Tropical Cyclone Owen

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Cyclone Tracy
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Tropical Cyclone Owen

Unread post by Cyclone Tracy »

EC ensemble lifting the potential for a tropical depression by the end of the weekend near the Solomon Islands on the 2711 12Z run. North American models have been bullish over this set up for the last 48 hours. Still too early to speculate on the path and intensity but conditions are quite favourable for cyclonic development early next week.
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Cyclone Tracy »

Invest 97P near the Solomon Islands now has a low level circulation and pressure around 1007 hPa. Deep convection exists in the SW region from the circulation with cloud tops breaking through the tropopause on the 10am NZT. This is a sign that the system is trying to organise.
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Cyclone Tracy »

Clear circulation appearing on the midday on the 1km visual sat pic for the invest 97P system. The disturbance is now generating wind speed in the south eastern region around 20 to 25 knots. Very favourable wind shear is in the circulation's path within the next 48 hours. Sea surface temps will be 32 to 30c in the next 48 hours.

The intensity and speed of development is crucial to the systems path. EC and UK ensembles show a gradual development which will send the system more west due to missing the connecting upper trough. GEFS has more rapid development which will mean a South to SE track. This will have an impact on its future track over the next week.

As this circulation is in the Australian area of responsibility, if it becomes a cyclone it will be named Owen.
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Cyclone Tracy »

Deep convection continues this morning on invest 97P. Currently 25 to 30 knots winds, pressure heading towards 1000 hPa. JTWC has now upgraded the system to a 'high' development likely to tropical cyclone strength within 24 hours.

IMO, with MJO heading east and no sign of the Monsoon gyre, the Equatorial Rossby wave seems the primary reason for this tropical depression. Butterfly effects from polar cut off lows also played their parts to kick off upper instability. Interestingly the EC ensemble is now showing a 2nd disturbance near Vanuatu next week from the same tropical wave.
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Cyclone Tracy »

Tropical depression 97P now displaying a powerful 'hot tower' on the southern side. Cloud tops an impressive -90 to-100c. High frequency strobe lightning beneath at the moment.
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Nev »

BoM issued track-maps this morn. No advisories as yet though…
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Cyclone Tracy »

JTWC have now issued their map, similar to the BoM's 2nd map released a short time ago. Large uncertainty on 2 scenarios in the next 24 hours has made the BoM start hedging their bets on their latest track. UK and NavGem has a deeper and more SE to east track compared to EC,GFS and Access S. Currently the system is a few knots short of being named 'Owen' by the BoM.
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Nev »

BoM named TC Owen just before 8pm this evening NZDT (0700Z)…
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Cyclone Tracy »

Currently TC Owen is around 991 hPa, cat 1 and heading southward at 6 knots with moderate vertical wind shear. From a model point of view, there is a fascinating battle under between the 2 best tropical cyclone ensembles on the planet. Based off the 12z run, in the next 6 hours EC takes Owen on a SW turn and the UK takes Owen a SE turn. The BoM and JTWC are going with EC on their track maps.
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Cyclone Tracy »

ADT satellite calculation method now has Owen as a Cat 2 Oz level cyclone. He also remains just east of 155 longitude. BoM would be fairly close to upgrading.

Longer term - the subtropical ridge is looking very strong on all models for the next 6 days. This will mean that if TC Owen weakens, the low level circulation / depression will remain in the tropics and not head towards the mid latitudes for now.
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Nev »

BoM downgraded Owen to an ExTC just before 5pm this evening NZDT (0400Z), less than 2 days after being named on Sunday night.
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Cyclone Tracy »

Ex TC Owen smashed by westerly wind shear, is an ugly old depression still circulating in the Coral sea. Whether the circulation can remain in existence is an unknown but a 2nd Depression has now formed near the Solomon Islands from that Equatorial Rossby wave. This morning newly named 98P invest is showing signs of trying to organise with a hot tower punching into the stratosphere around 6am NZT.
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Cyclone Tracy »

The equatorial Rossby wave straddling lows of EX TC Owen and invest 98P are still circulating with max gusts of 25 and 15 knots. Both are expected to continue circulating 48 hours from now and orbit each other in a tropical depression Fujiwhara effect. Models after 48 hours diverge but GFS 0512 18Z has an interesting scenario of Owen swallowing 98P and reforming as a cat 1 Tropical Cyclone moving into North Queensland by Monday morning. With no MJO phase or Monsoon gyre present, its an interesting but unorthodox start to the season :smile:
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Cyclone Tracy »

EX TC Owen is now approaching the Far North Queensland coastline north of Cairns. Some decent deep convection on the western side atm. Winds near Cat 1 cyclone strength in the western quadrant recording at Arlington Reef but the system is still quite asymmetrical with wind speed on the east side not near those cat 1 levels.

Longer term is quite incredible on models, especially EC. Owen looks likely to track into the Gulf of Carpentaria and redevelop as a strong TC, then could steer back over Queensland potentially undergoing a 'brown ocean effect' due to saturated soil. This starts to become interesting for NZ 'if' the subtropical ridge weakens and 'if' Owen moves into Queensland as EC is projecting. :)
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Dean. »

Cyclone Tracy wrote: Sun 09/12/2018 16:07 EX TC Owen is now approaching the Far North Queensland coastline north of Cairns. Some decent deep convection on the western side atm. Winds near Cat 1 cyclone strength in the western quadrant recording at Arlington Reef but the system is still quite asymmetrical with wind speed on the east side not near those cat 1 levels.

Longer term is quite incredible on models, especially EC. Owen looks likely to track into the Gulf of Carpentaria and redevelop as a strong TC, then could steer back over Queensland potentially undergoing a 'brown ocean effect' due to saturated soil. This starts to become interesting for NZ 'if' the subtropical ridge weakens and 'if' Owen moves into Queensland as EC is projecting. :)
Affecting us around the 24th as you mentioned in an earlier post...will certainly wind up again if it makes it to the hot waters of the Gulf and bring some huge rains to the wet tropics of Australia
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Cyclone Tracy »

Dean. wrote: Sun 09/12/2018 17:47
Cyclone Tracy wrote: Sun 09/12/2018 16:07 EX TC Owen is now approaching the Far North Queensland coastline north of Cairns. Some decent deep convection on the western side atm. Winds near Cat 1 cyclone strength in the western quadrant recording at Arlington Reef but the system is still quite asymmetrical with wind speed on the east side not near those cat 1 levels.

Longer term is quite incredible on models, especially EC. Owen looks likely to track into the Gulf of Carpentaria and redevelop as a strong TC, then could steer back over Queensland potentially undergoing a 'brown ocean effect' due to saturated soil. This starts to become interesting for NZ 'if' the subtropical ridge weakens and 'if' Owen moves into Queensland as EC is projecting. :)
Affecting us around the 24th as you mentioned in an earlier post...will certainly wind up again if it makes it to the hot waters of the Gulf and bring some huge rains to the wet tropics of Australia
Yes, could affect us leading into X-mas. EC certainly is starting to favour this scenario with that familiar NW to SE movement along the ridge into the Tasman toward NZ.
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Dean. »

Cyclone Tracy wrote: Sun 09/12/2018 20:08
Dean. wrote: Sun 09/12/2018 17:47

Affecting us around the 24th as you mentioned in an earlier post...will certainly wind up again if it makes it to the hot waters of the Gulf and bring some huge rains to the wet tropics of Australia
Yes, could affect us leading into X-mas. EC certainly is starting to favour this scenario with that familiar NW to SE movement along the ridge into the Tasman toward NZ.
Towards the north of the North Island...GFS has the low/cyclone in the Gulf now too...
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

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EX TC Owen lashed several areas of Far North Queensland overnight. Lowest official barometric pressure on land that I could see was read north of Cairns, 992.7 hPa at Low isles lighthouse. This site also had sustained winds in the BoM’s cat 1 wind range but metrologically speaking, the system remained asymmetrical with lesser winds on the eastern flanks so did not regain its TC status. Such systems are nicknamed 'zombie cyclones'

Owen is now over land, heading west towards the Gulf of Carpentaria and is most likely to be over 30 to 31c sea surface temperatures with 5 to 15 knot windshear within 24 hours. The Gulf is notorious for bamboozling even the best models, due to its simmering waters. The next chapter of Owen is about to commence :smile:
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Cyclone Tracy »

Longer term, both EC and GEFS ensembles showing close agreement on the ridge over central Australia blocking the exit point around the N.T and sending Owen back over Queensland and into the Tasman along the subtropical ridge. Currently with the projected strength of the subtropical ridge, the South Island / lower NI is firming as a target for an Extra-tropical cyclonic hit in the week leading into xmas.
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by NZ Thunderstorm Soc »

Cyclone Tracy wrote: Mon 10/12/2018 13:26 Currently with the projected strength of the subtropical ridge, the South Island / lower NI is firming as a target for an Extra-tropical cyclonic hit in the week leading into xmas.

A good Christmas present for many. NOT! :-$
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Nev »

Some impressive rainfalls in NE Queensland.
BoM expecting Owen to redevelop into a TC on Wednesday…
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Nev »

BoM upgraded TC Owen back to a Cat 1 system just after 11pm last night NZDT (1000Z) and is expected to reach Cat 3 tomorrow.

Latest BoM track-map...
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Cyclone Tracy »

Aggressive hot towers going up near the core on the 10.40am NZT IR image. BoM track map overlayed pretty much exactly representing the EC ensemble. Interesting 24 hours ahead, the gulf is notorious for making fools of models and the BoM as they found out with TC Nora in March 2018.
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Cyclone Tracy »

TC Owen is turning earlier than the BoM, GFS & EC predicted by about 100 to 150 km on the latest advanced dvorak check :smile:

UK Met the only one to pick the turn to 15 degrees south at this point =D>
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Re: Tropical & EX-Tropical cyclone season 2018-19 Sth Pacific / Oz

Unread post by Dean. »

Still moving west?
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