Record Heat in Western Washington and Oregon

Daily high temperature records were broken yesterday and more will fall today. Sea-Tac got to 58F (old record was 56F) and Hoquiam to 56F (old record of 55).

This morning's sounding at Quillayute, on the WA coast, shows a freezing level over 10,000 ft and an intense inversion (temperature increasing with height) in the lower few thousand feet (see below)

Yesterday's high temperatures got into the mid-50s all over the region yesterday, with some locations even rising into the mid-60s (only the highs above 54F are shown below).

The temperature this morning at 925 hPa (about 2700 ft)--16.4 C--was a record for the date and we have a strong offshore pressure difference this morning (much higher in eastern WA) that will produce offshore (easterly) flow and substantial downslope warming over the western slopes of the Cascades.  Mid-fifties will be commonplace and some locations downstream of terrain will get into the 60s.

Let me show you the latest UW WRF forecasts for surface (2-meter) air temperature--the details are fascinating.  Red indicates the warmest temperatures (check the legend below each figure). 

At 8 AM, the State is divided in two:  cold east of the Cascade crest and warmer to the west.  But notice there are ribbons of greater warmth along the western slopes of the Cascades and to the west of the Olympics--this is due to the downslope warming (air warms by compression as it sinks down the slopes).   So at 8 AM, head to North Bend, WA or the Olympic Coast for warmth,

By 10 AM, the warmth along the Cascade slopes and along the coast will be profound, with lots of locations well into 50s and even near 60F.

But the situation at 2 PM will amaze, upper 50s to lower 60s everywhere, with some locations getting above 65F.  It will feel like spring.

The only thing holding things back is the strong inversion (which represent great stability and slow the mixing of warm air down) and the fog that covers some areas this morning (see 9 AM satellite picture).   Fog covers the southern Sound, parts of the Strait, and extreme NW Washington. And, of course the eastern slopes of the Cascades and the passes.

So enjoy the warm days...things will change greatly this week.

from Cliff Mass Weather and Climate Blog http://ift.tt/2Ddx03n