A tropical low (08U) was located about 400 kilometres north northeast of Kalumburu at 0800 WST Tuesday 19 January. The system is forecast to strengthen in a favourable environment, with the ratings increasing to Moderate for Wednesday and High for Thursday. The system is expected to track generally southwest, staying offshore from the west Kimberley coast, before approaching the PIlbara coast on Friday or Saturday.
Likelihood of this system being a tropical cyclone in the Western Region on:
Wednesday:Moderate
Thursday:High
(1) AN AREA OF CONVECTION (INVEST 92S) HAS PERSISTED NEAR
10.8S 128.9E, APPROXIMATELY 148 NM NORTHWEST OF DARWIN, AUSTRALIA.
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 191335Z METOP-B
89GHZ MICROWAVE IMAGE DEPICT AN OVERALL LACK OF CIRCULATION AND
CONVECTIVE STRUCTURE ASSOCIATED WITH THE SYSTEM. ENVIRONMENTAL
ANALYSIS DEPICTS A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH
LOW (<15 KTS) VERTICAL WIND SHEAR, POLEWARD OUTFLOW, AND WARM (30-
31C). GLOBAL MODELS ARE IN GOOD AGREEMENT THAT INVEST 92S WILL TRACK
SOUTHWESTWARD AS IT CONSOLIDATES AND STRENGTHENS. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 10 TO 15 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1010 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS LOW.
(1) THE AREA OF CONVECTION (INVEST 92S) PREVIOUSLY LOCATED
NEAR 13.4S 104.5E IS NOW LOCATED NEAR 13.2S 122.7E, APPROXIMATELY
490 NM WEST OF DARWIN, AUSTRALIA. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY AND A 200455Z GMI 89GHZ MICROWAVE IMAGE SHOW A CONSOLIDATING
LOW LEVEL CIRCULATION CENTER (LLCC) WITH PERSISTENT DEEP CONVECTION.
A 200611Z PARTIAL ASCAT-B PASS DEPICTS A DEFINED CIRCULATION WITH 20-
25KT WINDS IN THE SOUTHERN SEMI-CIRCLE AND 15-20KT WINDS TO THE
NORTH. ENVIRONMENTAL ANALYSIS DEPICTS A FAVORABLE ENVIRONMENT FOR
DEVELOPMENT WITH LOW (<15 KTS) VERTICAL WIND SHEAR, POLEWARD
OUTFLOW, AND WARM (30-31C) SEA SURFACE TEMPERATURES. GLOBAL MODELS
ARE IN GOOD AGREEMENT THAT INVEST 92S WILL TRACK SOUTHWESTWARD AS IT
CONSOLIDATES AND STRENGTHENS. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1003 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO
MEDIUM.
WTXS22 PGTW 201500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 92S)//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/201451ZJAN2021//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT (WTXS21 PGTW 201500)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 13.3S 122.7E TO 16.8S 119.2E
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 25 TO 30 KNOTS. METSAT
IMAGERY AT 201200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 13.7S 121.4E. THE SYSTEM IS MOVING WEST-SOUTHWESTWARD AT 14
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 92S) PREVIOUSLY LOCATED
NEAR 13.2S 122.7E IS NOW LOCATED NEAR 13.7S 121.4E, APPROXIMATELY
265NM NNW OF BROOME, AUSTRALIA. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY SHOWS DEEP CONVECTION BUILDING OVER THE LOW LEVEL CIRCULATION
CENTER (LLCC). A 201200Z DIRECT ASCAT-A IMAGE DEPICTS 25-30KT WINDS
WRAPPING ALONG THE SOUTHERN PERIPHERY OF THE LLCC WHILE DEEPER CONVECTION
TO THE SOUTH HAS HIGHER WINDS (35-40KTS). ENVIRONMENTAL ANALYSIS
REVEALS A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH LOW (<10 KTS)
VERTICAL WIND SHEAR, ESTABLISHED POLEWARD OUTFLOW, AND WARM (31-32C) SEA
SURFACE TEMPERATURES. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT INVEST 92S
WILL TRACK SOUTHWESTWARD AS IT CONSOLIDATES AND STRENGTHENS. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. THE POTENTIAL FOR
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
211500Z.
4. SEE REF A FOR DETAILS ON A TROPICAL CYCLONE FORMATION ALERT
LOCATED NEAR 13.1S 99.3E.//
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