Pi Day 2016
4:55 pm
I apologize for not being in the blogosphere yesterday – I was up at Alpental introducing 5-year-olds to poles. I taught lessons up there this year on the weekends and had a spectacular time, and I’d highly recommend anybody who loves kids and skiing to consider teaching ski lessons up there. The kids are so fun, kind, and carefree, and they don’t judge me for being a complete goofball weirdo around them. It seems like we let go of these qualities as we grow older, which is too bad because I think they make us special. I hope the kids learned from me, because I know I learned a lot from them.
Yesterday was stormy throughout Western Washington. There were blizzard conditions at times up on some of the ridgetops at Alpental, and I believe ~250,000 people lost power here in Western Washington. Many of the kids were crying because the fierce winds were very scary! I’d estimate that there were gusts 40-50 mph affecting us at times… it was intense. The NWAC site at Dodge Ridge at Summit West clocked multiple gusts to 68 mph yesterday afternoon, and they are significantly lower in elevation than where we were at Alpental.
Sunday’s storm was not very well predicted. Early forecasts showed the potential for a major windstorm across the Puget Sound region, with sustained winds of 30-45 mph and gusts up to 70 mph. Storm warnings (sustained winds of 48-63 knots or 55-73 mph) were issued for Puget Sound, something that happens very rarely. Even late Saturday night/Sunday morning, these storm warnings were still up.
 |
| Credit: National Weather Service |
However, Saturday night’s model runs significantly cut back on the predicted strength of the windstorm, and by early Sunday morning, the National Weather Service had replaced the storm warnings in Puget Sound with lesser gale warnings. However, these models didn’t have a good handle on the storm either, and neither did Sunday morning’s runs, which were initialized approximately 6 hours before the storm was forecast to make landfall. UW’s flagship WRF-GFS model had the low making landfall just to the north of the mouth of the Columbia River around 11 am as a rather elongated 984 mb cyclone.
 |
| Valid 11:00 am PDT, Sun 13 Mar 2016 – 6hr Fcst Credit: University of Washington |
Instead, the storm made landfall significantly further north on the northern Olympic Peninsula and deepened to ~978 mb. This caused forecasters to increase the forecast strength of the winds for the coast and North Interior, but tone down their forecasts for the Puget Sound area due to the low traveling further north. Although high wind warnings were still up at this time, some forecasts from various outlets were calling for gusts below 45 mph for most of Puget Sound.
Instead, winds ended up being stronger than forecast, even for the Seattle area. Sea-Tac hit 56, and West Point in Magnolia hit 66! Here are some peak gusts from around the region that I retrieved from the National Weather Service… I bolded gusts from major stations or ones that were particularly high.
SEATTLE WA
HOURS…
WIND REPORTS FROM THE WEDNESDAY
EVENT. REPORTS OF LESS THAN 40 MPH WERE
GUSTS…EXCEPT (P) ARE PEAK WINDS AND (S) ARE
LIGHT 67 MPH 0406 PM 03/13 48.10N/122.69W
VICINITY…
LOWLANDS…
DE FUCA…
AREA…
0336 PM 03/13
47.91N/124.64W
56 MPH 0138 PM 03/13 47.44N/122.31W
INT 54 MPH 0130 PM 03/13 47.53N/122.30W
AIRPORT 48 MPH 0220 PM 03/13 47.49N/122.21W
0255 PM 03/13
47.27N/122.58W
0420 PM 03/13
47.86N/122.62W
GAUGE 55 MPH 0336 PM 03/13 48.12N/122.75W
0305 PM 03/13 47.69N/122.40W
CASCADES AND PASSES…
CENTRAL CASCADES AND PASSES…
CENTRAL CASCADES AND PASSES…
VERNON 46 MPH 0355 PM 03/13 48.47N/122.42W
COUNTY…
These gusts are strong, but they aren’t anything we’ve ever seen before. Still, it’s pretty impressive to have a 66 mph gust at West Point in mid-March! The Seattle NWS office dubbed this storm the “Pre-St. Patty’s Day Punch,” which is pretty awesome. When it comes to naming notable weather events, alliteration counts.
 |
| Retrieved from Cliff Mass Weather Blog |
Here’s a picture I took from Cliff Mass’ blog of max gusts recorded during the windstorm. As you can see, higher winds were located over the coast and North Interior. There are quite a few low gusts (10s and 20s), and these are from stations that are not well-exposed to the wind. Over water, gusts were in the 45-60 mph range across the region, and coastal headlands (like Destruction Island) accelerated these winds. Camp Muir at 10,110 feet on Mt. Rainier was the wind winner with a gust to 95 mph.
The most amazing thing about this storm, however, was simply how it appeared on radar and satellite. This was a compact storm, and had a very distinctive bent-back occlusion (the swirl of clouds that spirals counterclockwise to the center of the low). Take a look!
 |
| 09:15 am PDT, Sun 13 Mar 2016 Credit: University of Washington |
As this visible satellite image shows, the storm was off the mouth of the Columbia around 9:15 am, and was heading to the NNE. You can see the tight circulation around the low and the intense cold front along the Oregon Coast. Strong winds are occurring along the coast and mountain ridgetops at this time, but winds in the lowlands are relatively low.
I’ve seen some cool shots from our coastal radar, but this may very well be the coolest one yet. Take a look at the low! It almost looks like a hurricane. You can really see the movement of the storm with the animated gif below. Moreover, you can see how the reflectivity in the vicinity of the radar increases as time (and wind speed) goes on, and this is due to “sea clutter,” or the radar beam reflecting off the top of wave crests. More wind, bigger waves, and thus more sea clutter.
 |
| Created with NOAA Weather and Climate Toolkit |
Here’s the view at 12:10 pm. Compare it to the image from the NASA TERRA polar-orbiting satellite below, which was also taken around 12:10 pm.
 |
| Image taken ~12:10 pm by NASA’s TERRA satellite Credit: NASA |
There were strong winds over 520, and the bridge was closed for a while. I can’t remember the last time that happened, but it has been a long time!
 |
| Credit: National Weather Service |
But, of course, the day finished on a beautiful note. Take a look at this incredible photo out at Alki Point from Tim Durkan. That has to be one of the most brilliant double rainbows I’ve ever seen.
| Credit: Tim Durkan |
Thanks for reading! Things look much calmer this week, especially after Wednesday. Inclement weather returns for the weekend, but it won’t be anything like what we saw this past week.
