Location: New York
Author: Michael Schlacter
Date: Thursday, April 24, 2008
Despite prophetic or magnanimous claims you may hear, the percentage of Tropical Storms that evolve into Hurricanes and the number of Hurricanes that actually make U.S. landfall any given year, are very much at the whim of local environmental conditions & synoptic steering patterns which can only be accurately assessed as the Season is underway.
HURRICANE LESSONS, COMMENTS AND OUTLOOK [for 2008 SEASON]:
10.) The record-setting 2005 Atlantic Hurricane Season was undoubtedly going to set a benchmark after which all ensuing Seasons would seem anti-climatic. The psychological pendulum indeed swung in the opposite direction when only 10 Tropical Storms developed in 2006. These 2 large pendulum swings in Tropical Storm production should not obscure the bottom line which is 11 of the past 13 Seasons have produced more Storms than the long-term average (with only 1997 being decidedly below), and this trend is likely to continue during this active cycle of which we are in the midst.
9.) In 2005, Hurricane Emily was the strongest Atlantic Hurricane ever prior to August [160 mph], with Dennis being the 2nd strongest ever prior to August [150 mph]. This cautions that intense Tropical Storms can be a legitimate threat in the early stages of the Summer. Furthermore, Hurricane #1 in March 1908 [100 mph], Hurricane Abel in May 1951 [115 mph], Hurricane Lenny in November 1999 [155 mph], and Hurricane #2 in December 1925 [100 mph], demonstrate that legitimate Hurricanes can and do form on the periphery of the official "Hurricane Season".
8.) 2006 was quite remarkable that even an average number of 10 Tropical Storms were able to form in light of 2 powerful inhibitory factors that evolved. Firstly, a weak El Niño event emerged much more rapidly during the 2006 Summer than had been anticipated, creating disruptive shear patterns and essentially shutting down the back-half of the Season. Secondly, the perennial Saharan Air Layer (or SAL) was substantially more robust and persistent than usual, essentially "choking" numerous potential Tropical waves before they could organize, from August-October. If you exclude these 2 variables from the equation (as was the case in 2007 and again now in 2008), you can easily see 25%-75% more Tropical Storms and/or Hurricanes.
7.) Those who set their sights only on the U.S., may not realize what a dangerous bullet was dodged in 2007: For the 1st time in recorded history, 2 Category 5 Hurricanes made landfall in North America in the same year (Dean in Mexico and Felix in Nicaragua). You nudge either of those 2 storms just 50 miles further North when they were in the Eastern Atlantic, and you could have easily had an alarming GOM situation. Due to atmospheric parameters and SST projections, our research concludes that there are above-average odds that a Hurricane will make landfall in the North America as a Category 4/5, again in 2008.
6.) Louisiana has lost 1,900 square miles of (essential buffering) wetlands and bayou forest from 1937-2000 alone, due to coastal development (including urban subsidence and river channeling), and subsequent erosion. Similar huge losses of these natural silt and vegetative buffers have taken place during the past Century from Texas to Maine. Building, living in, and manipulating coastal areas satisfies the needs of industry, commerce and residents, but exponentially increases the vulnerability of these regions to storm devastation.
5.) You might be surprised to learn that not a single Hurricane made U.S. landfall the past 3 years as a Category 4 or Category 5 storm; Charlie [CAT 4] in 2004 was the last, and then you have to go back to Andrew [CAT 5] in 1992 before that. Thus, things could have been worse the past 3 Seasons, on isolated bases, believe it or not. Furthermore, it should be noted that it has literally been decades since a direct Hurricane hit has been made on major hubs such as Houston/Galveston, with only 3 Hurricanes of Category 4/5 striking anywhere from Brownsville Texas to Tampa Florida since 1950.
4.) Mostly due to geography, but not to be overlooked, is the fact that no Hurricane since 1950 has ever directly struck from the upper Outer Banks of North Carolina to New York City (a Mid-Atlantic coastal zone that represents Scores of Millions of people). The region has been impacted by storms traversing up the Atlantic States (i.e. Floyd - 1999), but time will eventually run out on avoiding direct primary landfalls. Due to steering mechanisms and SST projections, our research concludes that there are higher odds that at least 1 Hurricane will impact the U.S. Northeast/Mid-Atlantic Coast in 2008.
3.) From Loop Current, Thermocline and Oceanic Heat Content projections, our research concludes that there remain decent odds that an Atlantic Hurricane could even achieve the strength of 191-200 mph sustained winds (never before officially observed in a tropical storm on Planet Earth) during the 2008 Season (Dean and Felix in 2007 came close with 175 mph sustained winds). The pressure intensity record of 882 mb (established by Wilma in 2005) could also be challenged in 2008.
2.) Our research has detected an evolution this Decade of the Inter-Tropical Convergence Zone [ITCZ] shifting further southward toward the Equator. This now places traditional "Hurricane-Proof" islands like Aruba, Bonaire and Curaço in Tropical Storms' line-of-sight along along with several Central American Countries (such as Felix in 2007 remaining below 15°N latitude it entire life). Furthermore, this also allows for the turning radius of low-latitude storms to intersect the GOM (like Dennis, Emily and Wilma in 2005).
1.) Much attention has been given to Sea Surface Temperature Anomalies [SSTA's] - which by the way, are presently warmer-than-normal across the sub-basins of: the Gulf of Mexico, Sargasso Sea/Gulf Stream, and the Cape Verde/Eastern Atlantic [Caribbean should not be included in this list]. But more importantly, regardless of anomalies, Tropical Storms only require ocean temperatures above 75°F to form (even cooler for Sub-Tropical formation), and such temperatures are plentiful throughout the entire Atlantic Basin. In summary, Oceanographic and Atmospheric environments should be conducive for abundant Tropical development during the 2008 Atlantic Hurricane Season.
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