Vayu reached peak intensity as a high-end very severe cyclonic storm at 06:00 UTC on 12 June, with three-minute sustained winds of 150 km/h (95 mph) and a minimum pressure of 970 hPa (28.64 inHg).
[10] In early June, a strong pulse of the Madden–Julian oscillation (MJO) tracked eastwards into the tropical Indian Ocean, leading to increased cloudiness and rainfall across the region.
[12] On 9 June, the India Meteorological Department (IMD) noted the development of a low-pressure area over the southeastern Arabian Sea, to the north of the Maldives.
[13] Organisation increased throughout the day, and owing to the improved structure of the system, the United States' Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert at 22:30 UTC.
[15] Conditions were favourable for further intensification, with improving upper-level divergence, and ample energy being provided by extremely warm sea surface temperatures of 31 °C (88 °F).
[22] One-minute sustained winds increased to 165 km/h (105 mph) six hours later as a ragged eye developed on visible-light satellite imagery, surrounded by strong deep convection, particularly in the western semicircle of the storm.
[25][26] As Vayu approached the coastline of the state of Gujarat in northwestern India, the influence of a strengthening subtropical ridge over Saudi Arabia caused the system to gradually slow down and turn towards the west.
[30] Despite the low wind shear and warm ocean, upper-level outflow from the storm had begun to diminish, allowing the dry air entrainment from the northwest to start eroding the cyclone.
Vayu weakened to Category 1-equivalent tropical cyclone status at 12:00 UTC,[32] as the loose central convection expanded to leave a ragged eye 55 km (35 mi) in diameter.
[36] Upon weakening further to a cyclonic storm, strong low-level southwesterly flow caused the system to accelerate northeastwards through the break in the blocking high-pressure ridge, back towards the Gujarat coast.
[31][37] Strong vertical wind shear and dry air ingestion from the western semicircle of the storm's circulation continued to erode the cyclone, and Vayu weakened into a deep depression at 03:00 UTC on 17 June,[38] with the JTWC issuing their final advisory at this time.
[40] Soon afterwards, the IMD issued their final advisory on the system after Vayu degenerated into a well-marked low-pressure area, just before crossing the Gujarat coast near the India–Pakistan border.
[1] As Vayu was initially forecast to make landfall as a very severe cyclonic storm, the potential for major impacts prompted significant preparation measures in the state.
[1] All flights at airports in Porbandar, Diu, Bhavnagar, Keshod and Kandla were grounded from midnight local time on 13 June, and 77 train services cancelled and 38 others shortened.
[10][49] Approximately 2,300 personnel in 52 teams from the National Disaster Response Force were deployed to Gujarat help local authorities with evacuation efforts, as well as to aid in search, rescue and relief operations after the cyclone.
[50] After local governments were informed that Cyclone Vayu was likely to return to the coast of Gujarat, further preparations were undertaken, albeit minor due to the significantly weakened nature of the system.
The IMD warned that heavy rainfall and large waves were expected, and had the potential to inundate low-lying areas such as the coastal salt marshes.
As a precaution, the local government in the Kutch district of northern Gujarat asked salt pan workers in coastal areas from Bhachau to Mundra to stay home from work.
[48] Many low-lying coastal areas on the Saurashtra coast and southern Gujarat were flooded by waves and tides of up to 6 m (20 ft) in height,[54] and severe damage was caused to at least 15 houses in the city of Ullal.
[50] Rainfall associated with Vayu continued for several days in the state of Maharashtra, with the city of Nashik receiving 92.1 millimetre (0.039 in) of precipitation in a 24-hour period on 15–16 June.
[66][67] Enhanced waves and ocean swell generated by Cyclone Vayu while it was located in the northern Arabian Sea also affected some coastal areas of Oman, including the South Al Sharqiyah governorate.
[69] The onset of the Indian monsoon had been delayed past its usual commencement by about one week due to near-El Niño conditions in the tropical Pacific Ocean throughout 2019.
[73][74] One elderly resident in Karachi died of heat stroke on 15 June, and numerous other people were treated in hospitals and medical clinics for symptoms such as dehydration, dizziness and exhaustion.