Wrap Up: A Historic April Wind Storm

2pm Friday

The wind is slowly continuing to die off this afternoon and we’ll be down to just breezes by this evening.

I missed a haircut today due to this windstorm since I rushed into work, but it appears that’s a minor issue compared to what some of you have gone through.  There is now a ton of firewood available in the metro area since LOTS of trees have come down.  And it appears at least one person’s death was caused by falling trees/limbs in SW Portland.

This was most likely the strongest April windstorm in the metro area since the April 14 1957 event.  In fact it was quite similar to that storm with respect to track and windspeed reports.


Note that a stronger gust did hit the airport on the day of the Vancouver Tornado in 1972, but that wasn’t a widespread southerly windstorm.  As mentioned in a previous posting the airport wind sensor was quite close to the tornado when it first touched down on the Oregon side of the river.

This wind storm brought the most widespread power outages for PGE since the December 2006 “Hannukah Eve” storm as well.


1 in 5 customers had at least a brief interruption and some of us will likely be out of power for a few days.  At least in April we won’t get too cold!

Hardest hit was the west and central metro area, including SE Portland where OMSI recorded a gust to 76 mph on their rooftop sensor.  Note the gusts to 60 mph in SW Portland and Hillsboro.  That’s quite high for those areas.  In fact Hillsboro airport hitting 60 mph IS a rare event indeed.


You’ll notice the lower speeds east of I-205.  That’s okay, they get plenty of wind all winter long.  And poor Vista House got left out of this storm…just 32 mph.  The Gorge doesn’t get strong south wind storms, okay, maybe once every 20-30 years, but that’s it.  One other note.  There is a wind sensor up on SW Portland that shows up online.  It recorded gusts 80-101 mph for several hours this morning.  I’ve skipped over it because either A) It’s high up on a transmission tower or B) the sensor has gone bad.  There’s no way the wind was regularly gusting at that speed right in a neighborhood in SW Portland near ground level.


Today’s event was a glimpse into the future of weather forecasting.  The models beat the human forecasters!  Just about every model clearly advertised wind gusts in the 50-70 mph range during the morning to midday hours, some were even a bit stronger.  I was a bit doubtful so I dropped those numbers a bit to 40-55 mph gusts (which was slightly low, but close enough).  The NWS forecast gusts 45-50 mph.  There was a Wind Advisory out for the valleys but no High Wind Warning (criteria is gusts above 58 mph) out for this storm.   Using the classic rule of Eugene to Olympia pressure gradient (10 millibars), you would only get gusts in the 30-40 mph range.  Instead we immediately jumped into the 50-70 mph range right away this morning.  That strong wind just a couple thousand feet up mixed down to sea-level perfectly and the model simulations nailed it while the humans were doubting it.  This includes the HRRR, NAM, NAM-MM5, WRF-GFS, & ECMWF.

This will happen more often in the future and I expect within 10 years the vast majority of the time models will be correct and the humans will just be left to “babysit” the output.

This weekend we’ll see showers and sunbreaks as a cool airmass sits overhead Saturday, then mainly (or all) dry Sunday since we’ll be waiting for a front to come through Sunday PM.

For future analysis, here are 4 different model forecasts (wind gusts):

Chief Meteorologist Mark Nelsen

74 Responses to Wrap Up: A Historic April Wind Storm

  1. Man, sometimes I have really bizarre dreams.

    Last night, I dreamt that 3.3 inches of snow fell at PDX today and everyone was waiting for Mark to make a post on the unprecedented snowstorm. He never wrote anything, though, and for some reason, everyone decided that Mark Nelsen doesn’t actually exist, but an actor played the character on the news and the Unabomber has been writing all of the blog posts from his SuperMAX cell.

    • SortingHat says:

      It’s not as hard as one would think to smuggle in phones in prison which is a HUGE problem especially thru bribes. It’s illegal for some odd reason for prisons to make no cell zones I read about it once as it’s been mentioned to make blanket cell phone kill zones.

    • SortingHat says:

      By kill zones I mean zones that make smartphones not work no matter what.

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