JTWC 15Z把評級降為Low 已於早上登陸西澳

(1) THE AREA OF CONVECTION (INVEST 93S) PREVIOUSLY LOCATED
NEAR 19.2S 118.9E IS NOW LOCATED NEAR 21.8S 118.2E, APPROXIMATELY
235 NM EAST OF LEARMONTH, AUSTRALIA. ANIMATED ENHANCED INFRARED
SATELLITE AND RADAR IMAGERY SHOW THAT THE SYSTEM HAS TRACKED INLAND
AND IS NOW TRACKING SOUTHWESTWARD TOWARD THE NORTHWEST REGION OF
AUSTRALIA. THIS IMAGERY CONTINUES TO SHOW A BROAD, MONSOON
DEPRESSION WITH DEEP CONVECTION AND NEAR GALE FORCE WINDS ALONG THE
WESTERN PERIPHERY. SURFACE OBSERVATIONS FROM LEARMONTH INDICATE
PERSISTENT 20 TO 25 KNOT SOUTHWESTERLY SUSTAINED WINDS WITH GUSTS TO
30 TO 40 KNOTS. DYNAMIC MODEL GUIDANCE INDICATES THAT THE SYSTEM
WILL RE-EMERGE OVER WATER NEAR TAU 36, HOWEVER, TROPICAL CYCLONE
FORMATION IS UNLIKELY DUE TO COLD SST (21-23C) AND THE PRESENCE OF
COOLER, DRIER SOUTHERLY FLOW ASSOCIATED WITH A STRONG HIGH WEST OF
AUSTRALIA. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 987MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS DOWNGRADED TO LOW.

JTWC 06Z發佈TCFA

WTXS21 PGTW 072130
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
175 NM EITHER SIDE OF A LINE FROM 18.4S 119.6E TO 23.8S 115.0E
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 30 TO 35 KNOTS. METSAT
IMAGERY AT 072100Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 19.2S 118.9E. THE SYSTEM IS MOVING SOUTHWESTWARD AT 08
KNOTS.

請問各位大大一個問題，澳洲的地形、洋流跟西太有甚麼不一樣的？感覺西南太平洋或南印度洋有不少熱帶擾動再澳洲陸地或近海被付與編號或氣旋的，這在西太很少見？

BoM在展望中編號15U

Potential Cyclones:

At 2pm WST Tuesday, a weak tropical low (15U), 988hPa, was located near 17.4S 120.1E, about 230 kilometres west northwest of Broome and 360 kilometres north northeast of Port Hedland. Recent movement has been to the west southwest at about 9 kilometres per hour.
The low is expected to move in a southwesterly direction through the remainder of today and on Wednesday, towards the Pilbara coast. The low should cross the Pilbara coast during Wednesday, somewhere between Pardoo and Mardie. By this stage it is unlikely to have developed into a tropical cyclone.
Even though the low is not expected to develop into a tropical cyclone, gales are possible in the northern and eastern quadrants. As a result, damaging winds, heavy rainfall and dangerous surf conditions are possible along the coast between Cape Leveque and Port Hedland, including Broome. A Severe Weather Warning [IDW20032] is current; refer to www.bom.gov.au/wa/warnings/ for more details.
Heavy rainfall is expected with the passage of the low and with the vigorous monsoonal flow to the north of the low. Various Flood Warnings are current across the Kimberley and Pilbara; refer to www.bom.gov.au/wa/warnings/ for more details.

The likelihood of this system being a tropical cyclone in the Western Region on:
Wednesday: Low
Thursday: Low
Friday: Low

JTWC 18Z評級直接提升至Medium

(1) AN AREA OF CONVECTION (INVEST 93S) HAS PERSISTED NEAR
17.9S 122.9E, APPROXIMATELY 40 NM EAST OF BROOME, AUSTRALIA.
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 061336Z MHS METOP-
A 89 GHZ MICROWAVE IMAGE LACK A WELL DEFINED LOW LEVEL CIRCULATION
BUT DISPLAY FLARING CONVECTION THROUGHOUT THE INVEST AREA WHICH IS
CURRENTLY ASSESSED TO BE OVER LAND. THE DISTURBANCE IS CURRENTLY
LOCATED IN A MARGINAL ENVIRONMENT DUE TO MODERATE (15-20 KTS)
VERTICAL WIND SHEAR AND POOR UPPER LEVEL OUTFLOW. OBSERVATIONS FROM
BROOME REVEAL A 5MB PRESSURE FALL OVER THE PAST 24 HOURS, INDICATING
SIGNIFICANT DEEPENING OF THE DISTURBANCE. GLOBAL MODELS ARE IN GOOD
AGREEMENT ANTICIPATING A SOUTHWEST TRACK WITH DEVELOPMENT OVER WATER
WITHIN THE NEXT 24-48 HRS. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 994 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS MEDIUM.