Tropical Cyclone Hola

[Cyclone Tracy]

Strong equatorial flow and energy now appearing on many models including EC over the coming week. EC ensemble run 0203 12Z showing strong signs of a tropical disturbance / depression near Vanuatu and Fiji in the next 3 days. Then increased chances of further development into a cyclone from next Wednesday to Friday. Longer term, some models getting excited with a large hit on the NI around March 12th but still way too early to lock in IMO.

It's certainly becoming interesting

[Cyclone Tracy]

Invest 97P / 09F near Fiji and Vanuatu has a LLC pushing 25 knots in the SE quadrant, around 1004 hPa and being held back currently by westerly vertical wind shear and trough. It's environment is becoming very favourable in the next 48 hours with a weakening trough, 5 to 10 knot wind shear and a simmering 29 to 30c SST. TC Hola maybe born Wednesday morning if the projected environment unfolds .

Longer term, interesting that both GEFS and EC ensembles moved the possible TC slightly westward on their latest runs of 18Z and 12Z from the previous run. Hand full of strikes now on the NI across the 70 odd models

[Cyclone Tracy]

The Main EC model continuing the slight westward trend towards the NI early next week, producing a hybrid SW pacific cyclonic gyre. This will drag the EC ensemble west again.

There is plenty of uncertainty with possible TC Hola as models are struggling with projecting the strength of the ridge at this stage. This EC run would have certainly got the attention of MS

[Nev]

TD 09F/97P has become very well organised overnight and I'd be surprised if it isn't named today. RSMC Nadi issued its first Advisory earlier this morning and JTWC also issued a TC Formation Alert.

[Cyclone Tracy]

Significant increase in lightning activity and 'Hot towers' appearing around 10am NZT with cloud top reaching around -90c . She's gaining strength

[Cyclone Tracy]

JTWC now has upgraded to a tropical storm. ADT method estimating 998 hPa, sustained winds 39 knots approaching Vanuatu. She still has a uniform cloud dense overcast around the LLCC, 30c SST but a trough around her neck and will encounter 25 knots wind shear in the next 24 hours, so development will be slow. By Friday conditions will be ripe for rapid intensification.

I would expect Fiji met to offcially name Hola today.

[Nev]

TC Hola was named by RSMC Nadi around 1am this morn NZDT…

TROPICAL DISTURBANCE ADVISORY NUMBER A5 ISSUED FROM RSMC NADI
Mar 061404 UTC.

TROPICAL CYCLONE HOLA CENTRE 994HPA CATEGORY 1 WAS LOCATED NEAR 15.8S
169.0E AT 061200 UTC. POSITION POOR BASED ON HR HIMAWARI-8 EIR AND
PERIPHERAL SURFACE REPORTS. CYCLONE MOVING SOUTHWEST AT ABOUT 08
KNOTS. MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT
ABOUT 35 KNOTS.

EXPECT WINDS OVER 33 KNOTS WITHIN 90 NAUTICAL MILES IN EAST
SEMICIRCLE AND WITHIN 60 NAUTICAL MILES IN WEST SEMICIRCLE.

DEEP CONVECTION REMAINS PERSISTENT WITH BANDS TRYING TO WRAP AROUND
LLCC. OVERALL ORGANISATION HAS IMPROVED SIGNIFICANTLY IN THE PAST 24
HOURS. CYCLONIC CIRCULATION EXTENDS UP TO 300HPA. SYSTEM LIES UNDER
AN UPPER RIDGE WITH STRONG UPPER DIVERGENCE IN A MODERATE SHEARED
ENVIRONMENT. OUTFLOW GOOD TO THE SOUTH AND EAST. SST AROUND 29
DEGREES CELCIUS. DVORAK ANALYSIS BASED ON 0.6 WRAP YIELDS DT=3.0. PT
AND MET AGREE. THUS YIELDING T3.0/3.0/D1.0/24HRS.

GLOBAL MODELS HAVE PICKED UP THE SYSTEM AND MOVE IT WEST-SOUTHWEST
WITH FURTHER INTENSIFICATION.


FORECASTS :
AT 12 HRS VALID AT 070000 UTC 16.3S 167.8E MOV WSW AT 06 KT WITH 40
KT CLOSE TO CENTRE
AT 24 HRS VALID AT 071200 UTC 16.7S 166.8E MOV WSW AT 06 KT WITH 45
KT CLOSE TO CENTRE

OUTLOOK :
AT 36 HRS VALID AT 080000 UTC 17.2S 166.3E MOV SW AT 05 KT WITH 50 KT
CLOSE TO CENTRE
AT 48 HRS VALID AT 081200 UTC 17.9S 166.6E MOV S AT 05 KT WITH 50 KT
CLOSE TO CENTRE

THE NEXT TROPICAL DISTURBANCE ADVISORY ON TROPICAL CYCLONE HOLA WILL
BE ISSUED AROUND 062000 UTC.

[Nev]

I see JTWC now have Hola with 1-minute mean-winds of 125 kt by Saturday morn, which equates to 10-minute winds of about 110 kt, or another Cat 5 on the BoM/Fiji Met (and JMA) TC Scales, whereas RSMC Nadi currently only going for a Cat 3 around that time.

[Cyclone Tracy]

TC Hola currently on the ADT method is down to 993 hPa, sustained 49 knots and slowly intensifying but still being held back by some land friction over Vanuatu and a mid latitude trough. Even with less than ideal conditions, she appears to have hot towers erupting on the 2pm (NZT) IR sat pic with cloud tops reaching near -100c. As she turns SE on the subtropical ridge in the next 24 hours, projected conditions are as good as they get for a RI Tropical cyclone to develop.

Longer term GEFS ensemble is still taking her off the east coast of the NI but U.S navy run 18z has now jumped on board with the EC and UKmet scenario, for a hybrid subtropical XT attack on the NI early next week. The current UKmet scenario (12z) would be a significant impact on the upper NI including Auckland if it were to eventuate.

[Blowy]

Hola Amigo's!
I see it is 30 years today since the start of Bola

https://www.stuff.co.nz/business/farmin ... east-coast

Let's hope Hola is no Bola

[Cyclone Tracy]

Hola is now down to 973 hPa on the ADT method, down 16 hPa in 12 hours, sustained winds of 75 knots. Interestingly she has developed a small pinhole eye and is having a flash outbreak in her inner eye wall which is not that common. Significant lightning outbreaks in the inner eye wall generally means she is starting to mature into a severe and very dangerous tropical cyclone.

Longer term, major American models have now changed their minds on the strength of the ridge and are tracking her as a hit on the north island for the 12z runs on similar paths to EC and UKmet tracking over the last 48 hours.

[Nev]

RSMC Nadi have just upgraded Hola to a Cat 4 and expect he'll be a Cat 5 by tomorrow morn…

HURRICANE WARNING 011 ISSUED FROM RSMC NADI Mar 071915 UTC.

TROPICAL CYCLONE HOLA CENTRE 954HPA CATEGORY 4 WAS LOCATED NEAR 16.8 SOUTH 166.2
EAST AT 071800 UTC.
POSITION GOOD.
REPEAT POSITION 16.8S 166.2E AT 071800 UTC.
CYCLONE MOVING WEST SOUTHWEST AT 6 KNOTS. CYCLONE INTENSIFYING.
EXPECT SUSTAINED WINDS OF 90 KNOTS CLOSE TO THE CENTRE INCREASING TO 110 KNOTS
BY 081800 UTC.
...

[Nev]

Latest track-maps from JTWC and RSMC Nadi…

[Cyclone Tracy]

She has now dropped to 958 hPa on the ADT method and with sustained winds of 95 knots. That makes it 31 hpa in 16 hours and a 40 knot increase making her an official RI Tropical cyclone. She's put egg on the face of RSMC with their cat 3 projections over their last few updates before this morning.

[David]

Wow, potentially another Cat 5 cyclone based on JTWC projections. So soon after Gita.

[Cyclone Tracy]

Latest EC ensemble has a fairly tight agreement on the steering for the next 48 hours. Sub tropical ridge and the mid latitude trough is going to guide Hola towards the NI. Interesting half a dozen model runs off the main herd going into cook strait GEFS ensemble has certainy changed its tune and is now recognising weakness's in the sub tropical ridge

[Willoughby]

A heap of lightning activity near the eye the last 6 hours. Incredible for a TC!
https://gfycat.com/LinearBleakCowrie

[David]

I see GFS has come into agreement with EC in it's latest run, coming down across Northland/Auckland. Both models showing a centre around 990 hPa by the time it gets here, so wouldn't be particularly intense if that's the case.

[Cyclone Tracy]

Hola has plateaued in the last 4 hours remaining around 960 hPa and 90 knots sustained winds. In the last hour though the centre region cloud top temperature has warmed from -69c to -22c, an indication of another intensification period could be underway.

I just took a look at sea surface temperatures north of the NI and 26c is currently at around 30 degrees south (only 500 km north of Cape Reinga). If wind shear isn't too brutal and outflow is strong, there could be a decent TC still in existence at this point. The U.S specialised hurricane model HWRF on the 18Z run believes the SST's are going to support a powerful hit on the upper NI with torrential rain.

[Blowy]

I see GFS has come into agreement with EC in it's latest run, coming down across Northland/Auckland. Both models showing a centre around 990 hPa by the time it gets here, so wouldn't be particularly intense if that's the case.

I think Bola was similar hpa just saying

[David]

I think Bola was similar hpa just saying

Bola lingered a while though, this one looks to move through fairly quickly.

Of course, we can't really nail down such details until closer to arrival. I notice modeling has dropped it a little to around 986 hPa when it moves over northern NZ.

[David]

Most recent JTWC track map.

[Cyclone Tracy]

She weakened in the last few hours but it seems like Hola has undergone an eyewall replacement cycle and now has a new pinhole eye

http://tropic.ssec.wisc.edu/real-time/m ... splay.html

[Nev]

Looks like both JTWC and RSMC Nadi now expect that Hola won't quite reach Cat 5
(although that could change by morning)...

[Nev]

RSMC Nadi have downgraded Hola to Cat 3 this morning…

HURRICANE WARNING 015. ISSUED FROM RSMC NADI Mar 081920 UTC.

TROPICAL CYCLONE HOLA CENTRE 962HPA CATEGORY 3 WAS LOCATED NEAR 17.8 SOUTH 165.3
EAST AT 081800 UTC.
POSITION POOR.
REPEAT POSITION 17.8S 165.3E AT 081800 UTC.
CYCLONE MOVING SOUTH AT 2 KNOTS. CYCLONE WEAKENING.
EXPECT SUSTAINED WINDS OF 80 KNOTS CLOSE TO THE CENTRE DECREASING TO 65 KNOTS BY
091800 UTC.
...