For my Ph.D. research with Daniel Keyser and Lance Bosart, I have investigated the large-scale flow response to recurving and extratropically transitioning TCs in the western North Pacific from climatological, composite analysis, and case study perspectives. In particular, I have explored how recurving western North Pacific TCs can serve as precursors to extreme weather events and reductions in model forecast skill over North America.
A composite analysis of
292 western North Pacific TCs reveals that as a TC recurves, its
divergent outflow interacts with the midlatitude jet stream/waveguide
such that a Rossby wave train amplifies and disperses downstream
across the North Pacific into North America. A key finding of my
Ph.D. research is that recurving western North Pacific TCs are
associated with a characteristic downstream flow response: a trough
typically becomes established over the western U.S. three to five
days after western North Pacific TC recurvature. The strength of the
TC-jet stream interaction is found to be a key predictor of the
amplitude of the Rossby wave response and the potential for the
resulting Rossby wave train to reach North America and induce
high-impact weather there. Results of my research also suggest that
insufficient model representation of the diabatically driven
divergent outflow associated with recurving TCs is a critical source
of model forecast error often noted downstream of recurving TCs.
Recent
presentations
Mar
2011
Reduced
predictability and extreme weather events over North America
following the recurvature of western North Pacific tropical cyclones.
15th Cyclone Workshop, Pacific Grove, CA. pdf
Jan
2011
The
observed extratropical flow response to recurving western North
Pacific tropical cyclones.
23rd Conference on Climate Variability and Change/91st American
Meteorological Society Annual Meeting, Seattle, WA. pdf
Nov
2010
High-impact
weather and reduced predictability over the United States associated
with the recurvature of western North Pacific TC Malakas (2010). 12th
Annual Northeast Regional Operational Workshop (NROW), Albany, NY.
pdf