A low pressure system formed over the Bay of Campeche on Saturday.  The low pressure system was designated as Invest 91L.  At 8:00 a.m. EDT on Saturday the center of the low pressure system was located at latitude 18.8°N and longitude 92.7°W which put the center about 150 miles (240 km) west of Campeche, Mexico.  The low pressure system was moving toward the west at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 25 m.p.h. (40 km/h) and there were wind gusts to 35 m.p.h. (55 km/h).  The minimum surface pressure was 1005 mb.

A low pressure system formed in the northern end of a tropical wave over the eastern Bay of Campeche on Saturday.  There was a well developed low level center of circulation that was visible on satellite images.  However, there were few thunderstorms near the center of circulation.  Thunderstorms were starting to form in bands in the eastern side of the low pressure system.  Bands in the rest of the low pressure system consisted primarily of showers and lower clouds.

The low pressure system designated as Invest 91L will move into an environment mostly favorable for the formation of a tropical cyclone during the next 36 hours.  The low pressure system will move over water where the Sea Surface Temperatures are near 31°C.  It will move over the eastern part of an upper level ridge over northern Mexico and the western Gulf of Mexico.  The upper level ridge will produce northerly winds that will blow toward the top of Invest 91L’s circulation.  Those winds will cause moderate vertical wind shear.  The wind shear will inhibit the formation of a tropical cyclone, but the shear will not be enough to prevent the formation of a tropical depression or a tropical storm.

There is a second low pressure system embedded in a nearly stationary front over the northwestern Gulf of Mexico.  The second low pressure system could drift toward the southwest during the next day or two.  It is possible that the circulation around the second low pressure system and the circulation around Invest 91L could merge early next week.

The low pressure system designated as Invest 91L will move around the southwestern part of a high pressure system that extended from the western Atlantic Ocean to the Gulf of Mexico.  The high pressure system will steer Invest 91L toward the west-northwest during the next 24 hours.  On its anticipated track, the low pressure system designated as Invest 91L will move toward the western Bay of Campeche.

If the second low pressure system over the northwestern Gulf of Mexico interacts with Invest 91L, then the low pressure system designated as Invest 91L could get pulled toward the north during the first half of next week.  If Invest 91L get pulled toward the north, then it would spend more time over water and it would have more time to strengthen.  The low pressure system designated as Invest 91L could affect the coast of Texas and Louisiana in a few days.