Weather Blog

Convergence Zone brings radically different weather just 25 miles apart

Convergence Zone brings radically different weather just 25 miles apart
Photo of a somewhat sunny Seattle on Feb. 16, 2013. (Photo: Puget Sound Clean Air Agency)

If you were in Downtown Seattle today, Saturday probably went down as a relatively mild and sunny day albeit a bit breezy.

But if you lived just 25 miles to the north, your memories of Saturday's weather will be radically different, featuring an hours-long rain and chilly temperatures.

Sure enough, a very rascally Puget Sound Convergence Zone formed in the wake of a very weak front that was so weak. ("How weak was it?") that it didn't even bring any rain to Sea-Tac Airport.

Yep, as of 5 p.m. Saturday, the day was set to go down as a dry day. Sea-Tac hit 52 while closer to the city, Boeing Field hit 54 degrees with sunshine.

But up in Everett, it was a more typical January day than mid-February -- a constant light rain that started early Saturday morning and continued straight through into the early afternoon -- enough to register 0.44" or wetter than any day Seattle has had this month.

And the high temperature? Just 45 degrees. Again, Boeing Field and Paine Field are about 25 miles apart!

Blame those colliding northwest winds in the wake of the front for creating the zone, something you can see here on satellite image:



Note the band of intense clouds right over Snohomish County.

Here is a radar image as well:



And over at SkunkBayWeather.com they had a good shot of the zone forming then beginning its march south. Note the wind shift to the north.



The zone was shifting south, Saturday evening as it does sometimes when it weakens so Seattle is not out of the woods for some official rain, but it certainly won't be 0.44"!

Just another example of how variable the weather can be around here, and how those who live in the Convergence Zone are indeed picked on!