Hurricane Ilsa (1971)

Basin

Eastern Pacific

Dates

July 31, 1971 to August 8, 1971

Peak strength

Category 3, 100 kt (115 mph)

Lowest pressure

978 mb (28.88 inHg)

Landfall

No; closest approach 417 km (259 mi)

Accumulated cyclone energy

10.8

Fastest the center moved

22 kt (25 mph)

Identifier

EP091971

No source this site reads publishes a machine-readable casualty or damage figure for a storm of this era. The National Hurricane Center’s season tables begin in 1995 and carry deaths and damage only from 2005 in the Atlantic and 2020 in both basins; the US Storm Events record begins in 1996.

• Hurricane AgathaEastern Pacific · 1971Cat 285 kt · 972 mb
• Hurricane BridgetEastern Pacific · 1971Cat 285 kt
• Hurricane CarlottaEastern Pacific · 1971Cat 175 kt · 980 mb
• Hurricane DeniseEastern Pacific · 1971Cat 4120 kt · 951 mb
• Tropical Storm EleanorEastern Pacific · 1971Tropical Storm50 kt · 1009 mb
• Hurricane MaryEastern Pacific · 1971Cat 180 kt · 975 mb
• Hurricane Francene:FrancescaEastern Pacific · 1971Cat 3100 kt · 991 mb
• Tropical Storm GeorgetteEastern Pacific · 1971Tropical Storm50 kt · 991 mb
• Hurricane HilaryEastern Pacific · 1971Cat 285 kt · 964 mb
• Tropical Storm JewelEastern Pacific · 1971Tropical Storm60 kt
• Tropical Storm KatrinaEastern Pacific · 1971Tropical Storm55 kt
• Unnamed tropical depressionEastern Pacific · 1971Tropical Depression25 kt
• Hurricane LilyEastern Pacific · 1971Cat 175 kt
• Hurricane MonicaEastern Pacific · 1971Cat 3100 kt · 1005 mb
• Hurricane NanetteEastern Pacific · 1971Cat 285 kt · 990 mb
• Hurricane PriscillaEastern Pacific · 1971Cat 3110 kt · 951 mb
• Tropical Storm RamonaEastern Pacific · 1971Tropical Storm50 kt
• Tropical Storm SharonEastern Pacific · 1971Tropical Storm35 kt · 1009 mb

A best track is the record a warning agency settles on after the storm, not what it said at the time: position, maximum sustained wind and central pressure every six hours, revised against every observation that came in later. Category is the Saffir-Simpson scale, which runs from Category 1 at 64 kt to Category 5 at 137 kt and reads wind only, so it says nothing about surge or rain. Accumulated cyclone energy adds up the square of the wind through the storm's life, so it counts strength and duration together.

Storm history from NOAA NCEI’s International Best Track Archive for Climate Stewardship (IBTrACS), which merges the official best track of every warning agency. Live storms, cones, watches and warnings from the National Hurricane Center and the Central Pacific Hurricane Center. Archived radar from NOAA’s Level II archive.

The National Hurricane Center has published no tropical cyclone report for this storm.