IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0109 UTC 21/03/2018
Name: Severe Tropical Cyclone Marcus
Identifier: 20U
Data At: 0000 UTC
Latitude: 14.4S
Longitude: 112.2E
Location Accuracy: within 15 nm [30 km]
Movement Towards: west [270 deg]
Speed of Movement: 15 knots [27 km/h]
Maximum 10-Minute Wind: 110 knots [205 km/h]
Maximum 3-Second Wind Gust: 155 knots [285 km/h]
Central Pressure: 939 hPa
Radius of 34-knot winds NE quadrant: 70 nm [130 km]
Radius of 34-knot winds SE quadrant: 140 nm [260 km]
Radius of 34-knot winds SW quadrant: 120 nm [220 km]
Radius of 34-knot winds NW quadrant: 70 nm [130 km]
Radius of 48-knot winds NE quadrant: 50 nm [95 km]
Radius of 48-knot winds SE quadrant: 50 nm [95 km]
Radius of 48-knot winds SW quadrant: 50 nm [95 km]
Radius of 48-knot winds NW quadrant: 50 nm [95 km]
Radius of 64-knot winds: 30 nm [55 km]
Radius of Maximum Winds: 20 nm [35 km]
Dvorak Intensity Code: T5.0/6.0/D0.5/24HRS SST:S/06HRS
Pressure of outermost isobar: 1006 hPa
Radius of outermost closed isobar: 300 nm [555 km]
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+06: 21/0600: 14.6S 110.8E: 025 [050]: 110 [205]: 925
+12: 21/1200: 14.9S 109.6E: 040 [070]: 125 [230]: 919
+18: 21/1800: 15.3S 108.5E: 050 [095]: 125 [230]: 919
+24: 22/0000: 15.9S 107.6E: 065 [120]: 120 [220]: 925
+36: 22/1200: 17.4S 106.4E: 085 [155]: 100 [185]: 947
+48: 23/0000: 19.6S 105.6E: 105 [190]: 090 [165]: 955
+60: 23/1200: 22.0S 105.7E: 120 [225]: 070 [130]: 971
+72: 24/0000: 24.4S 106.4E: 140 [265]: 050 [095]: 986
+96: 25/0000: 27.2S 107.3E: 185 [345]: 030 [055]: 997
+120: 26/0000: 30.0S 110.1E: 275 [505]: 030 [055]: 998
REMARKS:
Marcus was located using Visible imagery and overnight microwave passes.It may
have gone through an eye wall replacement cycle overnight and it is expected to
form a consistent eye pattern again during Wednesday.
Dvorak: The eye pattern has fluctuated overnight with a gradual warming of the
surrounding shade and a cooling of the eye temperature. Surrounding grey shade
is currently B giving an E number of 5.5, Eadj have been between -0.5 and -1.0.
Time averaged DT is currently down at 5.0. MET/PAT is 6.0 based on D trend and
CI is 6.0. CIMSS ADT is currently 6.5 and NESDIS ADT 6.0. Both methods have been
fluctuating between eye pattern and other patterns. SATCON at 2000 UTC was 127
kt 1-minute wind. Microwave passes have mostly missed overnight. Intensity is
set at 110 kt which may increase further during Wednesday.
Marcus is moving towards the west under the influence of a strong ridge to the
south. NWP is in strong agreement for a westerly track on Wednesday before
moving in a more southerly direction during Thursday.
Vertical wind shear is around 10 knots from the E. There is good upper
divergence, with dual outflow channels [poleward and equatorward].
Ocean Heat Content is favourable and SSTs are around 30C along the forecast
track. Shear should remain low over the next few days.
Marcus will continue at a category 5 system during Wednesday as it continues to
track towards the west. From late Wednesday the ridge will move eastwards and an
approaching upper level trough will help steer the system towards the southwest
then towards the south late on Thursday and Friday.
As Marcus tracks towards the south on Thursday and Friday it will start to
weaken with decreasing SSTs and increasing wind shear.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 21/0730 UTC by Perth TCWC.
15S MARCUS
As of 06:00 UTC Mar 21, 2018:
Location: 14.8°S 110.9°E
Maximum Winds: 125 kt
Minimum Central Pressure: 935 mb
TPXS12 PGTW 210632
A. TROPICAL CYCLONE 15S (MARCUS)
B. 21/0600Z
C. 14.92S
D. 110.91E
E. THREE/HMWRI8
F. T6.5/6.5/D1.0/24HRS STT: D0.5/03HRS
G. IR/EIR
H. REMARKS: 09A/PBO RAGGED EYE/ANMTN. OW EYE SURROUNDED BY W
YIELDS AN E# OF 6.0. ADDED 0.5 FOR EYE ADJUSTMENT TO YIELD A DT
OF 6.5. MET AND PT YIELDS 6.5. DBO DT.
I. ADDITIONAL POSITIONS: NONE
LOWE
TXXS23 KNES 211215
TCSSIO
A. 15S (MARCUS)
B. 21/1130Z
C. 15.0S
D. 109.5E
E. ONE/HIMAWARI-8
F. T7.0/7.0/D1.0/24HRS
G. IR/EIR
H. REMARKS...THIS INTENSITY ESTIMATE WAS DERIVED USING 4 KM IR DATA. OW
EYE IS EMBEDDED AND SURROUNDED BY CMG WITH 0.5 ADDED FOR EYE ADJUSTMENT
YIELDING A DT OF 7.0. MET AND PT AGREE. FT IS BASED ON DT.
I. ADDL POSITIONS
NIL
...KIBLER
TPXS12 PGTW 211227
A. TROPICAL CYCLONE 15S (MARCUS)
B. 21/1200Z
C. 14.98S
D. 109.48E
E. THREE/HMWRI8
F. T6.5/6.5/D1.0/24HRS STT: S0.0/03HRS
G. IR/EIR
H. REMARKS: 09A/PBO RAGGED EYE/ANMTN. OW EYE SURROUNDED BY CMG
YIELDS AN E# AND DT (NO EYE ADJUSTMENT) OF 6.5. MET AND PT
YIELD 6.5. DBO DT.
I. ADDITIONAL POSITIONS:
21/0751Z 14.92S 110.47E GPMI
H. REMARKS: 05A/PBO IRREG EYE/ANMTN. WMG EYE SURROUNDED BY W
YIELDS AN E# OF 6.0. ADDED 1.0 FOR EYE ADJUSTMENT TO YIELD A DT
OF 7.0. MET AND PT YIELD A 6.5. DBO DT.
