The polar vortex may hamper holiday travel
Our first measurable snowfall arrived during our “full moon” cycle that began in early November. Many locations in the lower elevations reported about 6 inches of the white stuff. At Cliff’s station, he measured 8.8 inches compared to a November normal of 8.7 inches. It seems like we’re already off to a fast start for the winter of 2017-18.
At the Spokane International Airport, 7.2 inches of snow has been reported. In the outlying areas of North Idaho, our observer Dale in Rathdrum have seen about 16 inches of snow for this month. Spirit Lake, Athol and other locations away from Lake Coeur d’Alene have totals around 12-18 inches.
As of late last week, the mountain areas, to the delight of skiers and snowboarders, were reporting lots of new snow. At Silver Mountain, 43 inches has been measured with about 30 inches at Lookout Pass.
In Coeur d’Alene, the moisture total for 2017 will end up well above normal, despite having one of the driest summer seasons in recorded history. Cliff has measured, as of early Sunday, just over 32 inches of rain and melted snow since Jan. 1, 2017. The normal for an entire year is 26.77 inches.
The rest of November looks wet and windy across the Inland Northwest. Cliff and I see more snow, which will add to the above monthly average of 8.8 inches. However, a lot of the moisture that falls will also be in the form of rain, which is typical for this time of year. The higher elevations should also see some rain mixing in with the snow through the rest of November.
Based on the current forecasts, there is a chance for snow around the middle to the end of the week. As milder air pushes in from the south, the snow that does fall will change over to rain during the weekend.
For the Thanksgiving holiday weekend, it looks like a rain and snow event across the Inland Northwest. If you’re planning to do some traveling, make sure you have those snow tires on your car. The roadways will likely be very slick.
The Thanksgiving holiday weekend could turn into a nightmare for travelers along the East Coast. Conditions are setting up with a shift of the infamous “polar vortex” that may be joined by a strong storm to bring moderate to heavy rain, snow and strong winds to the northeastern portion of the country. To the south toward the Mid-Atlantic states and the Southeast, there will probably be a lot of rain and windy weather. Therefore, both the West Coast and East Coast may experience rain, snow and wind, while the center of the country is dry during the holiday period. Stay tuned.
Many of us have heard about this polar vortex. It started to become more familiar during the 2014 North American cold wave as extreme frigid temperatures were affecting parts of Canada, the north-central and upper eastern portions of the U.S. during an extended period through the late winter months of the 2013-14 season. Record lows were felt in those areas well into March of 2014.
This same polar vortex also brought our region the unbelievably frigid temperatures in January. From the 1st through the 17th, Coeur d’Alene’s high temperature was below the freezing mark. During that time, the normal high temperature during that time was only 25 degrees, or 11 degrees below normal. The average low at Cliff’s station the was only 12 degrees.
The polar vortex is a relatively large upper-level low pressure system consisting of large masses of cold, dense Arctic air that is located near the North Pole. There’s also a polar vortex at the South Pole. When the polar vortex is strong, the frigid cold air mass will often stay confined near the North Pole as the jet stream increases in strength. But, when the vortex weakens and splits into two or more vortices, the cold air will often push southward.
Most of the time, when the polar vortex moves southward, the strongest portions are near Baffin Island, Canada, an area just southwest of Greenland, and northeastern Siberia.
As I mentioned earlier, the polar vortex could become a major issue for travelers along the East Coast this Thanksgiving. Cliff and I think there is a possibility that this mass of frigid Arctic air may eventually “back up” over the western portions of the country. In other words, we may experience a round of very cold weather, perhaps as early as late December or January.
If the polar vortex does move over our region in late 2017 or early 2018, we don’t think it’s going to be as extreme as the one in early-to-mid January. Until then, it looks like an active weather pattern of rain and snow into December, which should great news for area skiers and snowboarders assuming the mountain areas see more snow than rain.
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Contact Randy Mann at randy@longrangeweather.com