This particular blog entry will continue our examination of the entire historical record (1851-present), with a focus on "May" Tropical Cyclone (TC) activity throughout the Atlantic Basin. A "May" TC will be characterized as one that initially developed at some point during the month of May (i.e. May 1-May 31). Those TCs (shown by year) that achieved hurricane (H) and/or "major" hurricane (MH) intensity, will be designated by bold case print, in the following respective sections.
ALL TROPICAL STORMS:
Note: These totals include Subtropical Storms (STS), as well.
2 = 1887.
1 = 1865, 1889, 1890, 1908, 1916, 1932, 1933, 1935, 1940, 1948, 1951 (MH), 1953, 1959, 1970, 1972 (STS), 1976 (STS), 1981, 2007 (STS), and 2008.
In addition: Storm #1 of 2008 (TS Arthur) maintained TS intensity into the month of June.
ALL U.S. TROPICAL STORM LANDFALLS/STRIKES:
1 = 1908, 1916, 1951, 1959, 1972 (STS), 1976 (STS), and 2007 (STS).
ALL U.S. HURRICANE LANDFALLS:
1 = 1908
Note: Although the eye of the 1908 H crossed the U.S. coastline as a 75 mph category one storm, there were no reports of hurricane force winds observed on land.
ALL U.S. MAJOR HURRICANE LANDFALLS:
1) All Atlantic Basin Tropical Storms:
a) There were a total of 21 "May" TS or STS systems that developed in the Atlantic Basin during the 161 year period of 1851-2011. This equates to one May TS or STS every 7.67 years, on average.
b) There were a total of 4 TCs that achieved hurricane intensity during the month of May. This equates to one May H every 40.25 years, on average.
c) There has only been one documented May TC to achieve "major" hurricane (MH) intensity during the month of May.
d) Hurricane Able of 1951 holds the record as the most intense May hurricane for anywhere in the Atlantic Basin. It became a category three storm (major hurricane intensity) during the early morning hours of May 20, 1951, as it passed offshore of the NC coastline. At the time, it contained a Maximum sustained wind (MSW) of 115 mph. It had previously impacted the extreme NW Bahama Islands as an 85-90 mph category one hurricane on the 18th.
e) TS Arthur of 2008 is the most recent "May" TC (of at least TS intensity) to develop anywhere within the Atlantic basin. It became a TS-with a MSW of 40 mph-very late on May 30, 2008. Less than nine hours thereafter, TS Arthur came ashore in NE Belize as a 45 mph/1004 mb storm. Unfortunately, its heavy rainfall triggered "devastating floods" that took the lives of 5 persons in the Country of Belize and caused extensive property damage.
f) H Alma of 1970 is the most recent TC of hurricane intensity to develop in the Atlantic basin. After developing in the SW Carribean Sea, the weak depression that would become "Alma" moved slowly Northwestward and subsequently achieved TS intensity during the late night hours of May 19, 1970. After turning to a due N and then NNE trajectory-while moving over increasingly warmer waters-Alma rapidly intensified into an 80 mph/993 mb category one H by 2 pm EDT on May 20th. A strong area of High pressure to its N caused "Alma" to abruptly turn back to a more westward heading by late on the 21st. A significant increase in vertical wind shear caused H Alma to quickly degenerate back to tropical depression status by 2 am EDT on the 22nd. From there, it would maintain this intensity as it tracked through the NW Carribean, across eastern Cuba, and through the western Gulf of Mexico to its eventual landfall near Cedar Key, Fl. After landfall, it moved off in a general N to NNE motion through the SE coastal states before ultimately becoming absorbed by a large low pressure system-just as it was about to exit the U.S. coastline near Norfolk, Va.-very late on the 26th.
g) The 1887 Atlantic Basin hurricane season is shown to have been the most prolific for "May" TC formations-with 2.
h) The 1889, 1908, 1951, and 1970 Atlantic basin hurricane seasons hold the record for spawning the most TC's of hurricane intensity-with one each, respectively.
i) The 1951 hurricane season is the only one known to have spawned a MH during the entire historical record of 1851-2011.
2) All U.S. Tropical Storm Landfalls:
a) There were a total of 7 May TS or STS systems that made a U.S. landfall (or strike) during the aforementioned 161 year period. This equates to one May TS or STS landfall (or strike) every 22.86 years, on average. Moreover, a full 33.3% of all "May" Atlantic Basin storms made landfall in the U.S.
b) Storm #2 of 1908 is the only known hurricane to have made a direct strike on the U.S. coastline during the month of May. The eye of this historic storm brushed along the extreme eastern portions of the NC Outer Banks as a 75 mph/989 mb hurricane-during the early evening hours on May 29, 1908. In doing so, it is estimated that a MSW of 65 mph likely impacted that area-with hurricane-force winds staying just offshore.
c) STS Andrea of 2007 is the most recent TC of either STS or TS intensity to bring tropical storm force winds to the U.S. shoreline-constituting a TS strike. Around noon on May 9, 2007, St. Simons Island, Ga. recorded a MSW of 40 mph, while STS Andrea was meandering about 100 nm offshore of NE Florida.