SIO: BILLY - Ex-Tropical Cyclone

[zzh]

90S INVEST 220311 0000 10.4S 111.3E SHEM 15 0

[wxman57]

Scatteromter indicates multiple 35+ kt winds south of the center this morning. BoM won't name it until those 35kt winds wrap more than half way around the center.

[doomhaMwx]

If the running joke on the IMD is "deep depression with an eye", can we also say "tropical low with an eye" for BoM?

 https://twitter.com/KeviShader/status/1503292947151925253

[wxman57]

Here's another shot of that BoM "Tropical Low" that doesn't qualify for a name. BoM requires TS winds to wrap more than half way around the center to upgrade. Haven't had a scatterometer pass over it in 2 days. Partial hit yesterday indicated 35kt wind in 2 quadrants.

[Foxfires]

As the topic title implies, they named it. I don't know when exactly (at least since yesterday) but they named it eventually.

Latest bulletin from the BoM:

IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE
at: 0134 UTC 16/03/2022
Name: Ex-Tropical Cyclone Billy
Identifier: 27U
Data At: 0000 UTC
Latitude: 17.6S
Longitude: 94.6E
Location Accuracy: within 30nm (55 km)
Movement Towards: west southwest (254 deg)
Speed of Movement: 9 knots (17 km/h)
Maximum 10-Minute Wind: 45 knots (85 km/h)
Maximum 3-Second Wind Gust: 65 knots (120 km/h)
Central Pressure: 996 hPa
Radius of 34-knot winds NE quadrant:
Radius of 34-knot winds SE quadrant: 120 nm (220 km)
Radius of 34-knot winds SW quadrant: 120 nm (220 km)
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: nm ( km)
Radius of Maximum Winds: nm ( km)
Dvorak Intensity Code: T2.5/3.0/S0.0/24HRS STT:W0.5/06HRS
Pressure of outermost isobar: 1004 hPa
Radius of outermost closed isobar: 100 nm (185 km)
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
(UTC) : degrees : nm (km): knots(km/h): hPa
+06: 16/0600: 18.0S 93.7E: 075 (140): 040 (075): 996
+12: 16/1200: 18.5S 92.9E: 085 (155): 040 (075): 997
+18: 16/1800: 19.1S 92.1E: 095 (175): 035 (065): 997
+24: 17/0000: 19.8S 91.3E: 105 (195): 035 (065): 996
+36: 17/1200: 20.4S 90.0E: 130 (235): 030 (055): 999
+48: 18/0000: 20.4S 88.5E: 155 (290): 025 (045): 1002
+60: 18/1200: 20.0S 86.0E: 180 (330): 025 (045): 1004
+72: 19/0000: : : :
+96: 20/0000: : : :
+120: 21/0000: : : :
REMARKS:
Convection associated with Ex-TC Billy has become sheared to the southeast of
the LLCC. The centre was located using extrapolation and microwave imagery. The
IR satellite imagery could not be used due to cirrus cover.

Dvorak analysis is based on shear pattern giving DT2.5 (>3/4 from deep
convection). MET is 2.5 using a 24 hour S trend. Final T is 2.5 with CI held at
3.0. Latest (one minute) objective estimates are SATCON 56 knots, ADT 77 knots
and AiDT 66 knots.
Intensity is maintained at 45 knots (10-minute mean) on the southern side.

CIMSS satellite winds continue to analyse the system under approximately 15
knots of northwesterly deep layer wind shear, increasing to 25 knots just to
the south of the system centre. Upper ventilation remains good on the southern
side due to an approaching upper trough. The downside is that the upper trough
is introducing the intrusion of dry air on the western flank.

The cyclone has been steered to the SW by a mid-level ridge. As the system
shears further over the next 24 hours, the steering influence will change to
the LLCC being steering towards the west due to a strong high pressure system
extending from the south.

Copyright Commonwealth of Australia
==
There will be no further bulletins issued for this system.