UPDATED: Some Precipitation Is In The Forecast Beginning Next Week…Maybe Not

We’ve kept pretty quiet over the last 24 hours about a storm developing during the first week of December. The models have been somewhat flipping around with the high pressure ridge and its ultimate demise. Both BA at OpenSnow.com and Paul at TahoeWeatherBlog.com came out of the gate fairly strong this morning pushing the possibility of a decent system in the Tuesday to Thursday time frame next week. We’re not totally convinced yet.

The Euro and Canadian models definitely are favoring a wetter solution. TahoeWeatherBlog.com has the graphic for the Euro model posted today. OpenSnow.com has graphics for the GFS, Euro and Canadian models, all showing the potential for 1-2 feet of snow next week.

Here’s what I have that’s different. Take a look at the difference between the morning and evening run of the GFS model. You’ll see what we mean by some uncomfortable variability.

Here’s the GFS for Thursday the 5th on the morning model run. That light blue coloring is juicy goodness. That storm also is coming straight from the north, bringing plenty of cold air.

Here’s the same GFS model, for the same period of the storm , hitting a bit sooner on Wednesday night, but from the evening run of the GFS. That picture is good, but it’s more of a 6 inch storm than 2 foot storm.

So the models are not consistent yet. Still anything is better than nothing. We seem to be entering a period where all of the models are agreeing that significant change is imminent. We just don’t really know the magnitude of the change yet or its exact onset. As always, we’ll be keeping an eye on the models….when we’re not washing cars and burning skis.

Updated: I just read the Forecast Discussion from the Reno office of NOAA…and it says pretty much the same thing. Here’s what they said:

ACROSS THE PACIFIC BASIN, MODEL GUIDANCE IS IN GENERAL CONSENSUS WITH DEVELOPING AN AMPLIFIED RIDGE NEAR 140W THIS WEEKEND WITH A COLD LOW OVER THE GULF OF ALASKA DROPPING SOUTH ACROSS THE WEST NEXT WEEK. THE UNCERTAINTY LIES WITH HOW MUCH THIS LOW DIGS ACROSS WEST COAST WHICH DICTATES HOW COLD AND HOW MUCH PRECIPITATION WE WILL GET. RECENT DETERMINISTIC RUNS OF THE GFS/EC/GEM HAVE BEEN SHOWING THE POTENTIAL FOR SIGNIFICANT QPF IN THE SIERRA WITH AS MUCH AS 3 INCHES OF LIQUID EQUIVALENT IN 24 HOURS IN SOME RUNS. EVEN THOUGH INDIVIDUAL RUNS MAY SHOW SOME APPARENT CONSISTENCY, THE ISSUE IS THAT ALL MODEL GUIDANCE HAS BEEN WILDLY INCONSISTENT WITH QPF RUN-TO-RUN AND ENSEMBLES SPREADS ARE HUGE WHICH INDICATE THAT THE MODELS ARE STRUGGLING WITH THIS SYSTEM. THIS IS LEADING TO LOW CONFIDENCE WITH HOW MUCH PRECIPITATION IS TO BE EXPECTED THROUGH THE FIRST PART OF NEXT WEEK. WHAT CAN BE SAID WITH HIGHER CONFIDENCE NOW IS THAT WE SHOULD HAVE A LONG WAVE TROUGH SETTING UP ACROSS THE WEST WHICH SHOULD DRIVE US INTO COLDER AND WETTER PATTERN NEXT WEEK. UNTIL RUN CONSISTENCY AND ENSEMBLE SPREADS IMPROVE FEEL ITS MUCH TOO EARLY TO SPECULATE ON PRECIPITATION AMOUNTS A WEEK OUT. FUENTES

Wednesday Morning update: <Large sigh> The models continued to build the ridge back in place and dry out the potential storm for next week. The latest GFS run gives us no precipation out of that storm and it builds the ridge back in pretty solid. Running the loop out the full sixteen days to show total precipitation paints a really sad ugly comical picture…is the KSL curse really true? We sure hope the Europeans or Canadians have the better forecast for next week. BA at Opensnow.com is saying exactly that in his Wednesday forecast. I am already a fan of cheap Canadian beers…I am also currently a fan of the Canadian weather models.