Comparison of HWRF Operational Cycles with and without Secondary Eyewalls

We present an analysis of the operational HWRF and HMON capabilities in forecasting the observed secondary eyewall in Harvye 2017. While Harvey developed the secondary eywall just before landfall in the coast of Texas, HWRF consistently predicted secondary eyewalls even in cycles initialized 5 days before, when the storm was in the Caribbean. Most cycles of HWRF generate secondary eyewalls as the storm moved through the Gulf of Mexico but HWRF failed to generate them when the storm was initialized over the Yucatán peninsula. We analyzed differences in cycles that had and did not have secondary eyewalls aiming further the understanding on the key ingredients of simulations to generate such structures.