WPAC: Ex-Tropical Storm MERANTI (1010/11W)
Moderator: S2k Moderators
JTWC upgrades to typhoon:
WTPN31 PGTW 091500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TYPHOON 11W (MERANTI) WARNING NR 007
UPGRADED FROM TROPICAL STORM 11W
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
091200Z --- NEAR 23.2N 118.9E
MOVEMENT PAST SIX HOURS - 345 DEGREES AT 10 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 015 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
REPEAT POSIT: 23.2N 118.9E
---
FORECASTS:
12 HRS, VALID AT:
100000Z --- 25.0N 118.8E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
VECTOR TO 24 HR POSIT: 360 DEG/ 12 KTS
---
24 HRS, VALID AT:
101200Z --- 27.4N 118.7E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
VECTOR TO 36 HR POSIT: 010 DEG/ 10 KTS
---
36 HRS, VALID AT:
110000Z --- 29.3N 119.1E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
091500Z POSITION NEAR 23.6N 118.9E.
TYPHOON (TY) 11W (MERANTI), LOCATED APPROXIMATELY 180 NM SOUTHWEST
OF TAIPEI, TAIWAN, HAS TRACKED NORTH-NORTHWESTWARD AT 10 KNOTS OVER
THE PAST SIX HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 091200Z IS 13
FEET. NEXT WARNINGS AT 092100Z, 100300Z, 100900Z AND 101500Z.//
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WDPN31 PGTW 091500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W WARNING NR 07//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
A. TYPHOON (TY) 11W (MERANTI), LOCATED APPROXIMATELY 180 NM
SOUTHWEST OF TAIPEI, TAIWAN, HAS TRACKED NORTH-NORTHWESTWARD AT 10
KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED (IR) SATELLITE
IMAGERY SHOWS A MIDGET SYSTEM WITH A WELL-DEFINED LOW LEVEL
CIRCULATION CENTER (LLCC) AND A 091128Z SSMIS DEPICTS A DEEP
CONVECTIVE MICROWAVE EYE. THE INITIAL POSITION IS BASED ON A RADAR
FIX FROM TAIWAN AND THE AFOREMENTIONED SSMIS IMAGE WITH HIGH
CONFIDENCE. THE INITIAL INTENSITY IS BASED ON THE CONVECTIVE
SIGNATURE AND NOT ON DVORAK ESTIMATES BECAUSE THEY ARE
UNDERESTIMATING THIS MIDGET SYSTEM. UPPER LEVEL ANALYSIS INDICATES
A TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) CELL HAS CONTINUED TO
MOVE FARTHER NORTHWESTWARD, WHICH HAS ALLOWED IMPROVED POLEWARD
OUTFLOW AND DECREASED VERTICAL WIND SHEAR (VWS). ADDITIONALLY, TY
11W CONTINUES TO MAINTAIN A GOOD EQUATORWARD OUTFLOW CHANNEL,
ALLOWING IT TO RAPIDLY INTENSIFY.
3. FORECAST REASONING.
A. THE CURRENT INTENSITY HAS INCREASED SIGNIFICANTLY SINCE THE
PREVIOUS FORECAST BECAUSE OF THE DECREASED VWS AND DUAL OUTFLOW
CHANNELS. THE FORECAST TRACK PHILOSOPHY HAS GENERALLY REMAINED THE
SAME EXCEPT FOR AN INCREASE IN TRACK SPEED DUE TO A STRAIGHTER TRACK.
B. TY 11W IS CURRENTLY TRACKING ALONG THE WESTERN PERIPHERY OF A
SUBTROPICAL STEERING RIDGE AND IS EXPECTED TO MAKE LANDFALL IN
APPROXIMATELY 12 HOURS OVER SOUTHEASTERN CHINA. TY 11W SHOULD BEGIN
TO FEEL THE AFFECTS OF LAND AND BEGIN TO WEAKEN BY TAU 12. BY TAU
36, TY MERANTI IS EXPECTED TO DISSIPATE AS A SIGNIFICANT TROPICAL
CYCLONE OVER THE MOUNTAINOUS TERRAIN OF CHINA. NUMERICAL MODEL
GUIDANCE IS IN GOOD AGREEMENT WITH THE EXCEPTION OF THE UKMO MODEL
WHICH ERRONEOUSLY TRACKS THE SYSTEM NORTHEASTWARD TOWARDS TAIWAN
BEFORE TURNING IT NORTHWARD. THIS FORECAST IS SLIGHTLY WEST OF
CONSENSUS TO ACCOUNT FOR THE UKMO MODEL AND IS WITHIN THE TIGHT
MODEL PACKING OF WBAR, ECMWF, NOGAPS, JGSM, AND GFS.//
NNNN
TPPN10 PGTW 091434
A. TYPHOON 11W (MERANTI)
B. 09/1332Z
C. 23.4N
D. 118.8E
E. ONE/MTSAT
F. T4.0/4.0/D1.5/26HRS STT: D1.5/06HRS
G. IR/EIR
H. REMARKS: 05A/PBO IRREG EYE/ANMTN. OFF HOUR DVORAK FOR RAPID
INTENSIFICATION. 5NM DG EYE WITH MG RING AND -.5 EYE ADJ YIELDS
A DT OF 4.0. MET AND PT AGREE. DBO DT.
I. ADDITIONAL POSITIONS:
09/1048Z 23.0N 119.1E AMSU
09/1128Z 23.2N 118.9E SSMS
GATES
WTPN31 PGTW 091500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TYPHOON 11W (MERANTI) WARNING NR 007
UPGRADED FROM TROPICAL STORM 11W
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
091200Z --- NEAR 23.2N 118.9E
MOVEMENT PAST SIX HOURS - 345 DEGREES AT 10 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 015 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
REPEAT POSIT: 23.2N 118.9E
---
FORECASTS:
12 HRS, VALID AT:
100000Z --- 25.0N 118.8E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
VECTOR TO 24 HR POSIT: 360 DEG/ 12 KTS
---
24 HRS, VALID AT:
101200Z --- 27.4N 118.7E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
VECTOR TO 36 HR POSIT: 010 DEG/ 10 KTS
---
36 HRS, VALID AT:
110000Z --- 29.3N 119.1E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
091500Z POSITION NEAR 23.6N 118.9E.
TYPHOON (TY) 11W (MERANTI), LOCATED APPROXIMATELY 180 NM SOUTHWEST
OF TAIPEI, TAIWAN, HAS TRACKED NORTH-NORTHWESTWARD AT 10 KNOTS OVER
THE PAST SIX HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 091200Z IS 13
FEET. NEXT WARNINGS AT 092100Z, 100300Z, 100900Z AND 101500Z.//
Uploaded with ImageShack.us
WDPN31 PGTW 091500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W WARNING NR 07//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
A. TYPHOON (TY) 11W (MERANTI), LOCATED APPROXIMATELY 180 NM
SOUTHWEST OF TAIPEI, TAIWAN, HAS TRACKED NORTH-NORTHWESTWARD AT 10
KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED (IR) SATELLITE
IMAGERY SHOWS A MIDGET SYSTEM WITH A WELL-DEFINED LOW LEVEL
CIRCULATION CENTER (LLCC) AND A 091128Z SSMIS DEPICTS A DEEP
CONVECTIVE MICROWAVE EYE. THE INITIAL POSITION IS BASED ON A RADAR
FIX FROM TAIWAN AND THE AFOREMENTIONED SSMIS IMAGE WITH HIGH
CONFIDENCE. THE INITIAL INTENSITY IS BASED ON THE CONVECTIVE
SIGNATURE AND NOT ON DVORAK ESTIMATES BECAUSE THEY ARE
UNDERESTIMATING THIS MIDGET SYSTEM. UPPER LEVEL ANALYSIS INDICATES
A TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) CELL HAS CONTINUED TO
MOVE FARTHER NORTHWESTWARD, WHICH HAS ALLOWED IMPROVED POLEWARD
OUTFLOW AND DECREASED VERTICAL WIND SHEAR (VWS). ADDITIONALLY, TY
11W CONTINUES TO MAINTAIN A GOOD EQUATORWARD OUTFLOW CHANNEL,
ALLOWING IT TO RAPIDLY INTENSIFY.
3. FORECAST REASONING.
A. THE CURRENT INTENSITY HAS INCREASED SIGNIFICANTLY SINCE THE
PREVIOUS FORECAST BECAUSE OF THE DECREASED VWS AND DUAL OUTFLOW
CHANNELS. THE FORECAST TRACK PHILOSOPHY HAS GENERALLY REMAINED THE
SAME EXCEPT FOR AN INCREASE IN TRACK SPEED DUE TO A STRAIGHTER TRACK.
B. TY 11W IS CURRENTLY TRACKING ALONG THE WESTERN PERIPHERY OF A
SUBTROPICAL STEERING RIDGE AND IS EXPECTED TO MAKE LANDFALL IN
APPROXIMATELY 12 HOURS OVER SOUTHEASTERN CHINA. TY 11W SHOULD BEGIN
TO FEEL THE AFFECTS OF LAND AND BEGIN TO WEAKEN BY TAU 12. BY TAU
36, TY MERANTI IS EXPECTED TO DISSIPATE AS A SIGNIFICANT TROPICAL
CYCLONE OVER THE MOUNTAINOUS TERRAIN OF CHINA. NUMERICAL MODEL
GUIDANCE IS IN GOOD AGREEMENT WITH THE EXCEPTION OF THE UKMO MODEL
WHICH ERRONEOUSLY TRACKS THE SYSTEM NORTHEASTWARD TOWARDS TAIWAN
BEFORE TURNING IT NORTHWARD. THIS FORECAST IS SLIGHTLY WEST OF
CONSENSUS TO ACCOUNT FOR THE UKMO MODEL AND IS WITHIN THE TIGHT
MODEL PACKING OF WBAR, ECMWF, NOGAPS, JGSM, AND GFS.//
NNNN
TPPN10 PGTW 091434
A. TYPHOON 11W (MERANTI)
B. 09/1332Z
C. 23.4N
D. 118.8E
E. ONE/MTSAT
F. T4.0/4.0/D1.5/26HRS STT: D1.5/06HRS
G. IR/EIR
H. REMARKS: 05A/PBO IRREG EYE/ANMTN. OFF HOUR DVORAK FOR RAPID
INTENSIFICATION. 5NM DG EYE WITH MG RING AND -.5 EYE ADJ YIELDS
A DT OF 4.0. MET AND PT AGREE. DBO DT.
I. ADDITIONAL POSITIONS:
09/1048Z 23.0N 119.1E AMSU
09/1128Z 23.2N 118.9E SSMS
GATES
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HKO 12z was only 45 knots...
Tropical Cyclone Warning
At 091200 UTC, Tropical Storm Meranti (1010) with central pressure 988 hectopascals was centred within 60 nautical miles of two three point one degrees north (23.1 N) one one nine point zero degrees east (119.0 E) and is forecast to move north at about 10 knots for the next 24 hours.
Maximum winds near the centre are estimated to be 45 knots.
Radius of over 33 knot winds 60 nautical miles.
Radius of over 2 metre waves 120 nautical miles.
Forecast position and intensity at 101200 UTC
Two six point nine degrees north (26.9 N)
One one nine point six degrees east (119.6 E)
Maximum winds 35 knots.
Forecast position and intensity at 111200 UTC
Dissipated over land.
Tropical Cyclone Warning
At 091200 UTC, Tropical Storm Meranti (1010) with central pressure 988 hectopascals was centred within 60 nautical miles of two three point one degrees north (23.1 N) one one nine point zero degrees east (119.0 E) and is forecast to move north at about 10 knots for the next 24 hours.
Maximum winds near the centre are estimated to be 45 knots.
Radius of over 33 knot winds 60 nautical miles.
Radius of over 2 metre waves 120 nautical miles.
Forecast position and intensity at 101200 UTC
Two six point nine degrees north (26.9 N)
One one nine point six degrees east (119.6 E)
Maximum winds 35 knots.
Forecast position and intensity at 111200 UTC
Dissipated over land.
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-
- Category 2
- Posts: 637
- Joined: Wed Mar 24, 2010 3:10 am
- Location: Holbrook, NY (Long Island)
JMA holding at 40 knots... big mistake imo.
WTPQ21 RJTD 091500
RSMC TROPICAL CYCLONE ADVISORY
NAME TS 1010 MERANTI (1010)
ANALYSIS
PSTN 091500UTC 23.6N 118.9E FAIR
MOVE N 11KT
PRES 992HPA
MXWD 040KT
GUST 060KT
30KT 140NM SOUTHEAST 70NM NORTHWEST
FORECAST
24HF 101500UTC 27.7N 119.1E 85NM 70% TROPICAL DEPRESSION =
WTPQ21 RJTD 091500
RSMC TROPICAL CYCLONE ADVISORY
NAME TS 1010 MERANTI (1010)
ANALYSIS
PSTN 091500UTC 23.6N 118.9E FAIR
MOVE N 11KT
PRES 992HPA
MXWD 040KT
GUST 060KT
30KT 140NM SOUTHEAST 70NM NORTHWEST
FORECAST
24HF 101500UTC 27.7N 119.1E 85NM 70% TROPICAL DEPRESSION =
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-
- Category 5
- Posts: 3420
- Joined: Sun Apr 11, 2004 5:51 pm
- Location: East Longmeadow, MA, USA
-
- Tropical Low
- Posts: 27
- Joined: Thu Sep 09, 2010 4:31 pm
- Location: Los Angeles (UCLA)
- Contact:
Re: WPAC: Tropical Storm MERANTI (1010/11W)
Landfall radar -- really well-developed eye, but such a small system
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Clearly was a typhoon at landfall.
But JMA totally busted on Meranti, 45 kt was its peak.
WTPQ21 RJTD 092100
RSMC TROPICAL CYCLONE ADVISORY
NAME TS 1010 MERANTI (1010)
ANALYSIS
PSTN 092100UTC 25.0N 118.8E FAIR
MOVE N 13KT
PRES 990HPA
MXWD 045KT
GUST 065KT
30KT 140NM SOUTHEAST 70NM NORTHWEST
FORECAST
24HF 102100UTC 30.5N 119.5E 85NM 70% TROPICAL DEPRESSION =
But JMA totally busted on Meranti, 45 kt was its peak.
WTPQ21 RJTD 092100
RSMC TROPICAL CYCLONE ADVISORY
NAME TS 1010 MERANTI (1010)
ANALYSIS
PSTN 092100UTC 25.0N 118.8E FAIR
MOVE N 13KT
PRES 990HPA
MXWD 045KT
GUST 065KT
30KT 140NM SOUTHEAST 70NM NORTHWEST
FORECAST
24HF 102100UTC 30.5N 119.5E 85NM 70% TROPICAL DEPRESSION =
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Re: WPAC: Tropical Storm MERANTI (1010/11W)
As ive said many times this season privately to friends it will be interesting to see what the JMA analysis Meranti is in 8 weeks time (W/B November 1) when they release their BT for Meranti. I strongly suspect that they wont throw out the Dvorak rulebook as the JTWC and as the HKO and CMA seem to have done and will just up it by 5kts to an STS. However when you look at all off the WPAC agencies peak windspeeds for Meranti you can tell that the JMA were not alone at being terrible at forecasting Meranti, both the KMA and VMD.
CMA: 65kts
JTWC: 65kts
JMA/KMA/VMD: 45kts
HKO: 60kts
I dont know what the Taiwan CWB forecasted Meranti as during its peak but i cant see it being to far away from the JTWCs peak estimate
CMA: 65kts
JTWC: 65kts
JMA/KMA/VMD: 45kts
HKO: 60kts
I dont know what the Taiwan CWB forecasted Meranti as during its peak but i cant see it being to far away from the JTWCs peak estimate
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Looks to me like it could have easily been 70kts given the radar presentation and the small system size.
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The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products
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