With these arctic blasts becoming less common, older folks are forgetting how common they once were, and younger folks simply lack the first-hand memory. Cliff Mass Weather and Climate Blog: Are Cold Waves Increasing Under Global Warming? The Answer is Clearly No. "The U.S. Environmental Protection Agency did a study of the trend of cold wave days from 1948 to 2015. The found very few locations where cold waves were becoming more frequent, but lots of locations in the western U.S. and the East Coast where cold waves were become less frequent, with the West Coast showing a huge decline of cold waves (see below)."
Young people today must think temperature was always like Lake Wobegon (the daily average) and hurricanes were always mild. Now you can see we are getting extreme variations on a daily basis, since it is never average, even the cold today is due to climate change, right? In truth is the jet stream was always fickle
Hummm, looks like Global Warming is a coastal effect: Source: State of the climate: How the world warmed in 2018 | Carbon Brief A number of records for the Earth’s climate were set in 2018: It was the warmest year on record for ocean heat content, which increased markedly between 2017 and 2018. It was the fourth warmest year on record for surface temperature. It was the sixth warmest year in the lower troposphere – the lower part of the atmosphere. Greenhouse gas concentrations reached record levels for CO2, methane, and nitrous oxide. Sea ice was well below the long-term average at both poles for most of the year. The summer Arctic sea ice minimum was the sixth lowest since records began in the late 1970s. Nice summary that helps explain the coastal warming. Bob Wilson
Yes, there has always been variability with the jet stream. However, the jet stream is slowing as the temperature gradient betrween the North Pole and the air around it has become less. This has led to wilder swings of the jet stream. Similar to a spinning top. As it slows it gets less stable.
The question should really be if wide temperature swings are increasing? Thursday was 15F in Philly. Sunday is forecasted to be in the 50's. I remember cold winters. I remember mild ones. I don't recall swinging ones like the past few.
Less stable is obvious... with both weather patterns and oil market. In other words, emphasis on the word "change".
According to the Climate Science Special Report (CSSR) for the Fourth National Climate Assessment (NCA4), temperature extremes are actually becoming less severe over the past century, in the U.S. anyway, especially with regard to cold temperature extremes. It is my experience as a former National Weather Service operational meteorologist (retired in 2012) that there tends to be decreases in the amplitude of upper level flow ("jet stream") as the temperature gradient between the poles and tropics decreases (e.g., typical of mid to late summer). Highly amplified upper-level toughs are the cause of extreme cold waves. That being said, we are entering uncharted territory as the poles continue to warm relatively faster than the tropics or subtropics.
Our winter finally showed up overnight. A few inches during some obscure ball game last night, then 5-6" on my Prius this morning. This view is after a morning appointment, where I was the first patient to actually check in. Had only one optometric test scheduled, but plenty of cancellations opened up their schedule and allowed me to get the full exam. Lots of articulated transit buses were jackknifed on hills and blocking arterials, but I had little issue getting around on X-Ice 3 snow tires. The snow on the spouse's car is not the full dump. It was cleared of 2.5" last night to put tarps over the windows, to reduce morning scraping. She then elected to take the garaged Subaru for her morning appointment, but that got cancelled by the other side. So she shoveled the garage entrance instead.
Yeah it got cold here, well: cold for us. Just a dusting of snow so far, but supposed to stay cold for a while. I put a second foam tube on the lower grill just now, 100% lower block. It's off to the dentist for me, in about an hour.
I think our snow is from our moisture colliding with your cold Fraser River air from the interior. The moisture is mostly freezing out and falling before it gets to you. Even our ski hills received less than the lowlands. Glad mine was just optometry.
This is what that looks like: There was just one like this at my nearest arterial intersection this morning (and still no tow truck two hours later). But attempting an errand on the other side of the freeway, there were three more like this on a single hill, two uphill and one downhill, essentially blocking the full arterial width. Plus two more non-articulated busses parked below, unable to proceed up the blocked hill. And probably unauthorized to take detours around the blockage, if my weekend transit experience at a congested event is any guide. At least I am allowed to take alternate routes of my choosing.
