由於垂直風切偏強，受到11S牽引掉頭東移的過程中未能順利發展，JTWC已於09Z再度取消評級。

(1) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 12.0S
93.2E, HAS DISSIPATED AND IS NO LONGER SUSPECT FOR THE DEVELOPMENT
OF A SIGNIFICANT TROPICAL CYCLONE IN THE NEXT 24 HOURS.

JTWC 14Z評級提升至Medium。

(1) THE AREA OF CONVECTION (INVEST 90S) PREVIOUSLY LOCATED
NEAR 12.0S 93.2E IS NOW LOCATED NEAR 11.0S 97.3E, APPROXIMATELY 72NM
NORTH-NORTHEAST OF COCOS ISLAND. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY DEPICTS INTENSE DEEP CONVECTION FLARING OVER THE
NORTHWEST QUADRANT OF AN EXPOSED LOW-LEVEL CIRCULATION CENTER
(LLCC). A 281052Z SSMIS 37GHZ COLOR COMPOSITE IMAGE SHOWS SHALLOW
CURVED BANDING WRAPPING INTO A DEFINED LLCC WITH ISOLATED DEEP
CONVECTION OVER THE NORTHWEST QUADRANT. A RECENT ASCAT IMAGE SHOWS
STRONG WESTERLY WINDS (30 TO 35 KNOTS) ALONG THE NORTHERN FLANK WITH
20 TO 30 KNOTS ELSEWHERE. SURFACE OBSERVATIONS FROM COCOS ISLAND
INDICATE SOUTHEASTERLY WINDS AT 18 KNOTS WITH SLP NEAR 1006 MB. THE
SYSTEM IS CURRENTLY LOCATED WITHIN AN UNFAVORABLE ENVIRONMENT WITH
STRONG (30 TO 40 KNOTS) EASTERLY VERTICAL WIND SHEAR AND BROAD
DIFFLUENCE ALOFT. SST VALUES, HOWEVER, ARE FAVORABLE AT 28-29C.
GLOBAL MODELS ARE IN GOOD AGREEMENT SHOWING A CONTINUED EASTWARD
TRACK WITH NEAR GALE FORCE SURFACE WINDS PERSISTING OVER THE
NORTHERN SEMICIRCLE OF A COMPACT SYSTEM. THE MODELS ALSO SHOW A
POTENTIAL INTERACTION WITH TC 11S IN THE LATER TAUS THAT COULD CAUSE
A TRACK SHIFT TO THE SOUTHEAST. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 25 TO 30 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.

JTWC 17Z再次評級Low

(2) AN AREA OF CONVECTION (INVEST 90S) HAS PERSISTED NEAR
11.6S 90.3E, APPROXIMATELY 389 NM WEST OF COCOS ISLAND. ANIMATED
ENHANCED INFRARED SATELLITE IMAGERY AND A 251515Z MHS 89GHZ
MICROWAVE IMAGE DEPICT A SLIGHTLY ELONGATED PARTIALLY EXPOSED LOW
LEVEL CIRCULATION WITH CONVECTION FLARING NEAR THE CENTER AND
SCATTERED POCKETS OF DEEP CONVECTION ELSEWHERE. A 251514Z ASCAT PASS
SHOWS A SLIGHTLY ELONGATED SYSTEM WITH PRIMARILY 20-25 KNOT WINDS
WRAPPING INTO THE CENTER AND 30-35 KNOT WINDS LOCATED ON THE
PERIPHERY. THE DISTURBANCE IS CURRENTLY LOCATED IN AN AREA OF GOOD
POLEWARD UPPER LEVEL OUTFLOW, MODERATE TO HIGH VERTICAL WIND SHEAR
(20-30 KNOTS), AND WARM SEA SURFACE TEMPERATURES (28-30 CELSIUS).
GLOBAL MODELS INDICATE AN EASTWARD TRACK WITH INTENSIFICATION TO
WARNING CRITERIA LIKELY IN THE NEXT FEW DAYS. THE MODELS ALSO SHOW A
POTENTIAL INTERACTION WITH TC 11S IN THE LATER TAUS THAT COULD CAUSE
A TRACK SHIFT TO THE SOUTHEAST. 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 LOW.

JTWC於18Z取消評級，評級Low僅維持18小時。

(3) THE AREA OF CONVECTION (INVEST 90S) PREVIOUSLY LOCATED
NEAR 11.5S 93.7E, HAS DISSIPATED AND IS NO LONGER SUSPECT FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE IN THE NEXT 24 HOURS.

JTWC於01230000Z評級Low。

(3) THE AREA OF CONVECTION (INVEST 90S) HAS PERSISTED NEAR
11.5S 93.7E, APPROXIMATELY 200 NM WEST OF COCOS ISLAND. ANIMATED
ENHANCED INFRARED SATELLITE IMAGERY AND A 221510Z MHS 89GHZ
MICROWAVE IMAGE DEPICT A SLIGHTLY ELONGATED LOW LEVEL CIRCULATION
WITH PERSISTENT FLARING CONVECTION LOCATED TO THE WEST AND
SOUTHWEST. THE DISTURBANCE IS CURRENTLY LOCATED IN AN AREA OF GOOD
POLEWARD AND EQUATORWARD OUTFLOW, LOW VERTICAL WIND SHEAR (5-15
KNOTS), AND WARM SEA SURFACE TEMPERATURES (28-30 KNOTS). MODELS ARE
INDICATING AN INITIAL WESTWARD TRACK BEFORE SOME MODELS SHOW A
QUASISTATIONARY OR SLIGHTLY EASTWARD TRACK. MOST GLOBAL MODELS
CURRENTLY SHOW A TREND TOWARDS INTENSIFICATION TO WARNING CRITERIA
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 1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.

BoM 展望已編號11U

Tropical Cyclone Outlook for the Western Region
Issued at 2:00 pm WST on Saturday 12 January 2019
for the period until midnight WST Tuesday 15 January 2019.

Existing Cyclones in the Western Region:
Nil.

Potential Cyclones:

There are no tropical lows in the Western Region at present.

A tropical low (11U) is likely to develop within a deepening trough over the western Top End of the Northern Territory or adjacent waters late in the weekend (outside the Western Region). It is expected that if the tropical low develops in the trough, it will likely track west to southwest over the Timor Sea during Monday and may be over the Browse Basin on Tuesday with a possibility of reaching tropical cyclone intensity later in the day. In the longer term, the system will track to the west-southwest throughout next week - possibly as a tropical cyclone - well to the north of WA over the the Indian Ocean.


Likelihood of this system being a tropical cyclone in the Western Region on:
Sunday:Very Low
Monday:Very Low
Tuesday:Low

There are no other tropical lows expected to develop in the Western Region over the next three days.


Likelihood of another system being a tropical cyclone in the Western Region on:
Sunday:Very Low
Monday:Very Low
Tuesday:Very Low