Let the battle of the basins begin!

As of this afternoon, the Atlantic has stolen the spotlight with the formation of Tropical Storm Alberto--the earliest forming tropical storm since Ana (2003). As you may remember, last week Tropical Storm Aletta formed in the East Pacific during the overnight hours of May 14--a day prior to the May 15 season start date.

Talk about hurricane history! Never before has a tropical storm formed before the official start of hurricane season in both the East Pacific and Atlantic basins.

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Located 110 mi (180 km) southeast of Charleston, SC, Alberto is churning over the warm Gulf Stream current, and is expected to strengthen (yet remain at tropical storm intensity) over the coming days. A tropical storm watch is currently in effect for the South Carolina coastline. With the storm's slow southwestward track, the main threat looks to be coastal flooding.

Meanwhile in the Pacific, Aletta is now a post-tropical system.

A mere 12 hours after being declared a tropical depression, Tropical Storm Aletta formed Monday evening in the east Pacific Ocean. It is the basin's first of the 2012 season (which by the way, doesn't officially start until today, May 15). Since hurricane records began in 1949, only 2 other storms have reached tropical storm strength at such an early date: Hurricane Alma (1990) and an unnamed 1996 storm.

While Aletta may strengthen through Tuesday, it's unlikely the storm will reach hurricane strength. It is forecast to continue tracking west over open waters, therefore posing no threat to land areas.

Yes...it's that time of year again! Tomorrow kicks off the first day of the Eastern Pacific hurricane season. Even at this early date, the waters are already teeming with convective activity. The above is a satellite image of an area of disturbed weather roughly 600 miles (966 km) southwest of Manzanillo, Mexico. The system has become better organized over the last 24 hours and stands a 60% chance of becoming a tropical cyclone within the next 2 days, advises the National Hurricane Center (NHC).

In another few weeks, the other basin monitored by NHC officials, the Atlantic, will fire up. Hurricanes occurring in the central Pacific share a June 1 season start with that of the Atlantic, but monitoring responsibilities for these storms falls under NOAA's Central Pacific Hurricane Center (CPHC). All three seasons share a close date of November 30.

Image credit: NASA

Cooler-than-normal sea surface temperatures (SSTs) have begun warming across the equatorial Pacific Ocean, signaling the end of a nearly 2-year La Niña event. According to Climate Prediction Center (CPC) model forecasts, ENSO-neutral conditions (that is, no active La Niña or El Niño) will now resume, with a near 50% chance of El Niño building by mid-summer/early fall.

There are generally two times a year when all eyes turn toward ENSO conditions: winter and hurricane season. If the CPC forecast proves accurate, El Niño's warmer-than-normal ocean waters could mean increased hurricane activity in the eastern Pacific. Since El Niño tends to increase wind shear (a "hurricane killer") across the Atlantic, a decline in activity may be in store for the Atlantic, Caribbean, and Gulf waters.