2022-2023 Official Winter Outlook
The Upper Peninsula is one of the most challenging places to predict long-range winter conditions. Considering we live above the 45th parallel we know it’ll be cold and snowy, but to what extreme?
There are several global circulations we can analyze to form a better picture of what to expect. Some include the El Nino Southern Oscillation or ENSO, the Pacific North American Oscillation or PNA, the North Atlantic Oscillation or NAO, and the Artic Oscillation. Each of these has positive and negative phases, which can result in specific global weather trends.
One index to monitor this winter is the Arctic Oscillation. It is the counterclockwise wind circulation around the arctic. In a negative phase, the wind flow is weaker allowing the Jetstream to shift farther south with blasts of cold air at times called the polar vortex. Currently, it’s in a positive phase. This is when the wind flow is stronger which keeps cold air outbreaks mainly in Canada. Some models show we start this winter in a positive phase and drop into a negative one. This setup allows for a few brief blasts of cold arctic air.
The main driving factor this year is Enso. Normally the trade winds blow warm sea surface water toward the western pacific. Currently, it’s in a moderate cold phase you know this as the La Nina! That’s when strong easterly winds push colder than average sea surface water farther along the equator. This affects the pressure systems around the world. Conditions become stormy off the east coast of Asia, a ridge of high-pressure forms in the Eastern Pacific Ocean, the Aleutian low is weaker and a prominent area of low-pressure forms in Canada. These features cause the Polar Jetstream to shift along the northern states into the Midwest during the winter.
We’ve had three La Nina cycles in the last 30 years. The first cycle was in the winter of 1998 to 2000, and the second cycle was from 2010 to 2012. Finally, 2020 to now, which puts us in the third year of La Nina conditions.
From 2020 to 2021 it was generally warmer with below-normal snowfall. Only a few spots reached over 200″ of snow in the Keweenaw. Winter was drier due to the influences of the Pineapple Express. Here in the Upper Peninsula, this led to weak and low moisture clipper systems moving through. In mid-February ice cover briefly reached 90% in western Lake Superior.
Last winter, was the opposite it was cooler than normal with above-normal snowfall. Several areas from the Keweenaw and near Lake Superior exceeded 300″ of snow. Ice cover reached 90-95% along the shoreline of Lake Superior for a brief period in late February. This shows La Nina years can be highly variable, indicating no clear-cut pattern.
Some seasonal models used during research for this outlook include the European Centre for Medium-Range Weather Forecasts (ECMWF), the Canadian Seasonal to Inter-annual Prediction System (CANSIPS), and NOAA’S Climate Forecast System (CFSv2). All three of those are predicting above-normal precipitation between December and February. When it comes to temperatures, most are trending with near-normal to below-normal conditions during winter.
Global circulations and seasonal model data only provide the most likely trend. Based on these features this winter a high-pressure ridge will remain in the pacific keeping the Polar Jetstream across the northern U.S. Systems will track north of the ridge, and dive south digging into the Northern Plains and Midwest. It’ll be drier and warmer in the southern states, while northern states will be cooler and wetter. Colder areas in the mountainous northwest will end up snowier. In the U.P. the trend puts us on the cusp of normal to slightly cooler temperatures with a few stints of colder air outbreaks, and a greater chance of above-normal precipitation or snowier conditions.
During La Nina years variations are more likely. Therefore, snow amounts come down to where storms are coming from, their moisture content, and interactions with Lake Superior and the topography. La Nina conditions are projected to turn neutral and end by early spring.
Before we wrap up one more climatic feature to monitor this year is the effects of the January 15th, 2022 Hunga Tunga submarine volcano in the South Pacific. This eruption caused an unprecedented amount of water vapor to be injected 36 miles into the stratosphere in the southern hemisphere. Recent research shows that water vapor is trapped within this layer. Why is this important? Water vapor absorbs heat causing a cooling effect in the stratosphere. It also reflects incoming solar radiation keeping the stratosphere cooler, but it prevents surface heat from escaping. Stratospheric cooling in the Southern Hemisphere could lead to warming in the Northern Hemisphere. This could impact the pressure circulations of the Polar Vortex and the North Atlantic Oscillation potentially causing more cold air outbreaks. It’s too early to tell the extent of the impact, if any, it will have in the Northern Hemisphere. However, it bodes watching.
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