Why Telangana received 72% excess rain in October?

Hyderabad: Telangana received a large excess rainfall of 72% even in October, during which southwest monsoon is expected to withdraw. Among the south-Indian states, all of which received excess rainfall, Telangana comes second only to Karnataka, which received 105% excess rainfall for the last month.

In Telangana, Warangal Rural district received the highest excess rainfall (217%) closely followed by Warangal Urban (208%). Karimnagar (198%), Jayashankar Bhupalapalle (191%), Siddipet (169%), Jangaon (136%), Peddapalle (107%) and Kamareddy (100%) are the other districts that recorded excess rainfall in October.

Under the influence of cyclone Maha, Andhra Pradesh faced heavy rainfall on October 30 and 31. The state has 31% excess rainfall for October, which does not come under the large excess category.

According to weather experts, the delayed withdrawal of monsoon has become the norm for the past ten years. Although October is not the typical monsoon month for Telangana, the changing weather systems have led to rainfall that sustained during withdrawal months as well. B Raja Rao, a meteorologist with Indian Meteorological Department (IMD) Hyderabad said, “The southwest monsoon occurs from June to September. The withdrawal is supposed to happen through October. However, the rainfall in October is a pattern that has been happening for the past few years.”

Changing weather systems developed over the Bay of Bengal and the Arabian Sea have affected the monsoon patterns in the state. According to Mahesh Palawat from private weather forecaster service Skymet, the entire southern peninsula recorded excess rainfall in October. “There is a formation of a confluence zone over Telangana, wherein north-easterly dry winds are merging with south-easterly humid winds from the Arabian Sea. This zone has given rise to cloud formation and subsequent rainfall. The frequent rain activity also has to do with the delay in withdrawal leading to southwest monsoon merging with the northeast monsoon. This might continue for another two-three days at least,” he said.

“The presence of the positive Indian Ocean Dipole (IOD), which creates warmer (than normal) sea surface temperature in the Arabian Sea and the Indian Ocean, has also led to increased frequency and intensity of these weather systems this year. This could be why despite monsoon withdrawal expected from October 15 onwards, rainfall has been on and off in the state,” he added.

Amritha Mohan

Amritha Mohan is a reporter at the NewsMeter. Shortly after completing her Master's in Communication at the University of Hyderabad, she began teaching courses on media and culture as a guest lecturer at the Department of Journalism and Mass Communication, North-Eastern Hill University (NEHU), Shillong. Amritha has previously interned with news organisations such as Greater Kashmir and Newslaundry. A lover of travel and photography, she spends most of her time planning road trips to the North-East. Nothing makes her happier than a green turf and a team to play football with. She primarily reports on education, tech, human-interesting and critical features.

2 comments on "Why Telangana received 72% excess rain in October?"

  • This is not unusual. This is a normal pattern. The average onset and withdrawal of southwest monsoon for Telangana are 10th June and 5th October, respectively. The earliest and the late onset and withdrawals are 28 May & 26 June and 12th September and 30th October. They are highly variable. Generally the withdrawal of southwest monsoon coincides with the onset of southwest monsoon. Same is the case with rainfall but it follows a 56-year cyclic pattern and the same was seen in cyclonic activity. Hyderabad’s Average rainfall for October was 70.8 mm. The highest in a month of October was 355.1 mm in 1916; and the highest per day was 117.1 mm on 6th 1903.

    Dr. S. Jeevananda Reddy

  • Cont—: About Rainfall:
    All-India level: The southwest monsoon rainfall forms 78% of annual rainfall at all-India level. Both the annual and southwest monsoon season rainfall presents 60-year cyclic pattern similar to Telugu Astrological Calendar [three years behind Chinese 60-year Astrological Calendar]. Indian rainfall completed two 60-year cycles in recoded rainfall data series. The third cycle started in 1987 [Prabhava]. The first 30 years form the above the average part of “Sign Curve” and it is now completed and moved in to next 30 year below the average part of “Sine Curve”. We are now in this part. The water availability in Godavari River follows this pattern — Bachawat Tribunal data series. The average water availability in the above the average part minus below the average part presented 650 tmc ft. The frequency of occurrence of floods in northwest Indian rivers also followed this pattern of All India rainfall, wherein floods during the above the average period occurred one in three years; and one in ten years during the below the average period occurred.
    However, with the Andhra Pradesh [that includes Coastal Andhra, Rayalaseema & Telangana met sub-divisions] the annual rainfall presents 132 year cycle as this part receives rainfall not only during the southwest monsoon season but also during northeast monsoon season and pre-monsoon through the cyclonic activity. Prior to 1935, 66-year below the average part showed 24 drought years and 12 wet years. The 1935-2000, 66 year above the average part showed 24 wet years and 12 dry years. Since 2001 the below the average 66 year part started. We have seen majority of the years recorded dry period since 2001. The water availability in Krishna River followed this pattern [Bachawat & Brijesh Kumar Tribunals data series]. Since 2001 we have seen the low inflows in to Srisailam & Nagarjunasagar dams.
    However, for dry land agriculture seasonal rainfall plays an important role. Southwest monsoon rainfall of Andhra Pradesh presented 56-year cycle. The northeast monsoon rainfall also presented the same but in reverse order. The cyclonic activity in Bay of Bengal followed the southwest monsoon pattern. Let me give figures for one cycle:
    Period 1 2 3
    1917-1944 75/78/68 46/50/60 10 [10-16]
    1973-2000** 54/54/54 41/45/41 <10 [0-8]

    1 = percentage years with rainfall < 90% of average during the southwest monsoon for Coastal Andhra/Rayalaseema/Telangana; & 2 = same for northeast monsoon; and 3 = number of cyclones. Blue showed 10-16 cyclones during the above the average period of 1945-1972. 1917-1944 presents the below the average part of the cycle.

    Kurnool rainfall followed this pattern. The average drought proneness is 45% of the years. During the below the average period it is 70% of the years and above the average period it is only 30% of the years under purely rainfed condition.

    Dr. S. Jeevananda Reddy

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