Today was a scorcher, officially 94 at PDX
That 94 is the warmest since the early June heat
For the geeks out there, the afternoon sounding over Salem showed an 850mb temp of +17.2; it's amazing we made it into the low-mid 90s. According to my chart from 1999-2009, even the warmest east wind events at +17 have not been able to produce a high temp higher than 90 in Portland in August. Today was day #7 at/above 90 degrees in Portland, a little more than halfway to our typical 13 day allotment each summer
Very little changes the next two days, in fact models warm those 850mb temps another 1-3 degrees. Marine layer along coastline remains very thin so there won't be much inland push. The result should be two more days in the lower 90s in the metro area. Overnight lows remain very warm in the Portland "urban heat island". The majority of each night will be spent in the 70s with just some mid-upper 60s after 3am. Outlying areas will be warmer than normal, but at least down into the upper 50s or 60 degrees.
We are right on the edge of the usual summertime western USA hot upper-level ridge. And once again there is a "hot" upper-level ridge across southern Alaska as well. Here's the ECMWF ensemble forecast of 500mb heights plus anomaly (in color) for Monday:
Notice there is a weak upper-level low offshore, by Thursday the low has deepened and is moving toward the West Coast.
The result is a much deeper marine layer Thursday, maybe even some spots of drizzle and high temps back into the 70s. As that low moves overhead Saturday (next image) a few showers may show up, similar to what we just saw Friday. PDX picked up .04" that day.
If you have a wedding or outdoor event Saturday, don't freak out yet. It might just be scattered AM showers, but too far out to see exactly what's going to happen. Regardless, the ridge seems to bounce back and Sunday-Monday sunshine and normal temperatures return.
Chief Meteorologist Mark Nelsen