Somerset Squall

Zena's small eye cleared out overnight and winds increased to 90kts. So much for the 45kt peak initial forecast! Zena has began to lose it's symmetrical structure this morning, so the cyclone has peaked and will weaken through today. Zena is going to provide flooding rains to Fiji, worsened by the fact a tropical disturbance (that has now moved off to the east) has already caused flooding to the country in the last couple days.

18P has rapidly strengthened and has been named Zena. Winds have increased markedly to 65kts according to JTWC. Zena has developed an eye feature embedded in a small central dense overcast. Some additional strengthening is possible in the next 12hrs before shear rises over Zena, inducing weakening.

After a March with no tropical cyclones in the South Pacific, one has formed in the northern Vanuatu Islands, bringing very heavy rains here. Winds are at 35kts according to JTWC. 18P is moving east-southeastwards at a fair pace, towards Fiji. Some additional intensification is expected as shear is relatively low and outflow good, especially in the eastern quadrant. In 36hrs, increasing shear will serve to inducea weakening trend as 18P continues to gain lattitude. JTWC expect a peak of 45kts.

Emeraude has weakened, not strengthened. Upwelling of cooler waters is a factor that combined with increased shear to weaken the system to 30kts. JTWC have ceased warnings on the system, stating that there is a chance of regeneration as the remains of Emeraude travel west into a potentially more favourable environment (certainly over warmer water anyway). For now, Emeraude is no more. Certainly a very odd track. Emeraude has actually completed a full loop and has degenerated into a remnant low pretty much where it formed a week ago.

Emeraude weakened to 60kts but has since re-intensified to 70kts. The storm is under low shear and warm sea temperatures, but is struggling with dry air. Nonetheless, Emeraude should intensify some over the next day or two as the track shifts to the west as a ridge to the south begins to dominate. Emeraude is currently forecast to have a second peak of 80kts, then weaken as outflow becomes choked once more. Currently, by day 5, Emeraude is forecast to turn south as an approaching trough weakens the ridge. This trough could increase poleward outflow which could provide a third round of intensification at this time. Due to the complex steering environment and varying upper level conditions, the forecast is subject to change and is of low confidence.

Looped track:

Indeed Vorticity, I think upwelling is a factor as Emeraude is now tracking back southeastwards over it's previous track. Winds are down to 85kts according to JTWC, but I agree, this could be a generous assessment. It does look like Emeraude could restrengthen in a day or two as it moves back over warmer water and into a temporary period of lower shear.

Emeraude has continued to rapidly intensify and now has winds of 125kts according to JTWC, a solid category 4 on the SS scale. Further intensification is possible over the next 24hrs, before environmental conditions worsen as Emeraude picks up speed on a southeasterly track.

Emeraude has rapidly intensified and now as winds of 90kts, a cat 2 on the SS scale. The cyclone has developed a pinhole eye, embedded in cold cloud tops with strong banding features surrounding the inner core. Further rapid strengthening is expected, with a peak of cat 4 on the SS scale forecast.

Finally, another tropical storm forms in this record breakingly quiet southern indian ocean season. Emeraude is located in the central/eastern portion of the basin, well west of Cocos Island. The storm has well developed banding features surrounding a fairly intense core of convection. This is a sign of a healthy and maturing storm. JTWC initiated advisories on ther system at 9pm past night, with winds of 40kts. I suspect this will rise at the next update (9am). Some fairly rapid intensification seems likely given the structure of Emeraude and the low shear and good outflow it is experiencing. The storm is expected to drift east, then south, then back to the west in the coming days as the steering environment shifts between ridges to the north and south. Emeraude is not expected to affect land, which is just as well as it is expected to become quite intense.

Winston's long and twisty track (including it's current remnant low stage)

Winston degenerated into a remnant low on the 24th Feb. However, a week later, and the remnants are still roaming about, and have reached east coast of Australia! Convection has recently redeveloped near the previously exposed LLCC, but regeneration into a tropical cyclone is not expected. This system just doesn't want to fully dissipate (it formed on February 10th).

2 week old Winston is gradually weakening as it moves south. Convection is becoming increasingly shallow and waters are cooling along track and dry air is wrapping around the cyclone. Winds are down to 45kts. A bend in track towards the west is expected, south of 25°S. Cool sea temps and increasing shear will cause Winston to become sub-tropical according to JTWC.

Death toll up to 29, damage extensive. this HTML class. Value is http://www.bbc.co.uk

Winston has weakened to 140kts, still cat 5, as it has battered Fiji. The westward motion is expected to continue, followed by a southward track as a trough digs in and a ridge settles to the east. At this time, shear and cooler waters will weaken Winston considerably. In about 5 days time, Winston is forecast to turn westwards again as a new ridge to the south steers the system. This track has got to be one of the oddest ones I have seen recently:

Latest JTWC estimates put Winston at 160kts, which, if confirmed at the 3am advisory, will make Winston the strongest South Hemisphere cyclone on record, beating Zoe (155kts) from 2002 and Monica (155kts) from 2006.

Winston has winds of 145kts according to JTWC, so it is the first cat 5 on the SS scale worldwide in 2016. Get this, they are forecasting a 160kt peak. If this verifies, Winston would be in the history books. What is going to be more telling is the devastation Winston will have on Fiji.

Yes, this looks very concerning. Winston is moving briskly westwards and is now on direct course for Fiji (previous forecasts had Winston moving just to the south of Fiji). Winds have increased to 125kts according to JTWC, which is a cat 4 on the SS scale (but yes, it is a cat 5 on the Australian scale). Cat 5 on the SS scale is not put of the question either as shear is low, waters warm and there is strong dual outflow channels causing the convection around the well defined eye to be quite intense. JTWC forecast a peak of 135kts before Winston slams into the east coast of Fiji, but there is a chance it could make it to cat 5 (140kts and above). This only matters in terms of statistics however, because either way, Fiji are in big trouble from a system as intense as Winston is.

Uriah peaked at 125kts. The cyclone is now weakening fast as it moves south through high shear and cool sea temps. Winds are down to 65kts. Further weakening should occur until dissipation in a few days, possibly sooner.

Winston continues to re-intensify, with winds currently at 90kts according to JTWC. Winston is slowing as the steering influence is transferring between the two ridges as described above. Winston is forecast to head back to the west for a few days, but then turn back southeast yet again in the longer term as a building ridge to the northeast this time gains influence longer term. That is what a you call a drunken system lol. The steering currents in and around Australia and the Coral Sea can often provide tracks like this however.

Winds are now at 115kts, cat 4 on the SS scale.

Uriah has rapidly strengthened overnight, with winds now at 105kts according to JTWC. Peak now forecast to be 130kts.

Winston is re-intensifying, and now has winds of 65kts. On the eastward track, Winston is expected to strengthen to 100kts then loop to the west. Models are still quite confident in this reversal of track.

Uriah has been quite slow to strengthen due to some unexpected shear as it moves southwestwards. However, shear has now eased, and a quicker intensification trend has began. Winds are up to 75kts. Uriah is developing an eye and has some pretty intense convection surrounding it. JTWC expect a peak of 95kts as Uriah's track bends to the south. Weakening will begin in a few days as shear rises and watets cool along track in the long term.

Shear and cooler waters have weakened Winston to 50kts. However, is now moving northeastwards, back towards warmer water and into an area of lower shear. This should allow Winston to restrengthen long term. The steering pattern in the long term becomes more complex however. The ridge to the northwest of Winston is forecast to weaken, and eventually, a building ridge to the southeast will assume steering influence. The net result is a period of slow motion then a reversed track, back towards the west-southwest by day 5. This is subject to change and heavily depends on the timings and positions of the ridges.