Workshop: Stratospheric predictability and impact on the troposphere

Sudden stratospheric warming (SSW) events can have significant impacts on surface weather that can prevail for several weeks. However, not all SSW events have a surface impact, and the timing of this impact can vary strongly between SSW events. Mechanisms both in the lower stratosphere and in the troposphere have been suggested to be responsible for the distinct downward influence of different...

Accurate representation of the stratospheric circulation in numerical weather prediction models is important for tropospheric predictability on medium-range and seasonal timescales. However, operational forecast systems at the European Centre for Medium Range Weather Forecasts suffer from a number of stratospheric biases, two of which are highlighted in this talk: i) The cold polar tropopause...

Sudden stratospheric warmings (SSWs) are the largest instance of the wintertime polar stratosphere and constitute one of the clearest examples of stratosphere-troposphere coupling in both directions. They are preceded by anomalously high upward-propagating wave activity, whose sources are located in the troposphere. In turn, SSWs also impact the tropospheric circulation up to two months after...

Recent studies have proposed that regional Arctic sea-ice anomalies influence
planetary wave propagation into the stratosphere and so affect the strength and
location of the stratospheric polar vortex. The polar stratosphere, in turn, is
known to significantly influence polar and midlatitude tropospheric weather
patterns, including affecting the likelihood of cold-air outbreaks and...