100″ on Mt. Hood; Big Ski Day Wednesday!

January 19, 2016

We passed the 100″ snow base threshold at both Timberline and Mt. Hood Meadows today…quite a change from last year!


I think Meadows only hit around 50″ last winter/spring.  As of now it looks like about 10-11″ new snow have fallen up above 4,500′.  With strong westerly flow this evening/tonight I expect another 8-12″ to fall during the night.  A colder airmass moves in with the westerly wind so Wednesday sure looks like a good powder day to me!  I put out a Powder Alert for Skibowl last night.  If you’re a skier/snowboarder you might want to subscribe to that here.


The January rain total also reached a benchmark here in Portland today.  We’ve now seen MORE than our typical January rain…with 11 days still to go.  It’s obvious now it’ll be a much wetter than normal January.  Once again, this El Nino is behaving like 1982-83 here in the Pacific Northwest.   Not to bring anyone down, but February and March were extremely wet that year as well.  On the positive side, I’m pretty sure the soil has recovered from the dry spell last summer…

Looking ahead, the wet pattern does continue the rest of this month, although I don’t see any flooding-type situation.  Our storms just aren’t that strong because of some minor splitting.  Plenty of rain but no huge soakers and no windstorms.  That said, the GFS is hinting at a wetter system next week.  Take a gander at the latest meteogram…looks warm and wet!



Chief Meteorologist Mark Nelsen




ECMWF Weekly Maps

January 18, 2016

The usual.  4 maps, each one is 500 millibar height/anomaly.  1 for each of the next 4 weeks.  The last map takes us to Valentines Day.

A couple thoughts:

  1. Mild pattern will continue.  A bit cooler at times…seems to be something right around the end of the month.  Also seeing that on 16 day anomalies from GFS/GEM
  2. Troughing just to our west backs offshore farther.  But compared to this run 10 days ago the ridging is not as strong to our north and northeast.
  3. Wet weather continues


That last map looks pretty mild for mid-February, but we’re still 4 weeks away from fork-time.

Chief Meteorologist Mark Nelsen

No Subduction Zone Quake or Mt. Hood Eruption

January 18, 2016

3pm Monday…

This “information age” is often more of a “disinformation age”.  With social media ANYONE can post ANYTHING and it gets picked up, shared, re-tweeted all around the globe in a short period of time.

It happened today when lots of you received this from a friend/neighbor etc…


or saw this Tweet


So dramatic!  My “male-cow poo” meter went up immediately.  It didn’t take much time to go to the site (which now appears to be offline at this very moment) and see something about Buffalo getting wiped off the map in a separate story.  Right…

There is no such radio station in New York.  Snopes.com has a story about another fake “report” from this website a month or so ago.

So much junk floating around the internet, including fake weather stories too.  Stick to reputable media/weather organizations while on the Internet.  It avoids a lot of confusion!

Chief Meteorologist Mark Nelsen

Snowpack Still Above Normal

January 15, 2016

The first half of January was relatively dry…until the past 3 days.  Take a look now at the mountain snowpack across the state as a percentage of average for January 15th:


The numbers are lower than 2 weeks ago, but still around normal in Northern Oregon and well above normal to the south.  What a difference a year makes…snow depth the past 8 years at the Mt. Hood Test SNOTEL on the lower part of the Timberline Ski Area:


Remember 2007-2008?  That was a crazy mountain snow winter; tons of snow to the lower elevations.  If I recall correctly the snow level didn’t rise above 4,000′ through all of January and February.  It was regularly in the 1,500-3,000′ range.  Detroit didn’t know where to pile all the snow at 1600′.  I also remember the dusting of snow on Christmas Day with some snow showers.  Little did we know that one year later we’d have piles of snow sitting around on Christmas.

Looking ahead, a mixed bag of snow/rain in the mountains for the big 3 day weekend


Stay up high this weekend…Saturday evening and Monday look best to me.


The wet weather pattern stays with us through the foreseeable future.  But it’s a different “kind of wet” than what we saw in December.  In this case the main stormy weather is well out in the Pacific and we just keep getting the weakening/dying storms (technically they have passed the mature phase of extratropical cyclones).  These systems still have enough life to give us rounds of clouds/rain/breezes but that’s about it.  Notice there are no forecasts of strong southerly wind, flooding, or huge piles of snow in the Cascades over the next week.  And the systems are very mild…get used to seeing high temps in the 48-55 degree range instead of the 42-50 we’ve been seeing.

Enjoy the wet weekend…Chief Meteorologist Mark Nelsen

ECMWF Monthly Run

January 14, 2016

10pm Thursday…

The usual maps…from the Wednesday night 32 day run of the ECMWF.  One map for each of the next 4 weeks.  They show the same pattern continuing for the next month.  That’s above average 500mb heights (ridging) to our northeast and below normal heights (troughing) to our west.  Theoretically this pattern tends to split storms and give us less rain than normal.  In this case that troughing is pretty close (especially in the first week or so) so we appear to still get plenty of rain, but warmer than average temps most likely with no freezes in sight.  Two days ago I turned on my outdoor faucets/water lines that my chickens/ducks use.  So I’m hoping we don’t get below about 28 again or at least for a couple weeks…we’ll see.

This El Nino seems to be tracking more like ’82-83 than the other real strong event ’97-98.    Take a look at rain anomaly December 82 & 97 vs. this past December.

What happened in January and February those two big years was the same though…mild and wet.  The temperature anomaly:


and the precipitation anomaly? Wetter all along the West Coast with the wettest action shifting down into northern/central California compared to now:


I went through the daily temps for Jan/Feb both those years and it was quite mild.  If our weather tracks similar to those winters then we’ve seen our coldest/snowiest weather of the winter already.  It is obvious that the pattern remains very mild through the rest of this month at least.  My gut feeling is the 1.1″ of snow in Portland so far this winter could be it for the season.

Chief Meteorologist Mark Nelsen


An Old Friend Returns; Another Leaves

January 12, 2016

10pm Tuesday…

Ahhh, a rainy and chilly day today.  It’s like an old friend is back.  A classic midwinter day in Western Oregon and Washington.  Rain totals as of 10pm:


The astute weather geek will notice 3 times as much rain west metro compared to the eastside.  That’s likely due to southeast/easterly flow in the lowest 2-4,000′ of the atmosphere giving the areas closer to the Coast Range a bit of an upslope lift.

It’s pretty obvious that we’re going to see PLENTY of rain over the next 10-15 days.  Take a look at the 00z GFS meteogram:


Possibly some breaks at times, but in general most days will have at least some rain.

So our rain is back…but that cold east wind is about to go away!

For the past 18 days, yes, since the day after Christmas, that cold Gorge wind has been blowing.  For a few of those days it was light, but most of the time it has been raging and very cold.  Today we saw the strongest wind of the past week…84 mph at Vista House and 67 mph at Corbett.  Take a look at the peak gusts at Troutdale and Crown Point the past 7 days:

Why is the wind going away?  Because an area of low pressure is finally moving through our region instead of just swinging by offshore.  Check out the surface pressure map for right now with surface low pressure offshore, then again at 10am tomorrow morning.  It moves east of the Cascades, giving us strong onshore (southwesterly) flow.  That means a surge of west wind through the Gorge by midday at the latest.  Those of you in The Dalles and Hood River will see the low level clouds break up by afternoon (sunshine!) and temperatures should soar up to around 50 degrees for the first time in 3 weeks!

Chief Meteorologist Mark Nelsen

Signs of Wetter Pattern Ahead

January 10, 2016

11pm Sunday…

January has sure been different than December.  Only .80″ rain in the past two weeks here in Portland but 6 times that much in the previous 2 weeks!


Now models are looking significantly wetter over the next 10+ days.    The general pattern is a strong upper-level trough to our west over the Gulf of Alaska and weak ridging over the Intermountain region. The 10 day ensemble average 500mb maps show the lower than normal heights on both the GFS and ECMWF models:

It’s a bit farther south than in a typical winter (Thank you El Nino?), so California will continue to get rain and mountain snow out of these systems.  The GFS seems to be the wettest model.  15 day rain forecast shows 15-20″ precip in the Siskiyous and Coastal Ranges of northern California.  That’s TOO much:


The latest ECMWF shows up around 10-15″ in the same area.  Wow.

15 day snowfall forecast:


That’s excellent news for water-starved California.   And after a 2-3 week lull in the Pacific Northwest we’ll see snow return to the Cascades too.  Just in time because we’ve come down to right around average snowpack for this time of year around Mt. Hood.

Systems appear to still be splitting a bit; so as of now I don’t see a real stormy pattern for us here in Oregon/Washington.  Just frequent wet systems.

Tired of the East Wind?

It’s been blowing almost constantly over the past two weeks.  Good news, it’s going dead for at least a day or two this week.  Wednesday’s system includes low pressure sliding by to our north and the pressure gradient actually turning WESTERLY through the Gorge.  Nice…those of you in the Gorge can enjoy the after two more days of wind Monday/Tuesday.

Chief Meteorologist Mark Nelsen