The 1970 season

Tropical Depression Isa (1970)

Tropical Depression Isa peaked at 25 kt in the South Pacific between April 14, 1970 and April 19, 1970, with a lowest pressure of 990 mb, and made landfall.

Track and intensity

The whole track of Tropical Depression Isa, colored by strength, with the other storms of the 1970 season in the same basin behind it, and its wind and pressure hour by hour. Every fix is in the track table below.

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The storm

Basin
South Pacific
Dates
April 14, 1970 to April 19, 1970
Peak strength
Tropical Depression, 25 kt (29 mph)
Lowest pressure
990 mb (29.23 inHg)
Landfall
Yes
Accumulated cyclone energy
0.0
Identifier
SH311970

Deaths and damage

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.

Track

Time (UTC)PositionWindPressureStatus
Apr 14, 00:009.6S 163.9E10 kt990 mbTropical storm
Apr 14, 06:009.7S 163.2E15 ktTropical storm
Apr 14, 12:009.8S 162.5E20 kt990 mbTropical storm
Apr 14, 18:009.9S 161.8E25 ktTropical storm
Apr 15, 00:0010.0S 161.1E25 kt990 mbTropical storm
Apr 15, 06:009.5S 160.8E20 ktTropical storm
Apr 15, 12:008.9S 160.7E20 kt990 mbTropical storm
Apr 15, 18:008.5S 160.5E15 ktTropical storm
Apr 16, 00:008.2S 160.0E15 ktTropical storm
Apr 16, 06:008.0S 159.3E20 ktTropical storm
Apr 16, 12:007.9S 158.7E20 ktTropical storm
Apr 16, 18:007.8S 158.0E20 ktTropical storm
Apr 17, 00:007.8S 157.4E20 ktTropical storm
Apr 17, 06:008.0S 156.5E20 ktTropical storm
Apr 17, 12:008.2S 155.6E20 ktTropical storm
Apr 17, 18:008.6S 154.8E15 ktTropical storm
Apr 18, 00:008.8S 154.2E15 ktTropical storm
Apr 18, 06:008.9S 154.0E15 ktTropical storm
Apr 18, 12:009.0S 154.0E15 ktTropical storm
Apr 18, 18:009.3S 154.2E15 ktTropical storm
Apr 19, 00:009.5S 154.7ETropical storm

Other South Pacific storms of 1970

What this means

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.

Sources

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.