Actions for Exploring the Sensitivity of Convection Initiation to Grid Spacing in Convection-Allowing NAM Simulations
Exploring the Sensitivity of Convection Initiation to Grid Spacing in Convection-Allowing NAM Simulations
- Author
- Dennis, Eli
- Published
- [University Park, Pennsylvania] : Pennsylvania State University, 2017.
- Physical Description
- 1 electronic document
- Additional Creators
- Richardson, Yvette, 1968-
Access Online
- etda.libraries.psu.edu , Connect to this object online.
- Graduate Program
- Restrictions on Access
- Open Access.
- Summary
- Forecasting the timing and location of convection initiation (CI) often is a difficult problem that, if done inaccurately, can affect predictions of storm motion, storm mode, and ultimately storm impact. As numerical weather prediction (NWP) models use increasingly finer grid spacing, processes involved in CI might be expected to be better represented, leading to increased forecast ability. In this study, we compare observations to rare 5-minute model output from the operational North American Mesoscale Forecast System (NAM) at both 4- and 1.33-km grid spacing. Two severe weather cases (28 April 2014 and 6 May 2015) are simulated, and compared for evidence of increased forecast performance with decreased horizontal grid spacing. The results show similar convective environments between the two nests, especially for strongly forced events. The dryline dynamics are explored, and limitations related to the model setup are exposed. Model artifacts related to physics parameterizations and the numerical framework are unveiled, and they contributed directly to changes in the operational NAM that were implemented officially in March 2017.
- Other Subject(s)
- Genre(s)
- Dissertation Note
- M.S. Pennsylvania State University 2017.
- Technical Details
- The full text of the dissertation is available as an Adobe Acrobat .pdf file ; Adobe Acrobat Reader required to view the file.
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