Tropical Cyclone Sarah

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The active (well, in comparison to recent years) South Pacific cyclone season continues with the formation of TC 17P, 800 miles east-northeast of Pago Pago, the eastern most formation of a tropical cyclone this year in this basin. The area around Pago Pago seems to be the spawning point of these TC's (Nisha, Oli, Pat, Rene and now this cyclone), with the western half of the basin (closer to Australia) having been devoid of activity.

Convection has persisted over a tightening LLC, prompting the upgrade from JTWC. Initial intensity is 35kts. 17P is in a moderately sheared environment at present which has slightly shifted convection to the east of the LLC. This moderate shear is expected to stop 17P from intensifying greatly for the next 24-36hrs. After which, shear is expected to ease and therefore outflow improve, which should allow for some bigger intensity gains. The cyclone is moving southeastwards but in a similar vein to 17P's predecessors, the subtropical ridge to the east should send 17P southwards then southwestwards as the ridge sinks towards the southeast again. If this track verifies, 17P should pass directly halfway between Pago Pago and Rarotonga, hopefully causing little damage to both islands.

[Somerset Squall]

The shear was much stronger than anticipated, and as a result, 17P has weakened to 30kts and JTWC has ceased advisories. Convection is disorganised and although covering the LLC presently, it is not persisting over the centre. Shear will remain strong for at least the next 24-36hrs. However, if the remnant low can survive this long it stands a chance of re-developing as shear will eventually ease. Some models are picking up 17P again beyond 24hrs as a result of the eventual decrease in shear. This may not be the last we here from 17P, but for now, this system no longer qualifies as a tropical cyclone.

[Cookie]

blimey, should i just go back on holiday?

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blimey, should i just go back on holiday?

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The remnant low of 17P has moved into an area of lower shear, and as a result, appears to be getting better organised again- so much so that JTWC have issued a tropical cyclone formation alert on the remnants. Sea temperatures are warm, despite the low having moved to the south since the final advisory was issued. Outflow is also good which is enhancing the current blow up of convection over the well defined LLC. Looks like 17P will rise from the dead later tonight or tomorrow if current trends continue.

[Cookie]

[Somerset Squall]

The remnant low of 17P has continued to re-strengthen and has been upgraded to Tropical Cyclone Sarah, with intensity rising to 35kts. Sarah is currently in a moderately sheared environment, but this should ease slowly though the next 24hrs to allow some modest intensification. Waters are warm but will taper off on the southward or southwestward track over the next day or two. Sarah probably has time to get to about 50-60kts in my opionion before conditions deteriorate. Sarah should pass between Rarotonga and Pago Pago, so hopefully land impacts will be minimal.

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the JTWC have issued a final warning on the system.