Cyclone Yemyin - Meteorological History

Meteorological History

A low pressure area associated with the monsoon trough was first detected by the Naval Research Laboratory in the Bay of Bengal on June 17. Over the next few days, it developed deep flaring convection near an exposed low-level circulation centre (LLCC) as it drifted in open sea. Despite moderate to high vertical wind shear, the disturbance produced surface pressure falls of up to 2.7 mbar (hPa) in Port Blair, in the Andaman Islands, on June 19. Convection persisted around the increasingly well-defined LLCC, and the disturbance continued to consolidate under favourable diffluence.

Early on June 21, the India Meteorological Department (IMD) declared the area a depression, 430 km (270 mi) east-southeast of Kakinada, Andhra Pradesh, India. Several hours later, the Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert (TCFA), with winds near 30 kt (55 km/h, 35 mph). The depression moved quickly west-northwest towards the northern Andhra Pradesh coast. A subtropical ridge to the north weakened the wind shear which had been paralysing the system, allowing for further intensification. Later that day, the IMD upgraded the system to a deep depression. As convection organised with increasing ocean heat content, the JTWC issued its first warning on Tropical Cyclone 03B. The deep depression made landfall near Kakinda early on June 22 local time. The JTWC issued its final advisory later, as the system began to weaken due to land interaction and wind shear. The next day, the IMD downgraded it to a depression while it crossed the Deccan Plateau. The final warning was issued on June 24, despite the storm having moved into the Arabian Sea.

The JTWC noted in its Significant Tropical Weather Outlook for the North Indian Ocean on June 24 that strong monsoonal low-level flow contributed to increased cyclonic vorticity, with low vertical wind shear and warm sea surface temperatures. It warned that these factors could lead to a rapid regeneration of the cyclone. Early on June 25, the JTWC issued the second TCFA for this system as its LLCC crossed the coast into the Arabian Sea. Shortly after, both the IMD and the JTWC resumed advisories on the depression.

As it moved northwest just off the Pakistani coast, winds of about 26 kt (48 km/h, 30 mph) and a surface pressure of 990 mbar (hPa) were observed in Karachi near midday on June 25. According to the PMD, the centre of the system reached within 90 km (55 mi) of Karachi. With favourable conditions and deep convection, the system intensified into a deep depression that day. After further organization, it made its second landfall at about 0300 UTC June 26 along the Makran coast, near Ormara and Pasni, Balochistan province, in southwestern Pakistan. Upon reaching land, the cyclone began to weaken slowly, and the JTWC issued its last advisory late on June 26.