Monthly Archives: February 2012

New pub

I am a co-author on a paper in this month’s issue of Monthly Weather Review, entitled Impact of the Environmental Low-Level Wind Profile on Ensemble Forecasts of the 4 May 2007 Greensburg, Kansas, Tornadic Storm and Associated Mesocyclones. Dan ran a set of NCOMMAS ensemble forecasts of the Greensburg storm, assimilating reflectivity and velocity data from the Dodge City, Kansas WSR-88D (KDDC). He varied both the 0-3 km AGL velocity profile in the initial model environment to reflect the onset of a low-level jet, and also cut loose forecasts at different times to see how the vorticity swaths changed. Not surprisingly, the forecasts are better when the lead time decreases. However, there are still issues with the simulated Greensburg storm moving too quickly toward the east, possibly as a consequence of cold pool buildup.

We consider this paper a proof-of-concept study in support of the Warn-on-Forecast project. It demonstrates probabilistic forecasting of a tornadic mesocyclone’s track using operationally available data, albeit not in a real-time framework.

My contributions to this study were the dealiased KDDC data, the low-level VAD wind profiles, some of the graphics, and of course, help with the writing. (Fortunately, Dan is a good writer and didn’t need much help!)

One minor erratum – I just noticed that my listed affiliation is partly incorrect. I do work for CAPS, but my previous affiliation was CIMMS, not NWC. That’s an “oops” that I should have caught during the editing process. Fortunately, it doesn’t impact the science!