Weather Blog

*Sniff,* they grow up so fast: Bellevue, Bremerton get their own NWS forecast

*Sniff,* they grow up so fast: Bellevue, Bremerton get their own NWS forecast
Photo by Flickr user rutlo.

Thursday marked a momentous day in the meteorological history of Bremerton and Bellevue. (OK, so "momentous" might be a bit of an exaggeration...)

After years of having to share with Seattle and the Foothills, Bremerton and Bellevue now get their own fancy individual forecast on the region's "Zone Forecast" product from the local National Weather Service office in Seattle.

It's the weather equivalent of finally getting your own room after having to share with your sibling for years.

Up until now, Bremerton has been lumped in the same forecast block as Seattle:



Why? According to NOAA: "The argument for this several years ago is the similarity of the climate and day-to-day weather in downtown Bremerton to Seattle, based primarily on comparisons of the old Bremerton Fire Department coop observation in downtown Bremerton with the Seattle observation."

But now, Bremerton, your microclimate is recognized!

"Away from the immediate downtown Bremerton area, the terrain rises sharply to several hundred feet above sea level; it is this terrain that characterizes the vast majority of the proposed zone. This is why the Bremerton Airport (where the only current observation within this zone is located) so often differs from observations in Seattle and its immediate vicinity. Generally speaking, the Bremerton and vicinity area is cooler, cloudier and wetter during winter with conditions similar to Shelton, Grapeview, Belfair and the rest of the Hood Canal Area zone. During cold air damming conditions, in particular, it is considerably more prone to low elevation snowfall than Seattle," NOAA wrote.



The new Bremerton Zone will essentially be the greater Bremerton, Bainbridge Island and east-central Kitsap County area. The Hood Canal area still gets to keep its own zone.

Bellevue gets to secede from the Foothills

Meanwhile, Bellevue has had to share with its neighbors in the foothills



But no more! NOAA says this new zone would include the large population centers of Bellevue, Kirkland, Redmond, and Issaquah, closely following the eastern border of the contiguous area that King County has designated as the Urban Growth Area.

The Sammamish Plateau and the Issaquah Alps, which is the higher terrain along the east side of the proposed zone, would remain in the old East Puget Sound Lowlands Zone.

NOAA says those towns in the foothills have a cloudier and wetter climate, plus they get hotter during periods of offshore flow in the summer -- two features that aren't as strong in the Bellevue metro area. So Bellevue has been broken off into its own.



In addition, the National Weather Service is breaking up the two zones in the Cascade Mountains -- previously a north-central and south -- into three zones, giving the north, central and southern Cascades their own zones. That will put Mt. Baker area in the northern zone, and allow forecasters to dedicate a zone to the Stevens Pass-to-Snoqualmie Pass area.

If you're still with me and interested in more information on these new zones, the National Weather Service has put a nice explainer with maps and everything on its site.