So what do the experts say is next for tropical storm Isaac?
Wednesday morning, the US National Hurricane Centre expected Isaac, a poorly organised storm, to dissipate over the next five days or sooner due to wind shear, but as of Wednesday afternoon, those predictions are evolving.
Chief Meteorologist Kerry Powery of the National Weather Service predicted Monday that wind shear could have an impact on then-hurricanre Isaac’s size and intensity.
“They’re expecting upper-level trough to begin to put shear to the equation and start to diminish the strength of the storm. That’s where the uncertainly comes in,” said Mr. Powery.
Since then, Isaac has been downgraded to a tropical storm. As of Wednesday morning, it appeared wind shear could take the wind out of Isaac’s sails entirely.
In general, wind shear refers to any change in wind speed or direction along a straight line.
The US National Hurricane Centre said an upper-level trough is dropping southward over the central Atlantic, which has increased wind shear over Isaac. This high shear is forecast to remain for the next day or two, and it’s possible that Isaac will degrade into a tropical wave during that time.
While wind shear could decrease over the East-central Caribbean sea, there might not be much of a system left to take advantage of the more conducive conditions. The official NHC forecast shows Isaac slowly weakening, as it tracks to the west near the 15th parallel, and as of Wednesday afternoon, the models continued to show dissipation over the next four or five days.
Now, the US National Hurricane Centre in its latest update Wednesday afternoon, models are suggesting Isaac may re-intensify as it reaches the Western Caribbean.
In its long range forecast, the National Hurricane Centre is no longer predicting dissipation. What a difference two hours makes.
Tropical storm warnings are already in effect for Martinique, Dominica, and Guadeloupe. Tropical storm watches have been placed for Montserrat, St. Kitts and Nevis, Antigua, and Saba and St. Eustatius.