There comes a point each winter when it is simply not possible to get really cold anymore.
Here in the Pacific Northwest, we are now crossing that line.
The figure below shows observed temperatures at SeaTac Airport so far this year as well as the daily record highs (red lines) and lows (blue lines) for the entire year. The brown band shows the average daily range throughout the year
Our temperatures so far this year have been quite normal, with warmer and cooler days.
But now look at the cold records. In January, record temperatures have dropped below ten degrees on many occasions. But past the first few days in February, there is an abrupt jump to warmer temperature records, with record lows never getting below 15F.
By early March, we never get below roughly 25F.
East of the Cascades at Yakima Airport, the situation is similar, except that the temperatures are much colder. After early February, sub-zero temperatures are history!
The key driver of the transition to warmer temperatures is that the sun is getting stronger and days are getting longer. You can see this in the plot of solar radiation reaching the top of the atmosphere over the year (below).
The sun now is about the same as it was in early to mid-November.
Talking about warmth, according to the highly accurate weather.com prediction, tomorrow through Friday should rise to near 60F at SeaTac.
But if you are willing to take a short drive, you may be able to experience 70F!
Where? In the western foothills of the Cascade!
High pressure has built over our region and will be in place overnight (see the upper level map--at 500 hPa pressure..about 18,000 ft for tomorrow morning). High pressure results in warm temperatures aloft.
Tomorrow, low-level easterly (from the east) winds will develop that produce sinking on the western slopes of the Cascades, producing additional warming by compression.
As a result, there will be a band of uber-warm temperatures on the slopes in areas such as North Bend. A UW model temperature prediction at 1 PM shows the warm zone.
A similar, if not stronger, warm zone will be apparent on Thursday (see below), with powerful warming on the western side of the Olympics tomorrow.
There are a lot of weather enthusiasts/weather chasers in our area. Will one of you take a hike up Tiger Mountain or Mount Si tomorrow, making temperature measurements every few hundred feet?
I will add it to this blog if you give me the information!
Appreciate the forecast insights. Those western Cascade slopes sound like the perfect spot for a sunny winter hike!
ReplyDeleteI live on Tiger Mountain. Approximately 900ft.
ReplyDeleteExterior sensor on the heat pump says 49. We’re all quite toasty in our winter sleepwear this morning!
When will the cold end in Ukraine this year?
ReplyDeleteWhat I want to know is, when will the war end? Putin is escalating with drones in Europe. He's very dangerous. If only they had Gorbachev back...
DeleteFriend sent picture of frozen Neris river from vilnuis lithuania froze last 20 years ago. Global warming only on the west coast and at the seattle times
ReplyDeleteA local weather event is not an indicator of climate change. That's not how it works.
DeleteSigh, there goes the ski season. 61 degrees @ 1100'
ReplyDeleteOn the central Oregon coast this afternoon it has reached 70 degrees at the tide station over the water with no east winds causing compressional warming. Low this morning with clear skies was 51 degrees!
ReplyDeleteLowland snow in the Western Washington is often accompanied by weather conditions that allow cold air to sink out of the Fraser River Gap and slide down the cascade crest; any chances?
ReplyDeleteWhat is the status of the La Niña? It seems more like El Niño. And what happened to the 90 day outlook being cooler and wetter than normal?
ReplyDeleteI can't believe we're talking about high temperatures in the 60s and 70s in Western Washington in early February. Simply incredible!
ReplyDeleteIn the PNW, even when it's not cold, it's still cold. It never actually warms up and stays warm. I think that is due to 1 - the terrain, and 2 - the surface cover. The entire surface is covered by either of 2 choices - cold water or forest. Neither absorb or retain heat.
ReplyDeleteCan you keep us apprised of the snowpack situation? Wondering if we are going to have a drought this summer.
ReplyDeleteI do believe it got down to 6 degrees when I lived in Seattle in February 1989, on the 3rd or 4th I think.
ReplyDelete