Cyclone Lin (2009)

Tropical Cyclone Lin

Category 2 tropical cyclone (Aus scale)
Tropical storm (Saffir–Simpson scale)
Tropical Cyclone Lin
Formed	March 31, 2009
Dissipated	April 8, 2009
Highest winds	10-minute sustained: 110 km/h (70 mph) 1-minute sustained: 100 km/h (65 mph)
Lowest pressure	975 hPa (mbar); 28.79 inHg
Fatalities	None reported
Damage	$1,000 (2009 USD)
Areas affected	Fiji, Tonga
Part of the 2008–09 South Pacific cyclone season

Tropical Cyclone Lin (RSMC Nadi designation: 14F, JTWC Designation: 15P) formed on March 31, 2009 as a tropical depression within a monsoon trough to the northwest of Fiji. Over the next few days, the depression moved towards the southeast through the Fijian archipelago until late on April 3, when the Regional Specialized Meteorological Center in Nadi reported that the depression had intensified into a category one cyclone, and named it Lin. The JTWC did not start issuing warnings on Lin until the next day as it was approaching its 10-minute peak windspeeds of 110 km/h (70 mph) and 1-minute peak windspeeds of 100 km/h (65 mph). Cyclone Lin then reached its peak windspeeds early on April 5 as it passed directly over Tonga. Later that day as it approached the edge of RSMC Nadi's area of responsibility Lin started to go through an extratropical transition with the JTWC issuing their last advisory on it. As it crossed into TCWC Wellington's area of responsibility the cyclone was declared extratropical, however TCWC Wellington kept issuing warnings on Lin until late on April 8.

In Tonga initial reports, suggested that only vegetation had been impacted. However, it was later reported that power lines had been knocked down by high winds and the heavy rains triggered minor flooding in Nuku'alofa. Power stations in Tongatapu were also forced to close to protect the system. No one was injured by the storm but there were reports of significant crop losses. The Tongan Meteorological Service also reported that about $2,000 2009 TOP, ($1,000 2009 USD) worth of damage had been done to property owned by the service.

During April 1, RSMC Nadi reported that Tropical Disturbance 14F, had developed along an active monsoon trough to the north of Fiji. During the next day the disturbance gradually developed into a tropical depression, as it moved eastwards and interacted with a shallow tropical disturbance that was located to the east of 14F. The disturbance was subsequently absorbed by 14F’s circulation early on April 3, while the system was located between Tonga and Fiji. Overall organization at this time was still poor with convection struggling to consolidate under shear and diurnal influences. Overnight of the 3rd, though, convection erupted over the centre with the primary band to the east wrapping tightly around the centre. On re-analysis, TD14F attained cyclone status around 031800 UTC while located to the north-northwest of Nukualofa and gradually accelerating towards the southeast. Through April 4, the cyclone moved into minimal shear with good outflow channels aloft. 12 hours later, at 040600 UTC, Lin was upgraded to a storm with 50 knots close to the centre. The cyclone intensified further under favourable conditions and reached a peak intensity of 60 knots while located about 15 nautical miles south-southeast of Nukualofa. As it left Tonga, interaction with drier air and shear increased. This was aided by an approaching upper-trough from the west. At 051800 UTC, intensity was reduced to 45 knots with further weakening anticipated due to stronger shear and cooler waters. Wellington took over warnings for the cyclone from 060000 UTC and downgraded Lin to an extra-tropical system in their first warning. TCWC Wellington subsequently continued to monitor the system until it was last noted on April 8.