First, we had uncommon chilly, then a freezing-rain ice storm, then heavy rain, after which uncommon heat.
However the climate gods should not via with us.
A strong storm might develop off our coast on Tuesday.
In such circumstances throughout historical days, people would ask themselves why the gods had been offended and ask their clergymen to intercede with an applicable prayer or sacrifice. In the present day, our trendy climate clergymen typically blame such storminess on sins of carbon emission and predict doom with out the correct response.
Human nature hasn’t modified. However on this weblog, let’s follow the science.
A Profound Change in Atmospheric Circulation
Let me present you the higher stage (500 hPa, about 18,000 ft) climate maps from three days in the past (Wednesday at 10 AM) and yesterday on the identical time.
A profound change. On Wednesday, a deep trough of low strain was inland whereas a ridge of low strain was offshore, leading to a powerful, chilly airstream from the northwest.
Wednesday
By yesterday, the ridge of excessive strain had shifted inland and south, whereas low strain has amplified over the Gulf of Alaska. The result’s a powerful, heat, moist move from the southwest.
We will likely be on this sample for fairly a very long time.
Saturday
The ensuing temperature change in western Washington has been exceptional (see temperatures at SEATAC under, purple is the traditional excessive, cyan the traditional low). We had been typically cooler than regular via 21 December after which the underside fell out. After which yesterday we warmed to effectively above regular.
This warming was accompanied by very heavy rain that led to native road flooding. The precipitation over the previous 36h has been exceptional (see under), with some areas getting over 5 inches. Over an inch over the Puget Sound lowlands.
The poor ice had no probability. Not less than the airports can function usually once more. And lots of of our rivers have crammed to bankful.
The Approaching Storm
Each American and European fashions recommend a significant low-pressure system will develop off our coast Tuesday morning, with very low strain.
Right here is the UW mannequin’s prediction of the ocean stage strain at 10 AM Tuesday. A deep 971 hPa low is off the WA coast, with an intense strain change (gradient) alongside the Oregon Coast. Which means sturdy winds.
The European Heart mannequin on the identical time has a 970 hPa low in a barely completely different place. There may be going to be a significant low off our coast. The query is the place it can go.
I’m assured now that the Oregon coast will get a very good blow.
The storm will then transfer east and north, however there may be nonetheless substantial uncertainty relating to its influence on the inside of western Washington. However 20-40 knots round Puget Sound just isn’t unreasonable.
I’ll depart that evaluation for one more weblog tomorrow, so keep tuned. However you may contemplate making an providing in your vacation fire.
