Born in the western Caribbean just after Columbus Day,  Irene was initially well behaved, moving
on a north-northwest track into the Gulf of Mexico, intensifying into a hurricane near the Isle of
Pines.  As shear increased out of the southwest, convection deepened to the point that an MCS-
type thunderstorm complex formed northeast of the center.  Like many MCSs, Irene moved to the
right of the mean flow, splitting the 500 hPa ridge to its north into two pieces; one over the Gulf,
the other remaining over the southwest Atlantic.  After crossing the Florida peninsula, the storm
moved parallel to the Gulf Stream for the remainder of its life, rounding the subtropical ridge to its
east and southeast.  As it began acquiring nontropical characteristics off the Carolinas, a comma
head precipitation pattern developed, similar to that of a subtropical cyclone.  This lead to vast
amounts of rain in the Norfolk/Suffolk/Newport News metropolitan area, well to the left of its
track.  After passing just offshore Cape Hatteras, Irene accelerated quickly northeastward,
contributing to the development of an intense extratropical low over the maritime provinces of
southeast Canada.  The track of the storm is located below, denoted every six hours, using
Universal Coorinated Time.  The time 1200 GMT is the same as 8:00 a.m. EDT.
 

The graphics below show the storm total rainfall for Irene.  Note the maxima along
the southeast Florida coast, and across northeast North Carolina and southeast
Virginia.  Data for this map was compiled from the Hourly Precipitation Data
publication from NCDC, and from the post storm report on the system from the
National Hurricane Center.

Below is the calendar for Daily Precipitation Maps.  Note that the 24-hour periods end
at 12z that morning.