Hurricane Humberto

Hurricane Humberto was a moderately powerful hurricane that briefly affected Bermuda in September 2001. It was the eighth named storm of the season, as well as the fourth hurricane. It formed on September 21 between Puerto Rico and Bermuda, partially related to previous Hurricane Gabrielle. Humberto passed about west of Bermuda, which spared the island with its strongest winds. After weakening and believed to be on the verge of dissipating, Humberto unexpectedly restrengthened to the southeast of Atlantic Canada. The intensification was short-lived and the storm dissipated on September 27. There were a series of significant observational flights into the hurricane that produced a wealth of data on the structure of hurricanes. Meteorological history Hurricane Humberto originated from a trough that extended southwestward from Hurricane Gabrielle, which had previously moved across Florida into the western Atlantic Ocean. The trough interacted with an upper-level low, resulting in an increase of convection, or thunderstorms, in the region. A surface low developed on September 19, and it gradually organized as it moved westward. After deep convection developed over the center, it is estimated the system reached tropical depression strength on September 21, about halfway between Puerto Rico and Bermuda. The National Hurricane Center (NHC) first published an advisory on the storm at 11 AM EDT, identifying it as Tropical Depression Ten. Upon its formation, the depression moved northwestward toward a break in the mid-level ridge. On satellite imagery, the depression looked well-organized, with banding features, outflow, and convection, although Hurricane Hunters had difficulty locating a closed center of circulation. The unfavorable conditions were from the upper-level low to its southwest, which was producing wind shear over the storm; nevertheless, the NHC anticipated strengthening. On September 22, the surface circulation rapidly became better organized, and based on confirmation from the Hurricane Hunters, the NHC upgraded the depression to Tropical Storm Humberto. Throughout its life, the storm was smaller than average, and as it moved around the subtropical ridge, it gradually intensified. Tropical Storm Humberto developed an eye feature on September 23. Shortly thereafter, the storm reached hurricane status about west-southwest of Bermuda.