Tropical Storm Cristobal Slowly Strengthens

Tropical Storm Cristobal slowly strengthened on Saturday morning.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Cristobal was located at latitude 24.2°N and longitude 90.1°W which put it about 345 miles (555 km) south of the Mouth of the Mississippi River.  Cristobal was moving toward the north at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 994 mb.

A Tropical Storm Warning was in effect for the portion of the coast from Intracoastal City, Louisiana to the Okaloosa/Walton County Line in Florida.

Although Tropical Storm Cristobal still did not exhibit the typical structure of a tropical storm, the circulation around it was more organized on Saturday morning.  A band of showers and thunderstorms wrapped around the western and southern sides of the center of circulation.  The strongest winds were occurring in a part of this band about 100 miles (160 km) south of the center of Cristobal.  A few thunderstorms formed just to the west of the center of circulation.  The structure of the wind field around Tropical Storm Cristobal was still asymmetrical.  Winds to tropical storm force extended out 240 miles (390 km) to the east of the center of circulation.  Winds to tropical storm force only extended out 140 miles (220 km) on the western side of Cristobal.

Tropical Storm Cristobal will move through an environment favorable for intensification during the next 24 hours.  Cristobal will move over water where the Sea Surface Temperature is near 27°C.  It will move under the western side of an upper level ridge.  The ridge will produce southerly winds which will blow toward the top of the circulation.  Those winds will produce some vertical wind shear, but the shear will not be great enough to prevent intensification.  The flow around the ridge will enhance upper level divergence to the northeast of Cristobal.  Enhanced upper level divergence could pump away enough mass to allow the surface pressure to decrease.  Tropical Storm Cristobal will strengthen during the next 24 hours.  If more thunderstorms form close to the center of circulation and an inner core develops, then there is a chance Cristobal could intensify into a hurricane.

Tropical Storm Cristobal will move around the western side of a subtropical high pressure system.  The high will steer Cristobal toward the north during the next 18 to 24 hours.  A ridge in the middle levels will move north of Tropical Storm Cristobal on Sunday afternoon.  That ridge could force Cristobal to move toward the north-northwest for a few hours.  On its anticipated track the center of Tropical Storm Cristobal could approach the coast of Louisiana on Sunday afternoon.

The large circulation around Tropical Storm Cristobal means that it will bring gusty winds to Northwest Florida, Southwest Alabama, Southern Mississippi, and Southeast Louisiana.  Those winds will push water toward the coast and they will cause a storm surge on the northern Gulf Coast.  The water level could rise 1 to 4 feet (0.3 to 1.3 meters) along the coast.  The storm surge could be 3 to 6 feet (1 to 2 meters) in parts of southeast Louisiana.  Areas outside levee systems could go under water.  Tropical Storm Cristobal will also drop heavy rain over southern Mississippi and southeastern Louisiana.  Fresh water flooding could occur.  Flood Watches have been issued for parts of those regions.