Three atmospheric rivers will be impinging on the Pacific Northwest, and substantial precipitation will be falling.
To illustrate, below is a plot of integrated water vapor transport (the intensity of the horizontal movement of water vapor by winds) on Friday at 5 PM. The arrows show the direction and intensity of the water vapor transport.
Lots of water vapor pushing into western WA and BC. Water vapor that will turn to precipitation as it is forced to rise by our local mountains.
When you get into the blue colors, you know the atmospheric river is a strong one!
Late Monday, another (but weaker) atmosphere will make landfall
And then a monster atmospheric river will make landfall on Wednesday, with heavier precipitation in Oregon and northern California.
You bet..and be prepared to be impressed.
After the first atmospheric river (Saturday at 5 PM shown below), the Washington and BC mountains (and their windward slopes) will have received two inches or more of liquid water.
This is just the start.
After the third atmospheric river moves through (Thursday at 4 PM shown), the accumulated precipitation totals will be stunning, with some locations getting over 10 inches of accumulated liquid water.
There will be a massive fill of regional reservoirs, and I suspect the persistent talk of drought will fade. Of course, no more regional wildfires.
But as in late-night TV commercials, there is MORE! The latest long-range European Center forecast for November through January predicts much more precipitation than normal over the region.
We're definitely on the rinse cycle for Halloween this year. Next week will likely mutate a bit, but definitely time to put away the summer toys!
ReplyDeleteWe typically get around 400-600 trick-or-treaters. Looks like we'll be breaking out the event tent and buddy heaters (again!) to hand out candy this year!
DeleteWow I sure am jealous.. wish we could get some of that rain here in southern California.
DeleteAn excerpt from the current NWS forecast discussion:
ReplyDelete"Unsettled conditions then look to persist through early next week as flow aloft becomes more zonal. Some progressive, weaker systems passing through the region may bring additional shower
activity to the area, but not expecting any significant impacts to the area at this time."
As if your post wasn't enough to suggest NWS needs to get a grip, I can look at the UW models, AND the operational Euro AND the GFS for good measure, and see an almost continuous series of moderate to very strong systems impacting us.
I recall the forecast discussions being much more insightful and relevant a few years back. Now, they're erratic at best, and sometimes (as in this case) completely out to lunch.
I would also expect consistent commentary on the timing and strength of Puget Sound convergence zone activity. In reality, they're often ignored (or missed). In some cases, one discussion will mention "possible" PSCZ activity, then the next will say nothing at all. The CZ over Snohomish County early Wed morning was narrow but very intense, for example, and the forecast discussions had nothing to say about them.
I get it: PSCZ activity can be wildly erratic and must be a real pain in the butt to predict. (One look at how badly the HRRR handles its CZ forecasting tells that story.) But isn't that why NWS invests in local forecast offices that can focus on these unique features and show some skill at forecasting them?
Bring it on!...the Puget Sound area needs it, and I am tired of being a victim of the typical rain shadow effect!
ReplyDeleteThe KC Flood app shows the Snoqualmie River reaching phase 2 flooding, about 14,000 cfs.
ReplyDeleteCan you explain the units of water vapor measured in the maps, please?
ReplyDelete