After Tropical Depression Two, quiet in the Atlantic
July 11, 2010
Things never got truly quiet in the tropic Atlantic after Hurricane Alex made landfall Thursday, a week ago. In the following weekend, Invest 95 very nearly became a tropical depression off the coast of Louisiana, while the area of disturbed weather designated as Invest 96 became Tropical Depression Two. Since TD 2’s landfall this past Thursday, it has been quiet, though. A robust Saharan Air Layer, is bringing dry and dusty air to the entirety of the deep tropics. Areas to the west lacking that tropical cyclone formation inhibition do not have any features of interest at this time. Global forecast models show no development throughout next week.
However, they are showing activity in the eastern Pacific within the next three to five days. In fact, while most models are showing some sort of tropical cyclone formation, they are developing different features. Some are developing an area of low pressure to the south of Guatemala/Mexico that was recently designated as Invest 97-E; others develop a tropical wave further to the east. Either way, this would be the first activity in that basin since the demise of Hurricane Darby, two weeks ago.
The burst of activity in the western hemisphere helped to close the deficit in Accumulated Cyclone Energy that existed in the northern hemisphere. When Celia became a hurricane in the eastern Pacific, northern hemisphere ACE was 50% below normal (roughly 20 units of ACE compared to a norm of 40). By making category five, Celia did quite a bit to close the gap and Alex helped bring the value to its normal value for this point of the year. But, the year-to-date average marches upward every day and there have been no ACE contributing storms since. Because of that, the 2010 TC activity shown on Ryan Maue’s Tropical Cyclone Activity update is once again showing a below normal amount of activity as the Atlantic and eastern Pacific have unsuccessfully labored to make up for the exceptional quiet in the western Pacific. The western Pacific is contributing to ACE again, though, as the Japan Meteorological Agency has upgraded a tropical depression west of the Philippines to Tropical Storm Conson.