Notes from 5/9/2013 CSTAR TC Boundary/QPF conference call
- Barrett Smith (RAH)
- Gary Lackmann (NCSU)
- Jordan Dale (NCSU)
- Jonathan Blaes (RAH)
- Jordan Dale continues to investigate the role of a Predecessor Rain Event (PRE) on the development of cold air damming, frontal positioning, and eventual track/rainfall associated with Hurricane Ernesto.
- Jordan is using potential vorticity to assess the strength of the PRE in the RUC analysis and WRF control run. The initial findings indicate that the WRF simulation of the PRE was too weak, compared to RUC analysis (which also showed PV slightly further to the south). This may explain why the WRF simulations have done a poor job in simulating the strength of the CAD.
- The PV analysis shows the two main PV features with Ernesto and a synoptic scale trough over the Ohio Valley merging as the Ernesto moves inland and undergoes extra-tropical transition. This likely explains the northwestward turn in the track of Ernesto as it moved north across Virginia.
- It was hypothesized that the PV generated from latent heating in the PRE may have had an impact on the track of Ernesto by altering the larger scale flow. This can be studied by inverting the PV with the PRE to see how to large scale flow changes. At the moment Jordan is not sure if there will be time to tackle this before his thesis defense.
- Analysis of relative humidity fields suggests the WRF simulation were too moist at low levels, which would also have limited the amount of stabilization and CAD development.
- To build upon on the findings that the WRF under-represented the CAD, Jordan plans to rerun the WRF model and reduce the relative humidity in hopes of strengthening the CAD. This is in progress at the moment.
- Jordan plans to defend his thesis in late June or early July.