Updated: 17 June 2020
[Australian Severe Weather index] [Copyright Notice] [Email Contacts] [Search This Site] [Privacy Policy]
| Tropical Cyclones
[Index] | Tropical Cyclone TUNI : JTWC Advisories |
| Season 2015-2016 Summaries (Operational Data): [AU] [SIO] [SPAC] [SH] | |
| ---> Tropical Cyclone TUNI Track Map and Data |
WTPS21 PGTW 20151126 19:30z
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
220 NM EITHER SIDE OF A LINE FROM 9.8S 179.4E TO 13.6S 174.3W
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 32 KNOTS. METSAT
IMAGERY AT 261832Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 10.5S 179.7W. THE SYSTEM IS MOVING EAST-SOUTHEASTWARD AT 09
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 10.5S
179.7E, IS NOW LOCATED NEAR 10.5S 179.8W, APPROXIMATELY 465 NM NORTH-
NORTHEAST OF SUVA, FIJI. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY SHOWS INCREASING ORGANIZATION OF THE LOW LEVEL CIRCULATION
CENTER (LLCC) WITH PERSISTENT CONVECTION LOCATED OVER THE AREA OF
SHARPEST TURNING. A 260653Z RSCAT PASS REVEALS THE LLCC IS STILL
ELONGATED, WITH 25-30 KNOT CENTRAL WINDS OUTSIDE OF THE RAIN-FLAGGED
REGION. ENHANCED CROSS-EQUATORIAL WESTERLIES NORTH OF THE LLCC ARE
HELPING TO QUICKLY SPIN UP THIS DISTURBANCE. UPPER LEVEL ANALYSIS
INDICATES THE DISTURBANCE IS LOCATED IN AN AREA OF LOW (10-15 KNOTS)
EASTERLY VERTICAL WIND SHEAR AND EXCELLENT POLEWARD OUTFLOW.
NUMERICAL GUIDANCE IS INDICATING THE LLCC WILL CONTINUE TO
CONSOLIDATE, WITH FORMATION OF A TROPICAL CYCLONE LIKELY OVER THE
NEXT 12-24 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT
25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR
1001 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
271930Z.
=========================================================================
WTPS31 PGTW 20151127 21:00z
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 04P (FOUR) WARNING NR 001//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/261921NOV15//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. TROPICAL CYCLONE 04P (FOUR) WARNING NR 001
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
271800Z --- NEAR 13.4S 174.9W
MOVEMENT PAST SIX HOURS - 125 DEGREES AT 13 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
REPEAT POSIT: 13.4S 174.9W
---
FORECASTS:
12 HRS, VALID AT:
280600Z --- 14.4S 172.8W
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
075 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 125 DEG/ 12 KTS
---
24 HRS, VALID AT:
281800Z --- 15.7S 170.7W
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT
075 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
090 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 140 DEG/ 12 KTS
---
36 HRS, VALID AT:
290600Z --- 17.6S 169.1W
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT
075 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
090 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 145 DEG/ 11 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
291800Z --- 19.5S 167.8W
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 140 DEG/ 06 KTS
---
72 HRS, VALID AT:
301800Z --- 21.3S 166.3W
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
272100Z POSITION NEAR 13.7S 174.4W.
TROPICAL CYCLONE (TC) 04P (FOUR), LOCATED APPROXIMATELY 251 NM WEST-
NORTHWEST OF PAGO PAGO, HAS TRACKED SOUTHEASTWARD AT 13 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED AND VISIBLE SATELLITE
IMAGERY INDICATE A CONSOLIDATING SYSTEM WITH INCREASING DEEP
CONVECTION OVER THE LOW-LEVEL CIRCULATION CENTER (LLCC). A 271809Z
SSMIS IMAGE DEPICTS IMPROVED DEEP CONVECTIVE BANDING OVER THE
SOUTHERN SEMI-CIRCLE WRAPPING INTO THE SOUTHWEST QUADRANT OF THE
LLCC WITH SHALLOW BANDING ELSEWHERE. UPPER-LEVEL ANALYSIS INDICATES
LOW TO MODERATE NORTHWESTERLY VERTICAL WIND SHEAR (VWS), ASSOCIATED
WITH A BROAD UPPER-LEVEL TROUGH, OFFSET BY GOOD POLEWARD OUTFLOW.
SST VALUES ARE FAVORABLE AT 28 TO 29 CELSIUS. OVERALL, THERE IS FAIR
CONFIDENCE IN THE CURRENT POSITION BASED ON THE SSMIS IMAGE AND
LIMITED VISIBLE IMAGERY. THE INITIAL INTENSITY IS ASSESSED AT 35
KNOTS BASED ON THE HIGHER RANGE OF DVORAK INTENSITY ESTIMATES
RANGING FROM T2.0 (30 KNOTS) TO T2.5 (35 KNOTS). TC 04P IS FORECAST
TO TRACK EAST-SOUTHEASTWARD ALONG THE SOUTHERN PERIPHERY OF THE NEAR-
EQUATORIAL RIDGE THROUGH TAU 24 BUT SHOULD GRADUALLY TURN
SOUTHEASTWARD AS IT TRANSITIONS TO THE STEERING INFLUENCE OF THE
SUBTROPICAL RIDGE. TC 04P IS EXPECTED TO INTENSIFY TO A PEAK OF 55
KNOTS BY TAU 24 TO 36 UNDER MARGINALLY-FAVORABLE CONDITIONS.
HOWEVER, AFTER TAU 36, VWS IS FORECAST TO INCREASE MARKEDLY WITH SST
VALUES DROPPING BELOW 26 CELSIUS, WHICH WILL SERVE TO WEAKEN THE
SYSTEM. ADDITIONALLY, THE SYSTEM WILL BEGIN EXTRA-TROPICAL
TRANSITION (ETT) AS IT INTERACTS WITH A WEAK BAROCLINIC ZONE. TC 04P
WILL COMPLETE ETT BY TAU 72 AS IT GAINS FRONTAL CHARACTERISTICS AND
IS EXPECTED TO REMAIN A GALE-FORCE LOW. OVERALL, THERE IS LOW
CONFIDENCE IN THE JTWC FORECAST TRACK DUE TO A LARGE SPREAD IN
DYNAMIC MODEL SOLUTIONS WITH SIGNIFICANT DIFFERENCES IN TRACK SPEED.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 271800Z IS 10 FEET. NEXT WARNINGS
AT 280300Z, 280900Z, 281500Z AND 282100Z. THIS WARNING SUPERSEDES
AND CANCELS REF A, JOINT TYPHOON WRNCEN 261921 NOV 15 TROPICAL
CYCLONE FORMATION ALERT (WTPS21 PGTW 261930).//
=========================================================================
WTPS31 PGTW 20151128 03:00z
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 04P (FOUR) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 04P (FOUR) WARNING NR 002
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
280000Z --- NEAR 13.7S 174.4W
MOVEMENT PAST SIX HOURS - 125 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 - 065 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
REPEAT POSIT: 13.7S 174.4W
---
FORECASTS:
12 HRS, VALID AT:
281200Z --- 14.8S 172.3W
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
075 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 135 DEG/ 12 KTS
---
24 HRS, VALID AT:
290000Z --- 16.4S 170.5W
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT
075 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
090 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 140 DEG/ 12 KTS
---
36 HRS, VALID AT:
291200Z --- 18.2S 169.0W
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 145 DEG/ 08 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
300000Z --- 19.6S 168.0W
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 140 DEG/ 06 KTS
---
72 HRS, VALID AT:
010000Z --- 21.5S 166.4W
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
280300Z POSITION NEAR 14.0S 173.9W.
TROPICAL CYCLONE (TC) 04P (FOUR), LOCATED APPROXIMATELY 218 NM WEST
OF PAGO PAGO, AMERICAN SAMOA, HAS TRACKED SOUTHEASTWARD AT 09 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) AND A 272115Z METOP-B 89GHZ IMAGE DEPICT A PARTIALLY-EXPOSED
LOW-LEVEL CIRCULATION CENTER (LLCC) WITH DEEP CONVECTIVE BANDING
OVER THE SOUTHERN SEMI-CIRCLE. UPPER-LEVEL ANALYSIS INDICATES LOW TO
MODERATE NORTHWESTERLY VERTICAL WIND SHEAR (VWS), ASSOCIATED WITH A
BROAD UPPER-LEVEL TROUGH, OFFSET BY GOOD POLEWARD OUTFLOW AND
SLIGHTLY IMPROVED EQUATORWARD OUTFLOW. SST VALUES ARE FAVORABLE AT
28 TO 29 CELSIUS. OVERALL, THERE IS FAIR CONFIDENCE IN THE CURRENT
POSITION BASED ON THE METOP-B IMAGE AND MSI. THE INITIAL INTENSITY
IS ASSESSED AT 40 KNOTS, HEDGED SLIGHTLY HIGHER THAN THE DVORAK
INTENSITY ESTIMATES OF T2.5 (35 KNOTS) BASED ON THE 272116Z ASCAT
IMAGE, WHICH SHOWS 35 TO 40 KNOT WINDS OVER THE EAST QUADRANT. TC
04P IS FORECAST TO TRACK EAST-SOUTHEASTWARD ALONG THE SOUTHERN
PERIPHERY OF THE NEAR-EQUATORIAL RIDGE THROUGH TAU 12 BUT SHOULD
GRADUALLY TURN SOUTHEASTWARD AS IT TRANSITIONS TO THE STEERING
INFLUENCE OF THE SUBTROPICAL RIDGE. TC 04P IS EXPECTED TO INTENSIFY
TO A PEAK OF 55 KNOTS BY TAU 24 UNDER MARGINALLY-FAVORABLE
CONDITIONS. HOWEVER, AFTER TAU 24, VWS IS FORECAST TO INCREASE
MARKEDLY WITH SST VALUES DROPPING BELOW 26 CELSIUS, WHICH WILL SERVE
TO WEAKEN THE SYSTEM. ADDITIONALLY, THE SYSTEM WILL BEGIN EXTRA-
TROPICAL TRANSITION (ETT) AS IT INTERACTS WITH A WEAK BAROCLINIC
ZONE. TC 04P WILL COMPLETE ETT BY TAU 72 AS IT GAINS FRONTAL
CHARACTERISTICS AND IS EXPECTED TO REMAIN A GALE-FORCE LOW. WITH THE
EXCEPTION OF NAVGEM AND GFDN, DYNAMIC GUIDANCE IS IN CLOSER
AGREEMENT. HOWEVER, DUE TO POSITIONAL UNCERTAINTY AND A LARGE SPREAD
IN DYNAMIC MODEL SOLUTIONS, THERE IS LOW CONFIDENCE IN THE JTWC
FORECAST TRACK. THE JTWC FORECAST TRACK IS POSITIONED FASTER THAN
THE MULTI-MODEL CONSENSUS TO OFFSET THE MUCH SLOWER, UNREALISTIC
NAVGEM AND GFDN SOLUTIONS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
280000Z IS 10 FEET. NEXT WARNINGS AT 280900Z, 281500Z, 282100Z AND
290300Z.//
=========================================================================
WTPS31 PGTW 20151128 09:00z
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 04P (TUNI) WARNING NR 003//
RMKS/
1. TROPICAL CYCLONE 04P (TUNI) WARNING NR 003
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
280600Z --- NEAR 14.2S 173.4W
MOVEMENT PAST SIX HOURS - 115 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 - 065 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
REPEAT POSIT: 14.2S 173.4W
---
FORECASTS:
12 HRS, VALID AT:
281800Z --- 15.3S 171.8W
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
075 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 135 DEG/ 09 KTS
---
24 HRS, VALID AT:
290600Z --- 16.5S 170.5W
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT
075 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
090 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 140 DEG/ 09 KTS
---
36 HRS, VALID AT:
291800Z --- 17.8S 169.3W
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 145 DEG/ 10 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
300600Z --- 19.4S 168.1W
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
280900Z POSITION NEAR 14.5S 173.0W.
TROPICAL CYCLONE (TC) 04P (TUNI), LOCATED APPROXIMATELY 157 NM WEST
OF PAGO PAGO, AMERICAN SAMOA HAS TRACKED EAST-SOUTHEASTWARD AT 11
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS AN ELONGATED CLOUD STRUCTURE WITH A SLIGHT INCREASE
IN CENTRAL CONVECTION AND SIGNIFICANT BROKEN CONVECTIVE BANDING
WRAPPING INTO THE CENTER FROM THE NORTHERN PERIPHERY. A 280641Z
SSMIS 91GHZ MICROWAVE IMAGE SHOWS THAT ALL SIGNIFICANT CENTRAL
CONVECTION IS BEING SHEARED ALONG THE SOUTHEASTERN PERIPHERY DUE TO
THE MODERATE NORTHWESTERLY VERTICAL WIND SHEAR (VWS) ASSOCIATED WITH
A HIGH AMPLITUDE MID-LATITUDE TROUGH TO THE WEST. ADDITIONALLY, THE
TROUGH IS PROVIDING AN ENHANCED POLEWARD OUTFLOW CHANNEL THAT IS
SUSTAINING THE CURRENT CONVECTION. THE INITIAL POSITION IS BASED ON
THE AFOREMENTIONED IMAGERY AS WELL AS A 280512Z AMSU-B 89GHZ
MICROWAVE IMAGE WITH FAIR CONFIDENCE. THE INTENSITY HAS BEEN HELD AT
40 KNOTS BASED ON A PREVIOUS ASCAT PASS SHOWING 40 KNOT WINDS AND
UNCHANGED DVORAK INTENSITY ESTIMATES FROM PGTW, PHFO, AND ABRF. TC
04P IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A NEAR-
EQUATORIAL RIDGE (NER). THE NER WILL REMAIN THE DOMINANT STEERING
MECHANISM OVER THE NEXT 12 TO 24 HOURS, PRIOR TO THE SYSTEM
TRANSITIONING TO A BUILDING SUB-TROPICAL RIDGE TO THE SOUTHEAST. TC
TUNI WILL STRENGTHEN SLIGHTLY DUE TO THE ENHANCED OUTFLOW CHANNEL;
HOWEVER, THE INCREASING VWS ASSOCIATED WITH THE STRONG MID-LATITUDE
WESTERLY WIND FLOW WILL HAMPER ANY SIGNIFICANT INTENSIFICATION. IN
ADDITION, SEA SURFACE TEMPERATURES WILL CONTINUE TO DROP OFF AS THE
CYCLONE GAINS LATITUDE. TC 04P WILL BEGIN TO EMBED WITHIN THE
BAROCLINIC ZONE AND START EXTRA-TROPICAL TRANSITION (ETT) BY TAU 36
AND COMPLETE ETT BY THE END OF THE FORECAST PERIOD AS THE SYSTEM
GAINS FRONTAL CHARACTERISTICS. DYNAMIC MODEL GUIDANCE REMAINS MOSTLY
UNCHANGED WITH NVGM AND GFDN REMAINING SIGNIFICANTLY SLOW AND
WESTERN OUTLIERS. BASED ON THE FORECASTED MID-LATITUDE PATTERN AND
ASSOCIATED STEERING FLOW, THIS SOLUTION SEEMS UNLIKELY. HOWEVER, DUE
TO THE CONTINUED SPREAD IN MODEL GUIDANCE AND THE BROAD NATURE OF
THE CYCLONE, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 280600Z IS 13 FEET. NEXT WARNINGS AT
281500Z, 282100Z, 290300Z AND 290900Z.//
=========================================================================
WTPS31 PGTW 20151128 15:00z
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 04P (TUNI) WARNING NR 004//
RMKS/
1. TROPICAL CYCLONE 04P (TUNI) WARNING NR 004
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
281200Z --- NEAR 14.5S 173.6W
MOVEMENT PAST SIX HOURS - 135 DEGREES AT 07 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
SATELLITE AND EXTRAPOLATION
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
070 NM SOUTHEAST QUADRANT
085 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
REPEAT POSIT: 14.5S 173.6W
---
FORECASTS:
12 HRS, VALID AT:
290000Z --- 15.6S 172.3W
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
095 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 130 DEG/ 09 KTS
---
24 HRS, VALID AT:
291200Z --- 16.8S 170.8W
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
090 NM SOUTHEAST QUADRANT
090 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 135 DEG/ 09 KTS
---
36 HRS, VALID AT:
300000Z --- 18.1S 169.5W
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
090 NM SOUTHEAST QUADRANT
090 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 145 DEG/ 10 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
301200Z --- 19.7S 168.4W
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
281500Z POSITION NEAR 14.8S 173.3W.
TROPICAL CYCLONE (TC) 04P (TUNI), LOCATED APPROXIMATELY 169 NM WEST
OF PAGO PAGO, AMERICAN SAMOA HAS TRACKED SOUTHEASTWARD AT 07 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY SHOWED A SIGNIFICANT DISORGANIZATION IN THE CONVECTIVE CLOUD
STRUCTURE OVER THE PAST SIX HOURS. HOWEVER, THE CLOUD TOPS
ASSOCIATED WITH THE CENTRAL CONVECTION HAVE COOLED, INDICATING A
SLIGHT INTENSIFICATION. THE CURRENT POSITION IS EXTRAPOLATED FROM AN
ASCAT PASS FROM 280854Z AND SUPPORTED BY AGENCY SATELLITE FIXES WITH
GOOD CONFIDENCE. THE INTENSITY HAS BEEN HELD AT 40 KNOTS BASED ON A
280949Z ASCAT PASS SHOWING 40 KNOT WINDS ALONG THE WESTERN
PERIPHERY. THE CURRENT AND FORECASTED WIND RADII HAVE ALSO BEEN
ADJUSTED BASED ON THE ABOVE ASCAT IMAGERY. THE UPPER LEVEL
ENVIRONMENT IS MARGINAL DUE TO AN APPROACHING MID-LATITUDE TROUGH
PRODUCING MODERATE VERTICAL WIND SHEAR (VWS) WITH GOOD POLEWARD
OUTFLOW. TC 04P IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A
NEAR-EQUATORIAL RIDGE (NER). THE NER WILL REMAIN THE DOMINANT
STEERING MECHANISM OVER THE NEXT 12 TO 24 HOURS, PRIOR TO THE SYSTEM
TRANSITIONING TO A BUILDING SUB-TROPICAL RIDGE TO THE SOUTHEAST. TC
TUNI WILL STRENGTHEN SLIGHTLY DUE TO THE ENHANCED POLEWARD OUTFLOW
CHANNEL; HOWEVER, THE INCREASING VWS ASSOCIATED WITH THE STRONG MID-
LATITUDE WESTERLY WIND FLOW WILL HAMPER ANY SIGNIFICANT
INTENSIFICATION. IN ADDITION, SEA SURFACE TEMPERATURES WILL CONTINUE
TO DROP OFF AS THE CYCLONE GAINS LATITUDE. TC 04P WILL BEGIN TO
EMBED WITHIN THE BAROCLINIC ZONE AND START EXTRA-TROPICAL TRANSITION
(ETT) BY TAU 24 AND COMPLETE ETT BY THE END OF THE FORECAST PERIOD
AS THE SYSTEM GAINS FRONTAL CHARACTERISTICS. DYNAMIC MODEL GUIDANCE
REMAINS MOSTLY UNCHANGED WITH NVGM AND GFDN REMAINING SIGNIFICANTLY
SLOW AND WESTERN OUTLIERS. BASED ON THE FORECASTED MID-LATITUDE
PATTERN AND ASSOCIATED STEERING FLOW, THIS SOLUTION SEEMS UNLIKELY.
HOWEVER, DUE TO THE CONTINUED SPREAD IN MODEL GUIDANCE AND THE BROAD
NATURE OF THE CYCLONE, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 281200Z IS 13 FEET. NEXT WARNINGS
AT 282100Z, 290300Z, 290900Z AND 291500Z.//
=========================================================================
WTPS31 PGTW 20151128 21:00z
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 04P (TUNI) WARNING NR 005//
RMKS/
1. TROPICAL CYCLONE 04P (TUNI) WARNING NR 005
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
281800Z --- NEAR 14.7S 172.8W
MOVEMENT PAST SIX HOURS - 115 DEGREES AT 07 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
070 NM SOUTHEAST QUADRANT
085 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
REPEAT POSIT: 14.7S 172.8W
---
FORECASTS:
12 HRS, VALID AT:
290600Z --- 16.0S 171.5W
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
095 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 140 DEG/ 08 KTS
---
24 HRS, VALID AT:
291800Z --- 17.2S 170.4W
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
090 NM SOUTHEAST QUADRANT
090 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 135 DEG/ 08 KTS
---
36 HRS, VALID AT:
300600Z --- 18.3S 169.2W
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
090 NM SOUTHEAST QUADRANT
090 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 135 DEG/ 08 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
301800Z --- 19.4S 168.0W
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
282100Z POSITION NEAR 15.0S 172.5W.
TROPICAL CYCLONE (TC) 04P (TUNI), LOCATED APPROXIMATELY 124 NM WEST
OF PAGO PAGO, AMERICAN SAMOA, HAS TRACKED EAST-SOUTHEASTWARD AT 07
KNOTS OVER THE PAST SIX HOURS. TC 04P HAS STRUGGLED TO ORGANIZE DUE
TO PERSISTENT VERTICAL WIND SHEAR. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY DEPICTS PERSISTENT DEEP CONVECTION WITH TWO
SEPARATE, DISTINCT AREAS OF DEEP CONVECTION--ONE AREA OVER THE EAST
QUADRANT OF THE LOW-LEVEL CIRCULATION CENTER (LLCC) AND ANOTHER AREA
DISPLACED FURTHER EAST. A 281756Z SSMIS 91GHZ IMAGE SHOWS AN
EXPOSED, ELONGATED LLCC POSITIONED ALONG THE WESTERN EDGE OF A
LINEAR AREA OF DEEP CONVECTION. BASED ON THIS MICROWAVE IMAGE, THERE
IS FAIR CONFIDENCE IN THE CURRENT POSITION. THE INITIAL INTENSITY
REMAINS ASSESSED AT 40 KNOTS PRIMARILY BASED ON RECENT ASCAT IMAGERY
SHOWING 40 KNOT WINDS NEAR THE CENTER. TC 04P IS FORECAST TO BEGIN
TURNING SOUTHEASTWARD AS IT TRANSITIONS TO THE STEERING INFLUENCE OF
THE SUBTROPICAL RIDGE WITHIN THE NEXT 12 HOURS. TC 04P IS EXPECTED
TO INTENSIFY SLIGHTLY TO A PEAK OF 45 KNOTS BY TAU 12 UNDER
MARGINALLY-FAVORABLE CONDITIONS. HOWEVER, AFTER TAU 24, VWS IS
FORECAST TO INCREASE MARKEDLY WITH SST VALUES DROPPING BELOW 26
CELSIUS, WHICH WILL SERVE TO WEAKEN THE SYSTEM. ADDITIONALLY, THE
SYSTEM WILL BEGIN EXTRA-TROPICAL TRANSITION (ETT) BY TAU 24 AS IT
INTERACTS WITH A WEAK BAROCLINIC ZONE. TC 04P WILL COMPLETE ETT BY
TAU 48 AS IT GAINS FRONTAL CHARACTERISTICS AND IS EXPECTED TO REMAIN
A GALE-FORCE LOW. WITH THE EXCEPTION OF NAVGEM AND GFDN, DYNAMIC
GUIDANCE IS IN BETTER AGREEMENT. HOWEVER, DUE TO POSITIONAL
UNCERTAINTY AND A LARGE SPREAD IN DYNAMIC MODEL SOLUTIONS, THERE IS
LOW OVERALL CONFIDENCE IN THE JTWC FORECAST TRACK. THE JTWC FORECAST
TRACK IS POSITIONED FASTER THAN THE MULTI-MODEL CONSENSUS TO OFFSET
THE MUCH SLOWER, UNREALISTIC NAVGEM AND GFDN SOLUTIONS. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 281800Z IS 13 FEET. NEXT WARNINGS AT
290300Z, 290900Z, 291500Z AND 292100Z.//
=========================================================================
WTPS31 PGTW 20151129 03:00z
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 04P (TUNI) WARNING NR 006//
RMKS/
1. TROPICAL CYCLONE 04P (TUNI) WARNING NR 006
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
290000Z --- NEAR 15.7S 171.9W
MOVEMENT PAST SIX HOURS - 140 DEGREES AT 10 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
070 NM SOUTHEAST QUADRANT
085 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
REPEAT POSIT: 15.7S 171.9W
---
FORECASTS:
12 HRS, VALID AT:
291200Z --- 16.8S 170.7W
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
095 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 135 DEG/ 08 KTS
---
24 HRS, VALID AT:
300000Z --- 18.0S 169.5W
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
090 NM SOUTHEAST QUADRANT
090 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 135 DEG/ 08 KTS
---
36 HRS, VALID AT:
301200Z --- 19.1S 168.3W
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
290300Z POSITION NEAR 16.0S 171.6W.
TROPICAL CYCLONE (TC) 04P (TUNI), LOCATED APPROXIMATELY 109 NM
SOUTHWEST OF PAGO PAGO, AMERICAN SAMOA, HAS TRACKED SOUTHEASTWARD
AT 10 KNOTS OVER THE PAST SIX HOURS. TC 04P HAS STRUGGLED TO
ORGANIZE DUE TO PERSISTENT VERTICAL WIND SHEAR. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY-EXPOSED,
BROAD LOW-LEVEL CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION
OBSCURING THE EASTERN SEMI-CIRCLE OF THE LLCC. A 282055Z METOP-B
89GHZ IMAGE SHOWS AN EXPOSED LLCC POSITIONED ALONG THE WESTERN EDGE
OF A LINEAR AREA OF DEEP CONVECTION. BASED ON THE MSI, THERE IS FAIR
CONFIDENCE IN THE CURRENT POSITION. THE INITIAL INTENSITY REMAINS
ASSESSED AT 40 KNOTS BASED ON AN AVERAGE OF DVORAK INTENSITY
ESTIMATES RANGING FROM T2.5 (35 KNOTS) TO T3.0 (45 KNOTS). TC 04P IS
FORECAST TO TRACK SOUTHEASTWARD THROUGH THE FORECAST PERIOD UNDER
THE STEERING INFLUENCE OF THE SUBTROPICAL RIDGE. TC 04P IS EXPECTED
TO INTENSIFY SLIGHTLY TO A PEAK OF 45 KNOTS BY TAU 12 UNDER
MARGINALLY-FAVORABLE CONDITIONS. HOWEVER, AFTER TAU 12, VWS IS
FORECAST TO INCREASE MARKEDLY WITH SST VALUES DROPPING BELOW 26
CELSIUS, WHICH WILL SERVE TO WEAKEN THE SYSTEM. ADDITIONALLY, THE
SYSTEM WILL BEGIN EXTRA-TROPICAL TRANSITION (ETT) BY TAU 12 AS IT
INTERACTS WITH A WEAK BAROCLINIC ZONE. TC 04P WILL COMPLETE ETT BY
TAU 36 AS IT GAINS WEAK FRONTAL CHARACTERISTICS AND IS EXPECTED TO
REMAIN A GALE-FORCE LOW. WITH THE EXCEPTION OF NAVGEM AND GFDN,
DYNAMIC GUIDANCE IS IN BETTER AGREEMENT. HOWEVER, DUE TO POSITIONAL
UNCERTAINTY AND A LARGE SPREAD IN DYNAMIC MODEL SOLUTIONS, THERE IS
LOW OVERALL CONFIDENCE IN THE JTWC FORECAST TRACK. THE JTWC FORECAST
TRACK IS POSITIONED FASTER THAN THE MULTI-MODEL CONSENSUS TO OFFSET
THE MUCH SLOWER, UNREALISTIC NAVGEM AND GFDN SOLUTIONS. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 290000Z IS 14 FEET. NEXT WARNINGS AT
290900Z, 291500Z, 292100Z AND 300300Z.//
=========================================================================
WTPS31 PGTW 20151129 09:00z
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 04P (TUNI) WARNING NR 007//
RMKS/
1. TROPICAL CYCLONE 04P (TUNI) WARNING NR 007
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
290600Z --- NEAR 16.5S 170.6W
MOVEMENT PAST SIX HOURS - 130 DEGREES AT 13 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
070 NM SOUTHEAST QUADRANT
085 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
REPEAT POSIT: 16.5S 170.6W
---
FORECASTS:
12 HRS, VALID AT:
291800Z --- 17.6S 169.5W
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
090 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 140 DEG/ 07 KTS
---
24 HRS, VALID AT:
300600Z --- 18.7S 168.5W
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
090 NM SOUTHEAST QUADRANT
090 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 135 DEG/ 08 KTS
---
36 HRS, VALID AT:
301800Z --- 19.8S 167.4W
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
290900Z POSITION NEAR 16.8S 170.3W.
TROPICAL CYCLONE (TC) 04P (TUNI), LOCATED APPROXIMATELY 132 NM SOUTH
OF PAGO PAGO, AMERICAN SAMOA HAS TRACKED SOUTHEASTWARD AT 13 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE
IMAGERY DEPICTS AN ELONGATED AND PARTIALLY EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC) WITH ASSOCIATED CONVECTION SHEARED TO THE
SOUTHEAST DUE TO PERSISTENT 20 TO 25 KNOT NORTHWESTERLY VERTICAL
WIND SHEAR (VWS). A STRONG POLEWARD OUTFLOW CHANNEL, ASSOCIATED WITH
A MID-LATITUDE TROUGH, IS PROVIDING SUFFICIENT VENTILATION FOR THE
PERSISTENT CONVECTION. THE CURRENT POSITION IS BASED ON THE EXPOSED
LLCC IN THE EIR LOOP AND IN A 290628Z SSMIS 91GHZ MICROWAVE IMAGE
WITH FAIR CONFIDENCE. THE INTENSITY HAS BEEN HELD AT 40 KNOTS BASED
ON PREVIOUS SCATTEROMETER PASSES AND IS SUPPORTED BY DVORAK
INTENSITY ESTIMATES RANGING FROM 35 TO 45 KNOTS. TC TUNI IS MOVING
SOUTHEASTWARD UNDER THE STEERING INFLUENCE A SUB-TROPICAL RIDGE
(STR) TO THE EAST. THIS STR WILL REMAIN THE DOMINANT STEERING
MECHANISM THROUGHOUT THE FORECAST PERIOD. AS THE CYCLONE MOVES
POLEWARD, VWS WILL CONTINUE TO INCREASE AND SEA SURFACE TEMPERATURES
WILL DECREASE LEADING TO A SLOW WEAKENING TREND. IN ADDITION, NEAR
TAU 12, TC 04P WILL BEGIN EXTRA-TROPICAL TRANSITION (ETT) AS IT
INTERACTS WITH THE WEAK BAROCLINIC ZONE. THE SYSTEM WILL FULLY EMBED
WITHIN THE MID-LATITUDE WESTERLY FLOW AND COMPLETE ETT BY THE END OF
THE FORECAST PERIOD. DYNAMIC MODEL GUIDANCE REMAINS CONSISTENT WITH
MOST TRACKERS SHOWING A SOUTHEASTWARD TRACK; HOWEVER, THE BROAD
ELONGATED NATURE OF THE SYSTEM CREATES A POSITIONAL UNCERTAINTY THAT
LEADS TO LOW CONFIDENCE IN THE JTWC FORECAST. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 290600Z IS 14 FEET. NEXT WARNINGS AT 292100Z AND
300900Z.//
=========================================================================
WTPS31 PGTW 20151129 21:00z
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 04P (TUNI) WARNING NR 008//
RMKS/
1. TROPICAL CYCLONE 04P (TUNI) WARNING NR 008
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
291800Z --- NEAR 17.9S 169.3W
MOVEMENT PAST SIX HOURS - 145 DEGREES AT 06 KTS
POSITION ACCURATE TO WITHIN 040 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 WATER
REPEAT POSIT: 17.9S 169.3W
---
FORECASTS:
12 HRS, VALID AT:
300600Z --- 18.9S 169.0W
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
292100Z POSITION NEAR 18.2S 169.2W.
TROPICAL CYCLONE (TC) 04P (TUNI), LOCATED APPROXIMATELY 231 NM SOUTH-
SOUTHEAST OF PAGO PAGO, AMERICAN SAMOA, HAS TRACKED SOUTHEASTWARD AT
06 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY INDICATES AN ELONGATED, FULLY-EXPOSED LOW-LEVEL
CIRCULATION CENTER (LLCC) WITH DEEP CONVECTION SHEARED TO THE
SOUTHEAST DUE TO STRONG NORTHWESTERLY VERTICAL WIND SHEAR (VWS). A
291744Z SSMIS 91GHZ IMAGE SHOWS SHALLOW BANDING WRAPPING INTO A
DEFINED LLCC WITH DEEP CONVECTION DISPLACED OVER THE SOUTHEAST
PERIPHERY OF THE SYSTEM. OVERALL, THERE IS GOOD CONFIDENCE IN THE
CURRENT POSITION. A 290833Z ASCAT IMAGE SHOWED 25 TO 30 KNOT WINDS
OVER THE NORTHERN SEMI-CIRCLE WITH STRONGER GRADIENT FLOW OF 35 TO
40 KNOTS OVER THE SOUTHERN SEMI-CIRCLE. SURFACE OBSERVATIONS FROM
NIUE, 75NM SOUTH-SOUTHWEST OF THE CENTER, CONFIRM SUSTAINED GALE-
FORCE SOUTHEASTERLIES AT 27 TO 35 KNOTS. THE CURRENT INTENSITY IS
ASSESSED AT 35 KNOTS BASED ON ALL AVAILABLE DATA INCLUDING THE ASCAT
DATA, DVORAK CURRENT INTENSITY ESTIMATES AND THE WEAKENED
ORGANIZATION. ALTHOUGH TC 04P IS DISSIPATING DUE TO STRONG VWS,
COOLER SST AND WEAK INTERACTION WITH THE BAROCLINIC ZONE, THE SYSTEM
MAY RE-INTENSIFY AS AN EXTRA-TROPICAL LOW, HOWEVER, THE SYSTEM IS
NOT EXPECTED TO REGENERATE AS A WARM-CORE TROPICAL SYSTEM. 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 291800Z IS 14
FEET.//
Tropical cyclone tracks developed by Michael Bath using operational warnings and advisories.
|
Document: tropical_cyclone_tuni_jtwc_advisories.htm
Updated: 17 June 2020 [Australian Severe Weather index] [Copyright Notice] [Email Contacts] [Search This Site] [Privacy Policy]
|