June 06, 2017

Welcome Rain is On the Way

After a very wet winter and early spring, I can't believe that I am looking forward to some rain....but it is true.  Digging in my garden, the soil is dry to some depth and many folks are already starting to water.  And the recent warm temperatures have greatly increased evaporation from the surface.

The precipitation for the past 4 weeks at Sea Tac (see below, red line is observed precipitation, blue line is normal), tells the story.  After a relatively wet period during mid-May, the rain gauge nearly flatlined during  the last two weeks.
In fact, the percent of normal precipitation over the past two weeks (see below) shows way below normal rainfall (red colors) over much of the western U.S.

Today's temps were well above normal, with a number of sites getting into the mid-80s around Puget Sound and SW Washington.  You don't want to know about Portland and the Willamette Valley.

However, the latest infrared satellite image (see below) suggests major change, as an impressive area of clouds approaches the West Coast.  Rain will arrive late Wednesday night.

The clouds are associated with a huge upper trough of low pressure that will amplify over the eastern Pacific.  Here is the impressive upper level height forecast for 8 AM Friday---pretty amazing for this time of year.  A strong jet stream (where the lines are close together) pushes far south into northern CA.

The forecast 24h precipitation totals ending 5 AM Thursday show the initial pulse of overnight precipitation.

However, the next 24 h (ending 5 AM Friday) is far more impressive with more than an inch in some of the mountains and even eastern WA getting some moisture.   You won't have to water your garden for a few days.

The latest 51-member European Center ensemble of 24h precipitation forecasts (see below, courtesy of WeatherBell, Inc.) indicates great certainty that it will rain, with nearly every forecast member going for precipitation.    And most keep it going on and off for a few days.

You won't need an air conditioner or a fan after tomorrow for quite a while.

 Wednesday will get near 80F for some, but after that we will fall into the 60s for a least a week.


  1. I don't care if don't see rain for another two months. This last rainy season was brutal.

  2. For the record rain falling from the sky is not a welcome sight to many fruit and vegetable producers. While plants need water in the root zone it need not come from the air, for quality produce consumers demand.

    Rain rots fruit, causes blights and disease, increases the need for herbicide and pesticides, increases carbon emissions , because of increased tillage to control all the weeds rain triggers.

    Think about it the majority of the world's produce are grown in deserts, like California's Imperial valley.

    Even in suburbia, it increases lawn mowing, so more carbon in the atmosphere.

    The perciptation chart presented goes out through June 17th, it is only the 7th so as of now we are average for perciptation. Likely by the 17th, we will add another 30 day period of above average perciptation! (A long string of those since last fall!!!!!)

    1. Yeah but I like my bon fires. So we need rain to keep the fire bans away.

  3. The land needs the rain. People are optional.

  4. This comment has been removed by the author.

  5. Wow, just read in Scott's blog it was the second wettest spring in 123 years!!!

    Wow. Now that is a little wet.

    Also found it interesting that we (Washington) were the ONLY state that has had below average temperature since January.

    Only state!


Please make sure your comments are civil. Name calling and personal attacks are not appropriate.