Dry weather started early this year amid cloudy conditions

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.

Holly, in the southwest part of the peninsula, received 10.4 inches of rain in April this year — the third wettest April in the record books, which go back to 1991. The wettest April was in 1996, when 13.3 inches fell in the Holly area.

Precipitation in Hansville (click to enlarge)

After April, things went dry. In May, Holly recorded just 0.15 inches, the second driest May on record. The driest May in Holly was 1992, with 0.05 inches. Then June came along this year with 0.95 inches.

Recall that Holly is not far from the wettest part of the peninsula. It has an annual average rainfall close to 80 inches, compared to Hansville at the northern tip, which gets about 30 inches a year. The major difference, according to climatologists, is the “rain shadow” from the Olympic Mountains, which block precipitation that would otherwise fall on Hansville.

Precipitation in Silverdale (click to enlarge)

Oddly enough, something different happened in Hansville in June this year. According to data from the Kitsap Public Utility District, Hansville received 2.26 inches of precipitation in June, compared to Holly with 0.95 inches. Other areas of North Kitsap also received more rainfall than Holly — or Central Kitsap for that matter — but Hansville was the highest. I will need to check with meteorologists to see if they have an explanation.

In April, Hansville was showered with 4.7 inches of rain, and that was the second wettest April on record, behind 2005 with 5.84 inches. In May, Hansville received just 0.39 inches, which was the second driest May behind May of 1992, when 0.35 was recorded.

Large ribbons of Noctiluca, a floating phytoplankton, can be seen in this photo taken June 28 off Poverty Bay near Federal Way in Central Puget Sound.
Photo: Eyes Over Puget Sound, Dept. of Ecology

Silverdale, in the middle of the peninsula, fell into line with 5.1 inches in April, the fifth wettest April on record; followed by 0.13 inches in a dry May, second only to May 1992 with 0.05 inches; and then came June with 0.93, the sixth driest June on record in Silverdale.

The graphs on this page show how the three areas this year (blue line) track with last year (orange), which was a wet year. The other lines represent the average for each area (purple), the maximum annual rainfall (green) and the minimum annual rainfall (brown). To see similar charts for other areas, go to the PUD’s Hydrodata page, click on “Rain Gauge” under the map, and then choose one of the red telemetered locations for the latest information.

Throughout Puget Sound, near-normal temperatures and low rainfall during June resulted in variable freshwater inputs into our inland waterway, according to the latest Eyes Over Puget Sound report (PDF 6.3 mb). A large bloom of the orange plankton Noctiluca has been spreading through South and Central Puget Sound and piling up on some beaches, according to the report. A large growth of green macroalgae also can be seen along some shorelines and drifting on the surface in some waterways, including Port Madison in North Kitsap.

Juvenile salmon have begun migrating out of the estuaries and are confronted with a complex mixture of water temperatures, as revealed by thermal images in the EOPS report.

Below-normal precipitation is expected in the Northwest over the next two weeks and through the end of the water year on Oct. 1, according to both short-term and long-term forecasts by NOAA’s Climate Prediction Center. (Check out the three-month outlook map on this page.) Meanwhile, temperatures in our region are expected to be above average. (See the temperature map.)

We are currently in the midst of a neutral phase in the El Niño Southern Oscillation, an oceanic condition expected to continue through the summer, according to most near-term climate models. Sometime in the fall, ENSO is expected to shift toward an El Niño condition that should continue into the winter, according to a discussion brief (PDF 626 kb) by the Climate Prediction Center.

El Niño conditions normally bring warmer temperatures with less precipitation to our region. A very strong El Niño in 2015 and 2016 led to significant ecological changes. I have not seen a prediction for the strength of the next El Niño, which is predicated upon a heat buildup in the tropical Pacific Ocean, but such ENSO predictions are frequently updated.