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1975 Porbandar cyclone

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1975 Porbandar cyclone
Cyclone on 21 October
Meteorological history
Formed17 October 1975
Dissipated24 October 1975
Very severe cyclonic storm
3-minute sustained (IMD)
Highest winds150 km/h (90 mph)
Lowest pressure66 hPa (mbar); 1.949 inHg
Category 2-equivalent tropical cyclone
1-minute sustained (SSHWS/JTWC)
Highest winds155 km/h (100 mph)
Overall effects
Fatalities85
Damage75 crore (equivalent to 21 billion or US$250 million in 2023)
Areas affectedGujarat, India
IBTrACS

Part of the 1975 North Indian Ocean cyclone season

The 1975 Porbandar cyclone, also designated Cyclone Sixteen (16A) by Joint Typhoon Warning Center, was a tropical cyclone that affected Gujarat state of India and southern Pakistan from 17 to 24 October 1975. It killed 85 people and caused damages of estimated 75 crore (equivalent to 21 billion or US$250 million in 2023).

Meteorological history

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Map plotting the storm's track and intensity, according to the Saffir–Simpson scale
Map key
  Tropical depression (≤38 mph, ≤62 km/h)
  Tropical storm (39–73 mph, 63–118 km/h)
  Category 1 (74–95 mph, 119–153 km/h)
  Category 2 (96–110 mph, 154–177 km/h)
  Category 3 (111–129 mph, 178–208 km/h)
  Category 4 (130–156 mph, 209–251 km/h)
  Category 5 (≥157 mph, ≥252 km/h)
  Unknown
Storm type
triangle Extratropical cyclone, remnant low, tropical disturbance, or monsoon depression

On 17 October 1975, the remnant of an earlier depression in the west central Bay of Bengal were moving towards India. Next day, the disturbance crossed the Andhra Pradesh coast and weakened into a low-pressure area. However, another low-pressure area formed in the east central Arabian Sea. The system was classified as T1 in the Dvorak technique, suggesting it was a tropical storm. On 19 October, these two low-pressure circulations merged to form a depression centered near Maharashtra coast. The system intensity was classified as T2. The depression continued to intensify and moved west-northwestwards moving into the Arabian Sea. On the morning of the 20 October, the system intensified into a deep depression and was centered near 18.5°N, 70°E in Arabian Sea. The system intensity was classified as T3.5. By the noon, the deep depression had intensified into a cyclonic storm. It continued to move towards northwest. The next day it intensified in the severe cyclonic storm and moved towards north-northeast. On 22 October morning, it slightly weaken before making a landfall on coast about 10-15 km north of Porbandar. It moved northeast and weaken into cyclonic storm by 23 October, centred near Radhanpur. By the next day noon, it had weaken into depression on 24 October near Kota in Rajasthan and then rapidly became a well-marked low-pressure area and moved northeastward before dissipating on 24 October evening near Uttar Pradesh.[1][2][3]

It was the first time since 1877 that a severe cyclonic storm landed in Gujarat in October month and second since a cyclonic storm in October 1917.[2]

Effects

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The height of swells were noted 4 m at Porbandar, 5 m at Dwarka and 6 m at Okha.[1]

The cyclone caused severe damage to livelihoods, killing 85 people. Total damages were estimated to be 75 crore (equivalent to 21 billion or US$250 million in 2023) which incuded buildings, crops, grain storages and others.[1][2] It caused severe damage in Junagadh, Rajkot and Jamnagar districts. Large number of houses were destroyed and the rail traffic was disturbed for about a week.[2]

See also

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References

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  1. ^ a b c Gupta, G. R.; Mishra, D. K.; Yadav, B. R. (1 April 1977). "The Porbandar cyclone of October 1975". MAUSAM. 28 (2): 177–188. doi:10.54302/mausam.v28i2.2687. ISSN 0252-9416.
  2. ^ a b c d Mukherjee, A. K.; Subramanian, S. K. (1 October 1977). "Some features of Porbandar cyclone of October 1975". MAUSAM. 28 (4): 439–446. doi:10.54302/mausam.v28i4.2756. ISSN 0252-9416.
  3. ^ Dube, S. K.; Sinha, P. C.; Rao, A. D.; Rao, G. S. (1 August 1985). "Numerical modelling of storm surges in the Arabian Sea". Applied Mathematical Modelling. 9 (4): 289–294. doi:10.1016/0307-904X(85)90067-8. ISSN 0307-904X.