text: subtropical storm andrea ( 2007 ) subtropical storm andrea was the first named storm and first subtropical cyclone of the 2007 atlantic hurricane season . it developed out of a non - tropical low on may 9 about 150 miles ( 240 km ) northeast of daytona beach , florida , three weeks before the official start of the season . after encountering dry air and strong vertical wind shear , andrea weakened to a subtropical depression on may 10 while remaining nearly stationary , and the national hurricane center discontinued advisories early on may 11 . andrea was the first pre - season storm to develop since tropical storm ana in april 2003 . additionally , the storm was the first atlantic named storm in may since tropical storm arlene in 1981 . the storm produced rough surf along the coastline from florida to north carolina , causing beach erosion and some damage . in some areas , the waves eroded up to 20 feet ( 6 m ) of beach , leaving 70 homes in danger of collapse . offshore north carolina , high waves of 34 feet ( 10 m ) and tropical - storm - force winds damaged three boats ; their combined nine passengers were rescued by the coast guard , although all nine sustained injuries . light rainfall was also reported in some coastal locations . damage was minimal , but six people drowned as a result of the storm . meteorological history in early may , an upper - level trough dropped southward through the western atlantic ocean , forcing a back - door cold front — a cold front that moves southwestward ahead of a building surface ridge to its north or northeast — southward . for several days , forecast models had anticipated for the trough to evolve into a closed low pressure area , and on may 6 , a frontal low with a large and well - defined circulation developed about 90 miles ( 140 km ) east of cape hatteras . the low maintained scattered convection around its circulation center , and in conjunction with the strong high pressure to its north , a very tight pressure gradient produced gale force winds near the coastline . the extratropical storm tracked southeastward and later turned to the southwest while steadily deepening ; on may 7 , it attained hurricane - force winds . with a lack of tropical moisture , its corresponding convection was minimal and scattered . the national hurricane center first mentioned the possibility of tropical cyclogenesis on may 8 , while the storm was located about 230 miles ( 370 km ) east - southeast of the south carolina coastline . its associated convection had steadily increased as it tracked slowly westward at 5 – 10 mph ( 8 – 16 km / h ) . the system changed little in organization throughout the day , though by the following morning , hurricane specialists indicated the low was acquiring subtropical characteristics as it tracked over progressively warmer waters . early on may 9 , a hurricane hunters flight into the system revealed winds of 45 mph ( 70 km / h ) and a flat thermal core , which indicated the system was neither warm - core nor cold - core . in addition , satellite imagery indicated a consolidation of the convection near the center , as well as hints of upper - level outflow and a contraction of the radius of maximum winds from more than 115 miles ( 185 km ) to about 70 miles ( 120 km ) . based on the observations and the hybrid structure of the system , the national hurricane center classified the low as subtropical storm andrea at 1500 utc on may 9 about 150 miles ( 240 km ) northeast of daytona beach , florida . during a subsequent analysis of the storm , researchers estimated that the storm had transitioned into a subtropical cyclone nine hours earlier . as andrea developed before june 1 — the traditional start of hurricane seasons in the atlantic ocean — it became the first pre - season storm since tropical storm ana in april 2003 . additionally , the storm was the first atlantic named storm in may since tropical storm arlene in 1981 . upon first becoming a subtropical cyclone , andrea was embedded within a large , nearly stationary deep - layer trough , resulting in a westward movement . drifting over sea surface temperatures of no more than 77 ° f ( 25 ° c ) , the organization of the system deteriorated with a significant decrease in convection . by early on may 10 , much of the associated weather was located to the east of the cyclone within a band of moderate convection due to a brief spell of westerly vertical wind shear . the center of circulation had become disorganized , with several small cloud swirls within the larger circulation . this disorganization of the center , combined with increasing wind shear and dry air suppressing convective activity , caused it to begin weakening later that morning . by 1500 utc on may 10 , only a few thunderstorms remained near the center , and thus the nhc downgraded andrea to subtropical depression status . though a few intermittent thunderstorms persisted over the eastern semicircle , the depression remained disorganized and weak ; the national hurricane center discontinued advisories early on may 11 , after it had been without significant deep convection for 18 hours about 80 miles ( 125 km ) northeast of cape canaveral , florida . later on may 11 , convection re - fired over the center as the system drifted south - southeastward , though it lacked sufficient organization to qualify as a tropical cyclone . by may 12 , shower activity had organized greatly to the east of the center , and the national hurricane center remarked that a small increase in convection would result in the formation of a tropical depression . it accelerated east - northeastward away from the continental united states without redeveloping , and after passing over cooler waters , the remnants of andrea merged with an approaching cold front on may 14 . preparations due to rough surf from the precursor low , local national weather service offices issued a high surf advisory for much of the coastline from florida through north carolina . upon first becoming a subtropical cyclone , the national hurricane center issued a tropical storm watch from the mouth of the altamaha river in georgia southward to flagler beach , florida . the watch was discontinued after andrea weakened to a subtropical depression . additionally , a gale warning was issued for much of the south carolina coastline . at isle of palms in south carolina , workers and dozens of firefighters prepared sandbags in preparation for high tide after waves from the storm previously caused moderate beach erosion . as a precaution , officials there intentionally cut power and gas to multiple uninhabited buildings . officials closed schools in dare county , north carolina due to the threat for high winds from the storm . the north carolina department of transportation also canceled ferry transportation to and from ocracoke and knotts island , north carolina . impact prior to becoming a subtropical cyclone , the low produced gale - force winds and dangerous surf near the coast from north carolina through georgia , and later along the coast of florida . significant swells were also reported in the bahamas . the waves caused beach erosion and washed up against coastal houses along the southeast coast of the united states . southeast u.s. off the coast of north carolina , the storm produced 34 - foot ( 10 - m ) waves and storm force winds which damaged three boats ; their combined nine passengers were rescued by the coast guard . all nine were injured to some degree ; three endured hypothermia , one received a broken rib , and one coast guardsman experienced back injuries from the surf . another boat and its four occupants were reported missing , and after twelve days they remain missing . rough waves from the precursor low left two kayakers missing near seabrook island , south carolina . one was found the next day , and the other was found dead a week later . onshore , winds reached 52 mph ( 84 km / h ) in norfolk , virginia , with an unofficial report of 57 mph ( 92 km / h ) near virginia beach . similar observations occurred along the outer banks , with the winds knocking some tree limbs onto power lines ; some isolated power outages were reported . wind damage included some roofs losing shingles from the winds . in elizabeth city , north carolina , an outer rainband dropped 0 . 5 inches ( 10 mm ) of precipitation in about two hours as well as several lightning strikes ; one bolt of lightning injured two firefighters . the winds covered portions of north carolina highway 12 with sand , and for a day the route was closed after waves from the storm washed out about 200 feet ( 60 m ) of roadway . in some locations , the waves eroded up to 20 feet ( 6 m ) of beach , leaving 70 homes in imminent danger . on st. simons island in georgia , the storm produced a storm tide of 8 . 09 feet ( 2 . 43 m ) . trace amounts of rainfall occurred in the southeastern portion of the state . florida in florida , waves of over 10 feet ( 3 m ) in height capsized a boat near lantana ; the two occupants were rescued without injury . additionally , the waves displaced a sailboat that had previously been washed ashore in juno beach . large waves flooded a parking lot and destroyed several fences and tree branches at jupiter beach , which resulted in its temporary closure ; nearby a maintenance shed was destroyed . eight leatherback sea turtle nests in boca raton were destroyed after the surf reached the dunes . due to high surf , the beach pier at flagler beach was closed for about a day . minor to moderate beach erosion caused the florida department of transportation to fill in areas near the seawall with sand . one death occurred when a surfer drowned in the rough waves off the coast at new smyrna beach in volusia county . outer rainbands produced light rainfall , with the highest report in the jacksonville national weather service area of responsibility totaling 0 . 77 inches ( 20 mm ) ; the bands also caused tropical storm force wind gusts in the northeastern portion of the state . the winds spread smoke from local brush fires through the tampa bay area to miami . high winds from andrea were reported as fueling severe wildfires in northern florida and southern georgia .