polar-vortex_gph-anomalies_20240116.png

Differences from average atmospheric thickness (standardized geopotential height anomalies) in the column of air over the Arctic from the troposphere to the stratosphere since mid November 2023. The lower stratosphere and upper troposphere have been most strongly connected for the last several days as denoted by the high thickness anomalies (orange areas, suggesting a weaker-than-average polar vortex). Based on the Global Forecast System (GFS) model, that connection may last for a few more days before weakening as indicated by the forecasted low tropospheric thickness anomalies (purple area) that do not extend into the stratosphere. NOAA Climate.gov image adapted from original by Laura Ciasto.