I should start by noting the return of much warmer than normal conditions after a few days of cooler conditions (see graph, with average highs and lows and observed temps). It is now certain that Seattle will beat its all time temperature record--we are now experiencing the warmest January in Seattle recorded history! Not a single day has had a mean temperature below normal. And this warmth has been observed over much of our region. The mean tempeature this month will come in close to 47F...that is warmer than an average March day (45.15F), but not quite April (49.4F). My garden is really responding right now...my grass is really growing and bulbs are pushing out of the ground.
The weather situation that we have been seeing this month, and which appears to be dominant in our future, is classic late-winter El Nino. In such a pattern there is unusual troughing offshore, with the jet stream..the current of strong winds...going south of us into California. They get more storms and precipitation. We get split flow and a dribble of weak systems. Really dead. Below I have put a graphics of the flow at 500 mb--roughly 18,000 ft for you to examine. The lines tell how high that pressure level is above sea level. Winds parallel the lines with higher heights to the right of the winds. The closer the lines are together, the stronger the winds. With all that said, you see the obvious--trough/low offshore and the main winds going to California.
We are running out of time for winter. In three weeks, we pass the unofficial end to NW winter...after which we rarely get major storms or flooding events. And our computer forecasts can see well 1/3 of the way and nothing is going happen here.
Finally, want to see a wonderful video of mountain wave clouds...lenticular clouds..downstream of the Olympics? Check this out!