An Extraordinary Storm Approaches

It is probably the most powerful April storm to approach the Northwest coast during the past half century.  A very large, well-formed oceanic cyclone that will cross Vancouver Island Friday evening.  And one that will surely bring power outages to the coast and parts of the interior.

Let's start by looking at the 9 PM infrared satellite image (below).  Beautiful storm with the low center in the middle of the swirl nearly due west of the Oregon/CA border.

Another way to view the storm is using the water vapor channel that uses wavelengths in which water vapor emits radiation effectively. The dark area indicates dry air aloft descending towards the low center--the mark of a rapidly intensifying storm.  The massive cloud shield is also classic for a powerful, rapidly intensifying cyclone.

We have a few buoys offshore to see what is happening.  Buoy 46002, off the Oregon coast (see map) is experiencing huge pressure falls (see plot).  A 25 hPa drop in 6 hr!   Wow.

The latest model forecasts are in and the forecasts are impressive. And I should note that virtually all modeling systems are providing a similar solution.  Thus confidence is high.

At 2 AM Friday, a 976 hPa low center is off the southern Oregon, with an intense pressure gradient to its south and west.  Classic for marine cyclones.

 By 11 AM the low is off the Washington coast, with an extraordinarily intense pressure gradient (and thus strong winds) over the Oregon coast.

 At 8 PM Friday, the low center is making landfall on central Vancouver Island, with the intense pressure differences (and thus winds) over the Washington coast.

The wind speed forecasts will impress.  Here are the gust predictions.
At 5 AM, the central and southern Oregon coasts are getting hammered with gusts to 60-70 mph.

By 2 PM, the strong winds have reached the southern WA coast.

 And the northern coast at 8 PM.

 Winds will pick up during the late morning over the western WA interior.  Here is the forecast gusts for 2 PM.  Seattle is rocking with local gusts to 40-50 mph in exposed locations.   The coast is another world (and much windier).

The NOAA/NWS HRRR model for the same time (2 PM) shows some startling winds, with gusts to 50-60 mph in some places.  These are serious winds, folks...perhaps the strongest of the winter at some locations.

 The National Weather Service has a high wind watch out for the western WA interior for tomorrow.

There will be substantial power outages along the coast with downed trees and associated damage. Some power outages should be expected in the interior.

________________________

Help Us Determine the Local Impacts of Global Warming

Society needs to know the regional impacts of climate change and several of us at the UW are trying to provide this information with state-of-the-art high resolution climate modeling.  With Federal funding unavailable, we are experimenting with a community funding to build this effort.  If you want more information or are interested in helping, please go here.  The full link is: https://uw.useed.net/projects/822/home    All contributions to the UW are tax deductible.