The Cold Facts About This Winter

It is not in your imagination.

 For much of the Pacific Northwest, this has been one of the coldest mid-winters in decades.

Seattle on Wednesday

Consider the daily average temperature in Seattle from January 15 to February 7 over the past thirty years (below).   This was the COLDEST year for that period.  

 I have also plotted the trend over that thirty years (brown line).   There is no trend.   

Little change from global warming or global cooling during this period.

What about in Pasco, in the Columbia Basin of eastern Washington? (see below).  This winter period was colder than normal but four other years we colder during the last thirty.  

Interestingly, the temperature trend at Pasco is DOWN....cooling... over the last thirty years.

You won't see that mentioned in certain local media outlets.😊

Considering the temperature departure from normal over the last 14 days across Washington State (below), we see the general colder-than-normal pattern, with particularly chilly temperatures over the WA coast, near Bellingham, and over the NE slopes of the Cascades.

Why have we been this cold for so long you ask?   

Because the large-scale atmospheric flow has been stuck in a very favorable pattern for NW cold, with an upper-level high-pressure ridge offshore, with troughs of lower heights/pressures on both sides.    

To illustrate, take a look at the upper-level (500 hPa pressure, about 18,000 ft) map for January 25.  This pattern puts cold northerly flow over our region.

This configuration is called an omega block, because it looks like the Greek letter omega.   It is generally a very stable pattern.

Amazingly, the best global model (European Center) is forecasting the same pattern for the next five days (see below).   I think I need to purchase some more thermal underwear.

In fact, the EC  temperature forecast IS for colder than normal weather over our region during the next week (see below).

The NOAA National Blend of Models (NBM) predicted temperatures for Seattle are very cold this week, some temps dropping into the low 20s at night.   Protect your pipes, hoses, and pets!

During this cold period, there has been a substantial increase in electrical demand for heating and because EV batteries are substantially less efficient in the cold.   As shown by the BPA statistics, renewal energy production (mainly wind, green line) has been relative low...far less than the sole nuclear plant in the region (purple).

Unfortunately this is a repeated pattern:  renewable energy like wind is least abundant when we need it the most.  Thankfully, we have the dams.  But we need to seriously think about a major expansion of nuclear.