 In early October , a cold front drifted through Texas and entered the Gulf of Mexico . On October 5 the front dissipated while a related trough persisted . Upper @-@ level air temperatures were generally warm , and a minimal anticyclone was situated over the Gulf . At this time , a Colorado low drew polar air into the Mississippi Valley , suggesting extratropical characteristics of the developing system . A tropical depression formed on October 6 ; it meandered in a north @-@ northeasterly direction for the next two days . The storm intensified into Tropical Storm Irene around 1800 UTC on October 7 . Around this time , a Hurricane Hunters flight indicated that the circulation was indistinct , although it was gradually evolving . On October 8 , Irene made landfall near Pensacola , Florida as a well @-@ organized tropical storm . The storm rapidly weakened to a tropical depression , before dissipating early on October 9 . 
