NZ Weather Forum

NIWA's October TC forecast for this season's Southwest Pacific and eastern Australia area is for about 6 to 10 named TC's, at least 3 of which may reach severe Cat 3 or higher. For NZ, which on average is affected by one Ex-TC per season, the risk is considered 'near or slightly elevated compared to normal'. The area typically averages about 10 named TC's per season and La Nina usually favours more TC activity in the west of basin and around the Coral Sea, although La Nina is expected to tend more neutral by the end of this season.

https://niwa.co.nz/climate/southwest-pa ... tober-2022

Meanwhile, Australia has already had 2 named TC's this season. The first was TC Darian, named by the BoM on Dec 18, about 440 km west of the Cocos Islands in the Indian Ocean and reaching Cat 5 later on Dec 21. The second was TC Ellie, named just a few hours before making landfall about 170 km SW of Darwin at about 11pm LT on Dec 22.

Keeping a eye on this one, which could form from the monsoon trough near Vanuatu in the next few days and could affect NZ early next week.

From today's MetService 5-day TC Outlook:

A tropical low is expected to develop over the northwestern Coral Sea on Friday, then move southeast towards New Caledonia during the weekend. Conditions could be favourable for development, with a small window of opportunity for the system to become a tropical cyclone over the Coral Sea before moving southeast out of the tropics next week. Hence there is a LOW risk of a tropical cyclone over the Coral Sea on Friday, increasing to MODERATE on Saturday and Sunday.

Mod Note: See new thread for TC Hale named by Fiji Met today.

Model consensus has been growing for the possible development of a TC west of Vanuatu on Tuesday or Wednesday, and possibly another forming off the northern Qld coast (99P) around the same time. Chances for both are rated low at this stage, but that could change in coming days and worth keeping an eye on.

deja vu again?

Blowy wrote: ↑Sat 14/01/2023 17:13deja vu again?

This is not a tropical cyclone, nor will it ever be one.

The tropical low (998 hPa) currently about 800 km west of Port Vila, Vanuatu is expected to be named today. Conditions favourable for further intensification over the next couple of days as it tracks between Vanuatu and New Caledonia.

Another tropical low moving off the northern Qld coast also currently has a moderate chance of developing into a TC from about Friday.

JTWC now have the tropical low (996 hPa) currently about 700 km west of Port-Vila as a TC based on 1-minute max winds.

The BoM have also upgraded the Qld coast tropical low's chances of becoming a TC from Friday to high.

TC Irene has been named by Fiji Met this evening. Currently 995 hPa and about 600 km west of Port Vila.

Irene has been upgraded to Cat 2 by Fiji Met this morning, as she 'threads the needle' between Vanuatu and New Caledonia.
Currently 985 hPa with max winds of 55 knots (100 km/h).

Bit belated, but for posterity, Fiji Met downgraded Irene to Cat 1 around 2:30pm Jan 19 and became extratropical by around 8:30am Jan 20.

Here's the last track-map issued by Fiji Met...

Mod Note: See new thread for TC Gabrielle, which was named by the BoM today.

Tropics are becoming more active again. A developing tropical low north of Fiji, with deep convection to its north, currently has a risk of becoming a TC from Monday onwards as it encounters more favourable conditions while it heads west towards Vanuatu, before ultimately turning SE and hopefully passing to the east of NZ. One or two other tropical lows may develop in the trough across the northern Coral Sea early in the coming week and follow in the first low's wake, or combine with each other. Something to keep an eye on...

Some interesting disagreements with future path

^ Yes, although I think EC has been fumbling a bit with this one. However, Access also brings it a little closer to eastern NZ than other models. It also looks more likely that this TD will interact with another Coral Sea low from the west (Fujiwhara effect), which might throw the models into a spin, so to speak.

Meanwhile our TD north of Fiji is looking a lot more organised, with SST's 30-31C and low to moderate shear.

Our developing TD NW of Fiji starting to take shape, with good deep convection to the NW of it centre. JTWC issued a TC Formation Alert yesterday afternoon and this morning Fiji Met issued its first TD Advisory. I expect she'll be named in the next 24 hours...

Fiji's updated track-map suggests she might be named later today and intensify to severe Cat 3 later tomorrow...

Tracks looking a bit more consisent, well to the east of NZ.

TC Judy was named by Fiji Met this afternoon...

First track-map from JTWC...

TC Judy has just been upgraded to Cat 2 by Fiji Met this morning, as she begins to track the length of the Vanuatu islands.
Currently 986 hPa with max winds of 50 knots.

Meanwhile, a small tropical low off the northern Qld coast is moving east and could also potentially develop into a TC in the next few days.

Judy continues to rapidly intensify as she slows over very favourable conditions and is expected to reach Cat 3 tonight (possibly even higher as she peaks sometime tomorrow). Currently 980 hPa with max winds of 55 knots.

Port Vila looks likely to get a hammering as Judy's centre passes overhead early tomorrow morning, particularly with high tides around then.

Fiji Met's site appears to have crashed overnight. However, Judy is now at Cat 3 and its centre currently just north Port Vila with estimated 10-minute max winds of around 70 knots.

TC Judy now at Cat 4 with 10 minute max winds of around 90 knots and down to 956 hPa.

JTWC notes that Judy made a direct hit on the island of Efate late this morning, passing a few miles east of Port Vila. A weather station at Port Vila reported a minimum pressure of 961 hPa at 2230Z (11:30am NZDT), as the core was at its closest point of approach.

Latest JTWC track map shows Judy continuing to intensify tonight reaching 1 minute max winds of 110 knots, or 10 minute max winds of about 97 knots (Cat 5 is 10 minute max winds greater than 107 knots).