The main issue of this forecast package is the possible tropical development of a closed low over the northeast Gulf. Models have come together with a closed low southeast of the Mississippi Delta later today into tonight. Weak upper level wind flow will allow further development into a deeper system, a tropical depression/storm possibly by early Thursday.
The NHC is currently setting the potential development of a tropical system at 90% by Thursday. Surface low is expected to track southwest into the Gulf through Thursday. At the same time, upper level disturbance will move west over north central Gulf. Both features will be very conducive for tropical development on Thursday. One model continues to show a track just south of the Louisiana coast Friday and Saturday. Another takes the low west but a little farther south. We will maintain 50 to 80 percent chance of rain over the forecast area Wednesday through Monday. As a result, rainfall amounts have been updated 3 to 8 inches with higher amounts. The NWS will more than likely issue Flash Flood Watch for part of all of the forecast area through the weekend.
In addition, prolong east flow will allow water to pile into the Mississippi coast and some coastal flooding is likely Thursday through Sunday. Once our system moves inland Saturday into Sunday, rain chances will remain elevated on Sunday.