Tropical Storm Debra (1978) - Meteorological History

Meteorological History

Debra originated in an upper-level cold-core low pressure system that developed over southwestern Florida in late August 1978. The low moved southwest towards the Yucatán Peninsula over the next day, as a tropical wave drifted westwards from the Caribbean Sea. The interaction between the upper-level system and the wave led to the formation of a tropical depression on August 26 around 460 miles (740 km) south of New Orleans.

At first the depression drifted westward but, as the western periphery of a high-pressure area weakened, it tracked towards the north and slowly strengthened. After a reconnaissance aircraft found surface winds of 45 mph (70 km/h) on August 28, the depression was upgraded to Tropical Storm Debra. The aircraft also recorded a minimum pressure of 1002 mbar (hPa; 29.59 inHg). While Debra approached the coast of Louisiana, an additional flight into the system found a drop in surface pressure to 1000 mbar (hPa; 29.53 inHg), as well as peak winds of approximately 60 mph (100 km/h) at 00:00 GMT on August 29. Observation stations off the coast recorded sustained winds of 45–50 mph (70–80 km/h) on August 28, as Debra passed 150 miles (240 km) to the west.

The storm made landfall between Beaumont, Texas, and Lake Charles, Louisiana, on August 28. Two stations recorded surface pressures of 1002 mbar (hPa; (29.59 inHg). As Debra moved north-northeast through Louisiana and Arkansas, the central pressure rose slightly. In south central Arkansas the residual low pressure system merged with a frontal trough on August 29; the frontal wave drifted into southern Illinois and traveled eastbound into the Ohio Valley for the next three days. Five tornadoes were reported from the system in Texas, Louisiana, and Mississippi shortly after Debra's landfall.