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#1421064 - 08/04/2017 22:59 Tropical Low (96S) NT-WA April 2017
Popeye Offline
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Registered: 30/12/2006
Posts: 7742
Loc: Cable Beach - Broome WA
We may as well get this thread up and running as it seems there is some confidence growing with its development. JTWC have put an alert out on it with a moderate chance. Models seem to be toying with the idea as well for some time now.

Will this be the final show of the 2016/17 season. Maybe, maybe not.

TROPICAL DISTURBANCE SUMMARY:
(1) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 7.0S
133.6E, IS NOW LOCATED NEAR 7.4S 132.4E, APPROXIMATELY 320 NM NORTH-
NORTHEAST OF DARWIN AUSTRALIA. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY AND A 080623Z AMSU 89GHZ IMAGE DEPICT AN AREA OF FLARING
CONVECTION TO THE SOUTHWEST OF A DEVELOPING LOW-LEVEL CIRCULATION
CENTER (LLCC). A 080054Z (METOP-B) ASCAT PASS INDICATES 20-25 KNOTS
(WITH ISOLATED 30 KNOT WINDS) ALONG THE SOUTHWESTERN PERIPHERY OF
THE LLCC. ENVIRONMENTAL CONDITIONS ARE CURRENTLY MARGINALLY
FAVORABLE WITH WARM (29C) SSTS, IMPROVING UPPER-LEVEL OUTFLOW,
OFFSET BY STRONG (30-40 KNOTS) VERTICAL WIND SHEAR (VWS). DYNAMIC
MODEL GUIDANCE INDICATES STEADY DEVELOPMENT OF THE SYSTEM OVER THE
NEXT 48 HOURS AS IT TRACKS SOUTHWESTWARD INTO AN AREA OF LOWER VWS.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.
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#1421065 - 08/04/2017 23:02 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
Popeye Offline
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Registered: 30/12/2006
Posts: 7742
Loc: Cable Beach - Broome WA
Early indications that I have read have alot of uncertainty in track and intensity but hints of CAT 2 are already being floated around. NT moving SW into WA.
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#1421081 - 09/04/2017 08:08 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
croc crew Offline
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Registered: 17/11/2007
Posts: 182
Loc: Maningrida, Arnhem Land, NT
I've been watching that one for about 4 days now and figured it may turn into something. Not far away from where I am. I'll stick my arm out the window and give it a wave and shout out some encouragement.

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#1421097 - 09/04/2017 12:29 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
JimmyGray Offline
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Registered: 29/08/2008
Posts: 1569
Loc: Palmerston NT
And here we go ...

PRIORITY
TROPICAL CYCLONE WATCH
TROPICAL CYCLONE ADVICE NUMBER 1
Issued at 11:26 am ACST on Sunday 09 April 2017
Headline:
A Tropical Low in the Arafura Sea may develop into a Tropical Cyclone early Tuesday north of the Tiwi Islands.
Areas Affected:
Warning Zone
None.
Watch Zone
Tiwi Islands.
Cancelled Zone
None.
Details of Tropical Low at 9:30 am ACST:
Intensity: Tropical Low, sustained winds near the centre of 35 kilometres per hour with wind gusts to 85 kilometres per hour.
Location: within 45 kilometres of 7.5 degrees South 131.9 degrees East, estimated to be 415 kilometres north of Croker Island and 455 kilometres north northeast of Milikapiti.
Movement: slow moving.

A Tropical Low is slowly developing in the Arafura Sea. The low is expected to move towards the south or southwest during the next few days and may form into a Tropical Cyclone to the north of the Tiwi Islands early on Tuesday
Hazards:
GALES are not expected in coastal areas within the next 24 hours, however gales could develop over communities on the Tiwi Islands early on Tuesday.

HEAVY RAINFALL may cause flooding of low-lying areas over the Tiwi Islands.

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#1421104 - 09/04/2017 13:59 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
tropicbreeze Offline
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Registered: 14/01/2011
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Loc: Noonamah
I suspect there's too much dry air around and high VWS for this one to amount to much.


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#1421107 - 09/04/2017 14:25 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
Snowy Hibbo Offline
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Registered: 30/12/2016
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Loc: Matlock, Victoria.

There's quite a lot of shear in this tropical low's path. I'd doubt at this point a TC would be formed.
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#1421109 - 09/04/2017 14:38 Re: Tropical Low (96S) NT-WA April 2017 [Re: Snowy Hibbo]
desieboy Offline
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Registered: 31/12/2002
Posts: 3043
Loc: Broome


Looks
Originally Posted By: Snowy Hibbo

There's quite a lot of shear in this tropical low's path. I'd doubt at this point a TC would be formed.


Not good shear for it atm but that shear will ease up a bit tomorrow and will drive it southwards slowly towards the NT coastline.

Pretty sure models agreeing it would have formed just north of Darwin as Cat 1 then move into a more favorable environment as far as wind shear goes off the north Kimberley coast.
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#1421121 - 09/04/2017 16:30 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
Popeye Offline
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Registered: 30/12/2006
Posts: 7742
Loc: Cable Beach - Broome WA
Considering what Ernie did out well offshore bombing from A LOW to CAT 5 in 18 hours it just goes to show how quickly things can escalate if the right conditions present themselves even for such a short time. From what I have read on this one there is so much doubt with intensity and track. Wait and see if To be Frances hits high gear at some stage.
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#1421167 - 09/04/2017 18:58 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
JimmyGray Offline
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Registered: 29/08/2008
Posts: 1569
Loc: Palmerston NT
Yes agree there Popeye. Its in nearly the very same spot that Blanche began to form and most models are not sure what its going to do in its initial stages

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#1421188 - 09/04/2017 20:54 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
darwindix Offline
Cloud Gazer

Registered: 12/03/2016
Posts: 42
Loc: Jingili Darwin
It is interesting in Darwin today.Most people are welcoming the dry with fresh sw winds and dry (50 percent rel humidity).It wouldn't seem like it will be getting much moisture from the SE

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#1421189 - 09/04/2017 20:56 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
darwindix Offline
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Registered: 12/03/2016
Posts: 42
Loc: Jingili Darwin
Sorry I meant south east winds.

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#1421246 - 10/04/2017 12:42 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
gecko Offline
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Registered: 01/11/2007
Posts: 408
Loc: Coconut Grove, Darwin, NT.
Latest track map has if affecting Darwin - just flew out on Saturday. Hopefully it stays a one and the house is packed up well enough.

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#1421257 - 10/04/2017 13:42 Re: Tropical Low (96S) NT-WA April 2017 [Re: gecko]
JimmyGray Offline
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Registered: 29/08/2008
Posts: 1569
Loc: Palmerston NT
Yeh Gecko this one is a tricky buggar. The latest track map takes it thru the guts of the Tiwis before tracking towards the Nth Kimberley coast. That is a huge swing east from the initial map.
Darwin now on a cyclone watch and Tiwis under a warning shocked

TROPICAL CYCLONE ADVICE NUMBER 5
Issued at 11:16 am ACST [9:46 am AWST] on Monday 10 April 2017
Headline:
A Warning has been declared for the Tiwi Islands and a Watch is now current for the Darwin area.
Areas Affected:
Warning Zone
Croker island to Cape Fourcroy, including the Tiwi Islands.
Watch Zone
Point Stuart to Daly River Mouth, including Darwin.
Cancelled Zone
None.
Details of Tropical Low at 9:30 am ACST [8:00 am AWST]:
Intensity: Tropical Low, sustained winds near the centre of 45 kilometres per hour with wind gusts to 85 kilometres per hour.
Location: within 85 kilometres of 9.0 degrees South 132.9 degrees East, estimated to be 365 kilometres northeast of Milikapiti and 440 kilometres north northeast of Darwin.
Movement: south at 11 kilometres per hour.

A Tropical Low is slowly developing in the Arafura Sea. The low is expected to move towards the south or southwest during the next few days and may form into a Tropical Cyclone to the north of the Tiwi Islands on Tuesday morning.
Hazards:
GALES with gusts to 110 kilometres per hour are expected to develop on the north coast of the Tiwi Islands and Cobourg Peninsula on Tuesday morning and extend along the Cobourg Peninsula between Goulburn Island and Cape Don later on Tuesday.

GALES may extend south to mainland coastal areas between Point Stuart and Daly River Mouth, including Darwin during Wednesday if the cyclone maintains its southwest track.

A STORM TIDE is expected between Cape Fourcroy and Goulburn Island as the cyclone centre approaches the coast on Tuesday. Tides are likely to rise significantly above the normal high tide, with DAMAGING WAVES and DANGEROUS FLOODING.

HEAVY RAIN is expected to cause flooding on the Tiwi Islands, Cobourg Peninsula and northwest Top End from Tuesday.

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#1421263 - 10/04/2017 14:31 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
desieboy Offline
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Registered: 31/12/2002
Posts: 3043
Loc: Broome


Should have no trouble maintaining its moisture levels once its get a good circulation going in the short term anyway.
Monssonal trough to the north east got heaps of convection around for the LLC to suck in.

Interesting to see how it steers in the next 24 hours especially with the ridge building from the SW and how much it will move to the south towards the vicinity of Darwin area.
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#1421269 - 10/04/2017 15:41 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
tropicbreeze Offline
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Registered: 14/01/2011
Posts: 118
Loc: Noonamah
The models don't seem to be giving this one much of a chance of developing into anything much more than a cat 1. BOM has been edging its track further east, the system is currently moving slightly to the east of south and is positioned a little to the east of dead north of Darwin (as at 12:22 CST). The track map puts it slightly west of that position and already moving to the south west. At this stage position and direction are critical as to whether it's a direct hit on the Tiwis or Darwin, or whether not. Slight changes will make a big difference. Be interesting to know what dry air there is pushing off from the continent towards this system. It was starting to reach Ernie, which is a long way off the coast.

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#1421293 - 10/04/2017 20:04 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
Popeye Offline
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Registered: 30/12/2006
Posts: 7742
Loc: Cable Beach - Broome WA
I think the way TC Ernie and TC Cook have bombed away either side of the Australian continent over the last week is a nice indicator as to what an mid April TC Frances might do. I am over looking at models and what they might say these days as they are usually crap and way off the mark. Recent history proves that. All I know is that it will only take 24hrs in a nice slot to get up to speed as a High end CAT 3 and away she will go. I honestly think the Cape Leveque to Eighty Mile will be cringing later in the week as this one sneaks in. Even in a weakening form she might still surprise.
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#1421294 - 10/04/2017 20:07 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
Popeye Offline
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Registered: 30/12/2006
Posts: 7742
Loc: Cable Beach - Broome WA
I reckon CAT 2 Bidyadanga to Eco Beach recurve. Complete pissed forecats this by the way lol
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#1421296 - 10/04/2017 20:17 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
Popeye Offline
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Registered: 30/12/2006
Posts: 7742
Loc: Cable Beach - Broome WA
High Baby. JTWC Talking her chances up a little which is a good sign.

2. REMARKS: THE AREA OF CONVECTION (INVEST 96S) PREVIOUSLY LOCATED
NEAR 7.5S 132.0E, IS NOW LOCATED NEAR 8.0S 132.9E, APPROXIMATELY 295
NM NORTH-NORTHEAST OF DARWIN, AUSTRALIA. ANIMATED INFRARED SATELLITE
IMAGERY AND A 090946Z SSMIS PASS DEPICT WEAK BANDING AND ASSOCIATED
DEEP CONVECTION FLARING TO THE WEST OF A CONSOLIDATING LOW LEVEL
CIRCULATION CENTER (LLCC). A 091310Z ASCAT (METOP-B) PASS SHOWS A
SYMMETRICAL LLCC WITH 20-25 KNOT SURFACE WINDS IN THE NORTHEAST
QUADRANT. ENVIRONMENTAL CONDITIONS ARE BECOMING INCREASINGLY
FAVORABLE, WITH GOOD UPPER-LEVEL DIFFLUENCE AND HIGH SEA SURFACE
TEMPERATURES (29-30 C), OFFSET BY HIGH, BUT DECREASING, VERTICAL
WIND SHEAR (25-30 KNOTS). GLOBAL MODELS INDICATE THAT THE
DISTURBANCE WILL TRACK TO THE SOUTHWEST ALONG THE NORTHWESTERN COAST
OF AUSTRALIA WHILE GRADUALLY CONSOLIDATING AND INTENSIFYING OVER THE
NEXT SEVERAL DAYS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT
20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR
1004 MB. BASED ON IMPROVING ORGANIZATION AND ENVIRONMENTAL SUPPORT,
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS HIGH.
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#1421298 - 10/04/2017 21:05 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
darwindix Offline
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Registered: 12/03/2016
Posts: 42
Loc: Jingili Darwin
Breeze now picking up and the rain squalls are just starting.Looking at the radar and sat images I think it will pass close to darwin.Still not showing much organisation though .Maybe the diurnal effect might ramp it up a bit.Quite a nice evening though.

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#1421300 - 10/04/2017 21:23 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
Sepo Offline
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Registered: 19/10/2010
Posts: 319
Loc: Broome, WA
Thangoo station is my bet popeye... it will lose steam but ramp up again just before crosssing - cat 2 like you said....

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#1421306 - 10/04/2017 23:04 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
desieboy Offline
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Registered: 31/12/2002
Posts: 3043
Loc: Broome


Forecast starting to ramp it up a bit in a couple of days.


_________________________
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#1421308 - 10/04/2017 23:37 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
desieboy Offline
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Registered: 31/12/2002
Posts: 3043
Loc: Broome


Tropical low has to suck in a much convection as possible from the monsoonal trough to the north to keep its integrity..

Should have no trouble with intensifying though as long it can maintain a good moisture level around its LLC to fend off the dry air to the south west .
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#1421311 - 11/04/2017 00:16 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
desieboy Offline
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Registered: 31/12/2002
Posts: 3043
Loc: Broome

See some good moisture levels and convection happening here.

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#1421314 - 11/04/2017 04:59 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
JimmyGray Offline
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Registered: 29/08/2008
Posts: 1569
Loc: Palmerston NT
Nice work Desieboy. Has been raining lightly/steadily all night and plenty of wind gusts but nothing too major. Just heading off to work now so will probably get sent home wink

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#1421322 - 11/04/2017 08:46 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
tropicbreeze Offline
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Registered: 14/01/2011
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Loc: Noonamah
Looks like EC is putting the system closer to Darwin than GFS and BOM. They also have is keeping within JBG and dissipating over the Kimberley.

BOM in it's technical bulletin (19:51 UTC 10/04/2017) notes:

In the longer term, the combination of increased vertical wind shear and dry air is likely to weaken the system below cyclone intensity by Saturday.

Saturday is still a fair way off (in a cyclone's life), there's no real certainty in any of it.

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#1421325 - 11/04/2017 09:27 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
Snowy Hibbo Offline
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Registered: 30/12/2016
Posts: 221
Loc: Matlock, Victoria.

Shear is still poor for its current position.
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#1421353 - 11/04/2017 14:45 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
tropicbreeze Offline
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Registered: 14/01/2011
Posts: 118
Loc: Noonamah
Commander Brent Warren of NT Emergency Management has just advised on ABC radio that all the warnings and watches have been cancelled. Doesn't appear the BOM website has caught up with that news just yet.

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#1421356 - 11/04/2017 15:08 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
tropicbreeze Offline
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Registered: 14/01/2011
Posts: 118
Loc: Noonamah
Finally came through


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#1421365 - 11/04/2017 16:49 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
Snowy Hibbo Offline
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Registered: 30/12/2016
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Loc: Matlock, Victoria.
The shear ruined its chances before Darwin. Even if it does turn into a cyclone, it will probably only be a Cat 1 with all the forecasted shear.
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#1421369 - 11/04/2017 17:16 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
desieboy Offline
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Registered: 31/12/2002
Posts: 3043
Loc: Broome


Yes SH the shear which was expected to ease last night and early today has stayed strong so has lowered it chances of strong intensification in the short term anyway.

Also the ridge from the west which was forecast to have moved a lot further to the east by now and give it that push towards the SW has not moved into its forecast position .That's left the system moving fairly slowly and is not in too favourable an area atm.

Hopefully things will change for the better when it starts to push more towards the SW in the next 18 hours.
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#1421387 - 11/04/2017 19:55 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
darwindix Offline
Cloud Gazer

Registered: 12/03/2016
Posts: 42
Loc: Jingili Darwin
it's interesting to see how much influence the sheer has had on this system .We've been seeing a few eyes -centres passing over us on the radar and observations on the ground.

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#1421390 - 11/04/2017 20:11 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
gecko Offline
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Registered: 01/11/2007
Posts: 408
Loc: Coconut Grove, Darwin, NT.
The record low max temp for April got well and truly beaten today.


Edited by gecko (11/04/2017 20:11)

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#1421394 - 11/04/2017 21:06 Re: Tropical Low (96S) NT-WA April 2017 [Re: gecko]
Mick10 Offline
Weatherzone Moderator

Registered: 02/11/2001
Posts: 24682
Loc: Kirwan, Townsville - NQld.
Originally Posted By: gecko
The record low max temp for April got well and truly beaten today.


record max low for april is 24.6C, the temp has to stay below that until 9am tomorrow for the record to be broken.
_________________________
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February 2017 total - 67.2mm (283mm)
March 2017 total - 172.2mm (197mm)
2017 Yearly total to date - 503.0mm (1107mm)

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#1421396 - 11/04/2017 21:16 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
Ahab Offline
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Registered: 31/01/2011
Posts: 169
Loc: Brisbane
I hate the way they measure this. What has tomorrow morning 9am to do with today? And the further east you go (within your time zone) the more strong is the morning sun at 9am and prevent record.

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#1421397 - 11/04/2017 21:27 Re: Tropical Low (96S) NT-WA April 2017 [Re: Ahab]
cold@28 Offline
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Registered: 07/02/2011
Posts: 1968
Loc: Chillagoe
Originally Posted By: Ahab
I hate the way they measure this. What has tomorrow morning 9am to do with today? And the further east you go (within your time zone) the more strong is the morning sun at 9am and prevent record.

Agreed, think of all that evaporation in four hours of daylight.
Is 9am an accepted world practice?
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January: 393.0mm | February: 221.0mm | March: 153.5mm | April: 11.5mm
-------
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2016: 668.5mm
2015: 599.0mm

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#1421398 - 11/04/2017 21:27 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
tropicbreeze Offline
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Registered: 14/01/2011
Posts: 118
Loc: Noonamah
Can't believe how cold it is. Don't ever remember feeling as cold as this with a tropical low or cyclone around. I'd like to know why the temp has plummeted so much.

It's unlikely the temp will get anywhere near 24.6 overnight while this low passes over.

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#1421399 - 11/04/2017 21:29 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
Mick10 Offline
Weatherzone Moderator

Registered: 02/11/2001
Posts: 24682
Loc: Kirwan, Townsville - NQld.
its happened several times here in townsville, winter rainband kept max temp low only for the cloud to clear overnight and 4 hours of sunshine in the morning goes above the recorded temp the day before. just the way it is.
_________________________
Kirwan, Townsville Nth Qld -
February 2017 total - 67.2mm (283mm)
March 2017 total - 172.2mm (197mm)
2017 Yearly total to date - 503.0mm (1107mm)

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#1421404 - 11/04/2017 23:00 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
desieboy Offline
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Registered: 31/12/2002
Posts: 3043
Loc: Broome

Technical info on NT Low at 5pm WST.

Recent satellite imagery shows an area of deep convection sheared southwest of the LLCC with banding features east of the centre along the NT north coast.

CIMSS shows 20-30 knot vertical wind shear over the system, which together with land interaction, continues to limit the low's development. Dvorak analysis is based on a shear pattern, with the LLCC about 1deg SW of the cold cloud giving a DT of 2.5. Based on a weakening trend, the adjusted MET=2.0. FT based on MET, but CI held at 2.5 as the system remains over water, consistent with surface
observations.

The system is expected to continue moving southwest and pass south of the Tiwi Islands under the influence of the subtropical ridge over WA. The low is expected to experience slightly lower vertical wind shear, allowing TC intensity to be reached Wednesday evening once the low moves into the Timor Sea.

The cyclone may strengthen slightly but remain at category 1 intensity as it passes close to the Kimberley region of WA on Thursday.

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#1421406 - 11/04/2017 23:17 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
desieboy Offline
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Registered: 31/12/2002
Posts: 3043
Loc: Broome


Still got the moisture just got to get into more favorable shear winds so it can get itself together .....

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Climate is what we expect, weather is what we get.
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#1421427 - 12/04/2017 09:40 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
tropicbreeze Offline
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Registered: 14/01/2011
Posts: 118
Loc: Noonamah
IDD20020
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - NORTHERN REGION
Issued by DARWIN TROPICAL CYCLONE WARNING CENTRE
at: 1953 UTC 11/04/2017
Name: Tropical Low
Identifier: 27U
Data At: 1800 UTC
Latitude: 12.1S
Longitude: 131.2E
Location Accuracy: within 30 nm [55 km]
Movement Towards: west southwest [251 deg]
Speed of Movement: 6 knots [12 km/h]
Maximum 10-Minute Wind: 25 knots [45 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 1003 hPa
Radius of 34-knot winds NE quadrant:
Radius of 34-knot winds SE quadrant:
Radius of 34-knot winds SW quadrant:
Radius of 34-knot winds NW quadrant:
Radius of 48-knot winds NE quadrant:
Radius of 48-knot winds SE quadrant:
Radius of 48-knot winds SW quadrant:
Radius of 48-knot winds NW quadrant:
Radius of 64-knot winds:
Radius of Maximum Winds:
Dvorak Intensity Code: T1.0/2.0/W1.5/24HRS STT:W1.0/06HRS
Pressure of outermost isobar: 1007 hPa
Radius of outermost closed isobar: 180 nm [335 km]
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+06: 12/0000: 12.5S 130.5E: 040 [080]: 025 [045]: 1005
+12: 12/0600: 12.8S 129.8E: 055 [100]: 030 [055]: 1002
+18: 12/1200: 13.1S 128.9E: 065 [125]: 030 [055]: 1002
+24: 12/1800: 13.3S 128.1E: 080 [145]: 030 [055]: 1002
+36: 13/0600: 14.0S 125.6E: 100 [180]: 040 [075]: 998
+48: 13/1800: 14.7S 123.1E: 120 [220]: 035 [065]: 1001
+60: 14/0600: 15.7S 120.8E: 140 [255]: 030 [055]: 1003
+72: 14/1800: 16.0S 118.9E: 155 [290]: 030 [055]: 1002
+96: 15/1800: 16.1S 116.6E: 200 [370]: 025 [045]: 1004
+120: 16/1800: 17.4S 116.4E: 290 [535]: 025 [045]: 1004
REMARKS:
The 1800 UTC position just northeast of Darwin is made with good confidence based on radar and surface observations surrounding the Van Diemen Gulf.

Radar indicates segments of weak spiral bands rotating around a LLCC with the strongest band of rain displaced well to the west due to shear. Satellite imagery over the last 6 hours has shown a significant reduction in deep convection, so Dvorak DT could not be determined. MET was 1.5 based on W trend, adjusted to PATof 1.0 due to lack of deep convection. FT is 1.0 based on PAT, with CI held at 2.0. An ASCAT pass at 1312Z showed an area of 25-30 knot winds to the west of the system. However, it is likely the intensity has now decreased due to land interaction and shear, so maximum intensity has been lowered to 25 knots, consistent with CI.

The current environment is unfavourable for significant development of the system due to a combination of land interaction and high vertical wind shear. CIMSS wind shear at 15Z estimates easterly shear of 30-40 knots across the system. The low is located north of the upper level ridge which is providing good poleward outflow and upper divergence. TPW and atmospheric soundings from Darwin and surrounds shows the circulation is within an area of deep moisture, being fed by moist NW monsoonal winds. However of note is the low low-level dew point air south of the system.

Recent motion to the south has been due to a mid-level high centred to the east. A new ridge is expected to develop over central Australia and in combination with weakening monsoonal winds, the system will be steered with a SW to W motion. NWP is in good agreement leading to a high confidence in the forecast track. This track should take the low over open water over the Timor Sea later on Wed and approach the Kimberley coast on Thursday. The low will continue tracking towards the SW until Friday before the system curves around the ridge ahead of an approaching trough.

As the low moves over the Timor Sea, NWP forecasts a slightly more favourable wind shear environment, while moisture and upper level outflow remain good. Therefore there is some potential for the low to deepen and it may reach TC intensity during Thursday. However, during Thursday NWP also shows that the NW moisture source is cut off with dry air wrapping around the W and N sectors, which may slow or limit development. From Friday the combination of increased vertical wind shear and dry air is likely to weaken the system below cyclone intensity during Friday, well north of the WA Pilbara coast. An additional limitation to TC development may be the forecast track towards the Kimberley. A track further to south will have the system cross the Kimberley before TC development can be attained.

Copyright Commonwealth of Australia

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#1421431 - 12/04/2017 10:11 Re: Tropical Low (96S) NT-WA April 2017 [Re: desieboy]
Coxy Offline
Weatherzone Addict

Registered: 31/01/2011
Posts: 1037
Loc: Jindalee, QLD
Originally Posted By: desieboy


Still got the moisture just got to get into more favorable shear winds so it can get itself together .....



It's a happy looking thing.

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#1421441 - 12/04/2017 12:04 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
Popeye Offline
Meteorological Motor Mouth

Registered: 30/12/2006
Posts: 7742
Loc: Cable Beach - Broome WA
I think she has had it? Oh Well was a little hope there for a while but maybe just wishful in the end. It was fairly obvious from the initial shear that it was going to struggle.
_________________________
Popeye's 2015/16 Broome Wet Season Images

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#1421454 - 12/04/2017 14:20 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
tropicbreeze Offline
Weather Freak

Registered: 14/01/2011
Posts: 118
Loc: Noonamah
I always thought that dry air and high vertical wind shear was going to be a problem. Never thought that level of wind shear would persist as much as it did though.

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#1421463 - 12/04/2017 16:38 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
desieboy Offline
Weatherzone Addict

Registered: 31/12/2002
Posts: 3043
Loc: Broome


Yes TB it didn't play the game basically .

Stayed too long in an unfavorable environment for intensification.

Most models saw it moving to South West a lot sooner than it did also wind shear was supposed to ease.

Sometimes only a small window of opportunity for development getting some good circulation going and this one missed that opening.

Having said that there is so many factors that if not all aligned throw each other out and mess up the whole scenario.
Which is what happened this time.

Just like those lows earlier on in the season which just happen to be developing in the right place but in the wrong time.
_________________________
Climate is what we expect, weather is what we get.
- Mark Twain

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#1421464 - 12/04/2017 16:45 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
desieboy Offline
Weatherzone Addict

Registered: 31/12/2002
Posts: 3043
Loc: Broome

Not much chance of TC status with too much dry air to the North and Western flanks of the system especially next couple of days even though it may have better integrity than it does now.

As a low though should bring some rain to the North Kimberley coastline and maybe the Pilbara in the longer outlook.

May be reduced to a trough by the time it comes towards the Pilbara coast though.
_________________________
Climate is what we expect, weather is what we get.
- Mark Twain

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#1421488 - 12/04/2017 23:09 Re: Tropical Low (96S) NT-WA April 2017 [Re: Mick10]
gecko Offline
Weather Freak

Registered: 01/11/2007
Posts: 408
Loc: Coconut Grove, Darwin, NT.
Originally Posted By: Mick10

record max low for april is 24.6C, the temp has to stay below that until 9am tomorrow for the record to be broken.


Got there in the end.

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#1421532 - 13/04/2017 18:42 Re: Tropical Low (96S) NT-WA April 2017 [Re: Popeye]
desieboy Offline
Weatherzone Addict

Registered: 31/12/2002
Posts: 3043
Loc: Broome
Says it all.....

Going, going ...gone...

Details of Tropical Low at 8:00 am AWST:

Intensity: tropical low, sustained winds near the centre of 45 kilometres per hour with wind gusts to 85 kilometres per hour.
Location: within 55 kilometres of 13.5 degrees South, 127.6 degrees East .
Movement: west at 25 kilometres per hour .

A tropical low lies close to the north Kimberley coast. The low will continue to move towards the west during the day and will be located offshore to the northwest of the Kimberley on Friday. The low is not expected to develop into a tropical cyclone.



_________________________
Climate is what we expect, weather is what we get.
- Mark Twain

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