Tropical Storm Erin Impacting the Cape Verde Islands

Watching the Caribbean and Gulf

Tropical Storm Erin is passing to the southwest of the Cape Verde Islands and is bringing heavy rain bands and gusty winds to the southernmost Cape Verde Islands. Total rainfall of 2-4 inches will occur through later today across the southernmost Cape Verde Islands as well as wind gusts to around 40 mph that may cause localized power outages. Due to the system moving off quickly to the west-northwest, wind and rain will subside by this evening and early tonight across the southernmost islands of Maio, Santiago, Fogo and Brava.


As the system remains on the west-northwest track, it should gradually strengthen later today as it is moving through a zone of fairly warm water and relatively light wind shear. The system should continue on this general west-northwest track and maintain its tropical storm status through the weekend. However, by later in the weekend, Erin will move into a zone of cooler ocean waters and higher wind shear.

Thus, Erin will struggle to strengthen beyond Saturday and may even begin to weaken by the end of the weekend. As a matter of fact, the shear may become strong enough that some computer forecast models suggest Erin could fall apart early next week. In the meantime, once Tropical Storm Erin pushes west of the Cape Verde Islands later today and tonight, it will continue across the open waters of the eastern and central Atlantic and not will not impact any more land masses in the foreseeable future.

The other order of business is to discuss the broad area of low pressure just east of the Yucatan Peninsula which is causing shower and thunderstorm activity over the northwestern Caribbean and Yucatan at this time. Over the last 6 hours or so, satellite imagery shows that the thunderstorm activity associated with this disturbance has actually weakened somewhat. The center of this low will move northwestward across the Yucatan today and tonight, which should prevent further tropical organization and development.

The low center will then move into the south-central Gulf of Mexico sometime on Friday. At this point, there will be some opportunity for further development as water temperatures are certainly warm enough to support it. However, wind shear will increase over the western half of the Gulf of Mexico tomorrow into the weekend and this will either prevent the low from developing all together or at the very least, prevent it from becoming all that strong.

Mid- and high-level moisture from the disturbance will likely stream northward into the Gulf Coast states even if the low-level center is left further behind across the southern Gulf of Mexico. This moisture being pulled northward could lead to localized heavy rainfall and flash flooding across parts of the Florida Panhandle, southeastern Alabama and southern Georgia through the weekend. If this disturbance were to become a named storm, its name would be Fernand.

Aside from the disturbance near the Yucatan Peninsula and Tropical Depression Five, we are also monitoring a pair of tropical waves approaching the Lesser Antilles. However, these waves have very little shower and thunderstorm activity associated with them and they are passing through an environment that is not all that conducive for tropical development. Thus, we do not expect any further development or organization from these waves over the next few days.