October 7, 2024
Dr. Judah Cohen from Atmospheric and Environmental Research (AER) embarked on
an experimental process of regular research, review, and analysis of the Arctic
Oscillation (AO) and Polar Vortex (PV). This analysis is intended to provide researchers
and practitioners real-time insights on one of North America’s and Europe’s leading
drivers for extreme and persistent temperature patterns.
During the winter schedule the blog is updated once every week. Snow accumulation
forecasts replace precipitation forecasts. Also, there is renewed emphasis on ice and
snow boundary conditions and their influence on hemispheric weather. In late Spring,
we transition to a spring/summer schedule, which is once every two weeks. Snow
accumulation forecasts will be replaced by precipitation forecasts. Also, there will be
less emphasis on ice and snow boundary conditions and their influence on hemispheric
weather.
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The AO/PV blog is partially supported by NSF grant AGS: 1657748
Summary
- The Arctic Oscillation (AO) is currently negative and is predicted to trend positive the next two weeks as pressure/geopotential height anomalies across the Arctic are currently mostly positive and are predicted to become increasingly mixed to negative over the next two weeks. The North Atlantic Oscillation (NAO) is currently negative with strongly positive pressure/geopotential height anomalies across Greenland and the NAO is predicted to also trend positive the next two weeks as pressure/geopotential height anomalies are predicted to remain positive to neutral across Greenland.
- This week ridging/positive geopotential height anomalies across Greenland will support troughing/negative eopotential height anomalies centered on Western Europe. Then next week as troughing overspreads Greenland, ridging will overspread Europe. This pattern will support this week normal to below normal temperatures across Northern and Western Europe including the United Kingdom (UK) while induced southwesterly flow will support normal to above normal temperatures across Southeastern Europe. Then next week normal to above normal temperatures will become more widespread across Europe.
- The general pattern predicted for Asia the next two weeks is ridging/positive geopotential height anomalies centered over the Urals forcing troughing/negative geopotential height anomalies across Central Asia with more ridging centered across East Asia. This pattern favors this week normal to above normal temperatures across much of Asia with normal to below normal temperatures limited to Siberia and Kazakhstan, however next week the colder temperatures are predicted to spread into East Asia.
- This general predicted pattern across North America is troughing/negative geopotential height anomalies in the Gulf of Alaska forcing ridging/positive geopotential height anomalies across the interior of North America. This pattern favors widespread normal to above normal across much of Canda and the United States (US) with normal to below normal temperatures limited to Southeastern Canada and the US East Coast.
- In the Impacts section I discuss the polar vortex and what might be its next move and its potential influence on the weather in the Northern Hemisphere (NH).