any sort of Weather Advisory for the area. BA


Skye said...

You said we usually get our first dusting of snow in September. Haven't we already had a dusting of snow? We had it in August. I will quote you on it. "Still can't see the top of Mt. Rose yet this morning. It's socked in with clouds. I doubt the snow accumulated at all or if it did it melted quickly. I drove over Mt. Rose last night around dinner time & it was 36 degrees with snow pellets at the summit."

BA said...

In Truckee & on Northstar, not at 10,000 ft. on the peak of Mt. Rose.

I do this blog because I enjoy studying the weather & sharing what I find with others. I don't get paid by my readers, so when & what I post is up to my discretion. Your comments are quite demanding. You could do this research yourself or write your own blog. This is mine & this is how I enjoy writing it.

Thanks for reading it & I hope you find it helpful.