Potential Tropical Cyclone 16 earned the name Nana yesterday afternoon after Hurricane Hunters found a closed center of circulation under the system’s cluster of thunderstorm activity. The initial Hurricane Hunter pass found a very small eyewall, prompting come concern that the storm might rapidly intensify. However, additional recon observations today show that the storm’s initial small core has dissipated, leaving a larger/broader circulation in its place. It’s a lot harder for larger storms without an already-consolidated inner core to spin up really quickly. As a result, rapid intensification now seems unlikely.

One other factor that will limit Nana’s potential for intensification is northerly wind shear from an upper-level low located near Jamaica. This shear is pushing most of Nana’s intense thunderstorm activity to the south of the storm’s center which will make any strengthening that does occur between now and landfall relatively modest.

The official NHC forecast is more or less unchanged since yesterday, and calls for modest strengthening in the next 18 hours before landfall in central or southern Belize. Whether or not Nana comes ashore as a 65-70 mph tropical storm or a 75 mph hurricane is mostly an academic distinction. The expected impacts from Nana include dangerous storm surge, heavy rain and associated flooding/mudslide threats, and strong winds/associated power outage and minor structural damage threats.

Nana will dissipate quickly over the mountains of Guatemala and southern Mexico tomorrow afternoon/evening.

-Jack

Posted on 9/2/2020 by Jack Sillin with the Hurricane Tracker App. These posts are meant to provide our users with a detailed analysis of the tropics as conditions warrant and may not be updated on a daily basis. For the latest up to date storm information, always go to “Current Storms” and select a system for the latest information.

We will have another tropical weather discussion as conditions warrant. Thanks for using Hurricane Tracker.