Summary:

Mild weather will continue through Monday.   Tuesday moisture will start to increase as a low approaches the coast.  We could see some showers and thunderstorms by afternoon.  Wednesday and Thursday the low slowly moves across CA with continued showers and high elevation snows.  Friday into Saturday a colder low may dive down into CA bringing more precip and dropping snow levels.  A colder storm may arrive to start the week of the 27th.

Details:

We are getting ready to go into what may be the most active 2 week period of the year.  That is not saying much, and it's April so the storms won't be as strong as they could have been in Winter.  Squaw announced a couple of days ago that they will extend the season another week for a closing date of the 26th, so we will have one ski resort to forecast for.  Plus the rest of the mountains you can hike to.

The biggest change over the past 2 days is that the trough associated with the low moving into CA this week now looks like it will stay to our North.  That will remove the cold air source for the storm on Wednesday into Thursday.  Still, we will see an area of low pressure break off from the trough and slowly spin across the state.  We could see showers arrive by Tuesday afternoon with the instability caused by increased moisture in the atmosphere and the warm April sun.  That could cause some thunderstorms as well.

Wednesday into Thursday the low spins across the state.  Without a cold front the precip should remain showers over the 2 day period.  That makes it hard to predict the amounts of precip and where they fall.  Overall we could see up to half an inch of rain across the basin, and up to an inch or more of liquid West of the basin on the mountains along the crest.  Snow levels may not lower below 8000 feet event though some colder air will work in with the core of the low by Thursday.  Above 8000 feet we could see several inches of snow.  The GFS is most agressive with precip amounts near Squaw through Thursday showing enough liquid for up to a foot of snow up top.  The European and Canadian models keep the heaviest precip South of the lake.

Here is the GFS total precip forecast through Thursday.

The GFS shows the next low dropping out of the Gulf of Alaska next Friday staying to our North.  The European and Canadian model runs show the low dropping into CA.  This low has much colder air with it.  If this low drops into CA Friday into Saturday we could see continued precip, but with snow levels dropping.  We need to keep watching this system as it has the potential to drop a decent amount of snow on the mountains depending on its track.

Long-Range:

After a one day break next Sunday the ensemble trends of the forecast models are still in decent agreement that another slow moving low moves into the West Coast around the 27th-28th.  It is too early to talk specifics, but right now it looks like this low could be stronger and colder than the ones this week if it does show up.  Maybe Squaw will extend one more week if they get decent snow this week and there is more forecast the following week?

The unsettled pattern may continue into the first week of May.

Stay tuned....BA

End of Season Survey...http://opsw.co/season-survey