Tropical Atlantic springing to life

[Updates follow original entry; latest as of 4pm EDT Thursday July 3.]

A surface low pressure center -- the most organized disturbance so far this season to emerge off the coast of Africa -- is in the eastern tropical Atlantic.

On the other side of the tropical Atlantic, a little doohickey (what appeared to be a sharp tropical wave at the surface but with a circulation spinning aloft) flared up Wednesday afternoon as it approached the Windward Islands.

What the location of the current two systems tells us is that we're shifting gears from June, when most tropical cyclone development takes place in the Gulf of Mexico and western Caribbean Sea, to July, which is a transition month on the way to August, when the balance tilts to the tropical Atlantic, and the basin as a whole becomes more conducive to development.

JUNE

EARLY JULY

MID JULY

LATE JULY

EARLY AUGUST

If that eastern Atlantic low were to become a tropical storm far to the east (it remains to be seen whether that will happen), such an occurrence would be unusually early. What would that portend for the remainder of the season? The peak is still 1-3 months away, and like with any long-range seasonal outlook, there's no way of knowing exactly what will happen far in advance ... and outcomes after early flare-ups can run the gamut.

For example, things got cranking early in the season in 2005, and we all now know how that season turned out. On this date (July 3) in '05, the depression that would go on to become already the third named storm (Cindy) formed; the center of Cindy would, in an eerie foreshadowing of what happened on August 29 of that year, pass just to the east of New Orleans.

However, as early as mid-June of the following year, as I similarly blogged at the time, the tropical Atlantic was lit up (below), and, Ernesto notwithstanding, the remainder of the 2006 season overall was like night and day compared to 2005.

The 2007 hurricane season was a rough one in some other countries, but with it and the '06 season having been much less destructive in the U.S. than the ones in 2004 and 2005, I hope there's not too much complacency. Not knowing what the outcome this year will be, let's hope for the best but be prepared for the worst. (Although a trite expression, it always rings true for hurricanes!)

THURSDAY MORNING UPDATE

With the surface circulation still well-defined, and convection (rain & thunderstorms) persisting around the center, the National Hurricane Center has designated the system in the far eastern Atlantic to be a tropical depression. After brushing Cape Verde with showers and gusty winds, it is not a threat to land for the foreseeable future. If T.D. #2 strengthens and becomes a tropical storm, it would get the name "Bertha."

Bertha was also the name of a hurricane in 1996 which formed in the Atlantic (not quite as far east) in early July, in fact its incipient circulation was first detected on satellite imagery on July 3! Bertha would go on to survive all the way across the Atlantic and make landfall on the North Carolina coast on the 12th of July.

UPDATE 11AM EDT THURSDAY JULY 3

The depression has been upgraded to Tropical Storm Bertha.

[Click on image for large version.]

UPDATE 4PM EDT THURSDAY

Per TWC's point of origin maps, and in double-checking the NOAA track climatology viewer, Bertha has apparently become an Atlantic tropical storm much farther east than any other storm on record so early in the season.

I've updated the map from earlier in this blog for the first 1/3 of July (no June storm is close) to put a red dot where Bertha was named (below). 1996's Bertha -- represented by the easternmost yellow dot -- had been the farthest east until eclipsed by 2008's Bertha.

Caveats:

-There may have been other tropical cyclones of storm intensity as far or farther east prior to the satellite era that were not officially designated to be tropical storms.

-Even during the modern era, when to designate a cyclone to be a tropical storm is a judgment made by the National Hurricane Center with some inherent subjectivity.

The latest TWC forecast track for Bertha can be found here.