By the end of November 2023, significant changes are expected to occur in weather and rainfall dynamics over the Indian subcontinent. The meteorological developments include the influence of a Western Disturbance and the formation of a Low-Pressure Area in the Bay of Bengal, both of which will impact different regions with varying intensities.
Western Disturbance and its Impact:
A Western Disturbance, defined as a trough in mid and upper tropospheric westerlies with its axis at 5.8 km above mean sea level, is currently positioned along Long. 79°E to the north of Lat. 23°N. This disturbance is expected to affect the Western Himalayan region starting from the night of November 29, 2023. Additionally, a trough in easterlies is predicted to run from the Southeast Arabian Sea to North Maharashtra, leading to an interaction between middle-level westerlies and lower-level easterlies over the central parts of the country during the period from November 29 to December 1, 2023.
Under the influence of these systems, the following weather conditions are anticipated:
- Jammu-Kashmir-Ladakh-Gilgit-Baltistan-Muzaffarabad: Scattered to fairly widespread light to moderate rainfall with isolated thunderstorm activity is very likely during November 29-30, followed by a significant reduction.
- Northwest India: Light rainfall is expected at isolated places over the plains during the next two days.
- Madhya Pradesh and Vidarbha: Light to moderate scattered to fairly widespread rainfall with thunderstorms and lightning at isolated places is likely over West Madhya Pradesh (next 2 days), East Madhya Pradesh (next 3 days), and Vidarbha (next 24 hours).
- Maharashtra and South India: Light to moderate scattered to fairly widespread rainfall with thunderstorm activity is expected over Madhya Maharashtra and Marathwada (next 2 days) and over Tamil Nadu, Puducherry, Karaikal, Kerala, and Mahe (next 5 days).
Low-Pressure Area in the BOB:
Simultaneously, a Low-Pressure Area over the South Andaman Sea, now a Well Marked Low-Pressure Area over the Southeast Bay of Bengal and adjoining South Andaman Sea, is forecasted to intensify into a Depression by November 30, 2023. Subsequently, it is expected to become a Cyclonic Storm over the Southwest and adjoining Southeast Bay of Bengal within the next 48 hours.
Warnings Associated with the Low-Pressure Area:
(i) Rainfall Warning:
- Nicobar Islands: Light to moderate rainfall at most places with isolated heavy rainfall likely from November 29 to December 1, including isolated heavy to very heavy rainfall on November 29.
- Andaman Islands: Light to moderate rainfall at most places with isolated very heavy rainfall expected on November 30.
(ii) Wind Warning:
- Andaman & Nicobar Islands: Strong wind speeds reaching 25-35 kmph, gusting to 45 kmph, are likely on November 29.
- Bay of Bengal: Squally weather is predicted with wind speeds reaching 40-50 kmph, gusting to 60 kmph, on November 30, increasing to 50-60 kmph, gusting to 70 kmph, on December 1, and further intensifying to Gale Wind speeds of 60-70 kmph, gusting to 80 kmph, on December 2.
(iii) Fishermen Warning:
Fishermen are advised to avoid venturing into specific regions on the specified dates, with a general advisory for those off the east coast of India to return to the coast by December 1.
Residents and travelers in the affected regions are urged to stay informed about the evolving weather conditions and adhere to the precautionary measures outlined in the official warnings.
Source: India Meteorological Department
