The 1970 season

Tropical Storm Gretchen (1970)

Tropical Storm Gretchen peaked at 45 kt in the Eastern Pacific between July 14, 1970 and July 21, 1970, with a lowest pressure of 1009 mb.

Track and intensity

The whole track of Tropical Storm Gretchen, 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
Eastern Pacific
Dates
July 14, 1970 to July 21, 1970
Peak strength
Tropical Storm, 45 kt (52 mph)
Lowest pressure
1009 mb (29.80 inHg)
Landfall
No; closest approach 552 km (343 mi)
Accumulated cyclone energy
4.0
Fastest the center moved
14 kt (16 mph)
Identifier
EP061970

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
Jul 14, 12:0015.1N 107.7W25 ktTropical depression
Jul 14, 18:0015.4N 109.1W30 ktTropical depression
Jul 15, 00:0015.8N 110.5W40 ktTropical storm
Jul 15, 06:0016.3N 111.5W40 ktTropical storm
Jul 15, 12:0016.7N 112.6W45 ktTropical storm
Jul 15, 18:0016.8N 113.4W45 kt1009 mbTropical storm
Jul 16, 00:0016.7N 114.2W45 ktTropical storm
Jul 16, 06:0016.6N 114.8W45 ktTropical storm
Jul 16, 12:0016.5N 115.4W45 ktTropical storm
Jul 16, 18:0016.5N 115.8W45 ktTropical storm
Jul 17, 00:0016.6N 116.2W45 ktTropical storm
Jul 17, 06:0017.0N 116.4W45 ktTropical storm
Jul 17, 12:0017.3N 116.7W45 ktTropical storm
Jul 17, 18:0017.4N 117.0W45 ktTropical storm
Jul 18, 00:0017.6N 117.2W45 ktTropical storm
Jul 18, 06:0017.8N 117.4W45 ktTropical storm
Jul 18, 12:0017.9N 117.7W45 ktTropical storm
Jul 18, 18:0018.0N 117.9W40 ktTropical storm
Jul 19, 00:0018.2N 118.2W40 ktTropical storm
Jul 19, 06:0018.3N 118.4W40 ktTropical storm
Jul 19, 12:0018.5N 118.6W40 ktTropical storm
Jul 19, 18:0018.6N 118.7W40 ktTropical storm
Jul 20, 00:0018.7N 118.9W35 ktTropical storm
Jul 20, 06:0018.9N 119.2W35 ktTropical storm
Jul 20, 12:0018.9N 119.6W30 ktTropical depression
Jul 20, 18:0018.8N 120.0W25 ktTropical depression
Jul 21, 00:0018.7N 120.4W25 ktTropical depression
Jul 21, 06:0018.6N 120.8W25 ktTropical depression
Jul 21, 12:0018.4N 121.3W25 ktTropical depression

Other Eastern 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.

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