WPAC: TROPICAL STORM KROVANH (0911/12W)

[Chacor]

WDPN31 PGTW 301500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 12W WARNING NR 11//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
A. TROPICAL STORM (TS) 12W (KROVANH), LOCATED APPROXIMATELY 220
NM SOUTH OF TOKYO, JAPAN, HAS TRACKED NORTHWESTWARD AT 07 KNOTS OVER
THE PAST SIX HOURS. RECENT ANIMATED INFRARED IMAGERY SHOWS THAT
DEEP CONVECTION HAS STARTED TO WANE AND IS NOW CONFINED TO THE
SOUTHEASTERN QUADRANT OF THE SYSTEM. ADDITIONALLY, IT APPEARS THAT
THE LOW LEVEL CIRCULATION CENTER (LLCC) MAY BE PARTIALLY EXPOSED
UNDER A LARGE, RAGGED EYE FEATURE. HOWEVER, TS 12W'S FORWARD MOTION
HAS ALSO SLOWED AS IT APPROACHES THE SUBTROPICAL RIDGE AXIS,
ENABLING THE SYSTEM'S POLEWARD OUTFLOW TO TAP INTO THE MID-LATITUDE
WESTERLY FLOW AND ALLOW KROVANH TO MAINTAIN TROPICAL STORM
INTENSITY. CURRENT POSITION IS BASED ON RADAR FIXES OUT OF JAPAN IN
CONCERT WITH FIXES FROM PGTW AND RJTD. CURRENT INTENSITY IS BASED ON
DVORAK ESTIMATES FROM PGTW, RJTD AND KNES.
3. FORECAST REASONING.
A. THE FORECAST REASONING HAS NOT CHANGED SINCE THE LAST
PROGNOSTIC REASONING BULLETIN.
B. TS 12W WILL CONTINUE TO TRACK NORTH-NORTHWESTWARD OVER THE
NEXT 12 HOURS UNDER THE INFLUENCE OF THE SUBTROPICAL STEERING RIDGE
BUILT IN FROM THE EAST. AT THE SAME TIME, THE APPROACHING MID-
LATITUDE TROUGH WILL CONTINUE TO BREAK DOWN THE RIDGE AND PUSH THE
RIDGE FINGER BACK TO THE EAST. 301200Z UPPER-LEVEL SOUNDINGS OVER
THE KANTO PLAIN SHOW MID-LEVEL SOUTHWESTERLY WINDS, INDICATING THE
WESTERN EXTENT OF THE RIDGE AND SIGNIFYING THAT TS 12W SHOULD CREST
THE RIDGE AXIS IN THE NEXT 12 TO 18 HOURS. BY TAU 24, KROVANH WILL
MAKE LANDFALL JUST EAST OF TOKYO, JAPAN AS A TROPICAL STORM AND
CONTINUE TRACKING NORTHEASTWARD UNDER THE INFLUENCE OF THE MID-
LATITUDE WESTERLIES. BY TAU 36 THE SYSTEM WILL START TO WEAKEN AS IT
ENGAGES WITH THE BAROCLINIC ZONE AND BY TAU 48 TS 12W WILL COMPLETE
ITS BAROCLINIC TRANSITION. THE AVAILABLE NUMERICAL MODEL AIDS ARE
IN VERY GOOD AGREEMENT WITH THE RECURVATURE SCENARIO AND THIS
FORECAST FAVORS THE ECMWF SOLUTIION REGARDING LANDFALL POSITION.
FORECAST TEAM: DELTA.//

[masaji79]

Seems like the track has shifted to the east. At least on that track Tokyo will be on the weaker side of the storm where Krovanh comes in as a TS or TY.

[HURAKAN]

30/1457 UTC 32.1N 140.0E T4.0/4.0 KROVANH -- West Pacific

Typhoon says Dvorak

[senorpepr]

WTPQ20 RJTD 301800
RSMC TROPICAL CYCLONE ADVISORY
NAME STS 0911 KROVANH (0911)
ANALYSIS
PSTN 301800UTC 32.7N 140.0E FAIR
MOVE NNW 09KT
PRES 980HPA
MXWD 055KT
GUST 080KT
50KT 30NM
30KT 180NM NORTHEAST 120NM SOUTHWEST
FORECAST
24HF 311800UTC 37.9N 141.8E 85NM 70%
MOVE NNE 16KT
PRES 980HPA
MXWD 055KT
GUST 080KT
48HF 011800UTC 43.3N 150.1E 180NM 70% EXTRATROPICAL LOW =

[senorpepr]

WTPQ20 RJTD 302100
RSMC TROPICAL CYCLONE ADVISORY
NAME STS 0911 KROVANH (0911)
ANALYSIS
PSTN 302100UTC 33.1N 139.9E FAIR
MOVE NNW 10KT
PRES 975HPA
MXWD 060KT
GUST 085KT
50KT 40NM
30KT 180NM NORTHEAST 120NM SOUTHWEST
FORECAST
24HF 312100UTC 38.4N 142.3E 85NM 70%
MOVE NNE 16KT
PRES 980HPA
MXWD 055KT
GUST 080KT
45HF 011800UTC 43.3N 150.1E 180NM 70% EXTRATROPICAL LOW =

[cycloneye]

WTPN31 PGTW 310300
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 12W (KROVANH) WARNING NR 013
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
310000Z --- NEAR 33.5N 139.9E
MOVEMENT PAST SIX HOURS - 355 DEGREES AT 09 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
SATELLITE AND RADAR
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT
110 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
REPEAT POSIT: 33.5N 139.9E
---
FORECASTS:
12 HRS, VALID AT:
311200Z --- 36.0N 140.8E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT
110 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
095 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 025 DEG/ 21 KTS
---
24 HRS, VALID AT:
010000Z --- 39.7N 143.2E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT
130 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
090 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 050 DEG/ 25 KTS
---
36 HRS, VALID AT:
011200Z --- 42.9N 148.2E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
310300Z POSITION NEAR 34.1N 140.1E.
TROPICAL STORM 12W (KROVANH), LOCATED APROXIMATELY 135 NM SOUTH OF
TOKYO, JAPAN, HAS TRACKED NORTHWARD AT 09 KNOTS OVER THE PAST SIX
HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 310000Z IS 23 FEET. NEXT
WARNINGS AT 310900Z, 311500Z, 312100Z AND 010300Z. REFER TO TROPICAL
DEPRESSION 02C (TWO) WARNINGS (WTPN32 PGTW) FOR SIX-HOURLY UPDATES.
FORECAST TEAM: BRAVO. //
NNNN

[Chacor]

WTPQ20 RJTD 310300
RSMC TROPICAL CYCLONE ADVISORY
NAME STS 0911 KROVANH (0911)
ANALYSIS
PSTN 310300UTC 34.0N 140.0E FAIR
MOVE N 09KT
PRES 975HPA
MXWD 060KT
GUST 085KT
50KT 50NM NORTHEAST 30NM SOUTHWEST
30KT 200NM NORTHEAST 100NM SOUTHWEST
FORECAST
24HF 010300UTC 39.7N 143.8E 85NM 70%
MOVE NNE 19KT
PRES 980HPA
MXWD 055KT
GUST 080KT
45HF 020000UTC 43.0N 150.1E 180NM 70% EXTRATROPICAL LOW =

[Chacor]

WTPQ20 RJTD 310900
RSMC TROPICAL CYCLONE ADVISORY
NAME STS 0911 KROVANH (0911)
ANALYSIS
PSTN 310900UTC 35.4N 141.2E FAIR
MOVE NNE 15KT
PRES 980HPA
MXWD 055KT
GUST 080KT
50KT 30NM
30KT 200NM NORTHEAST 100NM SOUTHWEST
FORECAST
24HF 010900UTC 41.2N 145.9E 85NM 70%
MOVE NE 16KT
PRES 980HPA
MXWD 055KT
GUST 080KT
45HF 020600UTC 43.2N 153.4E 180NM 70% EXTRATROPICAL LOW =

[HURAKAN]

Pretty close

[HURAKAN]

WTPN31 PGTW 310900
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 12W (KROVANH) WARNING NR 014
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
310600Z --- NEAR 34.7N 140.6E
MOVEMENT PAST SIX HOURS - 025 DEGREES AT 13 KTS
POSITION ACCURATE TO WITHIN 040 NM
POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
SATELLITE AND RADAR
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 105 NM NORTHEAST QUADRANT
100 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
REPEAT POSIT: 34.7N 140.6E
---
FORECASTS:
12 HRS, VALID AT:
311800Z --- 37.8N 142.4E
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
040 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT
110 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
095 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 035 DEG/ 24 KTS
---
24 HRS, VALID AT:
010600Z --- 41.6N 146.2E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT
130 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
090 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 070 DEG/ 24 KTS
---
36 HRS, VALID AT:
011800Z --- 43.2N 152.2E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
310900Z POSITION NEAR 35.5N 141.0E.
TROPICAL STORM (TS) 12W (KROVANH) LOCATED APPROXIMATELY 70 NM
SOUTHEAST OF TOKYO, JAPAN, HAS TRACKED NORTH-NORTHEASTWARD AT 13
KNOTS OVER THE PAST SIX HOURS. TS 12W HAS TURNED TO THE NORTH-
NORTHEAST AS EVIDENT IN RADAR IMAGERY. CURRENT POSITION IS BASED ON
RADAR FIXES FROM RJTD AS WELL AS SATELLITE POSITION FIXES FROM RJTD
AND PGTW. CURRENT INTENSITY IS BASED ON DVORAK INTENSITY ESTIMATES
FROM RJTD AND PGTW. THE SYSTEM IS FORECAST TO TRACK TO GENERALLY TO
THE NORTHEAST PARALLEL TO THE COAST OF JAPAN AND UNDERGO EXTRA-
TROPICAL TRANSITION, WHICH SHOULD BE COMPLETED NEAR TAU 36. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 310600Z IS 20 FEET. NEXT WARNINGS AT
311500Z, 312100Z, 010300Z AND 010900Z.
//
NNNN

[HURAKAN]

Latest

[HURAKAN]

Moving away from Tokyo

[HURAKAN]

It seems the JTWC decided to upgrade this system to typhoon when it was south of Tokyo

[senorpepr]

WTPQ20 RJTD 010900
RSMC TROPICAL CYCLONE ADVISORY
NAME TS 0911 KROVANH (0911)
ANALYSIS
PSTN 010900UTC 42.7N 147.0E FAIR
MOVE NE 16KT
PRES 994HPA
MXWD 045KT
GUST 065KT
30KT 240NM NORTHEAST 150NM SOUTHWEST
FORECAST
24HF 020900UTC 43.7N 155.2E 85NM 70% EXTRATROPICAL LOW =

[senorpepr]

WTPQ20 RJTD 011200
RSMC TROPICAL CYCLONE ADVISORY
NAME DEVELOPING LOW FORMER TS 0911 KROVANH (0911)
ANALYSIS
PSTN 011200UTC 43N 149E
MOVE ENE 25KT
PRES 996HPA
MXWD 045KT
30KT 300NM NORTHEAST 200NM SOUTHWEST =