May 13, 2015

Eastern Washington Gets Some Drought Relief

Next time you go to a local casino, you might want to take some farmers from the Roza Irrigation District in eastern Washington for good luck.  Those are the folks, with farms from roughly Yakima to the Tri-Cities (see map), that decided on May 11th to stop irrigating for several weeks in order to save water for later in the season.

Their gamble paid off, big time.   Today, substantial rain, associated with easterly flow circulating around a low pressure area east of the mountains, drenched the inland empire, with many locations enjoying 1-2 inches of steady rain this morning and early afternoon.  In contrast, the usually wetter western sides of the Cascades were far drier.   How could that be?

This rain was sufficient to thoroughly soak the ground and obviate the need for irrigation for a while, and even provided some water for the Yakima River reservoirs. The weather gods were clearly smiling on the eastern Washington agricultural community.

Let me show you some of the data.  Here is the 24h precipitation ending 5 PM from the National Weather Service observation site for eastern Washington (the reds and orange colors are the higher amounts, click on map to enlarge). Nearly two inches of rain fell northwest of the Blue Mountains around Walla Walla and similar amounts occurred over the Horse Heaven Hills above the Tri-Cities.   Much of the Roza district had over an inch, and substantial amounts fell over the eastern slopes of the Cascades.

The daily precipitation from the WSU Ag Weather network shows a similar situation (see map) with over two inches south of Benton City.   A dry wheat farmer from there called me today....he was a very happy fella.

The rain was heavy enough that some roadways were flooded, as were some commercial districts (see article below).

This situation was relatively well forecast by the models several days ago (my past blog is proof!).

So why so much rain on the eastern side compared to the west of the Cascades?

The winds in the lower atmosphere over eastern Washington were from the east or northeast, not the normal westerly direction.  The cause? A small, but intense, low pressure system moved northward east of the Cascades today, as illustrated by a weather map for around 5000 ft valid at 5 AM this morning (see graphic).  This system had a band of moisture that circled the low center, a band that was directed over southeastern WA and NW Oregon.

An infrared satellite image at the same time and a radar depiction at 9 AM, illustrate this "wrap around" plume of moisture.

More good news for eastern Washington farmers: cooler than normal, occasionally showery, weather is ahead, although not like the torrents of today. And the aggressive storage of water for the Yakima project by the Bureau of Reclamation is still obvious (see plot).  Even pulling water for agriculture and fish during the last few weeks, the total reservoir levels (blue lines) are still above average for this time of the year.  Hopefully, the recent rains and conservation in the Roza district will cause the decline in reservoir level to slow during the next week.

I am a bit more optimistic than some regarding eastern WA agriculture this summer.   Our region is undergoing a snowpack drought, not a precipitation drought.  Reservoir managers have stored more water than usual.  And, how do I say this diplomatically?   Some farmers have wasted water, including spraying during mid-days when evaporation is huge.  As noted in a recent radio segment by NPR's Ana King, some farmers/orchard owners are switching to drip irrigation, saving as much as 50% of the water.  Improving irrigation technology will take a few years to put in place, but the long-term impacts on water use could be huge.


  1. I'm thinking you meant sprinkling during mid day and not spraying. Spraying uses very little water and would be inconsequential. Drip is the most efficient way to irrigate but due to the current cost of drip system it can only be used profitably on higher value crops.

  2. Some of those rain totals are 1/5th of our annual precipitation. Pretty impressive. This pattern is reminiscent of El NiƱo. And I'm surrounded by orchards, and all the new varieties have cooling systems by misting. It's all automated with water kicking on at a certain temperature like 80 degrees. The risers are 15ft in the air. Huge use of power and water so don't think we're getting better.

  3. Smokejumper...are you saying that some orchards are misting water for cooling? Why? Is this prevalent? Sounds like a terrible waste of water..cliff

  4. Very prevalent. New orchards implement such strategies. It's very expensive to install such systems but there's so much money in new apple varieties.

    I can't say why it is done. Apples such as pacific rose, jazz, fuji, cripps pink, and honeycrisp dominate the landscape today. While they have been successful, I don't know if these expensive apples are optimal to be grown at 90+ degrees in the sun?

    It's a timed misting system used in the produce section at your local grocery store but on a grand scale to cover hundreds of acres.

  5. Smokejumper,
    Are you sure these are not misting systems to deal with below-freezing temperatures? They spray water on because water releases latent heat when it freezes...thus, helping to protect the buds from really cold temps..cliff

  6. If this was well-forecasted, maybe the Roza folks were well-informed, rather than lucky.

  7. Tree fruit orchards primarily irrigate below or within the tree canopy based on orchard structure and age and this occurs with efficient irrigation systems. Overhead irrigation systems are still utilized during frost protection season in the spring and during the heat of the summer to cool the fruit. Excessive temperatures can lead to sunburn and structural damage to the fruit tissue. Below are two links which provide more detail.

  8. I know Cliff. I didn't want to bring it up. I'm a irrigation user and it's our way of live here but if you knew how much water we waste.

    So I asked a friend who works at the local irrigation shop more about it. He said they are 100% designated for cooling. He designs and installs a system every week. I asked why and the specs...

    First is to reduce sunburn and scarring. Second it is used with bird and pest control. And finally it helps add color to the apple.

    It's all computer automated turning on around 85 degrees. Every new orchard has some type of reservoir because it takes so much water. That's why I said its a waste of power too because of the pumps. I used the grocery store example because the misters kick on every half an hour. I'm completely surrounded by it. Hundreds of acres. All four corners of me. July thru September. Noon to six lol.

    Anyway, my friend also said drip irrigation is becoming big too! It can reduce watering from 55 gallons/minute per acre to 12. He said his company is investing towards that direction while catering to the top dollar apple market too :/ Cheers.

  9. This probably way off the subject, and not sure how to 'ask a question' here, but here goes, I have been seeking an answer to what I would call an air quality question: Is there anything in the air that is causing an inordinate amount of nasal decongestion in the Pac. NW. I and others I work with at SeaTac Airport(as well as local friends that do not) have noticed a lot of folks, including myself, with "Spring or Hay fever" this year, and it has been pretty serious case its symptoms;- cold, runny nose, sore throat, etc.- of it. Besides the always present shedding of the cottonwoods, is there anything else that may be causing it? Or is it just me? I have it every year, but this year, especially so Is there anything that tests regional pollen count over a season and if so is this one notable? Thanks!-John


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