Above-average temperatures possible next week

Snow cover expected to go down next week due to warmer temperatures
Above-average temperatures possible next week

Coming off the 12th-coldest November on record in Madison and last winter’s bitter cold, a change in the large-scale weather pattern over the continental U.S. will bring a prolonged time period of average to above-average temperatures to the Madison area.

The overall pattern has recently consisted of a large “ridge” over the western U.S. and a large “trough” over the eastern U.S. This has led to both the significant drought in California and the persistent cold over the eastern U.S.

This pattern essentially means the upper air flow or jet stream has been far to the north in the west, while diving far to the south over the east, allowing Arctic air to flood across the eastern half of the country repeatedly.

Two of the factors that influence this pattern are known as the Arctic Oscillation and the North Atlantic Oscillation. Over the past year, these have largely been negative values, which lead to the pattern described above.

Over the next two weeks, these are forecast to shift into positive territory, which would lead to a “flat” jet stream pattern and generally average temperatures with a good chance of above-average temperatures, especially next week.

The current forecast includes mostly dry conditions and temperatures near or above average for the next week, which means snow cover will also be diminishing, leading to warmer temperatures as well.