Some uncertainty about the track of Lee after 7 days as steering currents collapse, wind shear increases, and the players on the field including a Northeast trough and potential Tropical Storm Margot decide on where Lee can go. The vast majority of ensemble guidance keeps Lee well off the East Coast of the U.S. with an outside (< 10%) chance of impacting New England. There is a slightly better chance (maybe 1 in 3) of some version of Lee (post-tropical) affecting Atlantic Canada. However, as I’ll show, there is all likelihood that Lee will undergo an unscheduled rapid disassembly in 7-8 days due to wind shear, dry air, and cooler ocean waters or low heat content.

Will Lee become Category 5 ? While the official NHC maximum forecast is 10-knots short at 130-knots, I think there is better than a 2 in 3 chance that Lee reaches Cat 5. The ocean heat content is high and wind shear will be almost non-existent. Lee is in an ideal environment that perhaps only exists infrequently over the SW Atlantic in an El Nino summer.