Big Bertha: A Bad Omen?
After explosive development yesterday, Hurricane Bertha is struggling today. Its maximum winds have dropped from 120 mph last night to 105 mph as of 11 a.m. and it has been downgraded to a category two storm. Positioned 660 miles east northeast of the northern Leeward islands, track models now generally project Bertha will continue heading to the northwest and then north -- most likely well east of Bermuda. As Bertha moves into cooler waters on its journey north, it should continue to slowly weaken.
While it remains to be seen whether Bertha will affect any land areas, it will go down in history as a record-breaking storm and may be a harbinger of a very active hurricane season.
Bertha easily broke the record for becoming the furthest east named storm prior to August 1. Bertha was classified as a tropical storm at 24.7W (longitude). The old record was set by Anna in 1969 (36.0W). Probably not coincidentally, sea surface temperatures where Bertha formed were running 2-3 degrees C above average.
Colorado State hurricane researcher Dr. Phil Klotzbach tells us Bertha puts 2008 in the company of only 5 other years (1954, 1960, 1961, 1996 and 2005) since 1950 that a hurricane developed east of 75.0W and south of south of 23.5N (latitude) prior to August 1. This area is associated with the development of "Cape Verde-type storms" where storms, which originate as disturbances off the coast of Africa near the Cape Verde islands, usually develop later in the hurricane season (August, September and October) and track westward across the tropical Atlantic before curving northeast.
In addition, Bertha already places 2008 among the top five years for named storm days (NSD, which includes days as tropical storms and hurricanes for any/all storms) in this region (prior to August 1). Since Bertha formed July 3 (and has remained in this region), 2008 has achieved five NSD to date. The top five NSD years prior to Bertha were: 2005 (9.75 NSD), 1996 (5.75 NSD), 1966 (5.25 NSD), 1969 (4.50 NSD), and 1954 (4.50 NSD). All five of those years featured quite active hurricane seasons.
Assuming Bertha stays south of 23.5N for another day, 2008 will rank second in NSD in this region (prior to August 1) less than one third into the month of July. If past storm history means anything, this may portend an ominous Atlantic hurricane season...
[Update: Jeff Masters' at Wunderblog writes that "Bertha holds the record for the farthest east a major hurricane has formed so early in the season (52Â°W longitude), easily beating the mark set in 1996 (67Â°W) by a previous incarnation of Hurricane Bertha. This year's Bertha now holds the record for farthest east formation as a tropical storm, hurricane, and major hurricane, so early in the season." He also finds Bertha's intensity may have peaked at category four levels.]
Capital Weather Gang meteorologists Jason Samenow and Steve Tracton produced this report.
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