Now TODAY was a fun weather day for the meteorologists! But it’ll be nice to relax after work now that the storm has moved on to the north.
First, a bit of a buried headline is the “heat”. You just enjoyed the warmest December day since…the 1995 windstorm day!
Notice Vancouver was just as warm.
On to the wind gusts. Here are the numbers:
Hillsboro, Aurora, & McMinnville reported those numbers and then went offline due to a power outage. So it’s possible the numbers were higher.
Let’s talk about what went right and what didn’t turn out as well:
TIMING: Wow, models were right on! Peak wind gusts were right about the time we expected. The winds picked up and dropped off quickly as expected.
DEPTH OF LOW: Looks like low pressure center bottomed out somewhere near 973 millibars according to NWS. That’s close enough to model forecasts, quite similar to WRF-GFS for sure.
TRACK: It took until 24 hours ahead of time for models to pull it together, but they all showed a reasonably accurate path. The low just scraped by the NW tip of Washington and is running into Vancouver Island right now.
MODEL FORECAST WIND: The WRF-GFS did really well, showing the higher speeds on this morning’s run.
WHAT DID WE MISS OR COULD IMPROVE ON?
MODELS: GFS was the first to latch onto the correct track…there, I said it. The ECMWF played catch-up until about 48 hours ahead of time. The NAM was terrible until the last 12 hours…reminder to ignore it in the future. GEM kept shoving the storm inland and didn’t correct itself even 24 hours ahead of time.
COAST FORECAST: A total miss here. It was nothing more than an average winter storm at the beaches, and definitely not a major storm as was advertised. Peak gusts were almost all below 70 mph. I saw a 79 at Newport Jetty and 89 at Sea Lion Caves, but that 2nd one was even out of our viewing area. Astoria only hit 56! Anyone on the coastline north of Lincoln City is thinking “that was it???”
INLAND WIND FORECAST: I first said 45-60 mph, then yesterday said 45-55 mph for metro area airport locations (official sites). Then this morning leaned more to 50-55 mph on my 10am posting. For much of the area that forecast was fine, but obviously we had some gusts around 60 mph. PDX airport seems to be a bit of an outlier at 67 mph, similar to that extra strong 55 mph gust last February when everyone else was much lower. The NWS first had gusts 55-65 mph yesterday (a good call!) then lowered it to around 50 (local gusts to 60) for the metro area in this morning’s forecast and tweets. Close enough.
SOCIAL MEDIA: It’s a scary medium! One where a bad fact can spread across the globe in minutes. One bit of info that went out said PDX’s peak gust was the strongest since 1971. Within minutes that was all over Twitter, and I saw a Weather Channel tweet about it! The 1981 storm had a stronger gust.
How did this windstorm rank?
For the Portland metro area ON AVERAGE I would say it was similar to the December 2006 storm when you compare damage and power outages. Looks like in some locations (PDX) it was stronger, but in 2006 we had far more power outages. I noticed today that Multnomah county had far fewer outages than Washington county. For whatever reason there was more impact central/westside than eastside and Clackamas county. Clark county was hit hard too. January 2000 was a similar storm to what we saw this afternoon.
The December 1995 was far stronger in our area. Several reports of 70-80 mph gusts in parts of the West Hills. Here’s a chart showing peak gusts at PDX compared to PGE outages. You can see how much more widespread the 2006 & 1995 events were:
It’s tough to compare these windstorms speed-wise because three different instruments have been used at PDX since the 1980s. Up until 1994, the sensor at PDX was an instantaneous gust measurement, but when ASOS units were installed in 1995, the gust had to register for 5 seconds! So recorded wind speeds went down for 11 years. Basically it was harder to get high wind speeds. All three storms on that chart above used the 5 second gust. Then right after the 2006 storm new sonic anemometers replaced those units and now it’s a 3 second gust. See how comparing the speeds is a bit of apples vs. oranges? Wolf Read has an excellent piece of work about this issue on his webpage.
During the December 1995 storm, BOTH units were operating at PDX. The new “official” gust was the 62 mph you see above. But the old unit read 74 mph with instantaneous gust. You can see the difference!
What are YOUR thoughts about the storm?
Chief Meteorologist Mark Nelsen