Wednesday, October 18, 2017

The First Significant Storm of the Season

The Seattle Times called it the onset of the "Big Dark", but those who know Northwest weather call it the "Big Normal".   Right on time we are enjoying the stimulating strong winds and heavy rain of a potent Pacific front.  And quite honestly, it feels good.

Winds have gusted to 50-60 mph along the coast and over parts of Northwest Washington, and even here in Puget Sound we have had gusts above 40 mph at exposed locations (and 25-35 mph elsewhere).  The map of the max winds in the 24h ending 7 PM wed is shown below.


Strong winds, untested vegetation with summer growth, and trees with leaves have resulted in thousands of customers losing power around the area.   Here is the Seattle City Light outage map at 7 PM.  Puget Sound Energy has 36,000 customers in the dark.


As I write this blog, a very wet front is moving through the region, as shown by the 7 PM radar.

In fact, we are experiencing a modest atmospheric river that is bringing warm, moist subtropical air into the region (it was near 60F last time I looked).  A satellite image of the vertically integrated water vapor in the atmosphere shows the plume of moisture from the southwest, originating from north of Hawaii.  You can almost smell the pineapples.

The latest infrared satellite image clearly shows the juicy frontal zone clouds associated with the "river."  And potent instability clouds (the popcorn-looking clouds out in the Pacific) are ready to move in tomorrow


A strong front is embedded in the plume of moisture, something a trained eye can tell from the coastal Langley Hill radar image late in the afternoon (see below).  You see the corrugated pattern offshore, with orange/red colors?  That is a strong cold front with a narrow cold frontal rainbands.   These always reflect strong fronts. And that front is now moving across Seattle, with pouring rain and strong winds.  I have to admit, I love it.

Plenty more rain will fall during the next few days.  Here is the total for the 72 hr ending 5 AM on Monday.  5-10 inches over the western slopes of the Olympics and Washington Cascades.  Fire season is over. Our reservoirs will start to fill.  Our rivers will be refilled.  And the "Big Normal" is back..


16 comments:

Deek Deek said...

Cliff, I share your sentiment: it feels good. It didn't start seriously raining in Winthrop (WA) until about 6:00 pm but its been dripping ever since. Per the climate data from the Spokane weather office, we had the driest summer (June 21-Sept 21) on record. Just a measly 0.06-in. For some perspective, the normal is 2.07-in and the data go back to 1906 for the Winthrop station. Indeed, for the 4 month period from June 16 to Oct 16, we only had 0.08-in. Last spring I figured we would revert to the mean after the wet winter but 0.08-in in 4 months seems a little absurd.

dampscribbler said...

I'm not ready. 😕

John said...

Sure,rain for the next few days,but it looks like widespread record, or near record, maximum temps for much of the Western U.S. next week.Could parts of Western Washington experience 70 degree plus weather if a strong offshore flow develops?

cgt said...

Our yard in Bellingham is covered with 1/2'' of cedar slag.
A few plants knocked over when the wind did it's "gust" thing.

Ellen Baker said...

Oh yes - we're getting whacked, and yes that's quite normal. I had 3.6" "in the tube" between my 7:25 am reading and midnight here in Glacier, WA. I wouldn't be surprised at all to see more than 4.5" for twenty four hours (love UW's radar: https://atmos.washington.edu/weather/radar.shtml - thanks for that!)

I've seen worse - 5-7" in a day - but we absolutely LOVE fall weather. Mother Nature's pruning, true. Life in the Pacific Northwest is a hoot.

As for the flood warnings for the Nooksack - I'll be surprised if there's much of a blip for a while. Why? There's not a great deal of snow above us yet (some, but nothing like spring snowmelt). Over many years I've come to understand that what drives serious floods is the combination of heavy rain-on-heavy snow + high tides. For all the rain we're getting, that's not the case at this time.

Unknown said...

Come and haunt us forest fire smoke if you dare! The conveyer of water will wallop you clear across the Cascades. You’re such a big sport now huh?? Come and get some why don’t you? Huh?? Big guy?? Coward

Patrick said...

Unknown, don't jinx us. It'll be July again before you know it.

Ansel said...

I've gotten 1.37 inches in north Bothell so far.

John Codling said...

I love it too! Doesn't look like this will result in much snowpack with yo-yo-ing freezing levels but we're heading in the right direction. Next week looks quite a bit different!

joe mama said...

oh, thank goodness our 3 months of nice weather is over. boy, was that a drag. now we can all relax and hide inside under dark, grey, moist skies. oh joy.

BIGWATER said...

White water season has begun! Let the rains fall and the rivers rage! If you dont like the NW winter, please move away. We dont want you here anyways. Haha

Ansel said...

Another inch last night. We've still got the "express" but I think we've lost the pineapples. Brrrr!

JayW said...

The storm produced impressive runoff in the Middle Fork Snoqualmie drainage. Three days ago, the river was running at 400 cubic feet/second. Today it peaked at nearly 6000 CFS!

Cascadian Engineer said...

For those of us with diagnosed summer depression this time of year is paradise.

Eric Blair said...

This is why I moved here in the first place - winters in Chicago are often nasty, brutal and long. Rain? Pfft, bring it on!

Placeholder said...

Nitpick: You meant "Offing," not "Offering" in your headline.