Tropical Storm Ignacio (1991)

Tropical Storm Ignacio

Ignacio off the coast of Mexico, on September 17
Meteorological history
Formed	September 16, 1991
Dissipated	September 19, 1991
Tropical storm
1-minute sustained (SSHWS/NWS)
Highest winds	65 mph (100 km/h)
Lowest pressure	994 mbar (hPa); 29.35 inHg
Overall effects
Fatalities	23
Damage	Minimal
Areas affected	Southwestern Mexico, Northwestern Mexico
IBTrACS
Part of the 1991 Pacific hurricane season

Tropical Storm Ignacio was a strong tropical storm that deluged the Mexican coast with heavy rains. The 9th named storm and 11th tropical cyclone of the 1991 Pacific hurricane season, the system formed from two tropical waves. The pair moved across the Atlantic during the first ten days of September. The second of the two spawned Tropical Storm Erika in the eastern Atlantic. Emerging into the eastern Pacific between the September 10 and September 12, an area of thunderstorms developed southeast of an upper level cyclone off the southern tip of Baja California Sur due to the interaction of the upper cyclone with the pair of tropical waves. By the September 15, the thunderstorm activity organized into bands, indicating the presence of a new tropical depression, the eleventh of the season. The cyclone moved north-northwest due to steering around the upper cyclone, and became a tropical storm by noon on the September 16. Once the upper cyclone moved away from Ignacio, its motion towards the Mexican coast stopped on September 17, and it executed a slow anticyclonic loop that would be completed late on the September 18. Proximity to land and west to southwesterly vertical wind shear weakened the cyclone, and Ignacio regained tropical depression status late on the September 18. The system dissipated as a tropical cyclone that night, and its remnants moved west-southwest into the tropical Pacific, occasionally flaring up new convection over the succeeding couple days.^[1]