A nice and sunny day Saturday is in store for us. Sunday the more active weather begins to enter the region with rain/snow showers possible through Monday. A stronger storm is going to come in by late Monday night into Wednesday. We'll see double digit totals by Thursday morning. It's likely we dry out fairly quick going into the last week of the month.
Short Term Forecast
We get one last full sunny day here on Saturday. Temps will be in the 40's and winds should generally be light. Enjoy the good weather since we won't see a real break till the middle of next week.
Sunday - Wednesday Storms
A fairly complex series of storms is going to impact the region. It's not likely that we'll see much snow accumulation until Tuesday though.
The weak system that's going to come through on Sunday and into Monday does not have much energy and thus will not able to deliver very much moisture to our region.
Rain & snow showers are possible during this 2 day period with more rain likely below 7K FT. Winds will be increasing up to 40 MPH out of the West Southwest by Sunday. They are likely to remain around the 40 - 60 MPH range through Wednesday as the next system comes through.
You can see the much stronger more powerful system with associated Atmospheric River in the following 2 graphics. You can really see the heaviest precip and AR moisture affecting the SoCal region. This track has been evolving the last couple days with a more Southerly orientation along with a more direct hit into SoCal. This means that we're likely to see colder air along with a better chance to see more accumulating snowfall.
This will be longer duration storm that likely begins by Monday evening and lasts through Wednesday afternoon. Temps will be dropping on Monday afternoon and the snow line is likely to come down below the resort levels. It should stay below 6K FT through Wednesday.
I'm going to show you the different precip scenarios with this storm. Overall the Euro is more bullish with this series of systems, specifically in the San Gabriel's.
The Ensembles specifically have the European mean favoring our region with almost an additional inch of liquid during the bigger Tuesday into Wednesday storm.
I'm a bit on the fence with forecasting big multi-foot snowfall totals with this system because of the March sun angle, the tricky track of this AR, and the lowering of snow levels.
Given that I'm apprehensive forecasting big snowfall numbers I'll be pretty conservative with these forecasts. Snow ratios will be running anywhere between 7:1 to around 10:1 with this storm. We start with pretty dense and heavy snow on Monday night and early Tuesday morning. By Tuesday afternoon the snow should be a lighter density and on Wednesday temps could be in the 20's across the mtns with even fluffier snow falling.
My forecast is for 16 - 26 inches of snow across the region. I'm expecting the highest amounts wherever the rain turns to snow fastest and that's honestly a bit hard to predict. The San Gabriel's have a fair chance of hitting the 20 inch mark, but some of the Big Bear Resorts also have higher summits and could see more snow because of less rain and higher snow to water ratios.
I'll provide another update tomorrow to discuss how I think this storm will evolve and what sort of snowfall amounts we could see.
There is another weak system showing up for Friday, March 24th but at this time it looks like accumulations could be pretty meager, it at all.
The following graphics show that the period for the last 7 days in March could be a drier one for us in SoCal.
Both the GFS and Euro Ensemble Means show either average or below average precip. For our region below average doesn't mean too much since average isn't very high this time of year. But since they aren't showing above average that would imply that the likelihood of wet weather is lower.
We have a good storm for this coming week so we'll focus on that first.
Till the next one... Mike out.