Temps are relatively warm today due to the clouds associated with the weather disturbance that moved through last night and this morning...but clearing will spread over the region today and the real cold is expected tomorrow morning. I spent some time yesterday preparing my home and plants...mulching them and moving some into the garage....they are ready!
Strong NE winds are coming out of the Fraser...some gusts to 30-40 mph in exposed locations last night (a few even higher). Look at the wind graphic below.
On the figure there is both temp (upper left) and dewpoint (lower left). You will note the dewpoints are very, very low (single digits)--a sign of continental, arctic air. Look at the winds taken by the sensors on Washington State Ferries- strong NE winds...with 38 knots in one channel. Wa Ferries does a very important public service by having such observations....and there are available for you to view on the web site...Ferry Weather (http://i90.atmos.washington.edu/ferry/Ferryjs/mainframe1.htm)
Finally, it will be very cold tonight and Tuesday morning...lots of places will see lower 20s and teens west of the Cascades....so be ready!By the way, several of you have asked about a line of clouds stretching southwest of the Olympics (see figure). You know what this...the anti-Puget Sound convergence zone! The winds aloft are from the NW and the winds are passing around the Olympics and then converging in the lee of the mountains. Normally the winds are westerly when we get a convergence zone over Puget Sound, but now the winds are
coming from the opposite direction...so the convergence switches side. Converging flow causes upward motion and clouds! You notice all the clouds offshore..that is cold air that has passed offshore and the atmosphere going unstable at low levels, as cold, dense moves over warmer water. Big change in temperature with height produces convection (cumulus to cumulonimbus).
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