As I write this weblog round 6 PM, marine air is surging into western Washington, with robust northwesterly winds pushing into the Strait of Juan de Fuca.
At Race Rocks, south-southwest of Victoria, BC winds simply gusted to 48 mph and the newest UW WRF forecast mannequin predicts robust westerly wind gusts, reaching over 40 knots, within the jap Strait at 8 PM (see forecast map beneath).
We are actually experiencing an onshore or marine push and the cool, dense marine air is shifting in at low ranges inflicting sea degree strain to rise. For the reason that Cascades block a lot of the cool air from shifting eastward, the strain stays decrease east of the Cascades.
Thus, the results of the low-level marine air instruction is to create a big strain distinction (or gradient) throughout the Cascades, as illustrated by the ocean degree strain forecast for 8 AM Wednesday (see beneath). The traces are isobars of fixed sea degree strain, and you’ll be aware quite a lot of them over the Cascades the place strain is altering quickly.
The Hazard
However there is a matter. Because the cool air within the west deepens, a few of it could actually push eastward throughout the Cascades, accelerated by the big distinction in strain. The air then accelerates because it descends the jap Cascades slopes inflicting robust winds.
And therein we come to the hazard. A preferred index of fireplace hazard created by a number of USDA Forest Service personnel (together with Brian Potter of the Seattle FS workplace) is an index referred to as HOT-DRY-WINDY (HDW), which principally is wind velocity occasions a measure of atmospheric dryness. The forecast of HDW for tonight (Tuesday night time at 8 PM) is threatening, with excessive values over and downwind of the jap slopes of the Washington Cascades (see beneath).
The inexperienced/yellows/reds are essentially the most threatening. This excessive hot-dry-windy index coupled with bountiful grass creates the potential for fireplace. Of us must be cautious to keep away from ignitions.
With cool marine air settling over the west, temperatures can be not less than 10 levels much less on Wednesday and the climate this week needs to be close to good west of the Cascade crest (dry and higher 70s to low 80s). No disagreeable warmth waves.
We suffered this spring…not it’s payback time. 😁
