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

EF-2 Tornado In Manzanita

October 14, 2016

The NWS concluded their storm survey and rated today’s twister the strongest in Oregon since 2010


The craziest fact?  This tornado moved directly through the “downtown core” of a small Oregon town.  That’s exactly what happened with the last EF-2 tornado in Aumsville.  That was in mid December 2010.  Take a look at the graphic from the NWS folks:


It could have been a quarter mile, or 1 mile, 2 miles etc… in some other direction but instead it went right through the middle of town.  Check out the Aumsville path from 6 years ago:

Aumsville Tornado_NWS-Damage_path

Crazy stuff eh?  Thanks to the Portland NWS for the quick storm survey.  AND thanks to those hardworking “government workers” for getting out the Tornado Warning BEFORE the storm hit.  I’ve never seen that west of the Cascades in my 23 year career.  Remember that before you lump all of those workers into one (usually negative) category.

Chief Meteorologist Mark Nelsen

Flooding In Portland This Evening

October 14, 2016

What a crazy 24 hours…high winds, 2 tornadoes, then the heaviest rain rates we’ve seen in almost a year this evening!

Flooding rains fell between 6-8pm in the southwest/southeast/east Portland areas.  Take a look at the daily totals from the Portland HYDRA network of rain sensors.  An inch fell in one our in parts of southwest and inner SE Portland!


The showers have moved east, but lots of flooded homes/cars/roads.



Saturday Storm Forecast

October 14, 2016

4pm Friday…

The strongest October storm we’ve seen in years will hit the Oregon Coast midday Saturday, and some of that wind will make it inland as well

Storm # 2 arrives tomorrow and the timing has speeded up.  A deep area of low pressure races up the coastline, much stronger than yesterday’s low.  That means a strong south wind will follow it, first arriving at the coast, then spreading inland quickly.



Here are my forecast windspeeds:

COAST:  South wind gusts 75-100 mph 10am-4pm

VALLEY:  South wind gusts 45-55 mph Noon-5pm  This is quite strong for October and should be a little stronger than the storm that gave us 75,000 PGE outages two years ago in late October.

GORGE:  Light wind

EASTERN OREGON:  South wind gusts 40-60 mph, midday through afternoon, especially central and north-central Oregon.

The wind backs off quite a bit by evening, then all quiet Sunday.

Important Notes:

  1. This is not a MAJOR STORM for us in the metro area and western valleys, but with leaves on the trees there will be plenty of outages and a few trees down.  It should be our strongest October storm in many years though and a very windy afternoon!
  2. This IS A MAJOR STORM for the north Oregon coastline.  Even in winter this would be a biggie.
  3. This is nothing like the Columbus Day Storm, just a similar track.


Technical info:  Models are in relatively good agreement on the movement of the surface low now with the 12z NAM and GFS sending a 970-975 millibar low up to the NW tip of Washington by Saturday afternoon.  The 12z GEM was around 967 mb but slightly farther north.  The ECMWF keeps moving slightly farther north with each run and now it is relatively “far” offshore as it passes by Astoria around noon.  It makes landfall on the NW tip of Washington at about 967 mb, like the other models.

So we’ve got quite a deep low pressure center quite close to the coastline on the “classic” track, but the really intense pressure gradients are north and west of the Portland metro area.  You can see it pretty clearly on the WRF-GFS run for 2pm tomorrow from this morning:


That means more of a “typical” wind storm from Salem north to Longview.  The cross-sections and meteograms from the WRF also support no huge storm in the valley.  In fact south of Salem the wind only looks to be in the 30-40 mph range.  For this reason I’m not going to crazy on windspeed and the Portland NWS is doing the same with their 45-60 mph gust range.  Still, as we saw two years ago, 45+ mph gusts can do a lot of damage with (most of) leaves still on the trees.

We’ll be keeping a close eye on evening models to see if there is any change in the forecast track or intensity.

Chief Meteorologist Mark Nelsen






First Oregon Coast Tornado Since 2009

October 14, 2016

3:45pm Friday…

Whew!  Today was the day that was going to be relatively slow, between storms.  Instead some of those heavy showers and thunderstorms produced the first tornadoes on the Oregon Coast since the 2009 event in Lincoln City:


Now that was Lincoln City 7 years ago.  Today a thunderstorm passed over Manzanita around 8:15am.  A waterspout moved onshore and turned into a tornado.

The NWS is doing a storm survey right now.  This is what we know as of now.

  • There were 2 tornadoes on the coast, one at Manzanita around 8:15am and then a 2nd about 9:10am at Oceanside about 18 miles farther south.  For the first time in Portland TV news history we have video of both from a distance AS they move through both towns!  Pretty cool
  • There was no damage in Oceanside
  • They were moving very quickly…40-60 mph
  • This appears to have been the first time a tornado warning has been issued west of the Cascades BEFORE a tornado arrived.  Manzanita was under a severe thunderstorm warning at the time regardless.

Wild stuff…apparently the NWS has only issued 5 tornado warnings in the past 11 years, but issued 10 today!  This was also the first tornado warning issued by Portland NWS since November 2014.

Coastal Wind Dying Down

October 13, 2016


A cold front is moving across the Willamette Valley, and behind it wind speeds have dropped off dramatically at the coastline.  It was a pretty good storm for October out there, and at least the forecast wind speeds have verified for you folks.

Now here in the valley and metro area it’s a totally different story.  The cold front moving across the region is giving us a brief burst of gusty wind, but below what we expected in most locations.  Yes, pretty much our first metro area wind “forecast bust” of the season!  I do see McMinnville hit 48 mph.  Hillsboro & Forest Grove both hit 37 as that cold front passed through.  Should have forecast 35-45 mph gusts instead of that 40-50 mph range!

Wind will remain breezy all the way through tomorrow and in the heavy downpours tomorrow a gust of 30-35 mph is always possible.  Thunder is a possibility as well.

Today has been our wettest day since December 17th!  Hope you enjoyed it.


Chief Meteorologist Mark Nelsen

Windy Evening Ahead: Storm Update

October 13, 2016

3:15pm Thursday…

Update for the first storm moving over us now…more on Saturday’s system at the end of the post

RAIN  There are no watches/warnings/advisories for any kind of flooding

It’s been raining steadily, but just a gentle Pacific Northwest style rain.  Still, we’ve already picked up over an inch.


Since it hasn’t come down heavily there has been no flooding of course.    This evening the rain will pick up for a few hours 5-9pm and at that point we could see some blocked drains etc… for localized flooding, then the rain mainly ends after 10pm.


Wind Advisory for the western valleys (including metro area) for this evening:  Gusts 35-50 mph likely sometime between 5-10pm.

High Wind Warning for coastal strip this evening: Gusts 65-80 mph between 5-10pm.

As expected, very quiet out there this early afternoon, and no wind has even made it to the south valley yet so we’re still at least a couple hours away from a gusty south wind.  Should be plenty of power outages and a few trees down here and there through the evening once it gets going.  The wind calms down to more reasonable levels after 10-11pm.  Keep in mind that gusts between 40-50 mph two years ago in late October (with leaves on the trees) caused quite a bit of havoc.  Some of you will be getting out the candles this evening!



Technical stuff for this evening:  The HRRR and NAM models keep shooting a closed and deepening surface low right up the coastline in the next 8 hours.  Looking at satellite imagery that seems overdone and I sure don’t see one.  I like the “open wave” look so the ECMWF/GFS are more likely correct.  As a result I’ve discounted the HRRR showing gusts 50-60 mph this evening.  I think 35-45 is the safest bet.  That’s not a big deal in winter, but as mentioned above a different story with the leaves on the trees and soaked ground.  There is still a perfect alignment of the isobars west-east perpendicular to the western valleys so we’re going to get a nice surge of wind.  After midnight the wind relaxes.



Lots of showers and a showers/sunbreaks sort of day between storms.  But some of the showers could be intense and a passing rumble is possible too.



Two important points

  1. There is no repeat of the Columbus Day Storm coming Saturday
  2. There will be more power outages and downed trees, likely a bit more wind than tonight both inland and at the coast

Models have come into FAR better agreement now and they all are quite similar.  The GFS came much farther east and the ECMWF gave up its nasty windstorm for Oregon inland areas.

A deep area of low pressure, somewhere around 965-970 millibars central pressure, will make landfall somewhere on the Washington coastline Saturday afternoon/evening.  Past storms that make landfall that far north tend to give us a “decent” windstorm here in the valleys, but not a crippling “every 20 years” sort of windstorm.  Still, if gusts go above 50 mph in the metro area (that may happen), we’ll get even more damage than tonight.  Regardless, the coast is going to get nailed by a stronger storm on Saturday.

It was very nice to see models come together this morning…48-60 hours before the event.  That’s pretty good.  Check out the ECMWF and NAM…quite similar:



A rough first guess for wind gusts in this setup would be 45-60 mph in the Portland metro area.  That said, during the past few windstorms the PDX observation site has been an overachiever compared to surrounding areas.  Remember the 67 mph gust during the December 2014 storm?


This could be a similar event, but someone else gets a 60 and the rest of us get 45-55 mph gusts.  That said, any gusts above 50 will be a big deal this early in the season.

Chief Meteorologist Mark Nelsen