Monday, August 27, 2012

Isaac Strengthens...Slowly, For Now

Isaac is moving northwest late this afternoon, sporting 70 mph max winds. There isn't an appreciable difference between 70 mph tropical storms and 75 mph hurricanes except a title, some hype, and a little bit more wind. Given Isaac is a large storm, its winds will push across a larger geographic area. Dry air, being near Cuba's terrain over Saturday and Sunday, and a bit of wind shear have slowed Issac's strengthening but those factors are waning and Isaac is now strengthening somewhat.

Isaac looks like an intensifying tropical cyclone on satellite and given it is over favorable ocean conditions tonight and tomorrow it should continue to intensify slowly, with the storm reaching hurricane status (hopefully) by tomorrow.  It's not going to take much to reach that status given its strengthening trend earlier today...the dry air needs to be fully mixed out, however.

Modeling still suggests landfall along the central portions of the Gulf Coast -- the farthest west outlier suggests a landfall in Southwest Louisiana, with the farther east models pushing the storm into the Mississippi coastline.  Most guidance is clustered with a small spread from Southeast Louisiana to the mouth of the Mississippi River.  Given the large circulation with Isaac, coastal flooding and gusty winds will occur a good distance east of the landfall point...wherever that may be. The National Hurricane Center suggests a Category 2 hurricane can't be ruled out at the time of landfall late tomorrow night and early Wednesday morning.

Modeling also suggests a stall out or very slow movement post landfall in Louisiana and Mississippi. While coastal flooding will be a big issue down there -- excessive rainfall will lead to flooding a good distance inland as well.

We'll have another update tomorrow morning on the storm.