Posted: Jun 25, 2010 8:02 AM by Dave Baker
The thunderstorm activity associated with a tropical wave in the western Caribbean is getting more consolidated this morning, which points to what may be our first tropical depression in its formation stage. This disturbance has been monitored for over a week, since it first appeared about half way across the Atlantic. Generally something developing in the Atlantic or even the eastern Caribbean during the month of June is rare, but the western Caribbean where the wave is located now, is considered one of the hot spots for development this time of year.
Water temperatures in the area are in the 84-88 degree range. Water temperatures over 80 are needed to sustain tropical systems. Also the heat content, and the depth of the warm water is ideal in this area. High moisture values through the column of air above the disturbance is another factor that can aid the development. Finally, low wind shear is present, and this low wind shear is forecast to remain in place as the system drifts westward. Reconnaissance aircraft are scheduled to be in the area to investigate this afternoon to see if a tropical depression is forming or may have already formed.
There were slight pressure drops measured on a buoy near the suspected area, but nothing that would signal that the depression has formed. Wind speeds in that area have been 20-25 knots, or just below tropical depression status.
Models have been trying to develop this system for a few days, and most models do bring this to depression or named storm status in the next couple of days. The track drifts it toward the west-northwest toward the Yucatan Peninsula. With its proximity to land, the intensity models have backed off, keeping this disturbance as a tropical depression, or weak tropical storm into the Bay of Campeche. A cold front is drifting southward and may reach the Gulf coast by Monday. This could pull the system more northerly, but a cold front reaching the coast in late June is pretty rare.