Cold April follows cold March

This turned out to be one of the coldest springs in a long time. As I noted in a previous blogMarch is very cold in much of the West Coast.

And now April is getting cold too!

Compare temperatures at Seattle-Tacoma Airport with normal highs (purple line) and lows (cyan) since April 1.

Oh…. not a single day of normal highs and many days of below normal lows.

A similar situation happened at Yakima!

As I’ve noted before, this cold spring is keeping our ice sheet in place with minimal melting. Therefore, the latest snowpack count indicates a snowpack in the area above normalalthough our rainfall has been below normal.

The forecast for the next ten days of Central Europe’s master forecasting system is surface air temperature much cooler than usual (see below). It’s going to be especially cold east of the Cascades: I’m worried about frost damage–so be prepared for agricultural benefits.

The NOAA Climate Prediction Center’s forecast concurs with the frost forecast for the rest of this month:

Looking forward to a 60F day in the next two weeks? Forget.

Why is the Northwest so cold this month?

Because a low above unusually deep will land itself off our coast–and it will stay there for at least a week (see forecast below for next Wednesday).

A question many of you may be wondering about global warming at this time of year. Has the high temperature in the first 12 days of April trended upward, downward or sideways over the past 50 years in our region?

Well, here’s the average maximum temperature at SeaTac over the past half-century in early April. Lots of ups and downs, but NOT in an uptrend.

Or see average temperatures at Olympia Airport, a terminal not severely affected by nearby development (see below). There is no trend. The Pacific Ocean has softened any long-term spring warming in our region.