Early Season Dustings:

Summer turned to winter pretty quickly on Tuesday as a cold front moved through and we saw a little snow on Mt. Rose down to around 8,500 feet.

There were thunderstorms in the area as well and some people thought the picture was just hail. But high temperatures were only forecast to be in the 30's in the upper elevations per the OpenSummit app for Tuesday and they dropped into the low 30's during these showers, so this was our first coating of snow!

High pressure has built back in over CA bringing back dry weather and warmer temperatures for the weekend.  Highs in the 50's the last couple days will rebound into the 70's for the weekend.

It won't last long as a cold trough pushes into CA Monday into Tuesday.  

Wind:

This system will be accompanied by a fairly strong jet stream for this time of year that will dip into CA. 

As the system approaches over the weekend we should start to see gusty winds increase.  Sunday into Monday we could see winds gusting to 60+ mph in the upper elevations, so don't be caught off-guard if you are out hiking.

The OpenSummit app has a red code for the upper elevations this weekend meaning a high wind warning.

Precipitation:

I have been watching this system for several days now as the forecast models have been pretty consistent in showing precipitation for our area.  I thought this could be our first chance for snow before we got surprised by the dusting on Mt. Rose Tuesday.

The average on the ensemble runs shows very light amounts of precip possible later Monday into Tuesday morning.

But what is interesting is that the latest GFS and European model runs show the chance for a bit more precip.

The forecast models aren't great this time of year a week out.  We are only 4 days out now, so as we go through the weekend it will be interesting to see if the models continue to show 0.25-0.5 inches of precipitation.  This isn't a strong system by Tahoe standards, but pretty strong by early September standards with good jet stream support.

The most interesting thing will be the snow levels if we get precipitation.  The latest model runs show the snow levels dropping near 8,000 feet on Monday, and bottoming out as low as 7,000 feet Monday night behind the cold front.  That should mean a coating of snow is possible for the upper elevations by Tuesday morning.  But there is an outside chance we could see a couple of inches along the crest if the wetter models verify, and a coating down to 7k near Donner Pass.

I will be updating as we get closer...

It looks like high pressure may build back in by the middle of next week into the weekend of the 20th.  That should bring a return of drier and milder weather.  Highs should rebound back into the 60's maybe to near 70 degrees at lake level.

The long-range ensembles do show a fairly large trough in the Gulf of Alaska towards the end of the month, with systems trying to push into the West Coast.  We will watch to see if we could see more shots of cooler air and mountain dustings of snow.

Fires:

Fire activity in CA picked up last week with 8 active fires being reported.  That increased to 15 for this week.  Even with the cooler temperatures, higher humidity, and showers we saw.

With the drier weather this weekend and higher winds, we will see a chance that the fire activity increases over the weekend.  The precipitation Monday-Tuesday should help diminish the fire activity in Northern CA.

The biggest fire this week is the Walker fire.  Here is a shot of it I took while driving by on 395 this past weekend.

The Upcoming Winter Season:

We went through some of the forecasts in the last post.  This week I'm still watching the sea surface temperatures in the Pacific.  We have ENSO neutral conditions with cooling temps along the equator, but a big drop in the SOI (southern oscillation index) this week may mean a westerly wind burst and a push of some warmer water to the east.  

So, for now, we will continue to watch and wait to see where things settle into this fall.

Stay tuned...BA