It’s Time for an Oregon Coast Radar!

October 27, 2016

The Oregon Coast has the WORST coastal radar coverage anywhere in the lower 48 states and it’s time to change that.  In fact there is no radar located along our coastline.  Local forecasters (private/public/media) have known about it for years.  I’ve blogged about it numerous times and Professor Cliff Mass up at the UW in Seattle has been pushing it for years too.

Important points:

  1. The central and southern Oregon coastline has no radar coverage below 10,000′;  almost all cool-season weather happens below that elevation.
  2. How is it possible Oregon’s 2nd largest city (Eugene) has no coverage below 10,000′???
  3. A tornado or squall line can roar ashore in Lincoln City, Newport, Florence, or Coos Bay with no warning.
  4. A tornado or squall line with damaging winds could move through the Eugene or Roseburg areas with very little indication on radar.
  5. NOAA’s Pacific Fleet is based in a location (Newport) with no good radar coverage…that’s a huge surprise.

#3 happened in the mid 1990s at Lincoln City, and #4 just happened January 16th this year in Lane County (near Eugene).

What Is The Problem?

  The National Weather Service completed a major modernization in the 1990s, a central component being the installation of powerful Doppler weather radars across the country.   Such units, known as WSR-88Ds or NEXRADs, describe precipitation and winds in their environs and have revolutionized forecasting and meteorological research.
  The range of useful radar coverage is controlled by a number of factors.  Terrain blockage is important in mountainous regions like the Northwest.  Furthermore,  the height of the radar beam increases with distance from the radar–resulting in an inability to see important low-level features at distances from the radar.  Under perfect conditions, the maximum range of the WSR-88D for wind information is 230 km (138 miles) and for precipitation sensing roughly twice as far.
  An official National Weather Service map of national weather radar coverage (for precipitation) is shown below.  A second image with a blow-up of the Northwest section is also provided.  These radar coverage maps are valid at 10,000 ft ABOVE THE RADAR SITES (many of which are already thousands of feet above the surface!), not at the surface.  Radar coverage near the surface is far poorer, particularly over the western U.S. where blockage by terrain is significant.  Even for the optimistic 10,000 ft coverage, the Oregon coastal zone is poorly served compared to the California, Gulf of Mexico, and Atlantic coastal regions. Click for a better view: 


Note there IS a radar on the Washington Coast.  That was just put in 4 years ago after a years-long lobbying effort by a group up there.  A closer view shows the situation here in Oregon:


The “partial coverage” refers to some blocking by mountains in the Coast Range.  The lowest beam from the Portland radar (located on Dixie Mtn. southwest of Scappoose) is intercepted in a few spots by the Coast Range.  We were extremely lucky that Manzanita was not behind one of those “blockages”.  But in general coverage is sketchy on the north coastline south of about Cannon Beach.

What about farther south?  It gets worse.   The Medford radar is even more problematic:  it is located at a very high (7500 ft) elevation to minimize blockage, causing it to miss most coastal and valley precipitation.  The Medford radar is also too far inland to provide useful information over the coast.  One has to go as far south as California (the Eureka radar) to get proper coastal radar coverage!  


You can see the issue here from the image above created by folks up at the UW before the Washington coastal radar was installed.  Very little useful information comes from that Medford radar in the cool season.  Dr. Mass has suggested moving the Medford radar down to the coastline around Coos Bay or Brookings.  However that would leave the largest southwest Oregon population (the Rogue Valley) with very little severe thunderstorm coverage in the summertime.  That’s not going to happen.

Where Would A New Radar Go?

The ideal location would be somewhere between Coos Bay and Newport.  Seems like Florence is a good location, up at a high enough elevation to get a clear path to watch Eugene, but not too high.  Coverage would look about like this:


Much better don’t you think?  How much would it cost?  Maybe $5 million dollars to install and then regular maintenance and operational costs of course.  Is it worth it?  Yes, even one big event could erase some of that cost.  Consider the South Valley Surprise windstorm of February 7, 2002.


A much deeper than expected low pressure center moved onshore just south of Florence, then raced northeast into the Columbia Basin.  The strongest wind gusts in that area since the Columbus Day Storm of 1962 peaked between 70-80 mph.  There was NO WARNING until the wind had already arrived.


Since there was no warning, local utility crews were caught completely off guard.  Nowadays utilities prepare for these storms days ahead of time by positioning their crews/supplies and having extra workers ready to go.  With some warning (even just a few hours) they may have been able to restore power more quickly thus saving a million or two worth of damage?  Just a guess, but you get the point.  That storm cost $10-$12 million dollars damage.  By the way, there was no strong wind in the Portland metro area or Salem because the low pressure passed by to the south.  We just had a breezy westerly wind.  This is just one example of what we’re missing.  A squall line moved into the southern Willamette Valley just this past January 16th, barely detectable (if at all) on Portland’s radar.  Check out the storm report, click for a better view.


Where Do We Go From Here?

First, don’t bother calling the Portland or Medford National Weather Service offices and complaining.  Those folks do all sorts of good work forecasting and keeping on top of our wild winter weather…but they don’t control the money!  It’s a political solution, which means the U.S. Congress has to appropriate the money.

A coordinated effort has begun in our area; that’s why the story has now appeared on two TV stations (and hopefully soon on the other two!).  A group started by the Oregon AMS (American Meteorological Society) will have its first meeting in a couple of weeks.  It involves members of the local media, former television meteorologists, former NWS employees, educators, and many others.

I’ll keep you in the loop as we go through what will likely be a very long, but hopefully productive, journey.   I know there are lots of you on the Oregon Coast and down south in the Valley that want to help out.  The effort to get a Washington coastal radar included support from all sorts of community groups.

The Other Oregon Radar Gap

Of course there is one more huge hole in Oregon radar coverage.  There is no cool season coverage in Central Oregon either.  By that I mean we can’t see anything below 12,000′ or so in the area from Warm Springs to Redmond to Bend to La Pine.  Late last November a foot of snow fell in one evening in Bend and the Pendleton radar showed nothing.  At least the very tall thunderstorms in summer are detectable by surrounding radars, but at some point that area (where 200,000 people live!) needs a radar too.  There are many other gaps in the interior west, so that one might be a tougher sell.

Chief Meteorologist Mark Nelsen

Thanks to Dr. Cliff Mass and his NW Radar Problem page for some descriptions used above.


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