WARNING 7/JTWC
https://www.facebook.com/groups/1817419381676514/
Location: 16.8°S 117.4°E
Maximum Winds: 125 kt ( 230km/h)
Gusts: 150 kt (280km/h)
Minimum Central Pressure: 930 mb
CATEGORY 4 US
REMARKS:
210900Z POSITION NEAR 17.0S 117.3E.
TROPICAL CYCLONE (TC) 21S (VERONICA), LOCATED APPROXIMATELY 221 NM
NORTH-NORTHWEST OF PORT HEDLAND, AUSTRALIA, HAS TRACKED SOUTH-
SOUTHWESTWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY SHOWS THE SYSTEM HAS MAINTAINED A
HIGHLY SYMMETRIC STRUCTURE WITH DEEP RAIN BANDS WRAPPING TIGHTLY INTO
A COMPACT CENTRAL CONVECTION WITH A SHARPLY-OUTLINED 10-NM EYE. THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EYE,
ADJUSTED FOR A SLIGHT POLEWARD TILT. THE INITIAL INTENSITY IS BASED
ON AN OVERALL ASSESSMENT OF AGENCY DVORAK ESTIMATES RANGING FROM
T6.0/115KTS TO T6.5/127KTS AND REFLECTS THE SUSTAINED INTENSE
CONVECTIVE SIGNATURE. UPPER LEVEL ANALYSIS INDICATES TC 21S IS UNDER
LOW (5-10KT) NORTHERLY VERTICAL WIND SHEAR (VWS) AND EXCELLENT RADIAL
OUTFLOW. SEA SURFACE TEMPERATURES AT 31C ARE ALSO HIGHLY CONDUCIVE.
THE CYCLONE IS TRACKING ALONG THE NORTHWEST PERIPHERY OF A
SUBTROPICAL RIDGE (STR) TO THE SOUTHEAST. AFTER TAU 24, IT WILL TURN
MORE SOUTHWARD AS THE STR RECEDES EASTWARD, MAKING LANDFALL ABOUT 30
NM WEST OF PORT HEDLAND AROUND 72. THE FAVORABLE CONDITIONS WILL FUEL
FURTHER INTENSIFICATION UP TO 135 KNOTS OVER THE NEXT 24 HOURS.
AFTERWARD, INCREASING VWS THEN LAND INTERACTION WILL RAPIDLY ERODE
THE CYCLONE DOWN TO 30 KNOTS BY TAU 120. NUMERIC MODELS ARE IN GOOD
AGREEMENT UP TO TAU 48 THEN SPREAD OUT SIGNIFICANTLY AFTERWARD, WITH
ECMWF DRIVING THE VORTEX DUE WESTWARD AND NAVGEM SOUTHEASTWARD. IN
VIEW OF THESE, THERE IS FAIR CONFIDENCE IN THE JTWC TRACK FORECAST
UP TO TAU 48, THEN LOW CONFIDENCE AFTERWARD. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 210600Z IS 50 FEET. NEXT WARNINGS AT 211500Z, 212100Z,
220300Z AND 220900Z.//
NNNN
Location: 16.8°S 117.4°E
Maximum Winds: 125 kt ( 230km/h)
Gusts: 150 kt (280km/h)
Minimum Central Pressure: 930 mb
CATEGORY 4 US
REMARKS:
210900Z POSITION NEAR 17.0S 117.3E.
TROPICAL CYCLONE (TC) 21S (VERONICA), LOCATED APPROXIMATELY 221 NM
NORTH-NORTHWEST OF PORT HEDLAND, AUSTRALIA, HAS TRACKED SOUTH-
SOUTHWESTWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY SHOWS THE SYSTEM HAS MAINTAINED A
HIGHLY SYMMETRIC STRUCTURE WITH DEEP RAIN BANDS WRAPPING TIGHTLY INTO
A COMPACT CENTRAL CONVECTION WITH A SHARPLY-OUTLINED 10-NM EYE. THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EYE,
ADJUSTED FOR A SLIGHT POLEWARD TILT. THE INITIAL INTENSITY IS BASED
ON AN OVERALL ASSESSMENT OF AGENCY DVORAK ESTIMATES RANGING FROM
T6.0/115KTS TO T6.5/127KTS AND REFLECTS THE SUSTAINED INTENSE
CONVECTIVE SIGNATURE. UPPER LEVEL ANALYSIS INDICATES TC 21S IS UNDER
LOW (5-10KT) NORTHERLY VERTICAL WIND SHEAR (VWS) AND EXCELLENT RADIAL
OUTFLOW. SEA SURFACE TEMPERATURES AT 31C ARE ALSO HIGHLY CONDUCIVE.
THE CYCLONE IS TRACKING ALONG THE NORTHWEST PERIPHERY OF A
SUBTROPICAL RIDGE (STR) TO THE SOUTHEAST. AFTER TAU 24, IT WILL TURN
MORE SOUTHWARD AS THE STR RECEDES EASTWARD, MAKING LANDFALL ABOUT 30
NM WEST OF PORT HEDLAND AROUND 72. THE FAVORABLE CONDITIONS WILL FUEL
FURTHER INTENSIFICATION UP TO 135 KNOTS OVER THE NEXT 24 HOURS.
AFTERWARD, INCREASING VWS THEN LAND INTERACTION WILL RAPIDLY ERODE
THE CYCLONE DOWN TO 30 KNOTS BY TAU 120. NUMERIC MODELS ARE IN GOOD
AGREEMENT UP TO TAU 48 THEN SPREAD OUT SIGNIFICANTLY AFTERWARD, WITH
ECMWF DRIVING THE VORTEX DUE WESTWARD AND NAVGEM SOUTHEASTWARD. IN
VIEW OF THESE, THERE IS FAIR CONFIDENCE IN THE JTWC TRACK FORECAST
UP TO TAU 48, THEN LOW CONFIDENCE AFTERWARD. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 210600Z IS 50 FEET. NEXT WARNINGS AT 211500Z, 212100Z,
220300Z AND 220900Z.//
NNNN
WARNING 7/JTWC
0817UTC
0709UTC
0810UTC
06UTC
