Early start to 2012 Atlantic Hurricane Season is not that rare!

It is not June 1 yet, the “official” start of the annual Atlantic hurricane season, and we have already had two named storms, Alberto and Beryl, in the basin. What is going on? How rare is this? Is this a glimpse of what is to come over the next six months?

GOES satellite image of 20 May 2012 showing water vapor in the atmosphere and Tropical Storm Alberto off the coast of northern Florida near Jacksonville

Visible light satellite image of 27 May 2012 showing tropical storm Beryl as it moved toward the coastline of northern Florida and southeastern Georgia

So both Alberto and Beryl were generated in the same area off the coast of northern Florida over the warm waters of the Gulf stream only one week apart, marking an early start for the 2012 Atlantic hurricane season.

Back to the question of how rare is it to have an early start for the Atlantic hurricane season?  Well, the answer to that is that it is not that rare, at least based on the recent historical record since 1950 when the naming of tropical cyclones generated in the Atlantic was instituted. In the 62 years from 1950 through 2011 there have been 13 times when there were tropical cyclones in the Atlantic prior to June, that is about 21% of the time for that period or more than one in five.

The years since 1950 when there were tropical cyclones generated prior to the official start of the annual season on June 1, were: 1951, 1952, 1953, 1959, 1970, 1972, 1976, 1978, 1981, 1992, 2003, 2007, and 2008.  On five of these early start seasons, 1972, 1976, 1978, 1992 and 2007 the early cyclones were actually subtropical storms, meaning either “cold core” storms that lacked some of the characteristics of tropical cyclones, or which combined attributes of both “warm core”  and “cold core”  systems. On six occasions, in 1952, 1953, 1959, 1981, 2003 and 2008, the early start annual season was marked by a tropical storm.

Of interest is the fact that both the early annual seasons in 1951 and 1970 actually got going with hurricanes. Category 3 Hurricane ABLE was generated on 15 May 1951, while category 1 Hurricane ALMA got going on 17 May 1970.

What else is happening in the tropics as we get going with early starts of both the eastern North Pacific and the North Atlantic 2012 hurricane seasons?  Currently what we are seeing is a more prevalent belt of tropical activity just north of the equator, as well as more continuous activity along the tropical-wave assembly line over equatorial Africa. Both of these elements are sources of potential contributors to tropical cyclone generation in the larger Atlantic basin. The current state of these tropical regions can be seen in the images below:

Full-disk satellite image of Earth's western hemisphere on 30 May 2012 showing the 'belt of tropical activity' recahing from the Eastern Atlantic to the Central Pacific

Color-enhanced infrared satellite image of 30 May 2012 showing the eastern North Atlantic and the western extreme of equatorial Africa with several tropical waves and cells of disturbed weather outlined in yellow

Mosaic of satellite images showing water vapor in the atmosphere and tropical waves and areas of disturbed weather over the Atlantic, eastern Pacific and Indian oceans on 30 May 2012

Beyond the above all that is left to do is to monitor coupled atmospheric-oceanic conditions closely over coming weeks and months as the annual 2012 Atlantic hurricane season plays out. Above all we must pay attention! Be prepared!! And MITIGATE!!!