By Nathan McCollumTROPICS — Tropical Storm Erika continues to have problems with wind shear. The latest plane investigation indicates a continued rise in the central pressure with a ragged center. The entire structure has taken on a “kidney” type appearance and this usually indicates upper level shear. As Erika continues moving west, it will interact with several of the Caribbean Islands. This will disrupt the evaporation flow and could eliminate the surface low pressure. It is difficult to forecast if Erika will survive the next few days, but the chance of this system becoming a hurricane is slim. There has been some consistency with Erika as far a forward motion and a constant center. This, combined with a clear southwest boundary of the subtropical ridge, is providing a moderate confidence in the 3-day forecast. The long term forecast is not clear because Erika may not survive. The location of Tropical Storm Erika is latitude 16.9 North – Longitude 63.5 West with sustained winds of 40 mph. The system is moving west-northwest at 8mph with a central pressure of 1010 mb. The tropical storm force winds extend 175 miles from the center.
The attached visible satellite picture shows an elongated structure with shear continuing on the west and north side. The attached infrared picture shows plenty of thunderstorm activity with no signs of strengthening. The attached water vapor picture shows the southern edge of the ridge intact and this will continue to steer Erika to the west for several days.
While we have a higher confidence in the forecast today, the interaction with land may offer some modifications to the forecast. The main issue over the next 24-48 hours is the overall structure of Erika. Simply, will it survive? We will continue to monitor the progress over the next few days and see if Ericka survives the Caribbean. There is not indication in the current forecast that Erika will impact Indian River County.
The next advisory will be Friday.
