Fay Moves Over Water and Lessons Learned

Sorry for the lack of delays the last couple of days. It's been a little hectic to keep up with the weather with classes beginning. After making landfall in Southwest Florida early Tuesday morning, Fay unexpectedly strengthened over the peninsula. This was not the result of the pressure gradient tightening commonly seen with landfalling systems. In fact, Fay's central pressure actually dropped and maintained itself near 986 mb for several hours.

It will require some research, but I will go back and investigate why this actually occurred. My initial thought is that the swampy, marshy soils in South Florida were fairly wet and acted as a temporary fuel source. That's pure speculation at this point, but it should be an interesting study nonetheless.


Even for a tropical storm, Fay still looks quite impressive on satellite and radar imagery. Currently, Fay has moved into the warm Atlantic waters just to the northeast of Titusville. Radar loops don't show a lot of movement with Fay, and as long as Fay stays over water, strengthening is possible. In fact, it wouldn't take much for Fay to regain hurricane strength. Still, the proximity to land, moderate wind shear, and potential upwelling should prevent significant strengthening.


Models all unanimously turn Fay back to the west as a strong upper-level ridge and associated surface high pressure establishes itself over the Eastern U.S. The models are also unanimous in taking Fay across Northern Florida Thursday and Friday, but there is some slight model divergence late Friday. Most models continue to take Fay west and a little northwest around the periphery of the subtropical ridge, but a few models actually do think Fay makes it back into the Gulf of Mexico. While it wouldn't surprise me to see this happen, I'm still leaning along the lines that Fay does stay over land once it moves back west. This would be excellent news for some of the drought-stricken areas in the Deep South.

This has been a frustrating storm to forecast the track, and it doesn't help matters that I made a critical error in my track forecast. If you'll remember back to last Thursday's post, I spoke in some detail about how I felt confident the U.S. would be hit due to the trough/ridge pattern in Eastern Asia earlier in the week. A large ridge was present over Eastern Asia on Monday, and this typically corresponds to a ridge of the Eastern U.S. about 9-10 days later. That matches up pretty well with the current trough/ridge pattern in the U.S. This is where I made my mistake. Before the ridge built into Eastern Asia last Monday, a trough had just lifted out over the weekend. This should have keyed me in on the idea that a potential tropical system in the Atlantic basin would be pulled poleward due to the departing trough. However, behind the departing trough, any tropical system would be pushed back to the west with the building ridge. This is exactly what has happened and is expected to happen with Fay, and I'm disappointed in myself for not correctly applying the teleconnection taught by Doug Gillham.