Tag Archives: Precipitation

Low rainfall during November contributes to smaller salmon runs

Salmon managers are reporting dismal returns of chum and coho salmon to Puget Sound streams this fall, and a sparsity of rainfall during November could result in low salmon survival during the next generation.

Low streamflows in November made it difficult for chum salmon to make it past obstacles, such as this log weir at the mouth of Chico Creek.
Photo: Meegan M. Reid, Kitsap Sun

“The run (of chum) was pretty darn small,” said Jon Oleyar, salmon biologist for the Suquamish Tribe who walks many streams on the Kitsap Peninsula. His surveys of living and dead salmon are used to estimate escapement — the number of migrating salmon that return to their home streams.

“Some of the streams had no fish at all in them,” Jon told me, “and many of the fish did not get very far up into the system.”

Low rainfall in November led to low streamflows in the upper portions of many streams, where the water levels were often too low to allow passage of chum and coho. The fish were forced to lay their eggs in the larger channels, where heavy rains this winter could wash the eggs out of the gravel before they hatch.

Low flows disrupted the normal run timing of the chum salmon, according to Aaron Default of the Washington Department of Fish and Wildlife. The final in-season estimate of run size for Central and South Puget Sound was 240,000 chum — barely half of the preseason forecast of 444,000. The 10-year average is about 527,000, as I reported in Water Ways in October. Final estimates for the year will come later.

Chum returns to Hood Canal also were low this year, Aaron reported in an email.

For the Kitsap Peninsula, average rainfall in November is second only to December in the longterm records, but this year more rainfall was seen in October and even September. The graphs on this page include nearly flat lines (blue), representing very low rainfall through most of October and November this year. Click on the images to enlarge them.

In Hansville, at the extreme north end of the peninsula, total rainfall for November was 1.14 inches. That was the lowest precipitation recorded in 30 years of records maintained by Kitsap Public Utilities District. The median average rainfall for November is 4.37 inches in Hansville.

In Silverdale, only 1.03 inches of precipitation was recorded during November. That’s just a fraction of the median average of 9.96 inches seen over the past 29 years. It was also the lowest rainfall ever seen for November except for 1994, when 0.90 inches established the current low record.

Holly, one of the wettest parts of the Kitsap Peninsula, received 2.47 inches of rain in November, compared to a median average of 12.41 inches. This November’s rainfall in Holly, as in Hansville, is the lowest amount going back 29 years. The previous record low was 3.29 inches set in 1994.

The shifts in rainfall from one year to the next are hard to explain. Just two years ago, Holly received 22.89 inches of rain in November, followed by 12.41 last year — which just happens to match the median average.

Overall, the low rainfall was detrimental to the salmon, which ended up spawning in the lower portion of streams where flows are higher. But Jon Oleyar observed a few positive features this year, such as beaver dams on Chico Creek — the largest producer of chum salmon on the Kitsap Peninsula.

Although beaver dams can impede the movement of chum during low flows, they also can hold back water during high flows, reducing the risk of extreme currents that can scour salmon eggs out of the gravel.

“In the Chico system, we had about 10,000 fish total, and 95 percent of them spawned below river mile 1.5,” Jon said.

That means most chum and even coho spawned this year in the mainstem of Chico Creek, with very few fish getting to Lost or Wildcat creeks. Those tributaries of Chico Creek normally support large numbers of juvenile chum and coho.

“The only saving grace that I can point to is the beaver dams,” Jon said. “In bad weather, the dams can hold back the water instead of having it shoot downstream like a fire hose.”

Jon spotted only handfuls of chum in some important salmon streams, including Scandia Creek in North Kitsap, Steele Creek in Central Kitsap and Blackjack Creek in South Kitsap.

“This might be the smallest run I’ve ever seen,” said Jon, who has been surveying salmon streams for years, “and some streams didn’t get any fish at all.”

The three-month precipitation forecast calls for above-average rainfall from now into February.
Map: NOAA Climate Prediction Center

Hatcheries in the region may not have enough returning salmon for full production next year, and the coho that did make it back were much smaller than normal. Jon said. Conditions leading to fewer and smaller salmon probably relate to temperatures in the open ocean and upwelling currents off the Washington coast. I’ll have more to say about those conditions along with some observations about chinook salmon in a future blog post.

For now, we can hope for adequate rains — but not enough to cause serious flooding — over the next few months, as the baby salmon emerge from the gravel and begin their fight for survival.

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In Hansville, September rainfall was highest in 30 years of records

September was a record-setting month for rainfall in Hansville in North Kitsap, but not for the rest of the Kitsap Peninsula, which overall still received lots of rain. This demonstrates again how different one part of our region is from another — and how Kitsap County is a world apart from the rest of the Puget Sound region.

As we close out Water Year 2019, we can see from the charts that that the annual rainfall (blue line) was below average (pink line), but September rains nearly pushed Hansville up to the average mark.

Hansville had a total of 3.56 inches of rainfall in September, according to data maintained by the Kitsap Public Utility District. That’s more rain than any other September going back to 1990, when the KPUD records begin. The second-highest September rainfall was in 2013, with 2.88 inches.

In Silverdale, the monthly total was 2.71 inches of precipitation. Typically, Silverdale gets more rain than Hansville. In fact, the median average for Silverdale in September is 25 percent higher — 1.0 inch, compared to Hansville’s 0.8 inch.

But if you’re talking about records for Silverdale, you need to go back to 2013, when 6.8 inches of rain fell in September. That’s far more than any other year going back to 1991. In 1997, 5.4 inches fell on Silverdale in September, but no other year had even 3 inches.

In fact, the month of September 2013 was reported as “one for the record books” in a Kitsap Sun story at the time. Reporter Brynn Grimley said rainfall Sept. 28-29, 2013, was 2.2 inches in one day — the most since 1899. The storm also brought winds that knocked down trees and power lines, Brynn reported.

The year 2013 set rainfall records throughout most of Kitsap County.

Holly, which typically gets some of the heaviest rainfalls on the peninsula, received 5.4 inches this past September. That is a lot, considering that September is typically fairly dry, but it is nowhere near the record of 9.6 inches set for Holly in 2013. The median average there is 1.5 inches in September.

We have to recognize that we are limited to a 30-year period when talking about records in the KPUD database, but it’s still worth discussing. Bellingham, where the records go back to 1949, set a new rainfall high last month with 4.73 inches of precipitation, just above the old record of 4.71 inches for September 1969, according to the National Weather Service’s Twitter feed.

In September, Western Washington and much of the Northwest experienced at least twice the normal rainfall, while dry weather was seen over much of the East.

So September was indeed a wet month on the Kitsap Peninsula and other places in the Puget Sound region. For Water Year 2019 as a whole, however, we did not reach the annual average. Hansville received a total of 29.4 inches, compared to a median average of 30.7 inches. Silverdale received 37.2 inches, compared to a median average of 42.8. And Holly received 68.5 inches, compared to a median average of 79.2.

While Western Washington and much of the Northwest experienced at least twice the normal rainfall in September, much of the country was fairly dry. By next week, most of the eastern portion of the country will get some rain, predicts Brad Rippey, meteorologist for the U.S. Department of Agriculture. Heavy rain may occur across the upper Midwest, where some rivers are already running high, he said.

Cooler-than-normal conditions with above-normal precipitation are expected to continue from the Northwest into Montana during the Oct. 8-12 time period, while large sections of the Plains, Southwest, Midwest and mid-South undergo drier-then-normal conditions, according to the forecast (PDF 5.7 mb) in the “USDA Water and Climate Update.”

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Ongoing lack of rainfall raises concerns for chum, coho salmon

We’ve just gone through one of the driest five-month periods on record in Kitsap County, yet the total precipitation for entire water year was fairly close to average.

Water year 2018, which ended Sunday, offers a superb example of the extreme differences in precipitation from one part of the Kitsap Peninsula to another:

  • In Hansville — at the north end of the peninsula — the total rainfall for the year reached 35.2 inches, about 3.5 inches above average.
  • In Silverdale — about midway from north to south — the total rainfall was recorded as 43.1 inches, about 5 inches below average.
  • In Holly — near the south end — the total rainfall came in at 82 inches, about 3.3 inches above average.

The graphs of precipitation for the three areas show how this year’s rainfall tracked with the average rainfall through the entire year. The orange line depicts accumulated rainfall for water year 2018, while the pink line represents the average. Click on the images to enlarge and get a better view.

Continue reading →

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Dry weather started early this year amid cloudy conditions

UPDATE:
July 5. Greg Johnson, who lives in Hansville and manages the Skunk Bay Weather station there, said the unusually high rainfall in June for Hansville, compared to the rest of the peninsula, was the result of the Puget Sound convergence zone settling over the area on several occasions. Weather conditions brought localized squalls during the month, he said, adding, “This is very unusual for us.”

The reading at Greg’s weather station, 1.98 inches for the month of June, was somewhat lower than the 2.26 inches recorded at Kitsap PUD’s weather station in Hansville.
—–

Cool, often cloudy conditions have helped obscure the fact that very little rain has fallen on the Kitsap Peninsula over the past two months.

Precipitation in Holly (click to enlarge)

Now that we are in the fourth quarter of the water year, we can see that rainfall levels for this year will be close to average for most areas on the peninsula. What might not be recognized, however, is that April was well above average, while May and June were well below average.

Continue reading →

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Rainfall pattern returns to normal across the Kitsap Peninsula

After two years of near-record rainfall across the Kitsap Peninsula, precipitation has returned to a more normal pattern.

Halfway through the water year, which begins in October, rainfall in Hansville, Silverdale and Holly are all within 10 percent of the average for this time of year, according to weather instruments managed by Kitsap Public Utility District.

This near-average total for the first half of the year comes about despite a very wet November, when Hansville broke the all-time record for precipitation for that month. Since then, the monthly rainfall numbers have been mostly below average, except for a wet January when Holly nearly broke the record for that month.

As we’ve seen time and again, the amount of rainfall decreases dramatically as one travels from south to north on the Kitsap Peninsula. That’s the general pattern for all times of the year, although the amount of precipitation can vary wildly.

Hansville received 25.5 inches for the six months ending April 1, compared to a 28-year average of 23.1 inches for that period. Last year, the six-month figure was 7 inches higher at 32.5 inches, and the first half of 2016 went down in the record books with a total of 37.0 inches.

Silverdale posted 35.1 inches of rain by April 1, compared to a 28-year average of 38.1 inches for this time of year. Last year, this Central Kitsap area received 51.7 inches by April, and in 2016 the number was 52.3 inches, second only to 1999 with 69.8 inches.

In rainswept Holly, residents experienced 68.7 inches by April 1, compared to a 27-year average of 65.0 inches. By April 1 last year, Holly was practically swimming with 95.9 inches, driven by 24.0 inches during the month of October 2016 and 21.8 inches the next month. But nothing compares to the first half of water year 1999, when Holly received 120 inches for the first half of the year. Following a fairly dry summer, water year 1999 in Holly ended with 127.5 inches of precipitation.

NOAA’s Climate Prediction Center has projected somewhat higher-than-average rainfall through the end of this month in the Pacific Northwest, followed by fairly average conditions going into summer. Forecasters rely heavily on observations about temperatures in the Pacific Ocean, which influence a natural cycle known as the El Niño Southern Oscillation, or ENSO. See video this page.

A very strong El Niño during 2015 and 2016 (associated with the much-discussed “blob”) shifted into a weak La Niña in 2017. Conditions have now reversed course again and seem to be headed toward neutral. La Niñas are generally associated with cooler and wetter weather for our region of the country, while El Niños suggest warmer and dryer conditions — although it does not always turn out that way.

Neutral conditions are expected to arrive by summer, and some forecasters predict that the warmer El Niño could arrive toward the end of the water year in September, according to information released today by the Climate Prediction Center.

“Some of the computer models are forecasting development of El Niño by next fall,” noted research scientist Emily Becker in a new post on the ENSO Blog, “but there are a number of reasons why we’re not completely taking the bait right now.

“First, forecasts made this time of year tend to be less successful,” she continued. “Another reason is that, while elevated subsurface heat content in the spring sometimes precedes the development of El Niño in the fall, some recent studies have found that this relationship has not been very reliable over the past two decades.”

Researchers observed a warming trend in March among subsurface waters in the Eastern Pacific. Those waters are expected to rise to the surface over the next few months to potentially neutralize any cool surface waters that remain. The outcome is likely to be the end of the current La Niña and possibly the beginning of a new El Niño, featuring warmer ocean conditions.

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It was a wet water year; it was a dry water year

Water Year 2017 was a crazy year for rainfall, with a precipitation pattern unlikely to repeat anytime soon, although forecasters say the coming year is somewhat likely to be wetter than normal.

Hansville (click to enlarge)
Chart: Kitsap Public Utility District

If you recall, Water Year 2017 (which began last October) started off soggy with well above average rainfall until December. Last year’s rainfall, represented by the orange lines in the accompanying charts, was not only above average in October and November, but it exceeded the rainfall observed during the wettest year recorded since 1982.

If you follow the chart for Hansville, you can see that last year’s total precipitation stayed above the record year until late January. From there, last year’s total rainfall tracked with the record year until this past May, when the rains practically stopped.

Talk about a dry summer. We got practically no rain until September, with minimal precipitation through the end of the water year on Sept. 30, as shown in these charts provided by the Kitsap Public Utility District.

Silverdale (click to enlarge)
Chart: Kitsap Public Utility District

Hansville’s annual rainfall last year totaled 39.5 inches, about 4 inches off the record of 43.8 inches in 1999. The record would have been broken if the rainfall this past spring and summer would have been normal. The year before — Water Year 2016 — was also a wet one with precipitation totaling 42.5 inches in Hansville.

In Silverdale, which gets a good deal more rainfall than Hansville, the pattern was similar except that last year’s total stayed ahead of the record until early December. The pattern was similar for Holly, one of the wettest areas of the county.

Silverdale’s total for Water Year 2017 was 61.8 inches, well off the record of 76.9 inches set in 1999. Still, the record books show only two wetter years: 1996 with 67.7 inches and 1997 with 64.8 inches.

Holly (click to enlarge)
Chart: Kitsap Public Utility District

Holly’s total for Water Year 2017 was 112.7 inches, second only to 1999, when Holly received 127.5 inches of precipitation. Other wet years were 1995 with 101.1 inches and 1997 with 100.1 inches.

The new water year, starting with the beginning of this month, showed little precipitation at first, then the rains came in mid-October, putting most areas near average, as shown by the blue line in the charts.

Overall, October so far has been a fairly wet month, up to twice the average rainfall in the Puget Sound region. For the nation as a whole, October has been mixed. We’ve seen extremely dry conditions in the Southwest, while up to four times the normal precipitation has been recorded for a swath from the Great Lakes down to the Central states, including the Oklahoma and Texas panhandles. Check out the map from the PRISM Climate Group at Oregon State University.

The outlook for the next three months from NOAA’s Climate Prediction Center shows the likelihood for wetter-than-normal conditions across the northern part of the U.S., although Western Washington should be about normal. Meanwhile, the southern tier states are likely to have drier conditions.

A La Niña watch remains in effect. If conditions in the Pacific Ocean continue to develop, we could see cooler- and wetter-then-normal conditions early next year. So far, there is no indication what the annual precipitation for our area might be. But after last year’s turn of events we should not be surprised by any weather pattern.

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It was a wet water year, but then the weather reversed its course

After unusually high amounts of rain fell on the Kitsap Peninsula last fall, this summer is starting out with a most unusual pattern of dryness.

It appears that we haven’t had any measurable precipitation anywhere on the peninsula since mid-June. That’s an oddity for dryness not seen in even the driest year on record since 1990, when Kitsap Public Utility District began keeping rainfall data.

Since May 17, Central Kitsap has seen only 1.4 inches of rain, while less than half an inch fell in Hansville during that time period. That’s barely any rain, given that we are talking about nearly two months. Holly has experienced about 2.4 inches in that time — still way low for the rain belt region of the Kitsap Peninsula. And to think that last fall I was contemplating that we might break a record this year. See Water Ways, Oct 27.

I will admit that I used to avoid writing weather stories for the Kitsap Sun. If an editor asked me to write about the weather, I would think for a moment and promise a “much better” story of a different kind. Now, as I try to keep up on climate change, I find myself fascinated with what I can learn from rainfall patterns — including the extremes you see going from south to north on the Kitsap Peninsula.

If you haven’t been around the area much, you may not know that we get more and stronger rainstorms in the southwest corner of the peninsula around Holly, while Hansville at the peninsula’s northern tip may get a third as much rainfall in some years.

Take a look at the pink lines in the charts on this page to see the average over 25-30 years. The scales on the left side of the graphs are different, but the charts show an average precipitation around 30 inches for Hansville in North Kitsap, 50 inches for Silverdale in Central Kitsap, and nearly 80 inches for Holly in Southwest Kitsap.

These charts also show the rainfall patterns in each area for this year with a blue line. Last year, which had above normal rainfall, is shown in orange. And the year that ended with the highest total rainfall is shown in green.

Hansville is especially interesting, because this year and last year essentially kept pace with the record rainfall year of 1999 as spring ended and summer began. In fact, on May 16 of all three years, the total accumulation to date in Hansville was 38 inches, give or take less than half an inch.

After May 16, the three years diverged in accumulated rainfall, and this year’s dry spell makes the blue line as flat as it can get for an extended period. Last year, the driest time came in April, as you can see from the flat section of the orange line.

July and August are typically the driest months of the year, but that can vary greatly by year. I used to tell people that we Puget Sound residents can expect a full three months of summer each year, but nobody can predict when it will happen or whether it will be divided up, say a week here and a week there.

Anyway, as I mentioned on April 1 in Water Ways, we are on a trajectory to exceed the average rainfall this year even if we get no more rain until the water year is over on Sept. 30. It appears our water wells will survive, but we need more rain for the streams to rise by early fall for salmon to increase their numbers.

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Washington state keeps its cool for the first five months of this year

For the first five months of this year, Washington state has stood out as the only state in the U.S. with a below-average temperature.

While most of the country was experiencing warmer-than-normal temperatures, we here in Washington were going outside to temperatures that averaged nearly 1 degree F. below normal.

In fact, the contiguous 48 states recorded the second-warmest January-through-May period on record, despite cooler conditions in Washington. Average temperatures were 1.4 degrees F. below the record set in 2012 for the same period, according to NOAA’s National Centers for Environmental Information (PDF 4.2 mb). Click on maps to enlarge.

The average temperature in Washington state was 38.6 degrees for the first five months of the year, compared to an average of 39.4 degrees for the 20th century. Out of 124 years on record, it was the 35th coolest for the five-month period, the coolest since 2011. The coolest on record was in 1950.

Forty states were much warmer than average during the same time period, with Florida, Georgia, North Carolina, South Carolina and Texas reaching record-warm levels.

Of course, temperatures can vary greatly from year to year, but climate conditions in Washington, as in most of the world, demonstrate an increasing temperature trend since records began in 1895, as shown by the blue line in the graphic.

The country as a whole has also been much wetter than normal so far this year. Average precipitation across the lower-48 has reached 14.85 inches, which is 2.46 inches above average and the fourth wettest January-through-May period on record. It is also the wettest first five months since 1998.

Washington state was 6.78 inches above the 20th century average of 20.03 inches for the five-month time period. This year was the sixth wettest on record.

Washington and five other western states were listed as much above average for snow and rain, while Idaho reached record precipitation for the first five months of the year. Record flooding was reported in the mid-Mississippi Valley. Below average precipitation was seen in the Northern Plains states and Florida.

Meanwhile, about 5 percent of the lower-48 was listed in drought conditions on May 30, up slightly from earlier in the year. Drought improved in the Northeast, Mid-Atlantic and Southeast, but it worsened in the Northern and Southern Plains and in Florida.

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Rainfall in the first six months of water year exceeds yearly average

Halfway through the current water year, which began on Oct. 1, rainfall patterns on the Kitsap Peninsula are shaping up to look a lot like last year.

Hansville rain gauge (click to enlarge)
Source: Kitsap PUD

For most areas, total rainfall is well above average, as it was last year at this time. It is also well below the record accumulation in most places. One exception is Hansville in North Kitsap, as you can see in the first chart on this page. There, the total rainfall is tracking both last year and 1999 — the highest year on record, which goes back 35 years at that station.

Moving into the drier half of the water year, it is now obvious that we will be above average in rainfall for the entire year, since we have already reached the average in most places.

Continue reading →

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It’s been a wet ride through the first half of the 2016 ‘water year’

With half of our “water year” in the record books, 2016 is already being marked down as one of the wettest years in recent history.

Hansvillej

The water year, as measured by hydrologists, runs from Oct. 1 to Sept. 30 each year, so we will be in WY 2016 for nearly six more months. If things keep going as they are, we will see some new lines plotted on the rainfall charts.

Joel LeCuyer, who keeps track of water data for the Kitsap Public Utility District, points out that the district’s two longest-running weather stations are on their way to record-high totals:

  • Bremerton National Airport, with records going back to 1983, accumulated 66.7 inches of rain at the midway point, compared to an average of 56 inches for the full year.
  • Hansville, with records going back to 1982, has accumulated 36.6 inches, compared to a yearly average of 32 inches.

Looking at the charts, you’ll see that both the airport and Hansville stations are slightly ahead of their maximum water year. It will be interesting to watch this chart as we get closer to June, when rainfall traditionally falls off dramatically. Whatever happens over the next two months will likely foretell whether annual precipitation records will be broken.

Airportj

To access the charts, go to the KPUD website. Under the tab “Water” click “Water Resources Data.” At the bottom of the map, click on the tiny bubble “Rain gauges.” The red ones track precipitation almost in real time.

Looking back, some rather dramatic downpours are already written into the record books this year. For example, when considering the top 10 rainfalls in a 24-hour period, nearly every station has at least one rain event from WY 2016 among the top 10.

At Holly, four of the top 10 rain events recorded over the past 25 years occurred during the past six months. That’s interesting, since Holly is one place where the total accumulation of rainfall is still falling short of the record. Holly has already surpassed the average annual rainfall of nearly 70 inches, according to the chart, but it is unlikely to reach the nearly 130 inches of rainfall recorded in 1999.

Hollyj

Above average precipitation was seen across Western Washington for the first half of the water year, according to the National Weather Service. The range was from 26 percent above average in the Olympic Mountains to 40 percent above average in the Puget Sound lowlands. Snowpack in the Olympic and Cascade mountains is about 10 percent above average.

Ted Buehner of the National Weather Service in Seattle reports that the current warm El Niño is expected to weaken through the spring. And there is a 50 percent chance that La Niña will return next winter. That would typically bring cooler and wetter weather, but rains over the coming winter will have a long way to go to match what we’ve seen during this water year.

As for what we might expect from now through the end of summer, the latest forecast from NOAA’s Climate Prediction Center says temperatures are likely to be warmer than average in the Northwest with slightly higher than even odds that the summer will be drier than average.

For details on a national scale, check out “ENSO: Recent Evolution, Current Status and Predictions” (PDF 3.5 mb).

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