weather 27/09/24 : CC to form near Sri lanka, intense rain expected in kerala

weather 27/09/24 : CC to form near Sri lanka, intense rain expected in kerala

As Metbeat Weather forecasted early intense rain expected onece more in kerala due to upcoming cyclonic circulation (CC) over Srilanka month end.

Another upper air circulation (UAC) is likely over south east Sri Lanka around 27th September. Under its influence easterly anomalies and a north – south shear zone running from north interior Maharashtra to south Tamilnadu through interior Karnataka around may cause widespread heavy thunder showers over south and central Tamilnadu and eastern pockets of Kerala from 28th to 1st October.

In the previous week ended at 23.59 hrs on 26th September 2024, the south-west monsoon is on its retreat mode. It has withdrawn mostly from the north western regions comprising Rajasthan, north- western parts of Gujarat . Conditions are becoming favourable for the further retreat of monsoon from Punjab ,Haryana , J&K, NCR Delhi, in the next 3&4 days as the north western heat low has started dissipating.

The monsoon trough has been tilted more south of its mean position at its north- west end and remained south of its normal at its south-east end. The western offshore trough has further weakened from Gujarat to the Malabar coast.

Meanwhile under the influence of the large scale synoptic upper air circulation and associated trough at middle and lower levels, heavy rains have been recorded over many places in gangetic west Bengal, Odisha, Jharkhand, Chattisgarh, east Uttar Pradesh. Another mid tropospheric low over north Arabian sea off the Mumbai coast caused widespread heavy rains along coastal Maharashtra, Konkan & Goa, besides pockets like Bhavnagar, Surat, gulf of Khambat in south coastal Gujarat and central Gujarat. Regions over east Madhya Pradesh, west Madhya Pradesh, and Vidarbha regions too recorded moderate to heavy rains.

In the north east, rainfal has been fairly active over sub- Himalayan west Bengal, west Bengal, upper Assam, Arunachal Pradesh, Meghalaya. In the south, impressive rainfall activity occurred over Telengana, north interior Karnataka & Marathwada. As the western monsoon offshore trough has been weak, only scattered rainfall occurred over Kerala.

Due to trough in the easterlies and wind discontinuity, isolated heavy rains occurred over north and central Tamil Nadu. With the autumn equinox falling on 22st September, coinciding with apparent transit of the Sun to the equator, intense heat has been experienced in central and south interior Tamilnadu. The highest day temperature over the country has been recorded at Madhurai at 41°C on September 25th.

Forecast: Effective from 06:00 hrs from. 27/09/24, to 23:59 hrs on 03/10/24.

The northern monsoon trough would continue to shift southward and dissipate as the north western heat low has lost steam. The large-scale upper air circulation over central India and the associated synoptic features is now favourable for heavy rains over most parts of Jharkhand, Bihar, east Uttar Pradesh from 27th to 29 th September.

Another mid tropospheric low off the Gujarat coast and and east-west shear zone from Gujarat to Jharkhand could trigger very heavy rains over south coastal Gujarat including areas around the Gulf of Khambat on 27 th 28 th & 29 th September.

A line of wind discontinuity and east – west shear zone may lie from north interior Maharashtra to sub- Himalayan west Bengal around 2nd October. An upper air circulation may lie over Assam and adjoining areas of Arunachal Pradesh from 1st October to 3 rd October.

Under its influence widespread thundershowers or rainfall activity is likely over Jharkhand , Odisha, coastal Andhra Pradesh, Telengana , north and south interior Karnataka, gangetic west Bengal, sub-Himalayan west Bengal, Assam & Meghalaya , on 2nd October.

The North east , Uttrakhand , Uttar Pradesh, Bihar, Jharkhand , gangetic west Bengal, regions .

Under the influence of the mid tropospheric cyclonic circulation moderate to heavy rains or thundershowers may be expected in Meghalaya , upper Assam, sub-Himalayan west Bengal, gangetic west Bengal, east Uttar Pradesh, Jharkhand and Bihar on 27 th and 28 th September.

Western, eastern,central and south India

The western offshore trough, is almost dissipated or showing nil activity . However , an upper air cyclonic circulation over south coastal Gujarat may result in very heavy rains over coastal and interior pockets of Gujarat, north coastal Maharashtra and pockets like Palghar, Nashik, Igatpuri , Kalyan Dombivali Virar, Vasai and pockets in north coastal Karnataka from 27 th to 28 th September .

Kerala, Karnataka and Tamil Nadu regions

The western offshore trough may be weak or absent over the Kerala coast . However due to the north-south shear zone extending from interior Karnataka to south interior Tamil Nadu through Kerala, isolated moderate to heavy rains may be expected over the eastern pockets of Kannur, Kozhikode, Wayanad, Malappuram Palakkad, Idukki , Kottayam and Pathanamthitta on 29 th September. Isolated thunder showers are also likely over south interior Karnataka on 29th September.

In the central and southern interior pockets of Tamil Nadu, due to the shear zone extending from north interior Karnataka to south Tamil Nadu, isolated thundershowers may be expected in pockets like Salem, Erode, Namakkal Trichy, Madhurai, Bodi, Theni, Madhurai, Dindigul , Peraiyur, and Arappukkottai on 28th and 29 th September.

General distribution of rainfall and pockets of heavy rainfall alerts for the upcoming week:

North west India:
Nil
North- East India ( moderate to heavy )
Meghalaya, sub- Himalayan west Bengal Imphal, Aizwal, upper Assam, Silchar, Jorhat, Guwahati on 28th September & 2nd October 2024.

Uttrakhand & Himachal Pradesh:
Nil
Bihar & Jharkhand
27 th &28 th September
Uttar Pradesh:( Moderate to heavy)
Bareilly, Faizabad, Agra, Jhansi , Kanpur ,Prayagraj, Varanasi, Jhansi on 27th and 28th September.

Madhya Pradesh: Nil

Gujarat: (Moderate to very heavy)
Surat, Valsad, Veraval , Bhavnagar, Ahmedabad , and Vadodara on 27th and 28 th September .

Maharashtra & Goa: ( Heavy to very heavy)
, Jagaon, Malegaon, Nashik, , Mumbai, Dombivali, Dhanau, Palghar on 27th & 28 th September.

Andhra Pradesh & Telengana ( Moderate to very heavy)
Vizag, Kakinada, Viyayawada, Jagadalpur, Warangal, Mehbubnagar , Khammam, Nalgonda on 24 th & 24th September.

Karnataka:( Moderate to heavy)
Hubbali, Hassan, Devanagare, Tumkur, Kunigal, Mysuru and Bengluru on 29 th September.

Tamil nadu: ( moderate to heavy)
Chennai, Thiruvannamalai, Vellore, Neyveli, Salem, Trichy, Erode, Namakkal, Madhurai and Thirunelveli , Kadayam, and Tenkasi on 28 th & 29 th September.

KERALA
There is no specific alert for extreme heavy rainfall events anywhere in Kerala. However, moderate to heavy thundershowers are likely over most of the eastern pockets and high ranges in all the districts on 29 th September. The rains may be heavier in Pathanamthitta, Idukki, eastern pockets of Kozhikode and Palakkad .

SPECIAL WEATHER ALERT FOR TRAVELLERS AND TOURISTS:
North East India:
Darjeeling, Gangtok, Siliguri, Arunachal Pradesh, Shillong Meghalaya likely to be rainy on 27 th & 28 September .
Maximum and minimum temperature: 22°C & 18°C.

Uttrakhand:(Moderate )
Pithoragarh , Champawat and adjoining hill stations on the eastern Himalayas may expect moderate rains on 27th September. Maximum day temperature 25°C and minimum 15°C in lower Himalayas and 10°C and 5°C in the greater Himalayas lying above 2500 metres above MSL.

The Kedarnath and Badrinath hill shrines in the Gharwal Himalayas may expect light rains on 27th September. Maximum day temperature in Kedarnath is likely to be 9°C and minimum -2°C. In Badrinath the maximum day temperature is likely to be 10°C and minimum at -3°C.
The Hemkund Sahib Gurudwara in the Gharwal Himalayas may remain cloudy with very light rain on 27th September. The maximum day temperature may be 10°C and minimum may range from 4°C to minus 2°C .

Himachal Pradesh .
Manali, Shimla, Bilaspur, Mandi , Kangra valley may remain generally dry or with overcast sky. Maximum & minimum temperature:
24°C and 15°C respectively in Shimla and the lower Shivalik ranges and 15°C and 4°C respectively in Manali and the upper Himalayas and Kinnaur ranges.

Jammu& Kashmir :
Generally dry.
Maximum day temperature in the lower Zabarwan ranges of Himalayas comprising Srinagar would be 27° and minimum 14°C. In the upper reaches of Zankar , Pir Panjal and Ladakh ranges the maximum day temperature would be 14°C and minimum 5°C.

South India:
Hillstations of Ooty and Kodaikanal may be pleasant with generally overcast skies. Kodaikanal may expect isolated moderate to heavy thunder showers or rains on 29th rd and 30th September . Maximum and minimum temperature: 20°C and 13°C in Ooty and 24°C and 13°C in Kodaikanal.

In Kerala the main hillstations of Kerala, , Wayanad , Munnar, Devikulam, Vagamon and Peerumade may expect moderate thunder showers rains on 28th September with maximum day temperature at 22°C and minimum at 16°C in Munnar and Devikulam and in other hill stations with maximum at 28°C and minimum at 20 °C. In Kanthalloor , Vattavada regions, the maximum temperature is likely to be in the range 19°C to 22°C and minimum temperature around 13°C to 15°C with chance of light rains on 28/9/24 . The backwaters in Ernakulam , Alappuzha and Kumarakom may expect moderate rains on 29th September.

(NB: Next weekly post on 03/10/24)