Welcome to the first part of a planned (but irregular in time interval between installments) six part series on the 2005 Atlantic Hurricane Season; later installments will cover July, August, September, October, and November/December. The active hurricane season of 2005 got started relatively quickly with two tropical storms in June -- Arlene and Bret -- and two near-misses, one in May (ex-Adrian) and another in June.
In May, the East Pacific basin got off to a quick start with the development of Hurricane Adrian southwest of Central America. The storm followed a climatologically rare path, heading toward the northeast in advance of an unusually deep trough across Mexico and the eastern Pacific. For some time, it appeared as though Adrian would be strong enough at landfall and moving at a fast enough rate of speed across land to be able to survive the passage and become the season's first classified system in the Atlantic basin, despite unfavorable upper-level conditions across the NW Caribbean. However, owing to increasing vertical shear and relatively cool waters -- both at the surface and below the surface -- in the extreme eastern Pacific, the storm weakened rapidly to landfall. The best-track NHC intensity at landfall, despite being a hurricane operationally, was as a tropical depression. Passage over land disrupted the circulation and caused the system to become disorganized; once it emerged into the NW Caribbean, it became entrained in the upper-level trough and never redeveloped. Nevertheless, it became the precursor for what has shaped up to be an active season.
Early June brought about the season's first tropical storm, Arlene, from a tropical wave in the western Caribbean on June 8th. Arlene's track was influenced by steering flow around a low-latitude ridge of high pressure to the east over the Greater Antilles and an upper-level trough across the western Gulf of Mexico, sending the storm to the north through its lifetime. It reached its peak intensity in the hours before landfall on June 11th of 70mph/989mb, ultimately making landfall during the early afternoon hours of June 11th as a strong tropical storm (operationally) near the Florida/Alabama border. Arlene was a well-forecast storm whose greatest impacts were felt in the way of locally heavily rainfall and high surf; measured winds along shore were only at minimal tropical storm force at their peak, largely between Pensacola, FL and Ft. Walton Beach, FL. Once inland, Arlene weakened quickly into a tropical depression, continuing northward for the next couple of days before dissipating on June 13th near the Great Lakes.
Later in the month, a tropical wave in the NW Caribbean and southern Gulf of Mexico slowly got its act together as it emerged off of the coast of the Yucutan Peninsula and organized into the second named storm of the season, Bret. Bret was a short-lived storm, forming late on June 28th and landfalling late the next day as only a 40mph/1002mb tropical storm in the provence of Veracruz in Mexico. Despite this, Bret was getting better organized as it made landfall with an improving satellite appearance being the best marker of this evolution. Steered by an upper-level ridge centered over the Gulf of Mexico, something that would later help spin-up three other storms in the same region and lead to favorable intensification regimes for several other storms further to the north and east, Bret continued to the west-northwest after landfall to a quick dissipation over the highlands of Mexico. The greatest impacts from Bret were felt in the way of locally heavy rainfall in Mexico.
Around the same time, a tropical wave that passed north of the Bahamas interacted with a trough of low pressure along the mid-Atlantic coastline, resulting in the development of a surface area of low pressure just southeast of the Outer Banks of North Carolina. A lack of convective activity and proximity to land helped to keep this system from developing further into a tropical depression, despite becoming better organized as it crossed the Outer Banks into mainland North Carolina and Virginia. Nevertheless, this feature brought tropical rains to the mid-Atlantic and northeast United States as it travelled slowly to the north late in the month.
The preceding tropical wave that became Tropical Storm Cindy early in July was located near the Lesser Antilles at the end of June, while the wave that ultimately developed into Hurricane Dennis was emerging off of the coast of Africa at the end of the month.
June 2005 was the first June since 1986 to see the development of two tropical cyclones in the North Atlantic basin. Markers for an active season to come manifest themselves in the form of well-above average SSTs across much of the tropical Atlantic and favorable upper-level conditions that became even more favorable across the western Atlantic late in June and into July. Despite this, it would have been tough for anyone to predict what actually would happen during the remainder of the season. The next feature in this series will focus on the record-setting month of July, the month that put us on the record-setting pace for tropical cyclone activity.
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2005 Atlantic Season-in-Review: May/June
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