Volcano Dust and Vacation Time

July 18, 2008

Volcanocloud[1] Well, it appears that the ash cloud from Okmok Volcano has arrived over the Pacific Northwest.  The volcano is just west of Dutch Harbor, Alaska (in the Aleutian Islands).  It erupted violently last Saturday and Sunday, spewing large amounts of ash and sulfur dioxide into the upper atmosphere (around 50,000′).  You can read all about it on the Alaska Volcano Observatory website.  What we see overhead is a very thin veil of ash moving in from the west-southwest, but a long ways up in the atmosphere…above 30,000′.  The image here is from NOAA.  It shows the sulfur dioxide cloud position early Thursday afternoon.  Of course that would contain some ash as well.  It sure produced a colorful sunset! 

As for weather, it’s not exactly life threatening, but tracking the depth of the marine layer is a very annoying forecast problem.  I was off by 5 degrees on the forecast high today due to a deeper-than-expected marine layer.  It looks thinner the next two days on the models, especially Sunday, that’s why I’ve gone with warmer temps.

The weather pattern stays GENERALLY the same the next 7-10 days.  A big ridge centered over the Rockies and weak troughs occasionally trying to get close to the West Coast, or at least tracking by to the north through Southern Canada.  Of course this pattern gives us a marine push from time to time, keeping temps in check.  No hot weather in sight, no rain, and probably no thunder even east of the Cascades.  Basically real pleasant summer weather…that’s good because I’ll be on vacation all next week.  I’ll only post if the weather is interesting.  Otherwise I’ll be back on the 28th…Mark Nelsen