The 1977–78 South-West Indian Ocean cyclone season was a near-average season, with eight tropical cyclones forming.

Seasonal summary

ImageSize = width:800 height:200 PlotArea = top:10 bottom:80 right:20 left:20 Legend = columns:3 left:30 top:58 columnwidth:270 AlignBars = early DateFormat = dd/mm/yyyy Period = from:01/10/1977 till:01/06/1978 TimeAxis = orientation:horizontal ScaleMinor = grid:black unit:month increment:1 start:01/10/1977 Colors = id:canvas value:gray(0.88) id:GP value:red id:TDi value:rgb(0,0.52,0.84) legend:Tropical_Disturbance id:TD value:rgb(0.43,0.76,0.92) legend:Tropical_Depression id:C1 value:rgb(0.3,1,1) legend:Category_1_=_63-87_km/h_(39-54_mph) id:C2 value:rgb(0.75,1,0.75) legend:Category_2_=_88-142_km/h_(55-74_mph) id:C3 value:rgb(1,0.85,0.55) legend:Category_3_=_143-158-km/h_(75-98_mph) id:C4 value:rgb(1,0.45,0.54) legend:Category_4_=_159–204_km/h_(99–127_mph) id:C5 value:rgb(0.55,0.46,0.9) legend:Category_5_=_≥205_km/h_(≥128_mph) Backgroundcolors = canvas:canvas BarData = barset:Hurricane bar:Month PlotData= barset:Hurricane width:10 align:left fontsize:S shift:(4,-4) anchor:till from:24/11/1977 till:04/12/1977 color:C2 text:"Steve (C2)" from:05/12/1977 till:11/12/1977 color:C1 text:"Tessa (C1)" from:23/12/1977 till:31/12/1977 color:C2 text:"Anne (C2)" from:31/12/1977 till:12/01/1978 color:C3 text:"Bob (C3)" from:13/02/1978 till:01/03/1978 color:C3 text:"Charles (C3)" from:15/02/1978 till:22/02/1978 color:C2 text:"Diana (C2)" from:17/02/1978 till:23/02/1978 color:C2 text:"Ernie (C2)" from:13/04/1978 till:22/04/1978 color:C3 text:"Hal (C3)" bar:Month width:5 align:center fontsize:S shift:(0,-20) anchor:middle color:canvas from:01/11/1977 till:30/11/1977 text:November from:01/12/1977 till:31/12/1977 text:December from:01/01/1978 till:31/01/1978 text:January from:01/02/1978 till:28/02/1978 text:February from:01/03/1978 till:31/03/1978 text:March from:01/04/1978 till:30/04/1978 text:April TextData = pos:(568,24) text:"(From the" pos:(617,24) text:" Australian tropical cyclone scale)"

Systems

Tropical Cyclone Steve

Tropical Cyclone Tessa

Tessa precursor tropical depression was first noted on December 5, while it was located in the southern

Line Islands The Line Islands, Teraina Islands or Equatorial Islands () are a chain of 11 atolls (with partly or fully enclosed lagoons, except Vostok and Jarvis) and coral islands (with a surrounding reef) in the central Pacific Ocean, south of the Hawa ...

of Kiribati. Over the next couple of days, the system moved southeastwards and gradually intensified, before it was named Tessa by the FMS during December 7. During December 9, the system moved in between Puka Puka and Reao as it continued to weaken and move south-eastwards towards the Gambier Islands. The system was last noted during December 11, while it was located about to the northeast of Adams Town in the Pitcairn Islands. As the system moved through the Tuamotu Islands of French Polynesia, Tessa caused significant precipitation over the islands, with the Puka Puka weather station recording a 24-hour rainfall total of during December 8.

Tropical Cyclone Anne

For several days during the week building up to Christmas 1977, a tropical disturbance persisted about to the northeast of Fiji and to the northwest of Samoa. A distinct cyclonic circulation subsequently started to develop during December 23, while it was located about to the northeast of Vanua Levu. Over the next day the system moved south-westwards and passed within of Futuna, before it was named Anne by the FMS during December 24, as satellite pictures showed that a tropical cyclone was developing. During December 25, the winds were indirectly estimated to be off gale-force, as it passed south-westwards through the Fijian Islands.

Severe Tropical Cyclone Bob

Severe Tropical Cyclone Charles

Tropical Cyclone Diana

During February 15, a tropical depression developed within the South Pacific Convergence Zone, to the west of French Polynesia's Society Islands. Over the next couple of days, the system moved eastwards towards Mopelia while gradually developing further, before it was named Diana by the FMS during February 16.

Tropical Cyclone Ernie

During February 17, the FMS started to monitor a tropical depression that had developed, about to the northwest of Udu Point in Fiji. During that day, the system deepened as it moved south-eastwards towards Fiji before the FMS named it Ernie.

Severe Tropical Cyclone Hal

Season effects

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References

{{Reflist, 2

External links

{{SPAC EL's {{TC Decades, Year=1970, basin=South Pacific, type=cyclone, shem=yes {{Tropical cyclone season, 1977, split-year=y {{DEFAULTSORT:1977-78 South Pacific cyclone season South Pacific cyclone seasons Articles which contain graphical timelines