MEDIUM - 西澳西北热带低压21U(99S) - 13.4S 120.7E

ygsj24

SH, 99, 2025021706,   , BEST,   0, 116S, 1296E,  15,    0, DB,   0,    ,    0,    0,    0,    0,    0,    0,   0,   0,   0,   S,   0,    ,   0,   0,     INVEST,  ,

pocketbox

ABIO10 PGTW 180300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN
REISSUED/180300Z-181800ZFEB2025//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/171952ZFEB2025//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.//
RMKS/
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY: NONE.
   B. TROPICAL DISTURBANCE SUMMARY: NONE.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.
2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY:
      (1) AT 17FEB25 1800Z, TROPICAL CYCLONE 14S (TALIAH) WAS LOCATED
NEAR 30.0S 77.0E, APPROXIMATELY 1202 NM EAST-SOUTHEAST OF PORT LOUIS,
MAURITIUS, AND HAD TRACKED SOUTHWESTWARD AT 05 KNOTS OVER THE PAST SIX
HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 40 KNOTS GUSTING
TO 50 KNOTS. SEE REF A (WTXS33 PGTW 172100) FOR FURTHER DETAILS.
      (2) NO OTHER TROPICAL CYCLONES.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) AN AREA OF CONVECTION (INVEST 99S) HAS PERSISTED NEAR 10.8S
128.6E, APPROXIMATELY 167 NM NORTHWEST OF DARWIN. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY DEPICTS A WELL DEFINED LOW-LEVEL CIRCULATION CENTER
(LLCC) WITH DEEP FLARING CONVECTION TO THE WEST-SOUTHWEST. A 180202Z
ASCAT METOP-B SCATTEROMETRY PASS REVEALS 15-20 KNOT WINDS BEGINNING TO
WRAP INTO THE LLCC, WITH STRONGER WINDS OF 20-30 KNOTS APPROXIMATELY 150
NM TO THE WEST-NORTHWEST OF THE LLCC. ENVIRONMENTAL ANALYSIS INDICATES
THAT INVEST 99S IS IN A FAVORABLE ENVIRONMENT FOR FURTHER DEVELOPMENT DUE
TO WARM (29-30C) SEA SURFACE TEMPERATURES, LOW TO MODERATE (15 TO 20
KNOT) VERTICAL WIND SHEAR, AND GOOD EQUATORWARD AND POLEWARD OUTFLOW
ALOFT. GLOBAL MODELS ARE NOT IN AGREEMENT WITH THE POTENTIAL DEVELOPMENT
OF INVEST 99S, HOWEVER THE ECMWF AND GFS ENSEMBLES ARE IN STRONG
AGREEMENT WITH THE POTENTIAL DEVELOPMENT AND GENERAL WEST-SOUTHWESTWARD
TRACK OVER THE NEXT 24-36 HOURS.  MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 18 TO 23 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 LOW.
      (2) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: ADDED LOW AREA IN PARA. 2.B.(1).//
NNNN

pocketbox

Tropical Low 21U
A tropical low is forecast to form in the Timor Sea and remain north of the WA coast.

• A tropical low (21U) is expected to form in the Timor Sea later in the week.
• 21U is expected to move westwards during the weekend and remain well to the north of the Kimberley and Pilbara coasts.
• The risk of 21U developing into a tropical cyclone increases to Low on Thursday and then to Moderate on Friday.
  

Last updated
5 hours ago, 08:44 am UTC

Tropical lows

Tomorrow 12:00 am

Tomorrow 12:00 pm

Thu 20  Feb 12:00 am

Thu 20  Feb 12:00 pm

Fri 21  Feb 12:00 am

Fri 21  Feb 12:00 pm

Sat 22  Feb 12:00 am

Sat 22  Feb 12:00 pm

Sun 23  Feb 12:00 am

Sun 23  Feb 12:00 pm

Mon 24  Feb 12:00 am

Mon 24  Feb 12:00 pm

Tue 25  Feb 12:00 am

Tue 25  Feb 12:00 pm

Tropical Low 21U

null (None)

1 (Very Low)

5 (Low)

10 (Low)

15 (Low)

25 (Moderate)

25 (Moderate)

30 (Moderate)

30 (Moderate)

35 (Moderate)

40 (Moderate)

40 (Moderate)

35 (Moderate)

35 (Moderate)

Leonardo

TPXS10 PGTW 181202

A. TROPICAL DISTURBANCE 99S (S OF TIMOR)

B. 18/1130Z

C. 11.42S

D. 126.71E

E. FIVE/GK2A

F. T1.0/1.0  STT: S0.0/03HRS

G. IR/EIR

H. REMARKS: 38A/PBO SBC/ANMTN. CNVCTN WRAPS .25 ON LOG10 SPIRAL
YIELDING A DT OF 1.0. MET AND PT AGREE. DBO DT.

I. ADDITIONAL POSITIONS: NONE


   RAE

Leonardo

TXXS24 KNES 181224
TCSSIO

A.  TROPICAL DISTURBANCE (99S)

B.  18/1130Z

C.  11.6S

D.  126.7E

E.  THREE/HIMAWARI-9

F.  T1.0/1.0

G.  IR/EIR/PRXY

H.  REMARKS...3/10 BANDING YIELDS A DT OF 1.5. THE MET AND PT ARE 1.0
BASED ON THE INITIAL DEVELOPMENT TREND WITHIN THE FIRST 24 HOURS. THE
FT IS BASED ON THE MET SINCE BANDING FEATURES WERE NOT CLEAR CUT.

I.  ADDL POSITIONS

    NIL


...COVERDALE

=

Leonardo

pocketbox

Tropical Low 21U
Tropical low (21U) developing to the northwest of the Kimberley and to remain well off the WA coast.

• Tropical low (21U) is expected to continue moving westwards into the weekend, while remaining well to the north of the Pilbara coast.
• The risk of 21U developing into a tropical cyclone increases to Moderate on Friday and High on the weekend.
• 21U does not pose a direct threat to Western Australian mainland or island communities.
• During next week, 21U is expected to curve towards the south and the southeast, while remaining well off the Western Australian coast.
  

Last updated
4 hours ago, 09:16 am UTC

Tropical lows

Tomorrow 12:00 am

Tomorrow 12:00 pm

Fri 21  Feb 12:00 am

Fri 21  Feb 12:00 pm

Sat 22  Feb 12:00 am

Sat 22  Feb 12:00 pm

Sun 23  Feb 12:00 am

Sun 23  Feb 12:00 pm

Mon 24  Feb 12:00 am

Mon 24  Feb 12:00 pm

Tue 25  Feb 12:00 am

Tue 25  Feb 12:00 pm

Wed 26  Feb 12:00 am

Wed 26  Feb 12:00 pm

Tropical Low 21U

10 (Low)

15 (Low)

25 (Moderate)

35 (Moderate)

45 (Moderate)

55 (High)

55 (High)

55 (High)

55 (High)

55 (High)

55 (High)

55 (High)

55 (High)

55 (High)

Leonardo

TPXS10 PGTW 191202

A. TROPICAL DISTURBANCE 99S (S OF TIMOR)

B. 19/1130Z

C. 13.10S

D. 122.73E

E. FIVE/GK2A

F. T1.0/1.0/S0.0/24HRS  STT: D1.0/03HRS

G. IR/EIR

H. REMARKS: 63A/PBO PRLY ORGNZD LLCC/ANMTN. LOOSELY DEFINED CLOUD
LINES LOCATED WITHIN 75NM OF COLD OVERCAST YIELD A DT OF 1.0. MET
YIELDS 2.0. PT YIELDS 1.5. DBO DT.

I. ADDITIONAL POSITIONS: NONE


   RAE

Leonardo

TXXS24 KNES 191309
TCSSIO

A.  TROPICAL DISTURBANCE (99S)

B.  19/1130Z

C.  13.2S

D.  121.7E

E.  THREE/HIMAWARI-9

F.  T2.0/2.0

G.  IR/EIR/SWIR

H.  REMARKS...3/10 WHITE CURVED BANDING RESULTS IN A DT OF 2.0. THE MET
IS 2.0 BASED ON REGULAR DEVELOPING TREND. THE PT IS ALSO 2.0. THE FT IS
BASED ON THE MET DUE TO BANDING FEATURES NOT BEING CLEAR CUT.

I.  ADDL POSITIONS

    NIL


...EVANS

=

Leonardo