IDD20020
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - NORTHERN REGION
Issued by DARWIN TROPICAL CYCLONE WARNING CENTRE
at: 0202 UTC 16/03/2018
Name: Tropical Cyclone Marcus
Identifier: 20U
Data At: 0000 UTC
Latitude: 10.3S
Longitude: 132.6E
Location Accuracy: within 30 nm [55 km]
Movement Towards: southeast [135 deg]
Speed of Movement: 7 knots [13 km/h]
Maximum 10-Minute Wind: 35 knots [65 km/h]
Maximum 3-Second Wind Gust: 50 knots [95 km/h]
Central Pressure: 998 hPa
Radius of 34-knot winds NE quadrant: 50 nm [95 km]
Radius of 34-knot winds SE quadrant: 40 nm [75 km]
Radius of 34-knot winds SW quadrant: 40 nm [75 km]
Radius of 34-knot winds NW quadrant: 50 nm [95 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: 15 nm [30 km]
Dvorak Intensity Code: T3.0/3.0/D1.5/24HRS D0.5/06HRS
Pressure of outermost isobar: 1006 hPa
Radius of outermost closed isobar: 150 nm [280 km]
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+06: 16/0600: 10.7S 132.7E: 050 [095]: 040 [075]: 998
+12: 16/1200: 11.1S 132.6E: 065 [120]: 040 [075]: 998
+18: 16/1800: 11.5S 132.3E: 075 [145]: 040 [075]: 998
+24: 17/0000: 12.0S 131.7E: 090 [165]: 035 [065]: 998
+36: 17/1200: 12.9S 130.3E: 110 [200]: 035 [065]: 996
+48: 18/0000: 13.4S 128.6E: 130 [235]: 040 [075]: 994
+60: 18/1200: 14.0S 126.3E: 150 [275]: 050 [095]: 992
+72: 19/0000: 14.5S 123.8E: 165 [310]: 055 [100]: 988
+96: 20/0000: 14.6S 118.3E: 210 [390]: 075 [140]: 973
+120: 21/0000: 14.6S 111.8E: 300 [555]: 090 [165]: 960
REMARKS:
Latest position based on Warruwi radar with good confidence.
A partial ASCAT pass at 15/13Z ind gales in the northwest quadrant and recent
microwave imagery has shown convective banding wrapping strongly around the west
to northwest to northeast quadrants.
Recent observations: 36kn at McCluer Island at 16/0130Z.
Dvorak 16/00Z: Curved band of 0.5 gives DT 2.5. MET and PAT are 3.0 based on D+
trend. FT is based on MET.
20U was upgraded to Tropical Cyclone Marcus based on improved structure in
microwave, radar and satellite and supported by the Dvorak subjective
assessment.
At 15/18Z CIMSS winds shear indicated moderate easterly shear of 20 to 30 knots
but recent satellite imagery suggests this is easing.
Initial track movement is to the SSE under the influence of a westerly wind
surge to the north of the system. The tropical low is forecast to turn south and
move close to the north coast of the Northern Territory today due to a mid level
ridge to the east. The system is expected to curve to the southwest and towards
the Timor Sea in 24 to 48 hours as a mid latitude trough moves east across the
Great Australian Bight and pushes the mid level ridge over southern Australia
further north, creating an easterly steering. Development is expected to be at a
standard rate, aided by a Rossby wave arriving over western Arafura Sea and
Timor Sea today, decreasing environmental shear closer to the NT coast and
continued favorouble low level surges.
Development may be hindered by land influences and ingestion of dry air on the
outer western flank. Once the tropical low moves into the Timor Sea during the
weekend, development is likely to continue at a standard after briefly
entangling with the north Kimberley coast. Steering will remain easterly long
term due to a strong mid level ridge to the south, taking the system into the
Indian Ocean.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 16/0800 UTC by Darwin TCWC
.
