Surface Trough in the Central GOMEX (Is Invest 91L)

[TheAustinMan]

The low-pressure system drifting north towards the Gulf Coast puts it under an area of slightly weaker wind shear (still high, "weaker" here is less than 40 kt). This lasts through about tomorrow. Area-average wind shear may drop to 20-25kt , which is still high but a bit more manageable than what's to come if the disturbance drifts southward thereafter as projected by model guidance. If that expected track is to hold, the system will find itself under the convergent part of an anticyclonically curved jet streak. That, 40-60kt deep-layer and drier continental air advecting into the storm, would probably not bode well for development. The window of opportunity for convective development is between now and about dawn on Friday, with diurnal maximum tomorrow probably providing the best opportunity for the system to get some more organized convection going (so, morning/early afternoon tomorrow). If a strong vortex can't take root by then, that convection will probably flying off to the east and southeast Friday and Saturday as the low dives south.

[cycloneye]

INVEST 91L is up