WTPS31 PGTW 062100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 10P (NAT) WARNING NR 005//
RMKS/
1. TROPICAL CYCLONE 10P (NAT) 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:
061800Z --- NEAR 17.4S 155.9W
MOVEMENT PAST SIX HOURS - 115 DEGREES AT 15 KTS
POSITION ACCURATE TO WITHIN 040 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 - 105 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
095 NM NORTHWEST QUADRANT
REPEAT POSIT: 17.4S 155.9W
---
FORECASTS:
12 HRS, VALID AT:
070600Z --- 18.1S 153.8W
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 105 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
095 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 100 DEG/ 11 KTS
---
24 HRS, VALID AT:
071800Z --- 18.4S 151.5W
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 105 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
095 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 085 DEG/ 11 KTS
---
36 HRS, VALID AT:
080600Z --- 18.2S 149.2W
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 - 120 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 090 DEG/ 11 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
081800Z --- 18.2S 146.8W
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
062100Z POSITION NEAR 17.6S 155.4W.
06FEB24. TROPICAL CYCLONE 10P (NAT), LOCATED APPROXIMATELY 361 NM
WEST OF PAPEETE, TAHITI, HAS TRACKED EAST-SOUTHEASTWARD AT 15
KNOTS OVER THE PAST SIX HOURS. MINIMUM CENTRAL PRESSURE AT
061800Z IS 993 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 061800Z
IS 18 FEET. NEXT WARNINGS AT 070900Z AND 072100Z.//
NNNN
WDPS31 PGTW 062100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 10P (NAT)
WARNING NR 005//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 17.4S 155.9W
INITIAL INTENSITY: 45 KTS
GEOGRAPHIC REFERENCE: 361 NM WEST OF PAPEETE, TAHITI
MOVEMENT PAST 6 HOURS: EAST-SOUTHEASTWARD AT 15 KTS
SIGNIFICANT WAVE HEIGHT: 18 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A BROAD,
PARTIALLY EXPOSED LOW-LEVEL CIRCULATION (LLC) WITH LIMITED DEEP
CONVECTION SHEARED OVER THE EASTERN QUADRANT OF THE LLC. A FORTUITOUS
061901Z ASCAT-B BULLSEYE IMAGE ALSO REVEALS A BROAD CENTER WITH 30-35
KNOT WINDS. THERE IS NO RECENT MICROWAVE IMAGERY, THEREFORE THERE IS
MEDIUM CONFIDENCE IN THE INITIAL POSITION. UPPER-LEVEL CONDITIONS
REMAIN MARGINALLY FAVORABLE WITH WESTERLY VERTICAL WIND SHEAR OFFSET
SLIGHTLY BY VIGOROUS POLEWARD OUTFLOW. THE INITIAL INTENSITY OF 45 KTS
IS ASSESSED WITH MEDIUM CONFIDENCE HEDGED BELOW THE SUBJECTIVE DVORAK
ESTIMATES IN CONSIDERATION OF THE RECENT ASCAT DATA AND THE CIMSS
OBJECTIVE ESTIMATES.
INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK
CURRENT STEERING MECHANISM: NEAR-EQUATORIAL RIDGE (NER) POSITIONED
TO THE NORTH.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.5 - 55 KTS
KNES: T3.5 - 55 KTS
NFFN: T3.5 - 55 KTS
CIMSS ADT: 32 KTS AT 061940Z
CIMSS DPRINT: 47 KTS AT 062000Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 15-20 KTS
SST: 30-31 CELSIUS
OUTFLOW: STRONG POLEWARD
OTHER FACTORS: DRY AIR ENTRAINMENT
ANALYSIS CONFIDENCE:
INITIAL POSITION: MEDIUM
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: LOW
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TROPICAL CYCLONE (TC) 10P IS FORECASTED TO
TRACK GENERALLY EASTWARD ALONG THE SOUTHERN PERIPHERY OF THE NER
THROUGH THE FORECAST PERIOD. THE SYSTEM IS EXPECTED TO GRADUALLY
WEAKEN THROUGH THE FORECAST PERIOD WITH PERSISTENT MODERATE TO HIGH
VWS (20-25 KTS) AND DRY AIR ENTRAINMENT. THE SYSTEM IS EXPECTED TO
DISSIPATE BY TAU 48.
MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT
WITH A 130 NM TO 170 NM CROSS-TRACK SPREAD FROM TAU 36 TO TAU 48.
INTENSITY GUIDANCE IS IN POOR AGREEMENT WITH A LARGE SPREAD.
GENERALLY, SEVERAL OF THE MODELS INDICATE A REINTENSIFICATION PHASE
AFTER TAU 60, WITH HAFS-A SHOWING A PEAK OF 58 KNOTS AT TAU 60.
THIS REINTENSIFICATION PHASE IS ASSOCIATED WITH A STRONG
SUBTROPICAL LOW, WHICH COULD LEAD TO SUBTROPICAL TRANSITION NEAR
TAU 72.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
INTENSITY 0 - 72 HR: LOW//
NNNN
WTPS11 NFFN 070000
TROPICAL DISTURBANCE ADVISORY NUMBER A9 ISSUED FROM RSMC NADI
Feb 070121 UTC.
TROPICAL CYCLONE NAT CENTRE 990HPA WAS LOCATED NEAR 18.0S 154.9W AT
070000 UTC.
POSITION FAIR BASED ON HR GOES EIR IMAGERY AND PERIPHERAL SURFACE
REPORTS. CYCLONE MOVING EAST SOUTHEAST AT ABOUT 04 KNOTS AND RAPIDLY
WEAKENING.
MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT ABOUT 40
KNOTS.
EXPECT WINDS OVER 33 KNOTS WITHIN 140 NAUTICAL MILES IN NE QUADRANT
AND WITHIN 120 NAUTICAL MILES IN SE QUADRANT
AND WITHIN 40 NAUTICAL MILES IN SW QUADRANT
AND WITHIN 100 NAUTICAL MILES IN NW QUADRANT
LOW LEVEL CENTER EXPOSED WITH LIMITED DEEP CONVECTION SHEARED TO THE
EASTERN QUADRANT AS CYCLONE RAPIDLY WEAKENS DRY AIR ENTRAINMENT FROM
THE SOUTHEAST FEEDING INTO THE SYSTEM. DVORAK CONSTRAINTS BROKEN DUE
TO GOOD ASCAT OBSERVATIONS SHOWING 35KT WINDS AROUND THE CENTER.
SYSTEM CONTINUES TO MOVE IN AN AREA OF MODERATE SHEARED ENVIRONMENT
WITH MODERATE UPPER DIVERGENCE. SST AROUND 29 DEGREES. CYCLONE
STEERED EAST-SOUTHEAST WITH SOUTHERN PERIPHERY OF NEAR-EQUATORIAL
RIDGE TO THE NORTH OF SYSTEM. DVORAK ANALYSIS BASED ON SHEAR PATTERN
YIELDS DT = 2.5 WITH PT AND MET AGREEING. FT BASED ON DT THUS YIELDS
T2.5/3.0/W1.5/24HRS.
FORECASTS :
AT 12 HRS VALID AT 071200 UTC 18.6S 152.7W MOV ESE AT 11 KT WITH 30
KT CLOSE TO CENTRE
AT 24 HRS VALID AT 080000 UTC 18.6S 151.0W MOV E AT 09 KT WITH 30 KT
CLOSE TO CENTRE
OUTLOOK :
AT 36 HRS VALID AT 081200 UTC 18.6S 148.9W MOV E AT 10 KT WITH 30 KT
CLOSE TO CENTRE
AT 48 HRS VALID AT 090000 UTC 19.0S 145.8W MOV E AT 11 KT WITH 30 KT
CLOSE TO CENTRE
TTHE NEXT TROPICAL DISTURBANCE ADVISORY ON NAT WILL BE ISSUED AROUND
0708000 UTC.
WTPS11 NFFN 070600
TROPICAL DISTURBANCE ADVISORY NUMBER A10 ISSUED FROM RSMC NADI
Feb 070711 UTC.
TROPICAL CYCLONE NAT CENTRE 995HPA WAS LOCATED NEAR 18.8S 153.0W AT
070600 UTC.
POSITION POOR BASED ON HR GOES EIR IMAGERY AND PERIPHERAL SURFACE
REPORTS. CYCLONE MOVING EAST SOUTHEAST AT ABOUT 20 KNOTS. MAXIMUM
10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT ABOUT 35 KNOTS.
EXPECT WINDS OVER 33 KNOTS WITHIN 140 NAUTICAL MILES IN NE QUADRANT
AND WITHIN 120 NAUTICAL MILES IN SE QUADRANT
AND WITHIN 40 NAUTICAL MILES IN SW QUADRANT
AND WITHIN 100 NAUTICAL MILES IN NW QUADRANT
LOW LEVEL CENTRE EXPOSED WITH LIMITED DEEP CONVECTION SHEARED TO THE
EASTERN QUADRANT AS CYCLONE RAPIDLY WEAKENS. DRY AIR ENTRAINMENT FROM
THE SOUTHEAST FEEDING INTO THE SYSTEM. SYSTEM CONTINUES TO MOVE IN AN
AREA OF MODERATE SHEARED ENVIRONMENT WITH MODERATE UPPER DIVERGENCE.
SST AROUND 29 DEGREES. CYCLONE STEERED EAST-SOUTHEAST BY THE SOUTHERN
PERIPHERY OF THE NEAR-EQUATORIAL RIDGE TO THE NORTH OF THE SYSTEM. CI
HELD DUE TO INITIAL WEAKENING. DVORAK ANALYSIS BASED ON SHEAR PATTERN
YIELDS DT = 2.5 WITH PT AND MET AGREEING. FT BASED ON DT THUS YIELDS
T2.5/3.0/W1.5/24HRS.
FORECASTS :
AT 12 HRS VALID AT 071800 UTC 19.1S 151.2W MOV E AT 09 KT WITH 30 KT
CLOSE TO CENTRE
AT 24 HRS VALID AT 080600 UTC 19.1S 149.4W MOV E AT 09 KT WITH 25 KT
CLOSE TO CENTRE
OUTLOOK :
AT 36 HRS VALID AT 081800 UTC 19.4S 147.0W MOV E AT 09 KT WITH 25 KT
CLOSE TO CENTRE
AT 48 HRS VALID AT 090600 UTC 20.3S 144.0W MOV E AT 11 KT WITH 25 KT
CLOSE TO CENTRE
THIS WILL BE THE FINAL TROPICAL DISTURBANCE ADVISORY ON NAT.
WTPS11 NFFN 070600 CCA
TROPICAL DISTURBANCE ADVISORY NUMBER A10 ISSUED FROM RSMC NADI
Feb 070752 UTC.
*****CORRECTION TO DVORAK AND NEXT ISSUE TIME*****
TROPICAL CYCLONE NAT CENTRE 995HPA WAS LOCATED NEAR 18.8S 153.0W AT
070600 UTC.
POSITION POOR BASED ON HR GOES EIR IMAGERY AND PERIPHERAL SURFACE
REPORTS. CYCLONE MOVING EAST SOUTHEAST AT ABOUT 20 KNOTS. MAXIMUM
10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT ABOUT 35 KNOTS.
EXPECT WINDS OVER 33 KNOTS WITHIN 140 NAUTICAL MILES IN NE QUADRANT
AND WITHIN 120 NAUTICAL MILES IN SE QUADRANT
AND WITHIN 40 NAUTICAL MILES IN SW QUADRANT
AND WITHIN 100 NAUTICAL MILES IN NW QUADRANT
LOW LEVEL CENTRE EXPOSED WITH LIMITED DEEP CONVECTION SHEARED TO THE
EASTERN QUADRANT AS CYCLONE RAPIDLY WEAKENS. DRY AIR ENTRAINMENT FROM
THE SOUTHEAST FEEDING INTO THE SYSTEM. SYSTEM CONTINUES TO MOVE IN AN
AREA OF MODERATE SHEARED ENVIRONMENT WITH MODERATE UPPER DIVERGENCE.
SST AROUND 29 DEGREES. CYCLONE STEERED EAST-SOUTHEAST BY THE SOUTHERN
PERIPHERY OF THE NEAR-EQUATORIAL RIDGE TO THE NORTH OF THE SYSTEM. CI
HELD DUE TO INITIAL WEAKENING. DVORAK ANALYSIS BASED ON SHEAR PATTERN
YIELDS DT = 2.5 WITH PT AND MET AGREEING. FT BASED ON DT THUS YIELDS
T2.5/3.0/W0.5/24HRS.
FORECASTS :
AT 12 HRS VALID AT 071800 UTC 19.1S 151.2W MOV E AT 09 KT WITH 30 KT
CLOSE TO CENTRE
AT 24 HRS VALID AT 080600 UTC 19.1S 149.4W MOV E AT 09 KT WITH 25 KT
CLOSE TO CENTRE
OUTLOOK :
AT 36 HRS VALID AT 081800 UTC 19.4S 147.0W MOV E AT 09 KT WITH 25 KT
CLOSE TO CENTRE
AT 48 HRS VALID AT 090600 UTC 20.3S 144.0W MOV E AT 11 KT WITH 25 KT
CLOSE TO CENTRE
THE NEXT TROPICAL DISTURBANCE ADVISORY ON NAT WILL BE ISSUED AT
AROUND 071400UTC.
WTPS31 PGTW 070900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 10P (NAT) WARNING NR 006//
RMKS/
1. TROPICAL CYCLONE 10P (NAT) WARNING NR 006
02 ACTIVE TROPICAL CYCLONES IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
070600Z --- NEAR 18.7S 152.7W
MOVEMENT PAST SIX HOURS - 110 DEGREES AT 13 KTS
POSITION ACCURATE TO WITHIN 025 NM
POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
SATELLITE AND SYNOPTIC DATA
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 105 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
095 NM NORTHWEST QUADRANT
REPEAT POSIT: 18.7S 152.7W
---
FORECASTS:
12 HRS, VALID AT:
071800Z --- 19.2S 150.7W
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 105 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
095 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 090 DEG/ 08 KTS
---
24 HRS, VALID AT:
080600Z --- 19.2S 149.1W
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 - 110 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
110 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 090 DEG/ 11 KTS
---
36 HRS, VALID AT:
081800Z --- 19.2S 146.8W
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
070900Z POSITION NEAR 18.8S 152.2W. 07FEB24.
TROPICAL CYCLONE 10P (NAT), LOCATED APPROXIMATELY
191 NM WEST-SOUTHWEST OF PAPEETE, TAHITI,
HAS TRACKED EAST-SOUTHEASTWARD AT 13
KNOTS OVER THE PAST SIX HOURS.
MINIMUM CENTRAL PRESSURE AT 070600Z IS 996 MB.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 070600Z IS
18 FEET. NEXT WARNINGS AT 072100Z AND 080900Z.
REFER TO TROPICAL CYCLONE 11P (ELEVEN) WARNINGS
(WTPS32 PGTW) FOR SIX-HOURLY UPDATES.//
NNNN
WDPS31 PGTW 070900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 10P (NAT) WARNING NR
006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 18.7S 152.7W
INITIAL INTENSITY: 35 KTS
GEOGRAPHIC REFERENCE: 191 NM WEST-SOUTHWEST OF PAPEETE, TAHITI
MOVEMENT PAST 6 HOURS: EAST-SOUTHEASTWARD AT 13 KTS
SIGNIFICANT WAVE HEIGHT: 18 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A MEDIUM-SIZED
SYSTEM WITH NO SIGNIFICANT FEEDER BANDS TRACKING SOUTH OF THE
FRENCH POLYNESIAN ISLANDS. THE LOW LEVEL CIRCULATION (LLC) IS
PARTLY EXPOSED WITH THE MAIN CONVECTION SHEARED EASTWARD. THE
INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON A RAGGED
LLC FEATURE IN THE 070409Z SSMIS MICROWAVE IMAGE. THE INITIAL
INTENSITY IS PLACED WITH MEDIUM CONFIDENCE BASED ON OVERALL
ASSESSMENT OF AGENCY AND AUTOMATED DVORAK ESTIMATES. ANALYSIS
INDICATES A MARGINAL ENVIRONMENT WITH WARM SST AND STRONG POLEWARD
OUTFLOW OFFSET BY HIGH VWS AND DRY AIR ENTRAINMENT AT THE LOW
LEVELS.
INITIAL WIND RADII BASIS: PERSISTENCE.
CURRENT STEERING MECHANISM: NEAR EQUATORIAL RIDGE (NER) TO THE
NORTH.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
CIMSS ADT: 33 KTS AT 070540Z
CIMSS AIDT: 35 KTS AT 070540Z
CIMSS DPRINT: 35 KTS AT 070600Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 25-30 KTS
SST: 29-30 CELSIUS
OUTFLOW: STRONG POLEWARD
OTHER FACTORS: DRY AIR ENTRAINMENT.
ANALYSIS CONFIDENCE:
INITIAL POSITION: MEDIUM
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: LOW
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TC NAT WILL CONTINUE WESTWARD UNDER THE
STEERING INFLUENCE OF THE NER TO THE NORTH. THE MARGINAL
ENVIRONMENT WILL SUSTAIN THE CURRENT INTENSITY AT BEST BEFORE VWS
AND DRY AIR ENTRAINMENT WILL DOMINATE AND DISSIPATE THE SYSTEM BY
TAU 36, POSSIBLY SOONER.
MODEL DISCUSSION: NUMERICAL MODELS ARE IN TIGHT AGREEMENT WITH AN
EVEN SPREAD TO 107NM BY TAU 36, LENDING HIGH CONFIDENCE TO THE JTWC
TRACK FORECAST. THERE IS ONLY MEDIUM CONFIDENCE IN THE INTENSITY
FORECAST DUE TO THE POSSIBILITY OF AN EARLIER DISSIPATION.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: HIGH
INTENSITY 0 - 72 HR: MEDIUM//
NNNN
WTPS11 NFFN 071500
TROPICAL DISTURBANCE ADVISORY NUMBER A11 ISSUED FROM RSMC NADI
Feb 071500 UTC.
TROPICAL CYCLONE NAT CENTRE 995HPA WAS LOCATED NEAR 19.0S 150.6W AT
071200 UTC.
POSITION FAIR BASED ON HR GOES EIR IMAGERY AND PERIPHERAL SURFACE
REPORTS. CYCLONE MOVING EAST AT ABOUT 23 KNOTS. MAXIMUM 10-MINUTE
AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT ABOUT 35 KNOTS.
EXPECT ABOVE 33 KNOTS WITHIN 100 NAUTICAL MILES IN NE QUADRANT
AND WITHIN 80 NAUTICAL MILES IN SE QUADRANT
AND WITHIN 80 NAUTICAL MILES IN SW QUADRANT
AND WITHIN 70 NAUTICAL MILES IN NW QUADRANT.
CONVECTION SHOWING IMPROVED ORGANISATION OVER SUPPOSED LLCC WITH
PRIMARY BAND WRAPPING FROM THE SOUTH TO THE WESTERN FLANK. THE SYSTEM
CONTINUES TO WEAKENS WITH DRY AIR ENTRAINMENT FROM THE SOUTHEAST
FEEDING INTO THE SYSTEM. SYSTEM CONTINUES TO MOVE IN AN AREA OF HIGH
SHEARED ENVIRONMENT WITH MODERATE UPPER DIVERGENCE. SST AROUND 28
DEGREES. CYCLONE STEERED EAST-SOUTHEAST BY THE SOUTHERN PERIPHERY OF
THE NEAR-EQUATORIAL RIDGE TO THE NORTH OF THE SYSTEM. CI HELD DUE TO
INITIAL WEAKENING. DVORAK ANALYSIS BASED ON SHEAR PATTERN YIELDS DT =
2.5 WITH PT AGREEING AND MET = 3.0. FT BASED ON DT THUS YIELDS
T2.5/3.0/W1.0/24HRS
FORECASTS :
AT 12 HRS VALID AT 080000 UTC 19.3S 148.8W MOV E AT 15 KT WITH 30 KT
CLOSE TO CENTRE
AT 24 HRS VALID AT 081200 UTC 19.4S 146.8W MOV E AT 11 KT WITH 30 KT
CLOSE TO CENTRE
OUTLOOK :
AT 36 HRS VALID AT 090000 UTC 19.7S 144.2W MOV E AT 15 KT WITH 30 KT
CLOSE TO CENTRE
AT 48 HRS VALID AT 091200 UTC 20.8S 140.8W MOV ESE AT 18 KT WITH 25
KT CLOSE TO CENTRE
THE NEXT TROPICAL DISTURBANCE ADVISORY ON NAT WILL BE ISSUED AROUND
0720000 UTC.
WTPS31 PGTW 072100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 10P (NAT) WARNING NR 007//
RMKS/
1. TROPICAL CYCLONE 10P (NAT) WARNING NR 007
02 ACTIVE TROPICAL CYCLONES IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
071800Z --- NEAR 19.5S 151.5W
MOVEMENT PAST SIX HOURS - 130 DEGREES AT 05 KTS
POSITION ACCURATE TO WITHIN 060 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 - 030 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
REPEAT POSIT: 19.5S 151.5W
---
FORECASTS:
12 HRS, VALID AT:
080600Z --- 19.4S 150.2W
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 090 DEG/ 11 KTS
---
24 HRS, VALID AT:
081800Z --- 19.4S 147.8W
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING SUBTROPICAL
RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT
120 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
080 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 100 DEG/ 17 KTS
---
36 HRS, VALID AT:
090600Z --- 20.0S 144.2W
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
SUBTROPICAL
RADIUS OF 050 KT WINDS - 010 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
010 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT
100 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
---
REMARKS:
072100Z POSITION NEAR 19.5S 151.2W.
07FEB24. TROPICAL CYCLONE 10P (NAT), LOCATED APPROXIMATELY 162 NM
SOUTHWEST OF PAPEETE, TAHITI, HAS TRACKED SOUTHEASTWARD AT 05
KNOTS OVER THE PAST SIX HOURS. MINIMUM CENTRAL PRESSURE AT 071800Z
IS 998 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 071800Z IS 18 FEET.
NEXT WARNINGS AT 080900Z AND 082100Z. REFER TO TROPICAL CYCLONE 11P
(OSAI) WARNINGS (WTPS32 PGTW) FOR SIX-HOURLY UPDATES.//
NNNN
WDPS31 PGTW 072100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 10P (NAT)
WARNING NR 007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 19.5S 151.5W
INITIAL INTENSITY: 45 KTS
GEOGRAPHIC REFERENCE: 162 NM SOUTHWEST OF PAPEETE, TAHITI
MOVEMENT PAST 6 HOURS: SOUTHEASTWARD AT 05 KTS
SIGNIFICANT WAVE HEIGHT: 18 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
CYCLONE (TC) 10P (NAT) HAVING COMPLETELY DECOUPLED FROM UPPER-LEVEL
SUPPORT, LEAVING A FULLY EXPOSED LOW LEVEL CIRCULATION CENTER
(LLCC) OVER THE LAST 12 HOURS. EXTENSIVE SHALLOW BANDING IS
OBSERVED WRAPPING INTO THE LLCC UP TO 250NM TO THE SOUTHWEST. SEA
SURFACE TEMPERATURES (SST) REMAIN VERY FAVORABLE (29-30C).
HOWEVER, POOR DIVERGENCE ALOFT AND STRONG VERTICAL WIND SHEAR WILL
LIKELY INHIBIT ANY FURTHER INTENSIFICATION. THE INITIAL POSITION IS
PLACED WITH HIGH CONFIDENCE BASED AN EXPOSED LLCC OBSERVABLE IN A
171820 GOES-W VISIBLE SATELLITE IMAGE. THE INITIAL INTENSITY OF 45
KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON A 071620Z SMOS
WINDSPEED IMAGE AND THE OBJECTIVE AND SUBJECTIVE INTENSITY GUIDANCE
LISTED BELOW.
INITIAL WIND RADII BASIS: SMOS DATA
CURRENT STEERING MECHANISM: NER TO THE NORTHWEST AND STR TO THE
SOUTHWEST.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
KNES: T3.0 - 45 KTS
PHFO: T3.0 - 45 KTS
CIMSS ADT: 47 KTS AT 071740Z
CIMSS AIDT: 41 KTS AT 072010Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
VWS: 30+ KTS
SST: 29-30 CELSIUS
OUTFLOW: MODERATE EASTWARD
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
INITIAL INTENSITY: HIGH
INITIAL WIND RADII: HIGH
3. FORECAST REASONING.
SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.
FORECAST DISCUSSION: TC 10P IS FORECAST TO TRACK EASTWARD THROUGH
THE FORECAST INTERVAL AS IT EXPERIENCES STEERING INFLUENCE OF THE STR
TO THE SOUTHWEST (TAU 00) AND SOUTH (TAU 24). THE INTENSITY
FORECAST HOLDS TC 10P AT CURRENT INTENSITY THROUGH TAU 24, AND THEN
GRADUALLY RISING THEREAFTER TO 50KTS BY TAU 36. ANALYSIS OF THE
SYSTEMS STRUCTURE AND ENVIRONMENTAL PARAMETERS IN GLOBAL NUMERICAL
GUIDANCE AND TC PHASE DIAGRAMS SHOW THE SYSTEM TRANSITIONING TO A
SUBTROPICAL CYCLONE NEAR TAU 24, HAVING FULLY COMPLETED SUBTROPICAL
TRANSITION BY TAU 36. THIS IS CHARACTERIZED, IN THIS INSTANCE, AS
HAVING A WEAK TEMPERATURE GRADIENT, PROMINENT COLD AIR
ADVECTION (POLEWARD) AND WARM AIR ADVECTION (EQUATORWARD), AND
GROWING SUBSTANTIALLY ASYMMETRIC AND SHALLOW BY TAU 36.
MODEL DISCUSSION: GLOBAL NUMERICAL GUIDANCE IS IN EXCEPTIONAL
AGREEMENT THAT TC 10P WILL TRACK EASTWARD THROUGH THE FORECAST
INTERVAL, SHOWING A TIGHT CROSS-TRACK SPREAD OF JUST 37NM BY TAU
36. INTENSITY GUIDANCE, WITH THE EXCEPTION OF GFS, SUGGESTS TC 10P
WILL PERSIST AT NEAR 45KTS INTENSITY AND EVENTUALLY (NEAR TAU 24)
EXPERIENCE SLIGHT REINTENSIFICATION TO TAU 36.
FORECAST CONFIDENCE:
TRACK 0 - 36 HR: HIGH
INTENSITY 0 - 36 HR: MEDIUM//
NNNN
WTPS11 NFFN 071800
TROPICAL DISTURBANCE ADVISORY NUMBER A12 ISSUED FROM RSMC NADI
Feb 072050 UTC.
TROPICAL CYCLONE NAT CENTRE 995HPA WAS LOCATED NEAR 19.3S 151.5W AT
071800 UTC.
POSITION FAIR BASED ON HR GOES EIR IMAGERY AND PERIPHERAL SURFACE
REPORTS. CYCLONE WEAKENING AND MOVING EAST AT ABOUT 04 KNOTS.
MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT ABOUT 35
KNOTS.
EXPECT WINDS ABOVE 33 KNOTS WITHIN 100 NAUTICAL MILES IN NE QUADRANT
AND WITHIN 80 NAUTICAL MILES IN SE QUADRANT
AND WITHIN 80 NAUTICAL MILES IN SW QUADRANT
AND WITHIN 70 NAUTICAL MILES IN NW QUADRANT.
CONVECTION HAS RAPIDLIY DECREASED WITH LLCC EXPOSED. SYSTEM CONTINUES
TO WEAKENS WITH DRY AIR ENTRAINMENT FROM THE SOUTHEAST. SYSTEM LIES
IN A LOW TO MODERATE SHEARED ENVIRONMENT WITH WEAK UPPER DIVERGENCE.
NAT CONTINUES TO MOVE INTO HIGH SHEAR TO THE SOUTH. SST AROUND 28
DEGREES. CI HELD DUE TO INITIAL WEAKENING. DVORAK ANALYSIS BASED ON
SHEAR PATTERN YIELDS DT = 2.5 WITH PT AGREEING AND MET = 3.0. FT
BASED ON DT THUS YIELDS T2.5/3.0/W1.0/24HRS.
FORECASTS :
AT 12 HRS VALID AT 080600 UTC 19.2S 150.1W MOV E AT 7 KT WITH 30 KT
CLOSE TO CENTRE
AT 24 HRS VALID AT 081800 UTC 19.3S 147.5W MOV E AT 9 KT WITH 30 KT
CLOSE TO CENTRE
OUTLOOK :
AT 36 HRS VALID AT 090600 UTC 20.0S 143.6W MOV E AT 12 KT WITH 30 KT
CLOSE TO CENTRE
AT 48 HRS VALID AT 091800 UTC 21.9S 139.6W MOV ESE AT 14 KT WITH 30
KT CLOSE TO CENTRE
THIS WILL BE THE LAST TROPICAL DISTURBANCE ADVISORY ISSUED ON TC NAT.