GERTIE
1970-71 season · AU197071_13U
History
Tropical Cyclone Gertie developed from a tropical low that formed over the eastern Indian Ocean to the north of the Kimberley coast of Western Australia on 11 February 1971. Steered on a south-westward course by a ridge of high pressure extending over the Australian interior, the low organised steadily and was classified as a tropical cyclone on 12 February, being assigned the name Gertie by the Bureau of Meteorology's tropical cyclone warning centre in Perth.
Over the following days Gertie ran roughly parallel to the West Kimberley coastline before bending onto a south-southwesterly heading that took it towards the Pilbara. The system reached its greatest strength on 15 February as it closed on Nickol Bay, peaking as a Category 2 system on the Australian scale with an estimated central pressure near 980 hPa. Maximum ten-minute sustained winds were in the order of 100–110 km/h (about 55–60 knots), while gusts near the landfall zone were estimated at 150–165 km/h.
Gertie crossed the coast near Dampier and Roebourne on the evening of 15 February, close to its peak strength. Moving inland across the rugged Pilbara, it weakened quickly, losing tropical characteristics and becoming a deep land depression on 16 February before dissipating over the interior desert.
The cyclone caused widespread damage through the West Pilbara settlements of Dampier, Karratha and Roebourne. Strong gusts stripped roofs from dozens of houses, damaged commercial premises, brought down power distribution lines and uprooted trees. Iron ore processing and port facilities at Dampier were badly affected, with ore loading platforms damaged and shipping suspended for several days amid wind damage and high seas along Nickol Bay. Heavy rainfall produced flash flooding in local river catchments, cutting the coastal highway and isolating pastoral stations. Although the damage bill ran into millions of dollars, no deaths were attributed directly to the cyclone.
Gertie stands out as a destructive early-season system in the 1971–72 Australian region cyclone year.
Sources: Bureau of Meteorology report Wikipedia
View full track data (16 observations)
| Date/Time (UTC) | Category | Position | Pressure | Wind |
|---|---|---|---|---|
| 1971-02-10 23:00:00 | 1 | -16.9, 149.5 | 1001 hPa | — |
| 1971-02-11 11:00:00 | 1 | -17.4, 150.5 | 1000 hPa | — |
| 1971-02-11 23:00:00 | 1 | -18.3, 152.1 | 1000 hPa | — |
| 1971-02-12 11:00:00 | 1 | -19.1, 153.4 | 996 hPa | — |
| 1971-02-12 23:00:00 | 1 | -20.0, 153.6 | 992 hPa | — |
| 1971-02-13 11:00:00 | 1 | -20.5, 153.3 | 983 hPa | — |
| 1971-02-13 23:00:00 | 1 | -20.8, 152.9 | 983 hPa | — |
| 1971-02-14 08:00:00 | 1 | -21.0, 152.2 | 983 hPa | — |
| 1971-02-14 11:00:00 | 1 | -21.0, 151.8 | 983 hPa | — |
| 1971-02-14 17:00:00 | 1 | -21.0, 150.7 | 983 hPa | — |
| 1971-02-14 23:00:00 | 1 | -20.6, 149.7 | 984 hPa | — |
| 1971-02-15 11:00:00 | 1 | -19.3, 148.0 | 988 hPa | — |
| 1971-02-15 14:00:00 | 1 | -18.9, 147.4 | 988 hPa | — |
| 1971-02-15 21:00:00 | 3 | -18.1, 146.0 | 988 hPa | — |
| 1971-02-15 23:00:00 | 2 | -18.1, 145.6 | 996 hPa | — |
| 1971-02-16 08:00:00 | 2 | -17.3, 144.2 | 999 hPa | — |