Tag Archives: Kitsap Public Utility District

The word is ‘average’ for the first three months of Water Year 2019

Average, very average. That was my first reaction as I looked over the rainfall data for the first quarter of Water Year 2019, which began Oct. 1.

The point was driven home when I looked at the rainfall totals for Silverdale on the website of the Kitsap Public Utility District. October’s rainfall total was 3.23 inches, compared to a median average of 3.74 inches. November’s total was 5.51, compared to a 6.83 average. And December’s total was 9.31, lining up perfectly with a 9.31 average. (Exactly the same! What’s the chance of that happening?)

Looking at Hansville at the northern tip of the Kitsap Peninsula and Holly in southwest region, monthly totals were pretty close to the averages — with one exception. In December, Holly received 19.86 inches of rainfall, well above the median average of 13.93 inches for the month.

As you can see from the charts, the current trend (blue lines) are fairly close to average (pink lines) and not far off from last year (orange lines), which also was a fairly average year.

Here are all the numbers for October-December in these three areas, with this year’s monthly totals followed by the long-range median average for that month:

  • Holly: October, 5.52, 6.51; November, 12.41, 11.86; December, 19.86, 13.93.
  • Silverdale: October, 3.23, 3.74; November, 5.51, 6.83; December, 9.31, 9.31.
  • Hansville: October, 3.04, 2.68; November, 3.88, 4.37; December, 5.12, 3.91.

As we well know on the Kitsap Peninsula, drier areas are found as you go north with wetter areas to the south. By the way, December is clearly the wettest month of the year for Silverdale and Holly, putting December at the peak of a bell-shaped curve for data collected over many years.

Hansville’s long-term pattern looks a little different, with November at the top of the curve and successive months going slightly lower than the previous month through September, when the rainfall jumps up in October and again in November.

All this information can be found on Kitsap PUD’s webpage for Hydrological Data. Click on “rain gauges” and choose a location. Especially helpful are the current water year daily reports, cumulative charts and monthly box charts.

Looking ahead, the National Oceanic and Atmosphere Administration is predicting warmer-than-average temperatures and lower-then-average precipitation over the next three months.

The predicted El Niño has not yet formed, although sea-surface temperatures in the northern Pacific Ocean are well above average. Forecasters for NOAA’s Climate Prediction Center say there is a 90 percent chance that El Niño will still form this winter and a 60 percent chance that it will persist through spring.

In the Pacific Northwest, El Niño often diverts the jet stream and winter storms to California, leaving us with warmer and drier weather. (La Niña brings the opposite.) So far, oceanic conditions remain neutral, which creates unsettled conditions which are less predictable over the long term.

Rainfall records are beginning to fall across the Kitsap Peninsula

Water Year 2017, which began on Oct. 1, got off to a rip-roaring start this month in terms of rainfall, and now records are falling for October rainfall totals across the Kitsap Peninsula.

holly

As shown in the three charts on this page, the graph started climbing steeply above the lines shown — including the green lines, which denote the highest annual precipitation recorded for the past 25 to 33 years.

So far this month, 19.5 inches of rain have fallen at Holly, which has averaged about 7 inches in October for the past 24 years. As you can see in the annual rainfall map at the bottom of this page, Holly lies in the rain zone on the Kitsap Peninsula — the area with the greatest amount of rainfall in most years. With four days left in the month, Holly has about an inch to go to break the record of 20.5 inches going back to 1991.

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