Issac becomes a hurricane

Hurricane Issac continued its push towards Louisiana this afternoon having reached hurricane status at 12:20 EDT today. Dry air and particulates had been keeping Issac from strengthening but this has been overcome as a complete eyewall has formed around the center of Issac. As the radar image shows below, Issac has a full circulation of thunderstorms around its center as it continues its trek towards the shore.

Live Updates: Hurricane Isaac, Heading Toward Louisiana(AccuWeather)

Isaac has crossed the threshold at 12:20 p.m. EDT Tuesday, becoming a hurricane, while rolling toward the southern coast of Louisiana.  

An eye has formed with thunderstorms wrapping around the center of Isaac by noon Tuesday. During Monday afternoon and evening, dry air worked its way into Isaac, cutting off its flow of deep moisture, which put a halt to the thunderstorm activity on the north side of the storm.  

Dry air entrainment has been an issue with Isaac even as it entered the Caribbean.