s6815711

05Z評級提升至Low

(1) AN AREA OF CONVECTION (INVEST 96S) HAS PERSISTED NEAR 7.0S
133.6E, APPROXIMATELY 365 NM NORTH-NORTHEAST OF DARWIN, AUSTRALIA.
ANIMATED INFRARED SATELLITE IMAGERY AND A 071256Z MHS METOP-A 89GHZ
DEPICT AN AREA OF FLARING CONVECTION TO THE SOUTHWEST OF A
DEVELOPING LOW-LEVEL CIRCULATION CENTER (LLCC). A 071258Z METOP-A
ASCAT PASS INDICATES 15-20 KNOT WINDS ALONG THE SOUTHWESTERN
PERIPHERY OF THE LLCC. THE UPPER-LEVEL ENVIRONMENT IS CURRENTLY
MARGINAL WITH WEAK UPPER-LEVEL DIVERGENCE AND 20-25 KNOTS OF
VERTICAL WIND SHEAR. SEA SURFACE TEMPERATURES IN THE AREA ARE
FAVORABLE AT 28-30 CELSIUS. GLOBAL NUMERICAL MODEL GUIDANCE TRACKS
THIS SYSTEM IN A SOUTHWESTWARD DIRECTION AND INDICATES STEADY
DEVELOPMENT OVER THE NEXT FEW DAYS. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1008 MB. BECAUSE THIS DISTURBANCE IS JUST
BEGINNING TO ORGANIZE, THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.

周子堯@FB

JTWC評級MEDIUM

(1) THE AREA OF CONVECTION (INVEST 96S) PREVIOUSLY LOCATED
NEAR 7.4S 132.4E, IS NOW LOCATED NEAR 7.5S 132E, APPROXIMATELY 306
NM NORTH-NORTHEAST OF DARWIN, AUSTRALIA. ANIMATED INFRARED SATELLITE
IMAGERY AND A 081236Z MHS (METOP-A)  89GHZ IMAGE DEPICT AN AREA OF
FLARING CONVECTION TO THE SOUTHWEST OF A SLOWLY DEVELOPING LOW-LEVEL
CIRCULATION CENTER (LLCC). A 080054Z (METOP-B) ASCAT PASS INDICATES
20-25 KNOTS (WITH ISOLATED 30 KNOT WINDS) ALONG THE SOUTHWESTERN
PERIPHERY OF THE LLCC. ENVIRONMENTAL CONDITIONS ARE MARGINALLY
FAVORABLE WITH WARM (29C) SSTS, IMPROVING UPPER-LEVEL DIFFLUENCE,
OFFSET BY STRONG (30-40 KNOTS) VERTICAL WIND SHEAR (VWS). DYNAMIC
MODEL GUIDANCE INDICATES STEADY DEVELOPMENT OF THE SYSTEM OVER THE
NEXT 48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20
TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004
MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS REMAINS MEDIUM.

周子堯@FB

FCFA!

1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 7.8S 133.0E TO 11.3S 130.2E
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 20 TO 25 KNOTS. METSAT
IMAGERY AT 091200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 8.0S 132.9E. THE SYSTEM IS MOVING SOUTHEASTWARD AT 05 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 96S) PREVIOUSLY LOCATED
NEAR 7.5S 132.0E, IS NOW LOCATED NEAR 8.0S 132.9E, APPROXIMATELY 295
NM NORTH-NORTHEAST OF DARWIN, AUSTRALIA. ANIMATED INFRARED SATELLITE
IMAGERY AND A 090946Z SSMIS PASS DEPICT WEAK BANDING AND ASSOCIATED
DEEP CONVECTION FLARING TO THE WEST OF A CONSOLIDATING LOW LEVEL
CIRCULATION CENTER (LLCC). A 091310Z ASCAT (METOP-B) PASS SHOWS A
SYMMETRICAL LLCC WITH 20-25 KNOT SURFACE WINDS IN THE NORTHEAST
QUADRANT. ENVIRONMENTAL CONDITIONS ARE BECOMING INCREASINGLY
FAVORABLE, WITH GOOD UPPER-LEVEL DIFFLUENCE AND HIGH SEA SURFACE
TEMPERATURES (29-30 C), OFFSET BY HIGH, BUT DECREASING, VERTICAL
WIND SHEAR (25-30 KNOTS). GLOBAL MODELS INDICATE THAT THE
DISTURBANCE WILL TRACK TO THE SOUTHWEST ALONG THE NORTHWESTERN COAST
OF AUSTRALIA WHILE GRADUALLY CONSOLIDATING AND INTENSIFYING OVER THE
NEXT SEVERAL DAYS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT
20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR
1004 MB. BASED ON IMPROVING ORGANIZATION AND ENVIRONMENTAL SUPPORT,
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS HIGH.

s6815711

17Z時發佈TCFA

(1) THE AREA OF CONVECTION (INVEST 96S) PREVIOUSLY LOCATED
NEAR 7.5S 132.0E, IS NOW LOCATED NEAR 8.0S 132.9E, APPROXIMATELY 295
NM NORTH-NORTHEAST OF DARWIN, AUSTRALIA. ANIMATED INFRARED SATELLITE
IMAGERY AND A 090946Z SSMIS PASS DEPICT WEAK BANDING AND ASSOCIATED
DEEP CONVECTION FLARING TO THE WEST OF A CONSOLIDATING LOW LEVEL
CIRCULATION CENTER (LLCC). A 091310Z ASCAT (METOP-B) PASS SHOWS A
SYMMETRICAL LLCC WITH 20-25 KNOT SURFACE WINDS IN THE NORTHEAST
QUADRANT. ENVIRONMENTAL CONDITIONS ARE BECOMING INCREASINGLY
FAVORABLE, WITH GOOD UPPER-LEVEL DIFFLUENCE AND HIGH SEA SURFACE
TEMPERATURES (29-30 C), OFFSET BY HIGH, BUT DECREASING, VERTICAL
WIND SHEAR (25-30 KNOTS). GLOBAL MODELS INDICATE THAT THE
DISTURBANCE WILL TRACK TO THE SOUTHWEST ALONG THE NORTHWESTERN COAST
OF AUSTRALIA WHILE GRADUALLY CONSOLIDATING AND INTENSIFYING OVER THE
NEXT SEVERAL DAYS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT
20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR
1004 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO HIGH.

t02436

BoM編號27U，預計明天早上命名。

IDD20020
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - NORTHERN REGION
Issued by DARWIN TROPICAL CYCLONE WARNING CENTRE
at: 0252 UTC 10/04/2017
Name: Tropical Low  
Identifier: 27U
Data At: 0000 UTC
Latitude: 9.0S
Longitude: 132.9E
Location Accuracy: within 45 nm [85 km]
Movement Towards: south [171 deg]
Speed of Movement: 6 knots [11 km/h]
Maximum 10-Minute Wind: 25 knots [45 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 1001 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:   
Radius of Maximum Winds:   
Dvorak Intensity Code: T2.0/2.0/D0.5/24HRS
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:  10/0600:  9.3S 132.6E:     055 [105]:  030  [055]: 1000
+12:  10/1200:  9.5S 132.0E:     070 [130]:  030  [055]:  998
+18:  10/1800:  9.9S 131.5E:     080 [150]:  030  [055]:  997
+24:  11/0000: 10.5S 131.2E:     095 [175]:  035  [065]:  996
+36:  11/1200: 11.5S 130.6E:     115 [210]:  040  [075]:  995
+48:  12/0000: 12.2S 129.6E:     135 [245]:  045  [085]:  992
+60:  12/1200: 12.8S 128.5E:     155 [285]:  055  [100]:  986
+72:  13/0000: 13.5S 126.4E:     170 [320]:  055  [100]:  987
+96:  14/0000: 14.9S 121.8E:     215 [400]:  050  [095]:  991
+120: 15/0000: 16.7S 118.4E:     300 [560]:  030  [055]: 1002
REMARKS:
Position poor based on Visible H-8 animation and overnight scatterometer passes.
The LLCC has moved south overnight and a renewed burst of deep convective cloud
has developed over the centre. Spiral bands are evident on Warruwi radar in the
southern sectors of the system. The 1315UTC ASCAT pass indicated SE winds up to
25 knots over the SW Arafura Sea, and a 15-20 knot circulation around the LLCC.

Moderate deep layer northeasterly wind shear has continued to displace deep
convection to the east and south of the system centre, but low-level convergence
has also maintained activity in bands to the SE of the centre. Dvorak analysis
at 0000UTC yielded MET=2.0, and DT=1.5 based on 0.3 curved band wrap; FT based
on the unadjusted MET.  

The system is expected to slowly move south during the next 24 hours as a short
wave trough traverses SE Australia, then turn towards the southwest as the
following subtropical ridge strengthens over WA. The low will experience a more
favourable environment with lower vertical wind shear as it moves south,
allowing a standard development rate, reaching T3.0 Tuesday morning. The cyclone
is expected to maintain category 1 intensity as it crosses the Tiwi Islands
overnight Tuesday/Wednesday and strengthen to category 2 as it moves into the
Timor Sea towards the Kimberley region of WA.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 10/0800 UTC by Darwin TCWC.

W環

BOM繼續上看澳式C2.