Invest 91L over the Bay of Campeche has not changed much in organization since yesterday. The associated thunderstorm activity remains somewhat disorganized, and the low-level circulation is not yet well defined enough to be classified as a tropical depression. An Air Force Hurricane Hunter aircraft was scheduled to visit 91L this afternoon, but the flight was canceled as 91L remains poorly organized.

As of 18:00 UTC Sunday, Invest 91L was centered near 19.7°N 94.5°W, and was nearly stationary. Maximum sustained winds were 25 knots (30 mph), with an estimated minimum pressure of 1007 mb. The National Hurricane Center (NHC) continues to give 91L a 60 percent chance of development, both within 48 hours and five days. If 91L develops into a tropical storm, it will be named Barry. The 18z SHIPS model indicated that conditions are expected to be favorable for development for the next 36 hours or so, with wind shear light (less than 10 knots), sea surface temperatures warmer than 28°C (82.4°F), and a moist-mid level atmosphere (relative humidity values greater than 70 percent). This favors development as long as 91L is able to develop a well-defined circulation and remains offshore.

Deep convection associated with 91L remains disorganized, and the diurnal convective maximum overnight was unable to significantly improve 91L’s organization. However, a recent ASCAT pass indicates that the circulation has become better defined since last night, but it still remains a bit broad. There is a window for 91L to develop into a tropical depression or weak tropical storm on Monday prior to moving inland over northern Mexico on Tuesday. The 12z ECMWF and GFS models were less aggressive on developing 91L today, but it should be noted this is a large Central American Gyre (CAG) system and models often struggle until a definitive low-level circulation develops, if at all. If 91L is able to take advantage of the diurnal convective maximum tonight, it is possible we will have a tropical depression by Monday afternoon. An Air Force Hurricane Hunter aircraft is scheduled to investigate 91L tomorrow if the NHC determines to be necessary. 91L is likely to begin its northward turn tomorrow, and it remains uncertain if 91L will remain offshore or if it will move inland into Mexico. Where a low-level circulation develops, if at all, will be very important for determining 91L’s future track. Interests along the Gulf coast of Mexico, as well as the southern Texas coast, should continue to monitor the progress of 91L over the coming days.

I will be back with an update on 91L tomorrow.