JTWC is up to 40kts.
WTXS31 PGTW 072100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 21S (TWENTYONE) WARNING NR 004//
RMKS/
1. TROPICAL CYCLONE 21S (TWENTYONE) WARNING NR 004
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
071800Z --- NEAR 11.2S 68.2E
MOVEMENT PAST SIX HOURS - 255 DEGREES AT 11 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 - 035 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
REPEAT POSIT: 11.2S 68.2E
---
FORECASTS:
12 HRS, VALID AT:
080600Z --- 11.6S 66.0E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 265 DEG/ 11 KTS
---
24 HRS, VALID AT:
081800Z --- 11.8S 63.8E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 265 DEG/ 10 KTS
---
36 HRS, VALID AT:
090600Z --- 12.0S 61.8E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 245 DEG/ 07 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
091800Z --- 12.6S 60.5E
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
085 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 215 DEG/ 03 KTS
---
72 HRS, VALID AT:
101800Z --- 13.5S 59.8E
MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT
100 NM SOUTHEAST QUADRANT
100 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 185 DEG/ 04 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
111800Z --- 15.0S 59.7E
MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 155 DEG/ 05 KTS
---
120 HRS, VALID AT:
121800Z --- 16.7S 60.5E
MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
072100Z POSITION NEAR 11.3S 67.7E.
TROPICAL CYCLONE (TC) 21S (TWENTYONE), LOCATED APPROXIMATELY 335 NM
SOUTHWEST OF DIEGO GARCIA, HAS TRACKED WEST-SOUTHWESTWARD AT 11
KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY
DEPICTS A PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC)
LOCATED EAST OF PERSISTENT DEEP CONVECTION. A 071543Z SSMIS 37 GHZ
IMAGE SHOWS GOOD LOWER-LEVEL BANDING STRUCTURE OVER THE WESTERN
SEMICIRCLE BUT VERY FRAGMENTED AND WEAK BANDS TO THE EAST. A 071740Z
ASCAT PASS DEPICTED 35-40 KNOT WINDS OVER THE WESTERN PORTION OF THE
LLCC WHICH ARE WRAPPING INTO THE CENTER. THE CURRENT POSITION IS
BASED ON THE AFOREMENTIONED IMAGERY WITH FAIR CONFIDENCE. THE
CURRENT INTENSITY IS BASED ON THE TIMELY ASCAT PASS. UPPER-LEVEL
ANALYSIS INDICATES TC 21S IS APPROXIMATELY FIVE DEGREES EQUATORWARD
OF THE SUBTROPICAL RIDGE (STR) AXIS. VERTICAL WIND SHEAR (VWS)
REMAINS MODERATE (15-20 KNOTS), CAUSING THE DEEP CONVECTION TO BE
SHEARED TO THE WEST. ANIMATED WATER VAPOR IMAGERY DEPICTS MODERATE
POLEWARD OUTFLOW; HOWEVER, EQUATORWARD OUTFLOW IS LIMITED DUE TO
TROUGHING. TC 21S WILL CONTINUE TO TRACK WEST-SOUTHWESTWARD THROUGH
TAU 48 UNDER THE INFLUENCE OF THE DEEP LAYERED STR TO THE SOUTH. A
GRADUAL DECREASE IN VWS AND FAIR OUTFLOW WILL ALLOW FOR
INTENSIFICATION. ADDITIONALLY, A POOL OF HIGHER OCEAN HEAT CONTENT
LOCATED ALONG THE FORECAST TRACK WILL AID IN THIS INTENSIFICATION.
AFTER TAU 72, A DEEP LAYER MID-LATITUDE TROUGH WILL MOVE IN FROM THE
WEST AND BEGIN TO REORIENT THE STR IN THE NORTH-SOUTH DIRECTION,
ALLOWING FOR TC 21S TO TURN POLEWARD. THE FORECAST CALLS FOR A PEAK
INTENSITY OF 95 KNOTS BY TAU 96. THOUGH DYNAMICAL MODEL GUIDANCE IS
IN GENERALLY GOOD AGREEMENT WITH THE POLEWARD DEFLECTION IN THE
EXTENDED FORECAST, THE TIMING AND SHARPNESS IN THE DEFLECTION ARE
STILL UNCLEAR. THIS IS FURTHER EVIDENCED BY INCREASING SPREAD NOTED
IN ENSEMBLE MODEL PRODUCTS. THERE IS HIGH CONFIDENCE IN THE THREE
DAY FORECAST, BUT LOW CONFIDENCE IN THE EXTENDED PORTION. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 071800Z IS 15 FEET. NEXT WARNINGS AT
080900Z AND 082100Z.//
![Image](http://oi50.tinypic.com/2j2vk1u.jpg)