Wetand News

The high-resolution satellite imagery yesterday morning revealed a transient, but fascinating feature:  a narrow current of fog emanating out of the western portion of the Chehalis River valley.    This fog current then passed over Aberdeen and Hoquiam before pushing out into the Pacific Ocean. Here is the NOAA/NWS GOES satellite image around 8 AM Sunday that shows this amazing feature.  You can see the fog collecting in the Chehalis River valley and then jetting out to the west.  Just amazing how this current was able to maintain integrity for tens of miles.  About roughly ten miles offshore it lost its structure, with the cool, moist air producing a blob of low clouds. If you look closely, a weaker fog jet was produced at the exit of the Columbia River.     Just as a reminder, here is the Google terrain map for the region.  The Chehalis River Valley is well defined with relatively steep side slopes.  Cool air can drain from side valleys into the main Chehalis channel, re

Sea breeze is quite an evocative term. One thinks of a tropical landscape with a cooling onshore wind that develops during the day, best appreciated while one sits on the beach with a sweet tropical drink.  There also seems to be a lot of coastal motels, often a bit seedy, that have "sea breeze" in there name. But believe it or not, Washington's coast gets decent breezes during the warmer part of the year, and this week, with rising temperatures, the sea breeze season has begun. First a tutorial for the sea breeze novices.  Sea breeze circulations occur at the coast, when the land becomes warmer than the ocean as the sun heats the land.  Generally, 5-10F warmer to get some good sea breeze action.   The ocean surface does not warm as quickly for many reasons, include the large capacity of water and the fact the solar radiation can warm some depth of the ocean.  The warmer temperatures over land result in a lowering of pressure, which drives a flow of cool air fr

After a startlingly cool March, we are going to get paid back in spades in April:  an extraordinary week is ahead, with the only exception being Saturday morning...and even that won't be that bad. Every day but Saturday will get into the 60s.  Dry, except perhaps a sprinkle Saturday morning, and temperatures gliding up to near 70F on Thursday. On several days, weather will be far better in Seattle than Los Angeles.  And that was particularly true today. The SpaceNeedle cam and the Long Beach Cams show perfect weather here in Washington State: The Del Mar Beach, CA cam is rainy, misty, wind and cold. And the seen in Hollywood, is well...wet. As noted in a previous blog, our perfect weather is the result of an atmospheric blocking situation, in which the atmosphere gets temporarily frozen in a certain configuration.  The upper level map for 5 AM this morning shows you the pattern we have been stuck in....an omega block , with ridge of high pressure over the N

Whatever you are doing tonight, take a break and go outside and look to the east. An amazing supermoon is the the sky:  a HUGE full moon, far brighter and larger than normal.  I went outside and was really impressed. Picture by Allan Jones.  The Ferry Kennewick is shown as well Supermoons occur when a full moon occurs when the moon is much closer to earth than normal, and the moon tonight is closer than it will be for the rest of 2020. In fact, the full moon tonight will be about 17,000 miles closer to Earth and roughly 30% brighter than normal. A nearly clear sky and lack of haze/smoke makes viewing tonight particularly good. But the viewing fun doesn't end there.    Venus is very bright and unusually high above the western horizon.  And the sunset tonight was spectacular--you can get a taste of the view from the Seattle Space Needle PanoCam (below).  Stunning.

The coronavirus crisis is one of the most disruptive events to hit the U.S. in a very long time. Major sectors of the economy are being shuttered, people lives are being altered in the most profound ways, and the nation is facing extreme stress, the implications of which we do not understand. Extraordinarily serious decisions are being made without key information:  how many individuals have active infections?  How many have had the virus and now have immunity?  What percentage of infected individuals have few or no symptoms?  Who is currently infected and needs to be quarantined?  Is the current reduction in cases in Washington and elsewhere mainly the result of social distancing or the herd immunity of an increasing number of individuals that have had the virus? For all these questions, we do not know the answer.  Our best medical scientists and epidemiologists, including a highly respected group at the University of Washington, are making projections of the future progressio

Get out your sunglasses and put away your umbrella--the next five days should be bright and dry here in western Washington. Who can you thank for this meteorological bounty?  The greek letter omega. The total precipitation for the five days ending Friday at 11 PM from the European Center model is, well, zero over most of western Washington.  Bizarrely,  all the precipitation will be going into normally much drier California!  Here is the California precipitation total for the same period.  Wow.  Much of California, particularly in the mountains, will get several inches.  While we are dry. This extreme difference in precipitation and the persistence of the pattern this week is due to a highly persistent "locking" of the atmosphere called an "omega block."  To illustrate, here are the forecast upper level (500 hPa) heights (like pressure)  for Tuesday evening.  The solid lines are the heights and the colors represent anomalies from normal (blue is lowe

Everything seems topsy turvy and unnatural these days, and there is a meteorological oddity that must be added to the list: March was cold than January in Seattle this year. I knew March was a cool one, but it was not until Dr. Joseph Zagrodnik, a talented atmospheric scientist working at WSU's AgWeatherNet organization, pointed in out to me, did I realize how unusual the past month had been. According to Dr. Zagrodnik, the average temp in March at Sea-Tac Airport was 44.8 degrees F compared to 45.1 F in January. How unusual is this?  Rare, but not unprecedented.  March has been cooler than January 8 times in the 126 years we have temperature records in Seattle, with the last time it occurred in 2006. To appreciate this oddity visually, the graph below shows the numbers of year the March minus January temperatures fell in various bins.  On average, March is about 5F warmer than January, but in some extreme years March has been as much as 17F warmer.  That would get folk