12:25 PM | *Incredible cold in Siberia and some impressive snow all around the Northern Hemisphere*
Paul Dorian
Huge snowballs formed earlier this month on a beach on Siberia's Yamal Peninsula just above the Arctic Circle indicative of some very cold air
Overview
While we’ve been enjoying warmer-than-normal weather in the US and Canada in recent weeks, much of Europe and Asia have suffered through sustained bitter cold. In fact, it is likely to get even worse for them later this week as some computer forecast models suggest temperatures could fall an astonishing 50 degrees below normal in Siberia - the coldest air yet this season. In addition to the cold, the month of November began with well above normal snow cover across the Northern Hemisphere with more snow than normal across both sides of the North Pole. All of this cold and snow around the Northern Hemisphere suggests it could indeed turn out to be quite interesting around here in the eastern US between Thanksgiving and Christmas.
Recent GFS model forecast of temperature anomalies for late this week showing temperatures more than 50 degrees below normal in parts of Siberia; map courtesy Weather Bell Analytics at weatherbell.com (Dr. Ryan Maue)
Discussion
For the first half of November, temperatures across much of North America have averaged well above normal. Here in the I-95 corridor, we have been averaging slightly warmer-than-normal temperatures despite some occasional outbreaks of colder-than-normal air. On the other side of the North Pole; however, sustained bitter cold conditions have dominated and are likely to get worse before they can get better. In parts of Siberia, for example, some computer model forecasts suggest temperatures could fall an incredible 50 degrees below normal later this week.
Snowcover at the beginning of November with some impressive totals; data courtesy Rutgers Snow Lab
Going into the month of November snowpack grew to well above normal amounts in Eurasia with an extension farther west into Europe in recent days. For example, Stockholm, Sweden had more snow last Thursday than on any other November day since records began there in 1905. The conditions that have led to the high snowpack across Eurasia actually resulted in an unusual formation of giant-sized snowballs (top image) along the coastline of the Yamal Peninsula region of NW Siberia. The frozen balls measured almost three feet across and stretched across an 11-mile section of coastline earlier this month near the village of Nyda which sits above the Arctic Circle, according to Russian media. A village administrator told The Siberian Times that the snowballs formed in late October when the Gulf of Ob rose up onto land and covered the beach in ice. As the water retreated, the remaining ice chunks rolled over creating snowballs which grew and grew in size until they hit gigantic proportions.
Temperature anomaly pattern for the first half of November across North America with above-normal conditions across much of the area; map courtesy Weather Bell Analytics at weatherbell.com (Dr. Ryan Maue)
Not only was snowpack quite high across Eurasia at the beginning of this month (3rd highest in the last 49 years), but the Northern Hemisphere as a whole had the third highest snow cover at the beginning of November compared to anytime since 1967. North America began November with its 2nd highest snow cover recorded in the last 49 years. Greenland’s surface has been gaining about 3.5 billion tons of ice per day since the first of September which is about 50% above normal. On the other hand, here in the US, snow is nearly non-existent at the current time. In fact, a measly 0.8% of the nation was covered with snow as of Saturday, November 12th which is considerably lower than the 14.9% of last year at this same time and the 19.5% in 2014.
Temperature anomaly pattern for the first half of November across Asia with below-normal conditions across much of the area; map courtesy Weather Bell Analytics at weatherbell.com (Dr. Ryan Maue)
Temperature anomaly pattern for the first half of November across Europe with below-normal conditions across much of the area; map courtesy Weather Bell Analytics at weatherbell.com (Dr. Ryan Maue)
AO index and possible signs of cold here
Greenland and Siberia are important cold air sources for the eastern US during the winter season and sustained cold air in those areas - especially early in the season - can certainly send us warning signals about the upcoming winter around here. Indeed, one of the factors in our colder-than-normal winter outlook had to do with the high snow pack across Siberia that began to form during the month of October.
Arctic Oscillation (AO) index with current and past values in black and forecasted values in red - a sharp turn into negative territory is predicted (circled area); courtesy NOAA
One index that meteorologists use to track pressure patterns across the northern latitudes in called the Arctic Oscillation and when it turns negative for a sustained period of time there are increased chances for sustained cold air outbreaks into the eastern US. In fact, the latest forecast for the AO index suggests a big drop into negative territory over the next couple of weeks. As a result, it appears that we’ll begin to experience more frequent cold air outbreaks as we head into next week (Thanksgiving week) and the month of December is quite likely to be colder-than-normal in the Mid-Atlantic region. One such cold air outbreak will arrive in the Northeast US this weekend and it is likely to result in the first widespread Great Lakes snow event.
Meteorologist Paul Dorian
Vencore, Inc.