Our research is varied and encompasses problems within synoptic and dynamic meteorology. More specifically, we study tropical cyclones, severe local storms, and their impacts from the mesoscale to the climate-scale. We primarily utilize numerical models to test hypotheses relating to the development, evolution, and underlying predictability of these phenomena. Examples of recent and ongoing research include, but are not necessarily limited to, the following:
|Warm-Core Vortex Development Associated with Convectively-Generated Mesolows
On 8 May 2009, an intense warm-core mesoscale convective vortex (MCV) developed over a period of several hours on the northern end of a strong squall line (termed a derecho) in the central United States. In conjunction with collaborators at NCAR and SUNY-Albany, we aim to describe the antecedent conditions associated with this development, understand how the vortex developed, and gain insight into the predictability and rarity of such features.
|Forecasting Convective Initiation
Convective initiation, or CI, poses a unique challenge to numerical models. Accurately predicting the timing and location of CI events requires the accurate simulation of interconnected physical processes on multiple scales from the misoscale to the synoptic-scale. Ongoing research aims to examine CI forecast skill and fundamental modeling system limitations hindering the skillful prediction of CI as manifest within sub-kilometer horizontal grid spacing simulations of observed warm-season CI events.
|The Extratropical Transition of Tropical Cyclones
As tropical cyclones enter the mid-latitudes, they transform from an initially symmetric, warm-core tropical cyclone into an asymmetric, generally cold-core extratropical cyclone. Ongoing research aims to address the erosion of the inner core warm potential temperature anomaly during the extratropical transition process. With colleagues at CIMSS at UW-Madison, research aimed at improving automated satellite-based intensity estimates of tropical cyclone intensity during extratropical transition will commence in 2013.
|Extreme Precipitation Associated With Tropical Storm Fay (2008)
In 2008, Tropical Storm Fay produced extreme rainfall (>20") across large portions of North Florida and Southwest Georgia. With colleagues at the National Weather Service in Tallahassee, FL, we seek to quantify the factors responsible for the placement and formation of the rain bands responsible for this rainfall. We are also exploring the skill of a convective-resolving ensemble of forecasts of Fay's rainfall and how forecasters interpret ensemble output when making forecasts for localized extreme meteorological events.
|African Easterly Jet Impacts Upon Tropical Cyclogenesis
Motivated in part by the PREDICT field campaign during Summer and Fall 2010, we seek to quantify the impacts of the African easterly jet (AEJ) upon developing and non-developing tropical disturbances. We utilize a combination of composite data analyses, idealized numerical simulations of jet-disturbance interactions, and real-data numerical simulations of observed genesis events to better understand the nature of the AEJ's impact, if any, upon the tropical cyclogenesis process.
We actively welcome new collaboration with other scientists and potential graduate students on topics of mutual interest. A listing of relevant publications, both peer-reviewed and non-refereed, is included below. Where available, clicking on the title of each article will take you to an Adobe PDF copy of the article.
- Evans, C. and R. E. Hart, 2013: The thermodynamic evolution of an extratropically transitioning tropical cyclone. Mon. Wea. Rev., in revision.
- Evans, C., D. F. Van Dyke, and T. Lericos, 2013: How do forecasters utilize output from a convection-permitting ensemble forecast system? Case study of a high-impact precipitation event. Wea. Forecasting, in review.
- Evans, C., M. L. Weisman, and L. F. Bosart, 2013: Development of an intense, warm-core mesoscale vortex associated with the 8 May 2009 "super derecho" convective event. Mon. Wea. Rev., in review.
- Weisman, M. L., C. Evans, and L. F. Bosart, 2013: The 8 May 2009 super derecho: analysis of a realtime explicit convective forecast. Wea. Forec., in press.
- Evans, C., and coauthors, 2012: The PRE-Depression Investigation of Cloud-systems in the Tropics field campaign: perspectives of early career scientists. Bull. Amer. Meteor. Soc., 93, 173-187.
- Evans, C., R. S. Schumacher, and T. J. Galarneau, Jr., 2011: Sensitivity of the overland reintensification of Tropical Cyclone Erin (2007) to near-surface soil moisture characteristics. Mon. Wea. Rev., 139, 3848-3870.
- Evans, C. and R. E. Hart, 2008: Analysis of the wind field evolution associated with the extratropical transition of Bonnie (1998). Mon. Wea. Rev., 136, 2047-2065.
- Hart, R. E., J. L. Evans, and C. Evans, 2006: Synoptic composites of the extratropical transition lifecycle of North Atlantic tropical cyclones: factors determining post-transition evolution. Mon. Wea. Rev., 134, 553-578.
- Weisman, M. L., C. Evans, and L. F. Bosart, 2011: Conference Notebook: "The 8 May 2009 'Super Derecho': Analysis of a 3-km Real-Time Forecast." Bull. Amer. Meteor. Soc., 92, 18-19.
- Evans, A. C., 2009: The thermodynamic evolution of recurving tropical cyclone Bonnie (1998). Ph.D. Dissertation, Florida State University, 131pp.
- Evans, A. C., 2006: Dynamics of the wind field expansion associated with extratropically transitioning tropical cyclones. M.S. Thesis, Florida State University, 111pp.
- Evans, C., 2004: Quantification of cloud and inversion properties utilizing the GPS radio occultation technique. 2004 Amer. Meteor. Soc. Father James B. Macelwane Award-Winning Paper, Unpublished manuscript, 50pp.
A listing of and citation information for many of my refereed and non-refereed publications may be found on my Google Scholar page.
Bulletins and Reports
- UCAR AtmosNews, 2012: Derecho in D.C.: Science and Surprise
- UCAR Magazine, 2011: Four Questions: Clark Evans, NCAR.
- UCAR Staff Notes, 2010: A super-sized storm.
- ASP Spotlight, 2010: Understanding the thermal evolution and impacts of extratropically transitioning tropical storms.