Eclipse Weather Update: Will the Partial Eclipse Be Visible in Seattle? What will happen in Oregon?

Many of you are in the final planning stages for the big solar eclipse.    So lets update the situation and discuss some of the nuances and details that I left out in previous blogs.

The basic story is still the same.  Partial cloudiness around Seattle, lots of clouds along the Pacific coast.   Good viewing in the Willamette Valley eastward, with the threat of smoke in parts of eastern Oregon.

First, the wildfire/smoke issue. There are several fires burning in the Oregon Cascades and some of the smoke is being blown to the east and south.  Fortunately, most of the smoke is avoiding much of the totality region in northeast Oregon.  The Willamette Valley is clear.  Smoke is probably not a major issue until you are near or immediately downstream of the fires.

Next, lets turn to the low cloud forecast of the latest high-resolution (4km grid spacing) UW WRF model run.  The resolution is important, since we need to get the blocking effects of the coastal mountains correct.

At 8 AM PDT, lots of clouds over the coast and some marine clouds over Puget Sound.

 By 9 AM, Oregon is clear (except for the coast) and the low clouds are retreating around Puget Sound (still near the water).

 By 10 AM (right before the greatest lunar coverage of the sun), Puget Sound is clear, but the Strait and the coast are covered.

 No here is a major issue.  The UW WRF model does not have the reduction of solar radiation by the eclipse, which will start to become significant around 9 AM.  So the clouds may burn off more slowly than forecast after 9 AM.

Thus, the Puget Sound region  is on the edge.  There could be some low clouds, particularly near the water, at eclipse time.   My advice is you want to see the eclipse and clouds are there around 8 AM...head east or up in elevation.  Even Bellevue and Issaquah would be much better.

Still looks good in the Willamette Valley based on the UW WRF model.

How about the European Center model?  Here is the forecast for 11 AM (don't have it every hour).  Oregon looks fine, although there is some high clouds (cirrus) around Portland.  An irritant, but you would still seen the show.   The coast is cloudy like UW WRF.  Puget Sound looks clear, but clouds in the Strait. Thicker high clouds over eastern WA.

How about the official National Weather Service forecast for cloud cover at 11 AM?  Good in the Willamette Valley (4% coverage), 0-2% coverage in eastern Oregon, bad on the coast, but good (7%) in Puget Sound.

As we get closer to the event, another modeling system will be available (the NWS HRRR), which DOES include the reduced strength of the sun in its prediction.   I will be watching it carefully and let you know.

So the bottom line is still pretty much the same.  The coast will not be the best place...if you are there, head a few miles east and upwards into the coastal mountains.  Salem and vicinity should be great, with no smoke.  Eastern Oregon will be clear, with smoke in places.   Seattle is on the edge, but probably will have decent sky opening away from Sound.

Enjoy.   I received about 20 emails today from folks looking for eclipse glasses...sorry, I don't know if any local stores have stock....many are sold out.