Subject: Indian-S: 1. Tropical Cyclone 20s (alistair) Warning Nr 008

From: SIU Weather Processor <[email-masked]>
Date: Wed, 18 Apr 2001 15:05:30 -0500

WTXS31 PGTW 182100
1. TROPICAL CYCLONE 20S (ALISTAIR) WARNING NR 008
   01 ACTIVE TROPICAL CYCLONE IN SOUTHERN HEMISPHERE
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
    ---
   WARNING POSITION:
   181800Z8 --- NEAR 15.0S6 123.2E8
     MOVEMENT PAST SIX HOURS - 240 DEGREES AT 14 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
   RADIUS OF 050 KT WINDS - 045 NM SOUTH SEMICIRCLE
                            035 NM ELSEWHERE
   RADIUS OF 035 KT WINDS - 100 NM SOUTH SEMICIRCLE
                            085 NM ELSEWHERE
   REPEAT POSIT: 15.0S6 123.2E8
    ---
   FORECASTS:
   12 HRS, VALID AT:
   190600Z6 --- 16.3S0 120.8E1
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
   RADIUS OF 050 KT WINDS - 050 NM SOUTH SEMICIRCLE
                            040 NM ELSEWHERE
   RADIUS OF 035 KT WINDS - 110 NM SOUTH SEMICIRCLE
                            095 NM ELSEWHERE
   VECTOR TO 24 HR POSIT: 240 DEG/ 12 KTS
    ---
   24 HRS, VALID AT:
   191800Z9 --- 17.4S2 118.6E6
   MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
   RADIUS OF 050 KT WINDS - 060 NM SOUTH SEMICIRCLE
                            045 NM ELSEWHERE
   RADIUS OF 035 KT WINDS - 115 NM SOUTH SEMICIRCLE
                            100 NM ELSEWHERE
   VECTOR TO 36 HR POSIT: 245 DEG/ 14 KTS
    ---
   36 HRS, VALID AT:
   200600Z8 --- 18.5S4 116.0E8
   MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT
   RADIUS OF 050 KT WINDS - 060 NM SOUTH SEMICIRCLE
                            050 NM ELSEWHERE
   RADIUS OF 035 KT WINDS - 120 NM SOUTH SEMICIRCLE
                            105 NM ELSEWHERE
   VECTOR TO 48 HR POSIT: 250 DEG/ 13 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   201800Z1 --- 19.4S4 113.4E9
   MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT
   RADIUS OF 050 KT WINDS - 065 NM SOUTH SEMICIRCLE
                            055 NM ELSEWHERE
   RADIUS OF 035 KT WINDS - 125 NM SOUTH SEMICIRCLE
                            110 NM ELSEWHERE
   VECTOR TO 72 HR POSIT: 215 DEG/ 11 KTS
    ---
   72 HRS, VALID AT:
   211800Z2 --- 23.0S5 110.8E0
   MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT
   RADIUS OF 050 KT WINDS - 060 NM SOUTHEAST SEMICIRCLE
                            050 NM ELSEWHERE
   RADIUS OF 035 KT WINDS - 125 NM SOUTHEAST SEMICIRCLE
                            110 NM ELSEWHERE
    ---
REMARKS:
182100Z2 POSITION NEAR 15.3S9 122.6E1.
TROPICAL CYCLONE (TC) 20S (ALISTAIR), LOCATED APPROXIMATELY 70 NM
NORTH-NORTHWEST OF YAMPI SOUND, AUSTRALIA, HAS TRACKED WEST-
SOUTHWESTWARD AT 14 KNOTS OVER THE PAST 6 HOURS. THE WARNING
POSITION IS BASED ON 181730Z0 INFRARED SATELLITE IMAGERY. THE
WARNING INTENSITY IS BASED ON CURRENT INTENSITY ESTIMATES OF 55 AND
65 KNOTS. ANIMATED SATELLITE IMAGERY REVEALS STEADY CONVECTION AND
AND AN EMBEDDED CENTER. TC 20S IS FORECAST TO TRACK WEST-
SOUTHWESTWARD UNDER THE STEERING INFLUENCE OF THE MID-LEVEL RIDGE
ESTABLISHED OVER AUSTRALIA THROUGH 48 HOURS. AFTER THAT, THE SYSTEM
SHOULD BEGIN TO TRACK MORE SOUTHWARD THROUGH A WEAKNESS IN THE
SUBTROPICAL RIDGE AS A MID-LATITUDE TROUGH APPROACHES. THE UPPER
RIDGE CURRENTLY SITUATED OVER NORTHERN AUSTRALIA IS MOVING OVER THE
TIMOR SEA AND WILL PROVIDE FAVORABLE OUTFLOW. TC 20S IS EXPECTED TO
SLOWLY INTENSIFY THROUGH THE FORECAST PERIOD. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 181800Z8 IS 16 FEET. NEXT WARNINGS AT 190300Z3,
190900Z9, 191500Z6 AND 192100Z3.//

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
To unsubscribe from WX-TROPL send e-mail to [email-masked] with
"unsub wx-tropl" in the body of your message. For help with WX-TROPL
write to [email-masked] or see http://wxlist.centerone.com. For more
information on tropical weather products, see the NHC Homepage
at http://www.nhc.noaa.gov.