Tropical Air over Seattle

Breath deeply this morning.   

A few days earlier the air was over the tropics.  Moist, warm and soothing to our wind and cold whipped skin.  And we just broke a major low temperature record.  This morning, our low temperature (56F) was the HIGHEST low temperature ever recorded in November at Seattle Tacoma Airport.  That is a big record to break.

Yesterday, Bellingham broke their daily high temperature record (60F) and today all sorts of daily high temperature records will be broken around the region.  

To certify the tropical origins of our air, I used the NOAA Hysplit trajectory model to trace the origin of the air above us at 500 meters (blue), 1500 meters (red), and 3000 meters (green) for the past 150 hours.  Our low level air, came from just east of Hawaii.  The 1500 meter air from the deep tropics.  No wonder many of us are fighting the urge to grab a Mai Tai today.

A plot of the winds and temperatures above Seattle for the past day (below), shows a freezing level of 10,000 feet, with strong southwesterly winds aloft--a sign of a potent atmospheric river event.

Over the past 24 hr (ending 5 AM), portions of the SW slopes of the Olympics received over 6 inches of rain, with the north Cascades getting as much as 3-5 inches.

But perhaps more impressive than the rain on the windward sides of the mountains, is the profound rain shadowing in the lee of the Olympics, where some locations only received 1-2 hundredths of an inch (see below).  Just amazing.

However, the wacky weather award yesterday had to go to Bellingham, Washington, where in less than an hour (around 4 PM Tuesday),  the winds turned southerly and surged to over 40 knots, and the temperature rose from 46 to 60F (see report below).

The temperature trace there shows the story and the fact the temperatures are EVEN WARMER right now--62F (and there are strong winds at Bellingham currently as well).

The temperatures today will delight you.  A plot of temperatures during the past two weeks at Seattle shows that our current morning temperatures are WAY higher than the normal highs (purple line below).

 And the UW high resolution model forecast for surface air temperature at 2 PM  today shows 60s all over western Washington.  Some locations in the upper 60s.

 So pull out a short-sleeve shirt and breath in the tropical air.  Today, will not feel like normal Seattle weather fare of November.

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