1. TROPICAL CYCLONE 17P (IRIS) WARNING NR 016
02 ACTIVE TROPICAL CYCLONES IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
030000Z --- NEAR 17.0S 149.0E
MOVEMENT PAST SIX HOURS - 090 DEGREES AT 01 KTS
POSITION ACCURATE TO WITHIN 045 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT
110 NM SOUTHEAST QUADRANT
095 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
REPEAT POSIT: 17.0S 149.0E
---
FORECASTS:
12 HRS, VALID AT:
031200Z --- 17.5S 149.5E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 005 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT
190 NM SOUTHEAST QUADRANT
140 NM SOUTHWEST QUADRANT
095 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 135 DEG/ 05 KTS
---
24 HRS, VALID AT:
040000Z --- 18.2S 150.2E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 115 NM NORTHEAST QUADRANT
190 NM SOUTHEAST QUADRANT
150 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 130 DEG/ 04 KTS
---
36 HRS, VALID AT:
041200Z --- 18.7S 150.8E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 010 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 115 NM NORTHEAST QUADRANT
170 NM SOUTHEAST QUADRANT
145 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 130 DEG/ 02 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
050000Z --- 19.0S 151.2E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 010 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
155 NM SOUTHEAST QUADRANT
135 NM SOUTHWEST QUADRANT
090 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 135 DEG/ 01 KTS
---
72 HRS, VALID AT:
060000Z --- 19.3S 151.5E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 010 NM NORTHEAST QUADRANT
135 NM SOUTHEAST QUADRANT
105 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 180 DEG/ 01 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
070000Z --- 19.7S 151.5E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT
135 NM SOUTHEAST QUADRANT
115 NM SOUTHWEST QUADRANT
010 NM NORTHWEST QUADRANT
VECTOR TO 120 HR POSIT: 270 DEG/ 01 KTS
---
120 HRS, VALID AT:
080000Z --- 19.7S 151.0E
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 17.1S 149.1E.
TROPICAL CYCLONE 17P (IRIS), LOCATED APPROXIMATELY 184 NM EAST OF
CAIRNS, AUSTRALIA, HAS TRACKED EASTWARD AT 01 KNOTS OVER THE PAST
SIX HOURS. ANIMATED ENHANCED MULTI-SPECTRAL (MSI) SATELLITE SHOWS A
DEEP CONVECTION TO THE SOUTH OF A PARTIALLY EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE MSI LOOP AND WILLIS ISLAND RADAR LOOP. THE
INITIAL INTENSITY OF 45 KNOTS IS BASED ON MULTI-AGENCY DVORAK
CURRENT INTENSITY ESTIMATES OF T3.0 (45 KNOTS) AND SUPPORTED BY A
SATCON ESTIMATE OF 47 KNOTS. UPPER LEVEL ANALYSIS
REVEALS THE SYSTEM HAS AN EXCELLENT POLEWARD OUTFLOW CHANNEL DUE TO
AN UPPER LEVEL ANTICYCLONE CENTERED TO THE NORTHEAST. ENVIRONMENTAL
ANALYSIS SHOWS THE SYSTEM IS IN AN AREA OF LOW (5-10 KNOTS) VERTICAL
WIND SHEAR, AND IS TRACKING THROUGH WARM (28 CELSIUS) SEA SURFACE
TEMPERATURES. OVERALL FAVORABLE CONDITIONS WILL ALLOW FOR STEADY
INTENSIFICATION THROUGH TAU 36, REACHING A PEAK INTENSITY OF 65
KNOTS. TC 17P IS UNDER COMPETING STEERING INFLUENCES WITH A NEAR-
EQUATORIAL RIDGE (NER) LOCATED TO THE NORTHEAST AND A
SUBTROPICAL RIDGE (STR) ANCHORED OVER AUSTRALIA. TC IRIS IS FORECAST
TO TRACK SOUTHEAST THROUGH TAU 48 ALONG THE NER. AROUND THIS TIME,
THE STR WILL TRANSIT TO THE WEST AND A TROUGH MOVES IN OVER CENTRAL
AUSTRALIA. AFTER TAU 48 THE SYSTEM WILL BECOME QUASI STATIONARY IN
AN AREA OF INCREASINGLY UNFAVORABLE VERTICAL WIND SHEAR, THE RESULT
OF THE TROUGH OVER AUSTRALIA. THE SYSTEM WILL STEADILY DISSIPATE
BETWEEN TAU 72 AND TAU 120, WITH THE REMNANT SURFACE LOW LEVEL
TRACKING BACK TO THE NORTHWEST DUE TO THE SOUTHEASTERLY SURFACE
FLOW. HOWEVER, THERE IS A BIFURCATION IN THE AVAILABLE MODEL
GUIDANCE. AN ALTERNATE SCENARIO, AND THE PREVIOUS FORECAST
PHILOSOPHY, IS THAT THE SYSTEM COULD TRACK EASTWARD AROUND THE
SOUTHERN EXTENT OF THE NER AND DISSIPATE UNDER INCREASING VWS. DUE
TO THE BIFURCATION IN THE DYNAMIC MODEL GUIDANCE, THERE IS OVERALL
LOW CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 030000Z IS 12 FEET. NEXT WARNINGS AT 030900Z, 031500Z,
032100Z AND 040300Z. REFER TO TROPICAL CYCLONE 18P (JOSIE) WARNINGS
(WTPS31 PGTW) FOR SIX-HOURLY UPDATES.
https://icons.wunderground.com/data/...01817_5day.gif