Southeast Gulf Sufficiently Warm to Allow 91L To Strengthen

Fig. 1: Tropical cyclone model tracks issued for 91L. Toward Fort Myers is the likely track.

Discussion: During the mid-afternoon hour, Tropical Disturbance 91L is located near the northeast coast of the Yucatan Peninsula. The system is disorganized and looks less impressive this afternoon compared to this morning. The over-land location coupled with strong shear axis to the north is suppressing development. However, once the low-pressure area is off-shore a tropical depression should form followed by a general northeast trek to southwest Florida by Saturday with strengthening to a tropical storm likely. Tropical cyclone models insist intensification to a tropical storm is unlikely but the Gulf of Mexico SST pattern is favorable for development and upper shear should ease.

Fig. 2: Tropical cyclone model intensity forecast issued for 91L. Models doubt tropical storm but SST sufficiently warm if upper shear eases for development.

Fig. 3: North Atlantic basin satellite view of 91L. Thunderstorm activity has diminished for now – that should change overnight.

Fig. 4: Gulf of Mexico sea surface temperatures. Threshold for development is in the 81-82F range which is available for the expected southeast Gulf track.