2pm: A “Regular” Minor Wind Event & Wrapup

March 13, 2016

That was a bit underwhelming, should have stuck with original thoughts last night.  I never saw more than 8,000 PGE customers out of power at one time.

While not a total bust (we still had “Wind Advisory Level” gusts, just barely)…most of the metro area has only seen gusts in the 35-45 mph range.  Not a single 50 mph gust in the lower elevations.  We’ll see these gusty winds die down over the next few hours.  Peak pressure gradient from Eugene to Olympia was only 11 millibars, barely a windstorm event and as weak as the WRF-GFS showed this morning (it forecast about 10).

Seattle is getting nailed at this hour, SEA went from light east so southerly gust 56 mph in a short period of time!

Peak Gusts as of 2pm:

PDX: 38
Hillsboro: 38
Troutdale: 40
Aurora: 44
Salem: 41
McMinnville: 55
Chehalem Mt: 57
The surface low is making landfall right about now at Forks, Washington as a sub- 980mb pressure.  Here is a map from the pre-dawn hours from the NWS showing the model forecasts as of the 6z runs.

ObservedLowPosition

Winners:  GFS/RGEM/GEM  These models generally did well with track, with the usual minor flip-flopping on low location around in the final runs beforehand.

Winner: HRRR low pressure track.  It did quite well, but it did over-forecast the inland wind speeds.

Winners:  In general ALL models did well with low pressure intensity…within 5 millibars or so of reality through the past 48 hours.

Loser:  NAM and NAM-MM5  It was far too south on more than one run.  In fact at one point yesterday the low was almost over Portland!

Loser:  ECMWF  (This one hurts!) While not a disaster, the ECMWF was too far offshore on the track a couple days ahead of time, then over-compensated and pushed it slightly too far south in the end.

On tap…tons of mountain snow and then warm spring sunshine for a few days later this week…

Chief Meteorologist Mark Nelsen


10:00am: Wind Arriving Coast, 55 mph Gust McMinnville

March 13, 2016

Now that’s a beautiful area of deep low pressure!  9:15am visible satellite pic

vis_915am

The low appears to be just west of Astoria with the trailing cold front just onto the coastline now.  When that passes over the valley in the next 90 minutes we can expect the wind to arrive in full force; a classic setup where the wind comes in the the sun/clouds/showers mixed.  At least it’ll be a “bright” windstorm.  McMinnville just had a gust to 55 mph.

Pressure observations from Buoy #46089 about 80 miles west of Tillamook show at 9am a pressure of 980.1 millibars.  That’s a bit deeper than forecast and the low appears to still be in the intensification phase.  Due to that, the McMinnville gust, and the HRRR model now calling for stronger gusts, I’m thinking gusts 50-60 mph are possible between now and 2pm.  We MAY have underforecast the storm a bit.  Here’s the HRRR showing gusts 40-50 kts within the next 2 hours:

hrrr_gust_15zrunfornoon

Exact speeds don’t matter…45, 50, 55, 60…If you live near large trees hunker down.  Definitely not the time to be driving through deep woods with the trees swaying overhead.  Be safe out there and enjoy the storm from inside.

Chief Meteorologist Mark Nelsen