Tropical Storm Andrea (2013)

Storm Active: June 5-7

On June 2, scattered shower activity associated with a trough situated near the eastern coast of the Yucatan Peninsula begin to organize. The system moved north-northwest, and despite only marginally favorable conditions, partially stemming from frontal boundaries moving through the north Gulf of Mexico, developed further. Surface pressures declined near the center of the disturbance during the day of June 4, but the circulation remained broad, and all convection was displaced to the east of the forming center by wind shear in the western Gulf. On June 5, conditions became briefly favorable for formation as the disturbance moved northward, and an aircraft investigating the system found that a well-defined center had formed. The system was therefore named Tropical Storm Andrea, the first tropical cyclone of the 2013 season.

By the early hours of June 6, Andrea was already accelerating north-northeast in the wake of a trough lifting out of the southeast United States. The structure of the cyclone already exhibited some extratropical properties, as its convection was still displaced generally to the north of the center, and a band southeast of the center, reminiscent of a frontal boundary, was forming. Despite this, the circulation deepened and Andrea underwent modest strengthening during that day.

Torrential rains had already begun over Florida and parts of South Carolina that afternoon as the northern bands of Andrea's circulation interacted with a frontal system moving towards the east coast. The system made landfall in northwestern Florida at its peak intensity of 65 mph winds and a pressure of 993 mb at 5:45 pm that evening. The system accelerated considerably and weakened quickly over land overnight as the circulation broadened and dry air invaded the center of circulation early on June 7. By that afternoon, the cyclone was declared post-tropical.

As the cyclone moved northeastward, it caused significant rainfall across the mid-Atlantic and towards New England as the center of circulation stayed near the coastline. The remnants of Andrea dumped a few inches of rain across a large swath of this region in conjunction with the frontal system steering it. By the afternoon of June 8, the cyclone had lifted out of New England.



Tropical Storm Andrea reached peak intensity shortly before making landfall in Florida.



Andrea tracked up the U.S. east coast, largely as a post-tropical cyclone, and brought heavy rainfall to many areas.