JTWC判定17P於03/06Z轉化為副熱帶氣旋

SH, 17, 2021020300, , BEST, 0, 219S, 1671E, 40, 990, TS, 34, NEQ, 75, 80, 110, 65, 1000, 230, 60, 0, 0, P, 0, , 0, 0, LUCAS, M,
SH, 17, 2021020306, , BEST, 0, 223S, 1670E, 45, 988, SS, 34, NEQ, 65, 165, 150, 70, 1000, 190, 60, 0, 0, P, 0, , 0, 0, LUCAS, M,
SH, 17, 2021020312, , BEST, 0, 227S, 1668E, 40, 991, SS, 34, NEQ, 60, 180, 180, 50, 1001, 225, 60, 0, 0, P, 0, , 0, 0, LUCAS, M,

FMS判定該系統已減弱成低壓區

Gale Warning 027 ISSUED FROM RSMC NADI Feb 031302 UTC.  

LOW PRESSURE L [FORMER TC LUCAS] WAS LOCATED NEAR 22.7S 166.5E AT 031200 UTC.

POSITION GOOD. LOW PRESSURE MOVING SOUTHWEST AT 05 KNOTS.  

EXPECT CLOCKWISE WINDS UPTO 35 KNOTS WITHIN 120 NAUTICAL MILES OF L IN THE QUADRANTS NORTHEAST, SOUTHEAST AND SOUTHWEST.  

EXPECT CLOCKWISE WINDS UPTO 35 KNOTS WITHIN 90 NAUTICAL MILES OF L IN THE NORTHWEST QUADRANTS.  

AREAS OF GALES MOVING WITH THE LOW.  

THIS WARNING CANCELS AND REPLACES WARNING NUMBER 026.

JTWC03Z發布Final Warning

WTPS33 PGTW 030300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 17P (LUCAS) WARNING NR 013//
RMKS/
1. TROPICAL CYCLONE 17P (LUCAS) WARNING NR 013   
   01 ACTIVE TROPICAL CYCLONES IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   030000Z --- NEAR 21.9S 167.1E
     MOVEMENT PAST SIX HOURS - 190 DEGREES AT 13 KTS
     POSITION ACCURATE TO WITHIN 020 NM
     POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
     SATELLITE AND SYNOPTIC DATA
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING SUBTROPICAL
   RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT
                            080 NM SOUTHEAST QUADRANT
                            110 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   REPEAT POSIT: 21.9S 167.1E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   031200Z --- 23.0S 166.8E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   SUBTROPICAL
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            130 NM SOUTHEAST QUADRANT
                            080 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
    ---
REMARKS:
030300Z POSITION NEAR 22.2S 167.0E.
03FEB21. TROPICAL CYCLONE 17P (LUCAS), LOCATED APPROXIMATELY 57
NM EAST-NORTHEAST OF NOUMEA, NEW CALEDONIA, HAS TRACKED SOUTHWARD
AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) SHOWS THE CENTRAL CONVECTION REMAINS SHEARED SOUTHWARD  
PARTLY EXPOSING THE LOW LEVEL CIRCULATION (LLC). THE MSI LOOP ALSO
SHOWS VIGOROUS COLD AIR ADVECTION AS EVIDENCED BY STRATOCUMULUS CLOUD
LINES WRAPPING INTO THE LLC. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE PARTLY EXPOSED LLC IN THE MSI LOOP, AND LINED
UP WITH A DEFINED LLC FEATURE IN THE 022226Z ASCAT BULLSEYE PASS. THE
INITIAL INTENSITY OF 40KTS IS BASED ON AN OVERALL ASSESSMENT OF
SURFACE WIND OBSERVATIONS, THE 030040Z ADT ESTIMATE OF 41KTS, THE
AFOREMENTIONED ASCAT PASS, AND PGTW/KNES DVORAK ESTIMATES OF
T2.5/35KTS. CYCLONE PHASE ANALYSIS INDICATES TC LUCAS IS QUICKLY
BECOMING SUBTROPICAL AND WILL COMPLETE SUBTROPICAL TRANSITION BY TAU
12. AS SUCH, THE SYSTEM NO LONGER MEETS THE JTWC WARNING CRITERIA.
THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON
WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR
SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 030000Z
IS 14 FEET.//
NNNN

在強大風切的利刃摧殘下,過去24小時減弱幅度明顯
FMS18Z降格澳式C1,JTWC18Z則定強40KT

GALE WARNING 022 ISSUED FROM RSMC NADI Feb 021920 UTC.

TROPICAL CYCLONE LUCAS CENTRE 987HPA CATEGORY 1 WAS LOCATED NEAR 20.2
SOUTH 167.5 EAST AT 021800 UTC.
POSITION POOR.
REPEAT POSITION 20.2S 167.5E at 021800 UTC.
CYCLONE MOVING SOUTH SOUTHEAST AT 9 KNOTS. CYCLONE WEAKENING.
EXPECT SUSTAINED WINDS OF 45 KNOTS CLOSE TO THE CENTRE WEAKENING TO
40 KNOTS BY 031200UTC.

EXPECT WINDS OVER 33 KNOTS WITHIN 120 NAUTICAL MILES IN NE QUADRANT
AND WITHIN 90 NAUTICAL MILES IN SE QUADRANT
AND WITHIN 90 NAUTICAL MILES IN SW QUADRANT
AND WITHIN 90 NAUTICAL MILES IN NW QUADRANT

FORECAST POSITION NEAR 21.6S 167.8E AT 030600UTC
AND NEAR 22.5S 167.5E AT 031800UTC.


ALL VESSELS WITHIN 300 NAUTICAL MILES OF CENTRE ARE REQUESTED TO SEND
REPORTS EVERY THREE HOURS TO RSMC NADI. VOS REPORTING SHIPS USE
NORMAL CHANNELS. OTHER VESSELS FAX PLUS 679 6720190 OR EMAIL NADITCC
AT MET DOT GOV DOT FJ

THIS WARNING CANCELS AND REPLACES WARNING 021.

FMS新報略微再將定強上調至60KT,距離澳式C3(三級強熱帶氣旋)只差臨門一腳
但照目前的各類資訊分析,實際情況很有可能已經是正在減弱當中,要達到澳式C3恐怕有點懸

TROPICAL DISTURBANCE ADVISORY NUMBER C2 ISSUED FROM RSMC NADI
Feb 012036 UTC.

TROPICAL CYCLONE LUCAS CENTRE 975HPA WAS LOCATED NEAR 17.0S 163.5E AT
011800 UTC. POSITION POOR BASED ON HR HIMAWARI-8 EIR IMAGERY AND
PERIPHERAL SURFACE REPORTS. CYCLONE MOVING SOUTH SOUTHEAST AT ABOUT
16 KNOTS. MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED
AT ABOUT 60 KNOTS.

EXPECT WINDS OVER 47 KNOTS WITHIN 40 NAUTICAL MILES OF CENTRE
EXPECT WINDS ABOVE 33 KNOTS WITHIN 120 NAUTICAL MILES IN NE QUADRANT
AND WITHIN 120 NAUTICAL MILES IN SE QUADRANT
AND WITHIN 90 NAUTICAL MILES IN SW QUADRANT
AND WITHIN 120 NAUTICAL MILES IN NW QUADRANT.

DEEP CONVECTION REMAINS PERSISTENT WITH LLCC EMBEDDED. SYSTEM MOVING
INTO AREA OF HIGH SHEAR. TC LUCAS STEERED TO THE SOUTHEAST BY THE
SOUTHWEST PERIPHERY OF THE NEAR EQUATORIAL RIDGE LOCATED TO THE EAST
OF THE SYSTEM. DVORAK ANALYSIS BASED ON EMBEDDED CENTRE IN DG
YIELDING DT=4.0, MET AND PT AGREE. FT BASED ON DT. THUS DVORAK
T4.0/4.0/S0.0/24HRS

FORECASTS :
AT 12 HRS VALID AT 020600 UTC 18.8S 165.5E MOV S AT 05 KT WITH 60 KT
CLOSE TO CENTRE
AT 24 HRS VALID AT 021800 UTC 20.6S 166.4E MOV SSW AT 10 KT WITH 60
KT CLOSE TO CENTRE

OUTLOOK :
AT 36 HRS VALID AT 030600 UTC 22.0S 166.6E MOV SSW AT 10 KT WITH 55
KT CLOSE TO CENTRE
AT 48 HRS VALID AT 031800 UTC 23.0S 166.4E MOV SW AT 10 KT WITH 50 KT
CLOSE TO CENTRE

THE NEXT TROPICAL DISTURBANCE ADVISORY ON LUCAS WILL BE ISSUED AROUND
020200 UTC.

於10Z的底層掃描可以發現底層型態已大不如前
另外FMS於12Z接手發報,定強維持BoM06Z的55KT,並認為已達顛峰

TROPICAL DISTURBANCE ADVISORY NUMBER C1 ISSUED FROM RSMC NADI
Feb 011520 UTC.

TROPICAL CYCLONE LUCAS CENTRE 985HPA WAS LOCATED NEAR 15.6S 162.6E AT
011200 UTC. POSITION GOOD POOR BASED ON HR HIMAWARI-8 EIR IMAGERY AND
PERIPHERAL SURFACE REPORTS. CYCLONE MOVING EAST SOUTHEAST AT ABOUT 23
KNOTS. MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT
ABOUT 55 KNOTS.

EXPECT WINDS OVER 47 KNOTS WITHIN 40 NAUTICAL MILES OF CENTRE
EXPECT WINDS ABOVE 33 KNOTS WITHIN 120 NAUTICAL MILES IN NE QUADRANT
AND WITHIN 120 NAUTICAL MILES IN SE QUADRANT
AND WITHIN 90 NAUTICAL MILES IN SW QUADRANT
AND WITHIN 120 NAUTICAL MILES IN NW QUADRANT.

DEEP CONVECTION REMAINS PERSISTENT WITH LLCC EMBEDDED. TC LUCAS IS
MOVING INTO AREA OF HIGH SHEAR. TC LUCAL EXPECTED TOANA WEAKENING AND
IS EXPECTED TO BE STEERED TO THE SOUTHEAST BY THE SOUTHWEST PERIPHERY
OF THE NEAR EQUATORIAL RIDGE LOCATED TO THE EAST OF THE SYSTEM.
DVORAK ANALYSIS BASED ON EMBEDDED CENTRE IN DG YIELDING DT=4.0, MET
AND PT AGREE. FT BASED ON DT. THUS DVORAK T4.0/4.0/D1.0/24HRS

FORECASTS :
AT 12 HRS VALID AT 020000 UTC 17.3S 165.3E MOV ESE AT 16 KT WITH 55
KT CLOSE TO CENTRE
AT 24 HRS VALID AT 021200 UTC 19.3S 167.0E MOV SE AT 14 KT WITH 50 KT
CLOSE TO CENTRE

OUTLOOK :
AT 36 HRS VALID AT 030000 UTC 21.0S 167.6E MOV SE AT 12 KT WITH 50 KT
CLOSE TO CENTRE
AT 48 HRS VALID AT 031200 UTC 22.1S 167.6E MOV SE AT 10 KT WITH 45 KT
CLOSE TO CENTRE

THE NEXT TROPICAL DISTURBANCE ADVISORY ON LUCAS WILL BE ISSUED AROUND
012000 UTC.

17P.LUCAS.21020112.65kts.980mb.15.7S.162.6E.

一度LG，臨門一腳JTWC升格C1，即將進入風切較大的局域並減弱