I know that, although rare, there are symmetric cold core cyclones (with a few of them even having a shallow cold core). They encompass some occluded extratropical cyclones, some dissipating tropical cyclones in the mid-latitudes, and lots of other groups of cyclones. Some of them can be found at any given time at http://moe.met.fsu.edu/cyclonephase/gfs/fcst/index.html. So, I wonder what kind of weather they produce (apart from what can be expected for a low pressure) and how it can be compared to asymmetric cold core cyclones and warm core cyclones, both symmetric and asymmetric.
