Over the past week, several Seattle Times articles have made headlines that Western Washington is experiencing a “false spring.”
Seattle is almost noon today
The Times also added that ” The Seattle area is known because of what some locals call “false spring”, which happens every year around February or March. The weather is so lovely it makes us think winter is over. And then it started to rain again. “
Furthermore, some environmental groups are warning that fake springs are threatening wildlife and fake springs are the result of climate change (earth warming).
So for those of you worried about “fake spring” threatlet me note that Seattle is NOT known for fake springs, that we have some of the longest springs in the country and there is NO evidence that a warming planet is producing many “fake springs” ” than in our area.
Spring 101
Everyone knows that astronomical spring lasts from about March 21 to June 21. But meteorological spring can be very different, depending on your definition.
Here in Washington State, I have suggested that meteorological spring usually begins around the third week of February (yes… next week!).
My reason? The likelihood of strong Pacific cyclones, atmospheric river flooding, and lowland snow falls rapidly afterward. The sun is getting stronger now… and the days are getting longer… so when there are clouds and storms, the temperature will rise in the 50s and even 60s.
This is normal and typical for our area.
Take a look at the average high (red line) and record the daily high (yellow line) at Seattle-Tacoma Airport (below). Seattle has a slow steady warming from January 1 to mid-July–so our youth lasts a long time. And you’ll notice that the record highs almost every day in February are in the mid to over 60s. Nothing is strange.
Sunday’s high temperature in Seattle? 57F. Above normal but not significant.
Meteorologists at the Iowa Environmental Mesonet (IEM) have come up with their own approach to determining the beginning of spring: they find the 91-day period of the coldest days of the year (which they call winter). , with the next date being the start of spring. (see map below). Their analysis showed the beginning of spring in western Washington to be February 23-25, dates that were consistent with my analysis based on storms and snow. Spring ends later in the eastern United States
So why does spring start so early in western Washington?
I believe the answer relies on the mild Pacific Ocean (around 50F year round) and cold blocking by the Rockies and Cascades.
It is very difficult for western Washington to really calm down. The shore currents bring mild air over the Pacific, and the Rockies/Cascades prevent cold air from the mainland from reaching us – keeping winter real in the bay. Soil temperatures have never been this cold and we rarely have snow cover at real depths.
So if we’re relatively mild year-round, as we head into February, with stronger sunshine, temperatures could warm to “springtime” levels if we have clouds. Nothing unusual. No fake spring.
Record high temperatures in spring are on the rise?
There are some stories that show that “fake springs” are getting more and more frequent or warmer. Is this right? Are we seeing more record high temperatures in spring?
University of Alabama Professor John Christy and Alabama State Climatologist put together the numbers (see below). There was no trend of increasing daily high temperatures over Oregon and Washington from January to March. So there’s no sign of a growing “pseudo-spring” threat.
Key point
There is no false spring happening around here. The false springs do not increase due to global warming.
Perhaps it was a slow reporting day at the Seattle Times and a few other media outlets repeated their stories.
