Date of Award




Document Type

Master's Thesis

Degree Name

Master of Science (MS)


Department of Atmospheric and Environmental Sciences

Content Description

1 online resource (ii, xiii, 107 pages) : illustrations (some color), color maps.

Dissertation/Thesis Chair

Andrea L Lang


Blocking, Ellipse, Predictability, SSW, Stratosphere, Whirlwinds, Polar vortex, Atmospheric circulation, Stratospheric circulation, Stratospheric winds

Subject Categories

Atmospheric Sciences


Recent analyses of numerical weather prediction models have shown that stratospheric regime changes (e.g. strong and weak vortex events) are not skillfully predicted at medium-range lead times. Motivated by these recent analyses, this thesis investigates the sources of variability in stratospheric forecast skill amongst several operational models initiated at different lead times prior to the 7 January 2013 sudden stratospheric warming (SSW). This study extends upon a previous analysis by the Stratospheric Network for the Assessment of Predictability (SNAP), which concluded that a change in forecast lead-time from 15 to 10 days increased model skill in predicting the 2013 SSW by roughly 50 percent. The sources of such variability in predictive skill are investigated further in this thesis.