A low pressure system formed over the Eastern Gulf of Mexico on Saturday. At 2:00 p.m. EDT on Saturday the center of The low pressure system was located at latitude 26.6°N and longitude 84.5°W which put the center about 125 miles (200 km) west of St. Petersburg, Florida. The low pressure system was moving toward the northwest at 4 m.p.h. (6 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 1015 mb.
The U.S. National Weather Service designated the low pressure system over the eastern Gulf of Mexico as Invest 91L.
A large but weak surface low pressure system formed over the eastern Gulf of Mexico on Saturday. The circulation around the low pressure system covered much of the eastern Gulf of Mexico. There were several smaller counterclockwise circulations rotating around the periphery of the large surface low. Those smaller circulations had formed inside clusters of thunderstorms. There were not many thunderstorms near the center of the large surface low. There were several broken bands of showers and thunderstorms revolving around the large low.
The large low pressure system will move through an environment somewhat favorable for the formation of a tropical depression during the next 24 hours. The low pressure system will move over water where the Sea Surface Temperatures are near 30°C. It will move under northern part of an upper level low that is over the eastern Gulf of Mexico. The upper low will produce easterly winds that will blow across the top of the surface low pressure system. Those winds will cause moderate vertical wind shear. The vertical wind shear will inhibit the formation of a tropical depression, but the shear may not be strong enough to prevent that formation. The U.S. National Hurricane is indicating the probability is 40% that a tropical depression forms.
The low pressure system will move around the southwestern part of a high pressure system that is over the western Atlantic Ocean. The high pressure system will steer the low pressure system slowly toward the northwest during the next 24 hours. On its anticipated track, the surface low pressure will move toward the northern Gulf Coast.
