Ski Season Update: A Slow Start, But No Need to Panic…Yet

December 6, 2019

6pm Friday…

Way back in late September, then more so in late October, there were hopes we might see an early ski season.  There was more snow on the ground in late October than right now!

That was due to a couple of very early season cold spells + snow.   This was my graphic on October 19th.

snow-mt-hood-totals

That all melted away, but then a huge Thanksgiving week storm dumped 1 to 2.5 snow up on the mountain.  Once again we’ve gone back to mild & mainly dry.  So we’re down to 1 to 1.5′ at Timberline and Meadows, and just a few inches down at Skibowl.  Timberline is hoping to have two lifts open tomorrow again, and Mt. Hood Meadows has some basic terrain open with a few lifts turning this weekend.

So when will real skiing begin?  That typically happens when a ski area has a solid 30″ base (or more).

MY THOUGHTS

  1. We are not in any sort of “crisis” right now. There have been LOTS of early seasons that don’t deliver; then suddenly in mid-late December the snow gods deliver the goods.
  2. There’s no need to freak-out/panic until we get to Christmas Vacation time…that’s the 20th this year.  Still a full two weeks away.
  3. Above 5,500′ there should be 4-8″ this weekend, but very little below that elevation.
  4. There are hints we may get some sort of a dumping late next week, maybe enough to get more runs open for NEXT weekend.  Maybe.

The reason for the lack of snow is obvious when looking at the upper-level height anomaly chart for the past 30 days.  A persistent area of high pressure over and just northwest of the Pacific Northwest.  This weakens approaching storms, splitting them as well.  Notice lower than normal “heights” in California; that explains wet and cool weather down there recently.

500z_30a.fnl

Now this weekend a weak system is moving onshore California and we’re getting southerly flow as it moves by.  This setup isn’t typically a big snow-producer in the Cascades and it tends to be quite mild as well.  In this case I think we could see up to 10″ WAY up high.  Like well above 6,000′.  But it’ll be tough to get any sticking snow below 5,500′.  Forget about snow at Government Camp

RPM Snow Accumulation Mt Hood Zoom In

Upper-level ridging wants to develop over the PACNW again Monday through Wednesday.  Notice the above-average heights on Wednesday…ridging

m500za_f120_bg_NA

But the ridge flattens a bit Thursday/Friday, allowing a more typical wet/snowy system into the Pacific Northwest.  In fact the ECMWF shows a cool upper-level trough or two slipping through the region that following weekend (14th/15th).  This would be much better for Cascade snow.

Both the ECMWF and GFS ensemble forecasts say we’re done with ridging after that time.  Going out a full two weeks, they both forecast upper-level troughing right over us.  Back to chilly weather like we saw Thanksgiving

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Yet the GEM (Canadian) builds the big ridge right over us again at the same time…hmmm.

gem_twoweeks

We’ll see how this plays out, but for now it appears we’ll get at least a bit more Cascade snow late NEXT week.   Our forecast for Government Camp temps plus ski area snow & snow levels around Mt. Hood

7 Day Forecast GOVT CAMP

By the way, there’s absolutely no sign of lowland snow/cold in the next 7-10 days.  The ECMWF ensembles for snowfall (51 separate runs from this morning’s data) say forget about it:

ecmwf-ensemble-KPDX-indiv_snow_24-5633600

Chief Meteorologist Mark Nelsen


December Starts Mild; Still No Stormy Weather Pattern In Sight

December 1, 2019

10pm Sunday…

That storm of flurries in the metro area was fun last night around midnight to 1am.  Lots of us saw a dusting, although no one saw more than 1/2″.  I see some totals up around 2-3″ max in the Gorge.  Not exactly a big snow storm…or even any sort of snow storm.  But a nice little start to the cold season weather fun.  Officially no measurable snow fell in Portland so we haven’t seen our “first snow” yet this season

Snow Official PDX Today

East wind is still screaming through the western Gorge this evening, gusting 70-80 mph at times at Crown Point.  But tomorrow the high pressure east of the Cascades weakens quite a bit; so the wind dies down too.  That means a bit warmer in the metro area and Gorge too.  Otherwise we should see a fantastic first Monday of December; abundant sunshine and high temperatures near normal.  That’s 45-50 this time of year.

November was very dry, in fact the driest in 26 years in Portland!

Driest November Ever Graph

Remember October was dry as well.  Just for fun I checked all the October/Novembers with less than 5″ rain in Portland (only 3.03″)  All 5 since 1976 ended up with little/no winter snow in Portland.  The winters following were all generally quite boring in our area. That’s 76-77, 87-88, 93-94, 02-03, 13-14.  That’s not a forecast; I’m just noting that it’s interesting.

What’s ahead?  A mild start to December.  There’s no sign of arctic air or lowland snow.  Check out the ECMWF ensemble forecast of 24 hour snowfall at PDX.  That’s 51 runs of the ECMWF model and not even a hint of snow in the valley through mid-month.

ecmwf-ensemble-KPDX-indiv_snow_24-5201600

There are hints that we MAY have a wetter pattern arriving, but it’s still 10 days out on the ECMWF…hmmm

ecmwf-ensemble-KPDX-indiv_qpf_24-5201600

The GFS ensembles show the mild weather first half of December

gfs-ensemble-all-KPDX-daily_tmin_tmax-5244800

I think the most striking feature is the lack of storminess continuing into early December.  Sure, we had one “bomb cyclone” move into the southern Oregon coastline.  But otherwise it’s been quiet most of the past two months.  There’s quite a bit of a “splitty” look to the upper-level pattern right now and into Tuesday.  See the upper-level low west of California?  It’s “cut off “from the main flow up to our north on Tuesday’s map.  This can tear weather systems apart

ecm_tue

An approaching cold trough on Friday appears to be splitting a bit as well

ecm_sat

At 10 days out (Wednesday the 11th), the flow is more consolidated, but heights are higher (warmer) than normal.  This would be a wet & warm December pattern.

ecmwf-deterministic-namer-z500_barbs-6065600

To summarize:

I don’t see any big weather “events” in the next week that will have any big impact on your life.

Chief Meteorologist Mark Nelsen