Before We Look Ahead, A Look Back

October 23, 2016

Yesterday we had our annual Winter Weather Conference at OMSI.  I think it was the 24th year!  Wow, I’ve only missed one or two of those…I’m getting old.  It was great to meet a few of you there and each year it’s fun to reconnect with previous coworkers or old competitors too.

I don’t forecast, but do a weather recap of the past winter and any other big weather events through the year.  The entire presentation will be online, along with the others, within the next few days at the Oregon AMS website:

Here are a few of the graphics I used Saturday…this should stimulate some discussion:


What a mild winter it was!  Interesting to note that it pretty much acted like an El Nino winter (very mild with most action early on).   It did so in the mountains too.  You want to stay up high in El Nino years and that was the case this past winter.  In fact no El Nino winter since 1970 has produced above normal snow at Government Camp!


Here in the valleys we had very little snow of course.  Officially 1.1″.  Just one brief snow storm on the Sunday after the New Year.  Plus a close call a few days before that:


One could argue we’re due for a bigger year…or maybe we have another 1 or 2 duds still ahead the next two winters.


Regardless, snow in Portland is more rare than it was back in the 1940s/50s/60s.  You older folks probably can concur.  This decade is averaging the lowest so far, but it would only take one big winter to make that up.  It was a very warm winter


It’s been 20+ years since we’ve had a winter with well below normal temps.  There have been a few slightly cool ones, but you can see the gradual warm up and (almost) loss of occasional cold winters.  Keep in mind that this is a collection of all climate sites in this zone, not just the 2 or 3 that would be influenced by urban heat island effects.  I received an email a few weeks ago, it was circulating around a skeptic email list.  It claimed our winters have been getting COLDER the past 10, 12, or 15 (not sure which) years.  Well, the data they showed didn’t include the past two winters.  That’s called cherry-picking.  I’ve seen people do that to support all sorts of causes.  It’s annoying.


Late winter and spring this year was very warm, contributing to snow melt in the mountains about a month early.  Note the thick blue line just dropping like a rock in late April and May, far faster than normal up at 5,400′.

There you go.  The weather remains quite mild for at least the next 7-10 days with plenty of rain still to go.  I don’t see a stormy pattern through at least the first couple of days in November, although models are hinting at a stronger Pacific jet stream heading toward us about that time.  We’ll see.

At some point this week I’ll post a few thoughts about the upcoming winter.

Chief Meteorologist Mark Nelsen


Winter Weather Conference This Saturday

October 19, 2016

I’m looking forward to seeing some of you again this Saturday morning for the 24th Annual Winter Weather Forecast Conference at OMSI.  That’s Saturday October 22nd at 10AM. I am part of the Oregon AMS board so I was involved in the planning again this year.

We are proud to have several forecasters joining us again this year. NEW — we will be raffling off a $250 voucher for accommodations at the Tolovana Inn Resort in Cannon Beach, along with the usual Davis Weather station raffle (it’s sitting in my garage right now). Storm season is coming! We want one lucky person to have a front row seat at the coast!


Please make sure you spread the word and arrive early to ensure the best seating possible. More than 300 people are expected at this meeting. All ages are welcome. Free admission and free parking for all guests.

What: 24th annual Winter Weather Forecast Conference

When: Saturday, October 22nd 2016 @ 10 AM.

Where: Oregon Museum of Science and Industry (OMSI), main auditorium, 1945 S.E. Water Ave. in Portland.

Chief Meteorologist Mark Nelsen

Wettest Start To October

October 17, 2016

11pm Monday…

You are living through the wettest October we’ve seen so far…Both in Portland and Salem we’ve never seen a wetter first 17 days of the month.  Here in Portland we’re heading toward 6″ this evening:


The end of October record, the wettest month we’ve ever seen, is just over 8″ set in 1994, so were only 2″ away from that.

But that’s nothing compared to the wetter parts of the region.  Check out some other westside locations.:


and Coast Range…yes, that’s a foot of rain in just the past 7 days up there!


But wait!  There’s more.  The biggest numbers are up in the usual spot just southwest of Mt. St. Helens…over a foot in a half in just a week!


Apparently models weren’t crazy looking for 10″ or more in just 3 days.  There’s a good reason a lot of moss grows on the west slopes of the Cascades, no wonder trees grow so well here!

The rain lightens up quite a bit the next week compared to the past one, but it still looks wet off and on.  I wouldn’t be surprised if another 1-3″ falls by next Tuesday.

Chief Meteorologist Mark Nelsen

Windiest October Day Since 1967: Storm Wrap-Up

October 15, 2016

6pm Saturday…

The wind warnings are all now cancelled in Oregon…as the wind has subsided.  Take a look at that…the highest October wind gust we’ve seen here since a 70 mph gust in 1967.  There was a gust to 52 mph on different wind equipment late October 1994, but that’s the problem with comparing historical windspeeds.  It’s possible either this or that one was really the higher gust, but for sure it’s fair to say this is one of the two windiest October days I’ve seen in my lifetime here!   That shows you how rare an October windstorm is in the valleys.


Other peak metro gusts…


Northern Willamette Valley…


A few things that stick out:

This was just an average “windstorm” for any winter here in the I-5 corridor EXCEPT that it happened in mid October!  44,000 PGE power outages at the peak

This was almost a perfect windstorm forecast for the metro area, both timing and speeds.  Last night I said 45-55 mph, then dropped it to 40-50 mph at the last minute.  That’s fine because only 3 of 7 metro area official reports made it to 50 mph.  Very happy with the metro forecast.


Wow, this one was way off.  Tillamook and Astoria had lighter gusts than Portland!  It was widely forecast and promoted as a major storm for the Oregon Coast, even if it was wintertime.  Not even close!




Coastal cities were generally in the 50-65 mph range.  We forecast 70-90, or even 70-100.  Sure, that exposed tower out at Barview Jetty in Garibaldi hit 77, but that’s about it.  The two big speeds in the 80s are up above 1,000′.  By the way, Mary’s Peak west of Corvallis went over 100 mph, but that’s not unusual during a windstorm…that’s in the mountains.

What happened?  The low tracked farther offshore, thus the south to north gradient was far weaker along the coastline.  Check out the 6pm forecast (right now) from this morning’s WRF-GFS run:


Pressure should be under 970 millibars on that northwest section of the Olympic Peninsula.  Instead the pressure is over 10 millibars higher!  981 mb right now at Forks, WA.  That’s a huge difference.  And check out the low well offshore, shown by the radar at Ocean Shores…


Right now there is an 18 millibar pressure gradient from Coos Bay to Forks.  The forecast was for 28 millibars!

There was also that strong hing on the gradient field that the wind might be much more closely confined to the low center than normal…leftovers from it’s tropical days?  Probably not but something to think about.

This storm stayed farther offshore and made a landfall farther north than expected = weaker wind at the coastline.

Chief Meteorologist Mark Nelsen


3pm Update: 53 mph in Portland

October 15, 2016

Our windstorm is likely peaking just about now.  Within the past hour we’ve seen a gust to 53 mph at PDX, 49 in the West Hills, 52 in Salem, & 51 in Hillsboro.


This should be the peak of the storm based on the low movement and pressure gradients, but gusts between 45-55 mph will continue for another hour or so and then die down.

Looks like 44,000 PGE customers currently out, which is better than the last October storm which had lower windspeeds in 2014.

The coastal speeds have been well below what we forecast in most locations and quite similar to Thursday’s storm.  Newport only gusted to 55 and Astoria 51 (so far).  Garibaldi reached 77.

Chief Meteorologist Mark Nelsen

1pm Storm Update

October 15, 2016

The timing for the windstorm along the coast and (relatively) minor windstorm in the valleys is on track.  The low pressure center appears to be out there west of Tillamook still deepening and headed north quickly.  This analysis by the HRRR model puts it around 974mb.  Generally with these storms the surge of south wind arrives about when the low crosses your latitude.  Basically as it “goes by” to your west the wind arrives.lowpressure_1pm


We could have REALLY used an Oregon Coastal Radar this morning to figure out exactly where the low was!  There is no coverage off the central Oregon coastline…the only part of the USA coastline left “radarless”.  But that’s a political, not NWS solution = lots of $$$.  Hard to believe NOAA has a major facility in Newport and they don’t even have radar coverage.


I’m tracking wind the old-fashioned way here in the weather center:


So far the wind is underachieving on the coast.  At 1pm gusts have barely reached 60 mph on the central coast.  A gust to 58 at Newport.  If it doesn’t bump up dramatically in the next hour, it’s possible the low is just far enough offshore (it’s quite a compact storm) that the huge wind stays just offshore…we’ll see.

Our forecast is for gusts 70-90mph still so we’ll see how that works out.

Inland the south wind has been blowing for a few hours in the valley with gusts into the low 40s at Eugene and Salem.  That tells me gusts 40+ are looking likely in the metro area in the next 3 hours.  We are closer to the low center as it moves north and the pressure gradient is tighter up here.  Still expecting widespread gusts 40-50 mph metro area between now and 4pm.  Expect lots of outages and trees down.

And one last time…

There is not a “severe” windstorm coming to the metro area and also not Columbus Day Storm II.   But a very windy afternoon!

Chief Meteorologist Mark Nelsen

Final Storm Update: Looking Slightly Weaker

October 14, 2016

11pm Friday…

It’s been a crazy day with tornadoes, flooding, and even a crack in the ground from lightning!  This from Timothy Dearden in Trout Lake


All 00z (evening) models are now in and they are all slightly weaker (again) with windspeeds both at the coast and inland.

As a result I’ve lowered the forecast slightly:

  • Still a huge storm at the coast
  • Not quite as windy in the valleys
  • Still enough wind to bring us lots of outages and a few trees down in the metro area

Here’s my final “pre-storm” forecast, we’ll see how it verifies by Saturday midday/afternoon:

Stay safe tomorrow!

Chief Meteorologist Mark Nelsen