AXAU01 APRF 051829
IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE
at: 1828 UTC 05/03/2021

Name: Tropical Cyclone Marian
Identifier: 15U
Data At: 1800 UTC
Latitude: 25.1S
Longitude: 95.5E
Location Accuracy: within 25 nm [45 km]
Movement Towards: south southeast [159 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: 990 hPa
Radius of 34-knot winds NE quadrant: 110 nm [205 km]
Radius of 34-knot winds SE quadrant: 140 nm [260 km]
Radius of 34-knot winds SW quadrant: 150 nm [280 km]
Radius of 34-knot winds NW quadrant: 100 nm [185 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:
Radius of Maximum Winds: 50 nm [95 km]
Dvorak Intensity Code: T1.5/2.0/W1.5/24HRS STT:W0.5/06HRS
Pressure of outermost isobar: 1006 hPa
Radius of outermost closed isobar: 200 nm [370 km]

FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+06: 06/0000: 25.6S 95.7E: 040 [075]: 040 [075]: 990
+12: 06/0600: 26.1S 96.1E: 055 [100]: 040 [075]: 990
+18: 06/1200: 26.5S 96.4E: 060 [115]: 040 [075]: 990
+24: 06/1800: 26.7S 96.5E: 070 [135]: 035 [065]: 992
+36: 07/0600: 27.2S 96.1E: 090 [165]: 030 [055]: 997
+48: 07/1800: 27.7S 95.4E: 115 [210]: 025 [045]: 1000
+60: 08/0600: 28.7S 95.1E: 140 [255]: 025 [045]: 1000
+72: 08/1800: 29.1S 95.0E: 160 [300]: 025 [045]: 998
+96: 09/1800: : : :
+120: 10/1800: : : :

REMARKS:
Microwave and IR imagery show modest convection well removed southeast of the centre. indicating further weakening. Marian is in a spin-down process as it moves over cool SSTs [-24C] and experiences increasing northwesterly shear [currently 20kn] but supported by strong poleward outflow.

Intensity of 40kn based upon HY2B scatterometer at 1230UTC supported by partial ASCAT passes showing gales to the east. This is higher than the Dvorak analysis that have fallen to CI=2.0 and FT=1.5 based upon DT=1.5 [shear pattern >90nm] and MET=2.0 based on a 1.5/24h weakening trend. ADT at 2.2 and SATCON at -40kn [1min ave].

Marian will track south southeast on Saturday under the influence of mid-latitude trough to the southwest. The system is forecast to maintain tropical cyclone intensity for the next 6-12 hours, although some model guidance
show this could extend to 18h. In any case there is consistency in the guidance that gales will persist on the southwestern side until Sunday owing to interaction with a ridge to the south.


Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 06/0130 UTC.
$$
T
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