A Record Storm and the Power Outages Begin

This morning, the offshore storm rapidly intensified and achieved record status, with the central pressure dropping to at least 943 hPa (the previous record for our region was 950 hPa).

And there is a very good chance it is even deeper right now.  

Here is the latest visible satellite image of the storm (around 10 AM).  

Stunningly beautiful creature, with the frontal clouds swirling towards the low center.  And you can see very unstable air with lots of convection (e.g., thunderstorms) over the southwest portions (the popcorn-looking clouds).  Some of that activity will reach us later today.


The official National Weather Service analysis indicated 943 hPa at 8AM (see sea level pressure map below)


The low center is now passing nearly directly over NOAA buoy 46005 (see map), about 300 nautical miles off the coast.


Below is the plot of sea level pressure at the buoy as of 11 AM.  Wow.  The pressure is down to 942.5 hPa and still dropping rapidly.  The winds are nearly calm there, as expected near the center of the low. 


As I mentioned, the central pressure of this storm is a record for our neck of the woods.  

To show this, here is a wonderful figure created by Dr. Ryan Maue, the shows the lowest pressure observed over the northeastern Pacific over the past 70 years using the ERA reanalysis dataset.  The star shows where our 943 hPa low is right now.    Notice there are green colors in the region of the star--indicating lowest pressures of 954 hPa and higher...not even close!  

To get similar record storms to our visitor today, one must go northwestward into the Gulf of Alaska and the Aleutian area.

We are all experiencing history..

This morning the region is experiencing stage 1 of this event, with a very strong east-west pressure difference driven by the approaching storm (see sea level pressure forecast for 11 AM below).  Mama Mia, there are a LOT of isobars.


Driven by this pressure gradient, powerful easterly winds have occurred over the eastern slopes of the Cascades and some pushed into south Seattle.  As a result, there are lots of power outages with tens of thousands of people out of power.



Strong easterly winds are blowing in the eastern Strait of Juan de Fuca  and off the coast now (up to around 60 mph)

In the next stage of the event, the low will move closer, bringing powerful winds to the coastal area (yes, some will lose power).  The plot below shows the forecast for 5 PM today.   And yes, there should be some big waves reaching the coast by then as well.
And tomorrow morning, as the weakened low goes north of us, the north-south pressure difference will increase, bringing stronger (southerly) winds to Puget Sound...and particularly northwest WA waters.

Before this is over, I suspect a few hundred thousand folks will lose power, with the situation worsened by the unusual direction of some of the strong winds (easterly in the interior) and the fact this is the first major blow of the season for many.
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My Podcast Has More Background Information on the Big Storms of the Northwest:

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