The Most Unusual Weather This Winter. Normal Weather.

Light rain and a chill in the air.  Some snow accumulation in the mountains.  Towering cumulus clouds and showers.  It seems so strange.  Normal weather.

Here is a plot of the temperatures at Sea-Tac Airport for the past 12 weeks, with the normal high (red) and low (blue) temperatures shown.

During the last few days our average high and lows were near normal. Amazing.

The freezing level dropped below 3000 feet today and the  snow level dipped to around 1500 feet for a short time.   Imagine that.  Paradise, on Mount Rainier, received over half a foot before it warmed a bit.  Here is a shot there near sunset today.

The NW Avalanche Center even has a high avalanche danger out for tomorrow.   First one this year?
The NW Avalanche folks have had plenty of time to repair instruments and complete advanced training this year.

And take a look at the 500 hPa weather map for this morning.  A trough of low pressure over our region.  Haven't seen that in a while.

But don't worry, the ridge from hell (actually from the tropics) is coming back with a vengeance.

A strong WARM front is right offshore and will move in tonight.  To illustrate this, here is the forecast for 11 PM tonight of sea level pressure (solid lines), surface winds, and low-level temperatures.  Look along the coast.  You see the shift from SE to SW winds, a kink in the pressure lines, and a transition from cold (green) to warmer (yellow) temperatures...that is the warm front.

As the warm front passes, our region will be flooded by moisture, warm air and strong SW winds that will dump lots of precipitation tomorrow (Wednesday).  Here is the precipitation total for the 24h period ending 5 PM Wednesday.  Several inches of rain in the mountains on top of the snow today...that is why the NW Avalanche Center folks are worried.

Then...ready for warmth?  A big ridge develops over us on Thursday and we bake, with lowland temperatures near 70F that day.  Remember!  The sun is much stronger now.   As strong as mid-September.  Remember your sunglasses and sunscreen...you will need them.