Hansville is the driest area in Kitsap County, but in November the skies opened up with more rain than we’ve seen there in the past 27 years. In November, enough rain fell in Hansville — 8.7 inches — to break the record for that location.
Longtime residents of our region realize that the amount of precipitation goes up dramatically as one travels south out of Hansville. For Silverdale, November 2017 was the sixth wettest November in 26 years, with a total of 11.0 inches. Holly experienced its fourth wettest November, with 22.9 inches, all based on rainfall data compiled by Kitsap Public Utility District.
The one glitch for Hansville is that three years of rainfall data are missing — specifically 2007, 2008 and 2009 — and 2007 was a particularly wet year in some parts of the county. In fact, record November rains were seen in 2007 in Holly but not in Silverdale. We may never know where 2007 would have fit into the records for Hansville, but November 2007 was only average in Port Gamble — the closest station. It’s very likely that Hansville really did break the record for November this year.
Consistent with those geographic differences, in Holly it rained 27 out of 30 days in November, compared to Silverdale with 22 out of 30 days and Hansville with 20 out of 30 days. This came after a fairly average October.
As you can see from the charts on this page, November rains pushed the lines up to begin tracking the wettest years in the record books from one end of the county to the other. But, as I discussed last month, anything can happen during the coming winter and summer. Last year started out well ahead of the wettest years on record. But, starting in mid-December, the rains did not keep pace with the record years, and then came a very dry summer. See Water Ways, Oct. 27.
Let me take a moment to further emphasize the difference in rainfall from north to south on the Kitsap Peninsula. Holly’s nonrecord precipitation of 22.9 inches in November is more than half of Hansville’s rainfall for the entire record year of 1999, when a total of 43.8 inches came down. Holly’s annual record is 127.5 inches set in 1999.
The average annual rainfall for Hansville is 30.7 inches, compared to Silverdale with a 42.8-inch average and Holly with 79.2 inches.
Looking forward, the rains are likely to continue, according to NOAA’s Climate Prediction Center (PDF 5.3 mb). La Nina conditions emerged in October and are predicted to continue through the winter in the Northern Hemisphere. The likely result will be below-average temperatures and above-average precipitation across the northern part of the contiguous U.S. — and the opposite across the southern tier of states, as shown in the map below.
Graphic: National Climate Prediction Center
