NC George wrote:
cheezyWXguy wrote:Nate is fascinating to me. How is such an inefficiency of mixing winds to the surface possible? My initial guess is dry air, but as was pointed out during Irma’s landfall in Florida, the subsistent quality of dry air would likely result in significantly higher gusts despite meager sustained winds. Radar would would seem to suggest the most intense part of the storm is on land now, but peak winds of 50mph, gusts to 60mph are baffling to me, considering that recon reported fl winds up to 89kt I believe (according to the latest advisory).
Do any of the pro Mets have any insight to this?
I think I have some insight: We have a 50-55 mph tropical storm here with wind speeds augmented by a fast forward movement creating just strong enough winds at one point (due east of the center) to classify this as a hurricane. I'm guessing the winds on the west side are around 25 mph. I think the lack of a southern eyewall at all along with the weak radar presentation corroborates this analysis.
I don’t think that’s it. If this were a 50mph storm being augmented by 20mph forward speed, we would probably be observing more reports of winds in the 60mph+ range. It also doesn’t account for the flight level winds earlier today that supported a 90mph intensity. If we were talking about a storm peaking at 75mph, this might hold some water, but I’m skeptical considering that recon found FL winds supporting a borderline 1/2 hurricane followed by winds reports at the coast only a couple hours later that support at most a 60mph landfall intensity. While the structure has never been great in this storm, there really wasn’t a whole lot of degradation between those two points in time, and certainly not enough to justify a 40% decrease in intensity
Edit for further thought: could it have been ingestion of continental dry air at the surface disrupting the core, and thus loosening the pressure gradient? The wind field was already rather spread-out as it was, and this loosening of the gradient may explain the weak winds despite Nate having a central pressure consistent with an 85mph hurricane