TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - NORTHERN REGION
Issued by DARWIN TROPICAL CYCLONE WARNING CENTRE
at: 1333 UTC 13/03/2012
Name: Tropical Low
Identifier: 17U
Data At: 1200 UTC
Latitude: 12.9S
Longitude: 128.0E
Location Accuracy: within 45 nm [85 km]
Movement Towards: south [180 deg]
Speed of Movement: 4 knots [7 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Central Pressure: 997 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:
Dvorak Intensity Code: T2.5/2.5/D1.0/24HRS
Pressure of outermost isobar: 1004 hPa
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 14/0000: 13.6S 128.4E: 075 [140]: 040 [075]: 993
+24: 14/1200: 14.5S 129.1E: 105 [195]: 040 [075]: 993
+36: 15/0000: 15.3S 130.4E: 140 [255]: 030 [055]: 996
+48: 15/1200: 16.3S 132.0E: 170 [315]: 030 [055]: 999
+60: 16/0000: 16.9S 133.4E: 220 [405]: 030 [055]: 999
+72: 16/1200: 17.4S 134.6E: 265 [490]: 030 [055]: 999
REMARKS:
The tropical low has been located using surface observations and a recent
scatterometer pass, in the Timor Sea, southwest of Darwin. A mid-level centre of
rotation is evident from satellite animations just to the west of the LLCC,
indicating that the circulation is tilted by vertical wind shear. Convective
structure is improving with deep convection developing close to the LLCC and
peripheral banding to the east, suggesting that the system is moving into an
area of decreasing shear. A band of 25 to 30kt winds was evident to the north of
the low's centre in the 00:25UTC Ascat pass. This vigorous monsoonal flow is
expected to interact with the low tonight, possibly leading to its
intensification.
Dvorak analysis yields an unrepresentative DT=3.0 based on a shear pattern, with
MET=PT=2.5. FT was held to 2.5, based on the PT, due to the improving structure
and central convection. The development rate has been slow but the low is moving
under the upper ridge axis, decreasing the deep layer shear. A standard
development is forecast in a favourable environment with a divergent upper
pattern. Model track forecasts are consistent, indicating an acceleration
towards the southeast, reaching the southwest Top End coast later on Wednesday.
Copyright Commonwealth of Australia
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The next bulletin for this system will be issued by: 13/1930 UTC by Darwin TCWC.
![Image](http://desmond.imageshack.us/Himg560/scaled.php?server=560&filename=idd65001.gif&res=medium)