Tropical Cyclone Outlook for the Western Region
Issued at 2:06 pm WST on Tuesday 21 March 2017
for the period until midnight WST Friday 24 March 2017.
Existing Cyclones in the Western Region:
A weak tropical low lies near 14.7S 117.2E (about 650km north northwest of port
Hedland). It is forecast to move southwest and then south towards the Pilbara
coast on Wednesday and Thursday. Model guidance does not develop it into a
tropical cyclone and maintains a tropical low before it crosses the Pilbara
coast during Friday.
The environment is not extremely favourable for development into a tropical
cyclone. However, if the system does show good development despite the
environment there is a chance it could reach category 1 intensity during Friday
From Saturday the system will weaken as it moves south over land.
Likelihood of this system becoming a tropical cyclone in the Western Region on:
(2) THE AREA OF CONVECTION (INVEST 99S) PREVIOUSLY LOCATED
NEAR 13.2S 117.8E, IS NOW LOCATED NEAR 16.0S 116.8E, APPROXIMATELY
150 NM NORTHWEST OF ROWLEY SHOALS, AUSTRALIA. ANIMATED INFRARED
SATELLITE IMAGERY DEPICTS PERSISTENT DEEP CONVECTION BEGINNING TO
WRAP INTO A DEVELOPING LOW-LEVEL CIRCULATION CENTER (LLCC). A
211347Z MHS METOP-A 89GHZ IMAGE DISPLAYS FORMATIVE BANDING WRAPPING
AROUND THE LLCC. UPPER-LEVEL ANALYSIS SHOWS A FAVORABLE ENVIRONMENT
WITH LOW VERTICAL WIND SHEAR (10-15 KNOTS) AND A WELL DEFINED
POLEWARD OUTFLOW CHANNEL. GLOBAL MODELS INDICATE THE SYSTEM WILL
TRACK SOUTHWARD TOWARD THE NORTHWESTERN COAST OF AUSTRALIA. GRADUAL
STRENGTHENING IS EXPECTED BEFORE MAKING LANDFALL. 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 MEDIUM.