Forecast for Rina
The hurricane hunters found Rina's eyewall had a gap in it during their 4:32 am EDT eye penetration this morning, probably caused by the moderate wind shear the storm has experienced over the past day. It is unlikely that Rina will be able to "bomb" and undergo rapid intensification unless it can close off this gap in the eyewall. Wind shear is not expected to increase until Wednesday night, so Rina still has a day and a half to continue its intensification process. Given the storm's inability to close off its eyewall so far, I expect that a Category 3 storm is the strongest that we will see. On Wednesday night, Rina will encounter a dry airmass with high wind shear that lies over the extreme northwestern Caribbean. These conditions should weaken the hurricane, but Rina could still be a major hurricane if it makes landfall in the Yucatan Peninsula on Thursday.
A trough of low pressure is predicted to pass to the north of Rina late this week, which should turn Rina more to the northwest by Thursday and northeast on Friday. However, it is uncertain if Rina will be strong enough to fully "feel" the steering influence of this through and be swept to the east-northeast into Southwest Florida and the Florida Keys. If Rina makes landfall in the Yucatan Peninsula and weakens significantly, the storm will likely be too weak to get caught up by the trough and will remain trapped in the Western Caribbean. This is the solution of the latest runs of the ECMWF, UKMET, and HWRF models. However, if Rina remains strong through Friday, it is more likely to get caught up by the trough and drawn into the Florida Keys as a weakening tropical storm on Friday or Saturday. This is the solution of the latest 2 am EDT runs of the GFDL and GFS models. There is high degree of uncertainty which set of model runs will be correct.