Tropical Cyclones [Index]

Tropical Cyclone HILDA Southern Hemisphere Summary

WTXS21 PGTW 262300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
155 NM EITHER SIDE OF A LINE FROM 15.5S 123.3E TO 19.8S 119.2E
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 28 TO 33 KNOTS. METSAT
IMAGERY AT 261200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 15.7S 123.2E. THE SYSTEM IS MOVING SOUTHWARD AT 06 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 16.5S
122.4E IS NOW LOCATED NEAR 15.7S 123.2E, APPROXIMATELY 645 NM
NORTHEAST OF LEARMONTH, AUSTRALIA. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC)
WITH FORMATIVE BANDING OVER THE NORTHERN SEMI-CIRCLE. A 261135Z AMSU
89GHZ IMAGE SHOWS CURVED, DEEP BANDING OVER THE NORTHERN PERIPHERY
WRAPPING INTO A LLCC IN THE SOUTHWESTERN QUADRANT OF THE LLCC. A
261307Z ASCAT PASS SHOWS AN AREA OF 25-30 KNOT WINDS LOCATED IN THE
NORTHWESTERN QUADRANT. THE UPPER LEVEL ANALYSIS REVEALS A FAVORABLE
ENVIRONMENT WITH LOW TO MODERATE (10-15 KNOTS) VERTICAL WIND SHEAR
AND RADIAL OUTFLOW. DYNAMIC MODELS INDICATE GRADUAL INTENSIFICATION
OVER THE 24-36 HRS AS THE SYSTEM TRACKS TO THE SOUTHWEST. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28 TO 33 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 998 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
272300Z.
=========================================================================
WTXS31 PGTW 272100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 02S (HILDA) WARNING NR 001//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/262251ZDEC2017//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. TROPICAL CYCLONE 02S (HILDA) WARNING NR 001
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   271800Z --- NEAR 18.8S 121.6E
     MOVEMENT PAST SIX HOURS - 210 DEGREES AT 09 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT
                            035 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            075 NM NORTHWEST QUADRANT
   REPEAT POSIT: 18.8S 121.6E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   280600Z --- 20.2S 121.9E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
   VECTOR TO 24 HR POSIT: 170 DEG/ 07 KTS
    ---
   24 HRS, VALID AT:
   281800Z --- 21.5S 122.2E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
    ---
REMARKS:
272100Z POSITION NEAR 19.2S 121.7E.
TROPICAL CYCLONE (TC) 02S (HILDA), LOCATED APPROXIMATELY 64 NM
SOUTH-SOUTHWEST OF BROOME, AUSTRALIA, HAS TRACKED SOUTH-SOUTHWESTWARD
AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY DEPICTS FLARING CONVECTION AROUND THE LOW LEVEL
CIRCULATION CENTER (LLCC) ASSOCIATED WITH TC 02S. THE STRONGEST
CONVECTION IS LOCATED TO THE NORTH OF THE LLCC. THE INITIAL POSITION
IS BASED ON A 271810Z HIMAWARI SATELLITE IMAGE SHOWING GOOD
CONVECTIVE BANDING. THE INITIAL INTENSITY OF 40 KNOTS IS HEDGED
BETWEEN A PGTW DVORAK ESTIMATE OF T3.5 (55 KNOTS) AND A 271226Z OSCAT
IMAGE SHOWING 30 KNOT WINDS. UPPER LEVEL ANALYSIS SHOWS FAVORABLE
VERTICAL WIND SHEAR (10 TO 15 KNOTS), MODERATE EQUATORWARD OUTFLOW
AND GOOD POLEWARD OUTFLOW. TC 02S WILL TRACK SOUTH-SOUTHEASTWARD AS
IT MOVES OVER LAND. TC 02S WILL GRADUALLY DECREASE IN INTENSITY AND
DISSIPATE BY TAU 24 DUE TO CONTINUED LAND INTERACTION. THERE IS GOOD
AGREEMENT AMONG DYNAMIC MODEL GUIDANCE, SO THERE IS HIGH CONFIDENCE
IN THE JTWC TRACK FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
271800Z IS 9 FEET. NEXT WARNINGS AT 280300Z, 280900Z AND 281500Z.
THIS CANCELS AND SUPERSEDES REF A (WTXS21 PGTW 262300).//
=========================================================================
SUBJ: TROPICAL CYCLONE 02S (HILDA) WARNING NR 002
WTXS31 PGTW 280300
1. TROPICAL CYCLONE 02S (HILDA) WARNING NR 002
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
280000Z --- NEAR 19.4S 121.7E
MOVEMENT PAST SIX HOURS - 170 DEGREES AT 05 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
000 NM SOUTHEAST QUADRANT
000 NM SOUTHWEST QUADRANT
000 NM NORTHWEST QUADRANT
REPEAT POSIT: 19.4S 121.7E
---
FORECASTS:
12 HRS, VALID AT:
281200Z --- 20.7S 122.0E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
280300Z POSITION NEAR 19.7S 121.8E.
TROPICAL CYCLONE 02S (HILDA), LOCATED APPROXIMATELY 94 NM SOUTH-
SOUTHWEST OF BROOME, AUSTRALIA, HAS TRACKED SOUTHWARD AT 05 KNOTS
OVER THE PAST SIX HOURS.
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 280000Z
IS 9 FEET.