Isaac’s remains and what to do about Leslie

As I write this, I’m enjoying a view of beautiful, tropical cumulus clouds in the Baltimore area. This is courtesy of a large plume of tropical moisture that has moved north from the Gulf of Mexico, well in advance of Isaac’s remains. The remnant circulation is making its way through the Ohio Valley today and will move into western PA by late Tuesday. Heavy rain will continue to be a threat in the Mid-Atlantic to Northeast U.S. until Thursday.

As you can see by the QPF forecast above, 3″ to locally 5″ of rain is expected through the next 5 days in parts of the Mid-Atlantic region. The threat for tornadoes should start to dwindle over the next few days. A series of cold fronts will move towards the Eastern Seaboard through the end of the week with the possibility of a stronger storm developing over the Ohio Valley over the weekend.

Tropical Storm Leslie is struggling against moderate shear today, keeping the storm from strengthening. The current intensity is 60 mph and the center of the storm has recently become exposed from the waning thunderstorms to the southeast.

The track forecast for Leslie is a big challenge over the next few days. The NHC forecast shows a slow north-northwest motion over the next five days, similar to the track guidance above. I included the overnight Canadian model run which shows a close approach to the Mid-Atlantic by Sunday, 09/09. Although this is the only model showing such an approach, this is something to think about as the aforementioned developing storm next weekend in the Ohio Valley could actually “attract” Leslie. At that time, Leslie could be a modest hurricane.

Thanks for reading!