SIO: ROBYN - Remnants

[Subtrop]

96S INVEST 241118 0600 5.2S 90.1E SHEM 15 0

[Pasmorade]

Seems to be in a favorable environment for development with somewhat low shear and SSTs near 29C. How are the models handling this?

[Pasmorade]

Also, is that the tropical low that the BoM is monitoring?

[cycloneye]

The disturbed weather zone 01U was located, this afternoon, by points 09S/94E over the Indonesian zone of monitoring.
The BOM (Australian Meteorological Centre) anticipates the formation of a tropical storm by Wednesday (ROBYN), thanks to a more favorable environment, including a drop in wind shear and high humidity.
The trajectory should aim towards the southwest then the south, bringing the system closer to the border of the Australian and South West Indian Ocean zones of ​​responsibility (90E).
However, environmental conditions quickly become unfavorable over the weekend and it is a weakening storm that will likely enter the South West Indian Ocean basin by that time.
Thus, there is a moderate risk that a tropical storm will form by November 27-28 over the Australian region and then enter the South West Indian Ocean basin.
However, it poses no major threat to any inhabited lands.

[Subtrop]

IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE
at: 0705 UTC 28/11/2024
Name: Tropical Cyclone Robyn
Identifier: 01U
Data At: 0600 UTC
Latitude: 15.3S
Longitude: 90.8E
Location Accuracy: within 25nm (45 km)
Movement Towards: south (184 deg)
Speed of Movement: 8 knots (14 km/h)
Maximum 10-Minute Wind: 40 knots (75 km/h)
Maximum 3-Second Wind Gust: 55 knots (100 km/h)
Central Pressure: 994 hPa
Radius of 34-knot winds NE quadrant: 50 nm (95 km)
Radius of 34-knot winds SE quadrant: 100 nm (185 km)
Radius of 34-knot winds SW quadrant: 120 nm (220 km)
Radius of 34-knot winds NW quadrant: 60 nm (110 km)
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: nm ( km)
Radius of Maximum Winds: 40 nm (75 km)
Dvorak Intensity Code: T3.0/3.0/D1.0/24HRS STT:D0.5/06HRS
Pressure of outermost isobar: 1004 hPa
Radius of outermost closed isobar: 220 nm (405 km)
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
(UTC) : degrees : nm (km): knots(km/h): hPa
+06: 28/1200: 16.0S 91.2E: 035 (070): 045 (085): 994
+12: 28/1800: 16.6S 91.8E: 045 (085): 050 (095): 989
+18: 29/0000: 16.9S 92.1E: 055 (100): 050 (095): 987
+24: 29/0600: 17.2S 92.2E: 060 (110): 050 (095): 986
+36: 29/1800: 17.6S 92.1E: 080 (150): 035 (065): 994
+48: 30/0600: 17.6S 91.1E: 095 (175): 030 (055): 998
+60: 30/1800: 17.4S 89.9E: 110 (210): 030 (055): 999
+72: 01/0600: 17.3S 88.2E: 130 (235): 025 (045): 1002
+96: 02/0600: 17.8S 84.9E: 175 (325): 025 (045): 1001
+120: 03/0600: : : :
REMARKS:
Tropical Cyclone Robyn 01U has continued to develop with gales now evident in
all quadrants.

Analysis based on scatterometry (ASCAT-B 0326UTC and SAR 2332UTC) and animated
visible imagery.

Intensity 40kn influenced by scatterometry and consistent with subjective
Dvorak, most objective guidance and model guidance. Dvorak analysis: FT/CI=3.0
based on shear pattern (edge of deep convection) and also curved band of 0.6
with some uncertainty, and adjusted MET. Objective guidance (1min mean winds):
SATCON: 46kn; ADT: FT=3.7, 59kn; AiDT: 44kn; DPRINT: 59kn; DMINT 38kn. Note:
ADT is erroneously higher based on position further under deep convection than
is actually the case.

Development is occurring in a marginally favourable environment: strong low
level southeasterly flow to south; upper divergent flow poleward; SSTs 27-27.5C
but with a shallow thermocline; and now low wind shear; against

marginal moist inflow in low to mid-levels; and dry air wrapping around the
west and north of the circulation.

Further development is forecast in the next 12-18 hours before the shear
increases under stronger upper level northwesterlies and combines with the dry
air to lead to a weakening trend from later Friday. Gales are likely to persist
southwest of the centre into Saturday.

Forecast motion is now towards the south southeast influenced by a mid-level
ridge to the east and an upper trough to the southwest. The weakening to more
shallow circulation is then forecast to turn the system abruptly to the west on
the weekend and then move out of the Australian region (90E).

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 28/1330 UTC.