There are rain shadows…. after which there are tremendous rain shadows.
On Sunday, a brilliant shadow will produce an space of nearly no rain over northern Puget Sound nation. And one other tremendous rain shadow will happen over the jap slopes of the Cascades.
As I’ve mentioned many instances on this weblog, when air approaches a terrain barrier, it’s compelled to rise on one facet, producing bountiful precipitation, and when it descends the opposite facet, the air is compressed, warms, and dries (see determine). The moist facet is the windward facet, the dry facet, the leeward one.
The results of terrain–both windward enhancement and the lee rain shadow– are enhanced when the wind is powerful and headed straight up the mountain vary on one facet and straight down on the opposite, like the instance proven under.
On Sunday, the scenario can be good: robust winds from the west will strategy the north-south terrain boundaries of our area. And this wont be simply any air…however a moist atmospheric river as effectively!
Here is the forecast 24-h whole precipitation ending at four AM Monday. As a lot as 2-5 inches on the windward facet of the Olympics and Cascades, however NOTHING east of the Olympics and over northern Puget Sound and NADA over the decrease jap slopes of the Cascades and close by easterly Washington.
Here is a better look over western Washington. NOTHING from north Seattle to southern Snohomish County and again in direction of northern Kitsap.
The good day to go to Richmond Beach Park on the Sound. The people in Sequim, usually smug of their rain shadow ascendency, can be jealous.
To present you the way good the arrange is, listed below are the winds and heights (like strain) round 5000 ft (850 hPa strain) at four PM Sunday. Winds are parallel to the peak traces….and you may see wind barbs should you look intently.
Just wow. HUGE north-south variation in heights (which implies STRONG winds), with the winds popping out of the west. Due west. Winds are directed perpendicular to the north-south mountain ranges of our area, which implies robust uplift (and precipitation) on one facet, and extraordinary sinking on the lee facet of the terrain crests.
And this westerly (from the west) circulation can be very moist, as proven by this forecast of atmospheric moisture at 10 PM Sunday. You see the orange/crimson areas directed proper into Washington? THAT is a plume of moisture, generally often known as an atmospheric river.
But even with all that “juice”, the robust sinking to the lee of native boundaries will make it bone dry downstream of them.
A significant concern can be heavy precipitation…together with rain… within the decrease passes on Sunday and Monday. It may get disagreeable
So benefit from the dry rain shadows if you might be in a popular spot, and maybe take a brief journey to a neighborhood rain shadow in case you are not.
Finally, it seems that there’s a Super Rain Shadow motion determine (see under). I must get one!