APCEDI Alert SP/SI Cyclone Yani (02P/04F)#3-2007: Cyclone Yani meanders slowly southward into open waters.

The RSMC-Nadi Tropical Cyclone Centre and the Joint Typhoon Warning Centre continue to issue guidance on Cyclone Yani that formed yesterday south of Makira and east of Rennell and Bellona.

The Solomon Islands Meteorological Service's Cyclone Website is also now up and running and issuing guidance.

Cyclone Yani is currently centred 200 km south of Makira or 220 km southeast of Rennell/Bellona. It is nearing Category 1 strength on the Saffir Simpson Scale. It is moving very slowly southward at 2-4 kts with a forecast shift in direction to the southwest, but continued slow southerly meandering is likely in the next 12-24 hours along with slow strengthening.

On its current slow southeasterly track, no land areas are immediately threatened, and the storm is moving into the open sea. Nonetheless, early season storms are notoriously unpredictable, and current model guidance for Yani has been all over the place, providing little useful forward prognosis. Therefore, all interests in Makira, Guadalcanal, Rennell and Bellona should pay close attention to this storm and be ready to make any preparations should conditions warrant and authorities advise. Seas in the area are now very rough and local small boating interests should stay in port until advised. All interests in Northern and Central Vanuatu and Nouvelle Caledonie (New Caledonia) should also monitor this storm.


From the RSMC-Nadi Tropical Cyclone Centre

Tropical Disturbance Advisory Number A5 issued from RSMC NADI
Nov 22/2013 UTC 2006 UTC.

Tropical Cyclone YANI 04F [985hPa] centre was located near 12.9S 162.8E at 221800 UTC moving south-southeast about 03 knots but expected to turn west. Position fair based on HRES MTSAT EIR imagery with animation. Maximum 10-minute average winds estimated at 50 knots increasing to 60 knots in the next 12 to 24 hours. Winds over 47 knots within 30 miles of centre and over 33 knots within 120 miles of centre in the southeastern semicircle and within 90 miles of centre in the northwest semicircle.

Organisation steadily increasing though appearing sheared. Primary band still wrapping tightly around llcc. Outflow good to south and west but restricted elsewhere. Dvorak based on curved band wrap of 0.85 on log10 spiral yielding DT=3.5, MET and PAT agree. Final T based on DT thus T3.5/3.5/D1.5/24hrs. Cyclone is located just south of a 250-hPa ridge axis in a divergent and weak shear region. SST around 28-29C. Yani expected to move west under strong mid level ridge to east and south. Global models generally agree on a westward track with gradual intensification.

FORECAST:
12hrs valid 230600UTC near 12.8S 162.4E mov W at 02kt with 55kt close to centre.
24hrs valid 231800UTC near 12.9S 161.8E mov W at 02kt with 60kt close to centre.

OUTLOOK:
36hrs valid 240600UTC near 13.3S 161.0E mov WSW at 03kt with 65kt close to centre.
48hrs valid 241800UTC near 13.7S 159.9E mov WSW at 04kt with 70kt close to centre.

The next Tropical Disturbance Advisory on TC YANI will be issued around 230200 UTC.
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APCEDI will continue to issue further bulletins on Cyclone Yani as the need arises.

Kevin Vang
APCEDI Coordinator

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