WTXS31 PGTW 030300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 01S (DAHLIA) WARNING NR 013//
RMKS/
1. TROPICAL CYCLONE 01S (DAHLIA) WARNING NR 013
01 ACTIVE TROPICAL CYCLONE IN SOUTH IO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
030000Z --- NEAR 12.5S 112.4E
MOVEMENT PAST SIX HOURS - 180 DEGREES AT 07 KTS
POSITION ACCURATE TO WITHIN 035 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
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
REPEAT POSIT: 12.5S 112.4E
---
FORECASTS:
12 HRS, VALID AT:
031200Z --- 14.5S 112.0E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 195 DEG/ 10 KTS
---
24 HRS, VALID AT:
040000Z --- 16.4S 111.5E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 195 DEG/ 08 KTS
---
36 HRS, VALID AT:
041200Z --- 18.0S 111.1E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 155 DEG/ 07 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
050000Z --- 19.3S 111.8E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
030300Z POSITION NEAR 13.0S 112.3E.
TROPICAL CYCLONE 01S (DAHLIA), LOCATED APPROXIMATELY 588 NM
NORTHWEST OF PORT HEDLAND, AUSTRALIA, HAS TRACKED SOUTHWARD AT 07
KNOTS OVER THE PAST SIX HOURS. ANIMATED MUTLI-SPECTRAL SATELLITE
IMAGERY DEPICTS A FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC)
WITH LIMITED FLARING CONVECTION IN THE NORTHERN SEMI-CIRCLE. THE
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE FULLY
EXPOSED LLCC EVIDENT IN THE MULTI-SPECTRAL LOOP AND IS SUPPORTED BY
A 022216Z 91GHZ SSMIS IMAGE. THE AFOREMENTIONED MICROWAVE IMAGE ALSO
SHOWS LIMITED POCKETS OF DEEP CONVECTION PRESENT TO THE NORTH OF THE
LLCC. THE INITIAL INTENSITY OF 35 KNOTS IS HEDGED ON THE UPPER END
OF MUTLI-AGNECY DVORAK CURRENT INTENSITY ESTIMATES RANGING FROM T1.5
TO T2.5 (25-35 KNOTS) FROM PGTW AND APRF RESPECTIVELY. ENVIRONMENTAL
ANALYSIS SHOWS THAT THE SYSTEM IS IN AN AREA OF LOW TO MODERATE (15-
20 KNOTS) VERTICAL WIND SHEAR (VWS) AND IS TRACKING THROUGH AN AREA
OF WARM (28-29 CELSIUS) SEA SURFACE TEMPERATURES (SSTS). UPPER LEVEL
ANALYSIS SHOWS THAT TC 01S HAS POLEWARD OUTFLOW THAT IS CURRENTLY
BEING ENHANCED BY THE MID-LATITUDE WESTERLY JET. TC DAHLIA IS
CURRENTLY TRACKING SOUTH ALONG THE WESTERN EDGE OF A SUBTROPICAL
RIDGE BUILDING OVER THE AUSTRALIAN CONTINENT. THE SYSTEM WILL
MAINTAIN ITS CURRENT INTENSITY AS ENVIRONMENTAL CONDITIONS REMAIN
MARGINALLY FAVORABLE. AFTER TAU 36, THE SYSTEM WILL WEAKEN AS THE
ENVIRONMENT BECOMES UNFAVORABLE WITH COOLER SSTS, UNFAVORABLE SHEAR
ENVIRONMENT ASSOCIATED WITH A PASSING TROUGH, AND AN EXTENSIVE DRY
AIR MASS WILL FULLY DISSIPATE THE SYSTEM OVER WATER BY TAU 48. ALSO
AFTER TAU 36, THE SUBTROPICAL STEERING RIDGE RETROGRADES TO THE
NORTH AND CAUSING TC 01S TO ROUND THE SOUTHWESTERN EXTENT OF THE
RIDGE AND TRACK TO THE SOUTHEAST. DYNAMIC MODEL GUIDANCE REMAINS IN
STRONG AGREEMENT ON THE TRACK DIRECTION THROUGH TAU 36. AFTER TAU
36, THE WEAKENING NATURE OF THE SYSTEM CAUSES THE MODEL GUIDANCE TO
SPREAD. DESPITE THE SPREAD AFTER TAU 36 THERE IS OVERALL HIGH
CONFIDENCE IN THE JTWC TRACK FORECAST. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 030000Z IS 12 FEET. NEXT WARNINGS AT 030900Z, 031500Z,
032100Z, AND 040300Z.
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