By Montserrat Arqué
25 Oct 2023, 3:30 PM EDT
Everything seems to indicate that the time has come to dust off the thick jackets and coats, since in some parts of the United States there will be changes in temperature, so the first ravages of this season’s cold weather may soon be felt.
Calculations made by various meteorologists warn that starting at the end of this week and in some cities or states, at the end of October, when extreme cold will begin to be felt due to pressure anomalies that will modify the shape of the polar vortex.
Let us remember that during this season, the weather and the polar vortex have a close relationship. According to the National Oceanic and Atmospheric Administration (NOAA), the polar vortex is a large area of low pressure and cold air surrounding the Earth’s poles. It always exists near the polar areas, but weakens in the summer and intensifies in the winter.
The term “vortex” refers to the counterclockwise rotation that allows cold air to stay close to the poles. Often during the Northern Hemisphere winter, the polar vortex expands, sending cold air southward along with the jet stream. This happens regularly during the winter and is mostly associated with extreme cold waves coming from the Arctic in the US.
A strong/stable polar vortex generally means a strong polar circulation and jet stream. This holds the colder air back toward the Arctic Circle, creating milder conditions for most of the country.
But a weak or disturbed polar vortex creates a weak jet stream pattern. As a result, it is more difficult for it to contain cold air, escaping from the polar regions towards our territory, which would cause a colder winter with more snow.
The polar vortex is currently of normal size and has a growing cold core over the polar regions.
The National Weather Service (NWS) indicated that a winter storm will affect the northwest of the United States and some parts of the northern plains from the night of Tuesday, October 24 to Thursday, the 26th.
Likewise, the NWS is forecasting heavy snowfall, so between four and thirteen inches of snow is likely depending on the altitude in the area.
The main affected regions will be Idaho and Montana, as well as the Oregon Cascades, as temperatures are expected to hover below 30°F. The storm will also be accompanied by winds gusting to 35 mph in central, north central and southwestern Montana.
Likewise, it also issued an alert regarding a wave of cold air and humidity that will spread from Washington and Oregon, through much of Montana this Tuesday. Several high-altitude mountain passes, including Stevens Pass, Snoqualmie Pass and Stampede Pass in Washington’s Cascade Range, could be affected by heavy snowfall.
Keep reading:
* New York: the weather for today, Wednesday, October 25
* The “El Niño” phenomenon will cause heavy snowfall in New York, New Jersey and at least 10 other states
* The damage to the climate that “El Niño” could cause in the United States during the winter