NW Pacific: TY Rammasun (0802/03W)

[senorpepr]

12Z suite on 94W is interesting. We're starting to get more models--woohoo!

Climo/Persistence model (C120) keeps 94W on a west-northwestward track, cross over Mindanao between T+24 and T+48. Consensus (CONW), GFS, and NOGAPS has the disturbance moving north-northwestward, missing the Philippines altogether. Of course, with the current structure of 94W, it's still too early to say. I'm still leaning more toward a climatological solution, even though the dynamic models say otherwise. Monitoring METSAT, you can see 94W consolidating as it moves westward toward Mindanao and the Visayas.

[senorpepr]

0WWPN20 KNES 062152

A. TROPICAL DISTURBANCE (94W)

B. 06/2030Z

C. 7.6N

D. 133.7E

E. FIVE/MTSAT

F. T1.5/1.5/D0.5/24HRS

G. IR/EIR/MSI

H. REMARKS...BROAD CIRCULATION ASSOCIATED WITH 94W WITH MULITPLE BAND
SEGMENTS. THIS IS MAKING IT A LITTLE DIFFICULT TO PIN DOWN A CENTER. HAVE
PLACED CENTER NEAR INCREASING CONVECTION JUST WEST OF PALAU. 17Z AMSRE
PASS ALSO AIDED IN POSITION. 3 TENTHS BANDING GIVES DT=2.0. =2.0 AND
PT=1.5...RUMINSKI



TPPN11 PGTW 070004

A. TROPICAL DISTURBANCE 94W (SW OF PALAU)

B. 06/2330Z

C. 7.1N

D. 133.9E

E. FIVE/MTSAT

F. T1.5/1.5/D0.5/24HRS STT: D0.5/06HRS (06/2330Z)

G. IR/EIR/VIS/MSI

40A/PBO SBC/ANMTN. CONVECTION WRAPS .30 ON LOG10 SPIRAL
YIELDING A DT OF 1.5. MET AND PT AGREE. DBO DT. BROAD
CIRCULATION MAKES FINDING LLCC DIFFICULT.

UEHARA

[senorpepr]

Looking pretty nice...

[HURAKAN]

[RattleMan]

PAGASA has designated 94W as Tropical Depression Butchoy.

http://www.pagasa.dost.gov.ph/wb/tcupdate.shtml

[RL3AO]

WWJP25 RJTD 070000
WARNING AND SUMMARY 070000.
WARNING VALID 080000.
WARNING IS UPDATED EVERY 6 HOURS.
GALE WARNING.
DEVELOPING LOW 992 HPA
AT 44N 146E SEA AROUND KURILS MOVING EAST 30 KNOTS.
OCCLUDED FRONT FROM 44N 146E TO 44N 148E 43N 150E.
WARM FRONT FROM 43N 150E TO 41N 152E 40N 154E.
COLD FRONT FROM 43N 150E TO 40N 148E 38N 145E.
WINDS 30 TO 35 KNOTS WITHIN 700 MILES OF LOW NORTHEAST SEMICIRCLE AND
400 MILES ELSEWHERE.
ANOTHER LOW 996 HPA AT 50N 142E
MOVING NORTH 15 KNOTS.
WARNING.
TROPICAL DEPRESSION 1004 HPA
AT 07.4N 133.8E CAROLINES MOVING WESTNORTHWEST 06 KNOTS.
POSITION POOR.
MAX WINDS 30 KNOTS.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER SEA OF OKHOTSK YELLOW SEA.
WARNING.
DENSE FOG OBSERVED LOCALLY OVER WATERS BOUNDED BY 46N 152E 51N 157E
40N 180E 34N 180E 34N 165E 46N 152E.
SUMMARY.
HIGH 1016 HPA AT 25N 162E ESE 10 KT.
LOW 1002 HPA AT 39N 168E EAST 20 KT.
LOW 1006 HPA AT 36N 178E EAST 10 KT.
HIGH 1014 HPA AT 32N 132E EAST 10 KT.
HIGH 1016 HPA AT 33N 151E EAST SLOWLY.
STATIONARY FRONT FROM 23N 124E TO 25N 130E 26N 135E 24N 139E.
JAPAN METEOROLOGICAL AGENCY.=

[HURAKAN]

WTPN31 PGTW 070900
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
REF/A/NAVPACMETOCCEN PEARL HARBOR HI/062200Z MAY 08//
AMPN/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. TROPICAL DEPRESSION 03W WARNING NR 001
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
070600Z --- NEAR 7.4N 133.0E
MOVEMENT PAST SIX HOURS - 295 DEGREES AT 07 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 7.4N 133.0E
---
FORECASTS:
12 HRS, VALID AT:
071800Z --- 8.0N 131.9E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 325 DEG/ 04 KTS
---
24 HRS, VALID AT:
080600Z --- 8.6N 131.5E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 005 DEG/ 05 KTS
---
36 HRS, VALID AT:
081800Z --- 9.6N 131.6E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 010 DEG/ 07 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
090600Z --- 11.0N 131.8E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 005 DEG/ 07 KTS
---
72 HRS, VALID AT:
100600Z --- 13.9N 132.1E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 360 DEG/ 08 KTS
---
LONG RANGE OUTLOOK:
NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 250 NM
ON DAY 4 AND 350 NM ON DAY 5... AND FOR INTENSITY
NEAR 20 KT EACH DAY.
---
96 HRS, VALID AT:
110600Z --- 17.1N 132.0E
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 015 DEG/ 11 KTS
---
120 HRS, VALID AT:
120600Z --- 21.3N 133.3E
MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
070900Z POSITION NEAR 7.5N 132.7E.
TROPICAL DEPRESSION (TD) 03W, LOCATED APPROXIMATELY 100 NM WEST
OF PALAU, HAS TRACKED WEST-NORTHWEST AT 07 KNOTS DURING THE PAST
SIX HOURS. RECENT SCATTEROMETRY AND DVORAK INTENSITY ESTIMATES
INDICATE 30 KNOT WINDS AT THE SYSTEM CENTER. THE STORM IS EXPECTED
TO TRACK WEST-NORTHWESTWARD BEFORE TURNING NORTHWARD NEAR TAU 24.
THIS WARNING SUPERSEDES AND CANCELS REF A, NAVPACMETOCCEN 062200Z
MAY 08 TROPICAL CYCLONE FORMATION ALERT (WTPN21 PGTW 062200 )
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 070600Z IS 10 FEET.
NEXT WARNINGS AT 071500Z, 072100Z, 080300Z AND 080900Z.

[HURAKAN]

07/0830 UTC 7.4N 133.0E T2.5/2.5 03W -- West Pacific Ocean

[Chacor]

Well, the good news is that this looks like it'll be a fishie. Fun to track, if anything.

For what it's worth, JMA are already issuing bulletins and expect a TS within 24 hours.

WTPQ20 RJTD 070900
RSMC TROPICAL CYCLONE ADVISORY
NAME TD
ANALYSIS
PSTN 070900UTC 07.5N 132.6E POOR
MOVE W 08KT
PRES 1000HPA
MXWD 030KT
GUST 045KT
FORECAST
24HF 080900UTC 09.2N 131.4E 150NM 70%
MOVE NNW SLOWLY
PRES 998HPA
MXWD 035KT
GUST 050KT =

[HURAKAN]

[HURAKAN]

PAGASA forecasting a much closer encounter.

[Chacor]

551
TCNA21 RJTD 071200
CCAA 07120 47644 NAMELESS 04079 11315 14144 220// 92913=

12z: T2.0, at 7.9N 131.5E

[Chacor]

185
WTPQ20 RJTD 071200
RSMC TROPICAL CYCLONE ADVISORY
NAME TD
ANALYSIS
PSTN 071200UTC 07.8N 131.7E POOR
MOVE WNW 10KT
PRES 1000HPA
MXWD 030KT
GUST 045KT
FORECAST
24HF 081200UTC 09.2N 130.7E 150NM 70%
MOVE NW SLOWLY
PRES 996HPA
MXWD 040KT
GUST 060KT =

[senorpepr]

Well, the good news is that this looks like it'll be a fishie. Fun to track, if anything.

I wouldn't be so quick to say that.

If you notice, JMA and PAGASA have Butchoy moving toward the Philippines (Visayas), which is more in line with climatology. JTWC is following the consensus model strictly, which has had Butchoy moving practically due north for a few days now--something that the system has yet to do.

[Chacor]

JTWC continues to insist on a northerly track.



WDPN31 PGTW 071500
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 03W WARNING NR 02//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
A. TROPICAL DEPRESSION (TD) 03W (NONAME) INTENSIFIED ABOVE
WARNING CRITERIA AS THE LOW LEVEL CIRCULATION CENTER (LLCC)
DISPLAYED GOOD CONSOLIDATION TRACKING SLOWLY WEST-NORTHWESTWARD
ACROSS THE PHILIPPINE SEA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
SHOWS CONVECTIVE BANDING WRAPPING TOWARD THE LLCC AND AN ANTICYCLONE
ALOFT HAS AIDED DEVELOPMENT BY PROVIDING EXCELLENT RADIAL OUTFLOW.
B. TD 03W IS TRACKING WEST-NORTHWESTWARD ALONG THE WESTERN PERI-
PHERY OF A STRONG RIDGE LOCATED TO THE NORTHEAST OF THE SYSTEM.
INTENSITY IS BASED ON DVORAK ESTIMATES OF 2.0 FROM PGTW, UNFLAGGED
QSCAT DATA RANGING FROM 20 TO 30 KNOTS NEAR THE LLCC AND NEARBY
SURFACE OBSERVATIONS OF 25 KNOTS.
3. FORECAST REASONING
A. FORECAST PHILOSOPHY HAS NOT DEVIATED SINCE THE LAST FORECAST.
B. TD 03W WILL BE STEERED WEST-NORTHWESTWARD BY THE SUBTROPICAL
RIDGE THROUGH TAU 12. AFTER TAU 12 THE STORM WILL TURN NORTHWARD AND
TRACK ALONG THE WESTERN PERIPHERY OF THE RIDGE WHICH WILL SHIFT TO
THE EAST UNDER THE INFLUENCE OF AN APPROACHING MIDLATITUDE TROUGH
MOVING OFF EASTERN ASIA OVER THE WESTERN PACIFIC. ALL AVAILABLE OB-
JECTIVE AIDS ARE IN SOLID AGREEMENT WITH THIS TRACK. THE STORM WILL
STEADILY INTENSIFY THROUGH TAU 72 AS IT REMAINS NEAR THE 200 MB
ANTICYCLONE AND TRACKS OVER WARM WATERS. THE STORM WILL REACH TYPHOON
STRENGTH SHORTLY AFTER TAU 72.
C. THE FORECAST REASONING WILL NOT CHANGE SIGNIFICANTLY IN THE
EXTENDED PERIODS. THE MIDLATITUDE TROUGH TRANSITING ACROSS THE
WESTERN PACIFIC WILL CONTINUE TO BREAK DOWN THE SUBTROPICAL RIDGE
ALLOWING THE SYSTEM TO CONTINUE ALONG A NORTHWARD TRACK. NEAR TAU
120 TD 03W WILL TURN SLIGHTLY TO THE NORTHEAST AS INTERACTION WITH
THE BAROCLINIC ZONE INCREASES. THE STORM WILL CONTINUE TO INTENSIFY
GRADUALLY THROUGHOUT THE FORECAST PERIOD AS FAVORABLE CONDITIONS
PERSIST.
FORECAST TEAM: CHARLIE//

[Chacor]

Looks like PAGASA are now going with a northerly track too, senor.

[KWT]

Yeah this hopefully is going to be a fish, looks pretty good right now with reagrds to the convective pattern of the system ,steady development looks to be a decent call as of now.

Also interesting to see it progged to reach 85kts...

[senorpepr]

Looks like PAGASA are now going with a northerly track too, senor.

I just saw that as well.

I'm interested if JMA will follow suit.

I'd still like to see sizable northward movement before I'm confident in that solution. The consensus models have been firm on a north movement since this was declared an invest. If you observe the satellite trends as well as any tracking chart, you will notice a west-northwest direction instead. I'm not saying an eventual northward motion is out of the question, but I do think it's a little too early to say the Philippines are safe.

I do notice JTWC's reasoning:

TD 03W WILL BE STEERED WEST-NORTHWESTWARD BY THE SUBTROPICAL
RIDGE THROUGH TAU 12. AFTER TAU 12 THE STORM WILL TURN NORTHWARD AND
TRACK ALONG THE WESTERN PERIPHERY OF THE RIDGE WHICH WILL SHIFT TO
THE EAST UNDER THE INFLUENCE OF AN APPROACHING MIDLATITUDE TROUGH
MOVING OFF EASTERN ASIA OVER THE WESTERN PACIFIC. ALL AVAILABLE OB-
JECTIVE AIDS ARE IN SOLID AGREEMENT WITH THIS TRACK. THE STORM WILL
STEADILY INTENSIFY THROUGH TAU 72 AS IT REMAINS NEAR THE 200 MB
ANTICYCLONE AND TRACKS OVER WARM WATERS. THE STORM WILL REACH TYPHOON
STRENGTH SHORTLY AFTER TAU 72.

Personally, after studying the charts, visibility, infrared, and water vapor satellites, and accomplishing a few streamline charts, I'd venture a blend between the models and climatology. It appears that the models are under forecasting the axis of the subtropical ridge. Additionally, JTWC stated that "the storm will turn northward and track along the western periphery of the ridge..." Well, if that's the case, we should have already seen more northward movement. Secondly, "...the ridge . . . will shift to the east under the influence of an approaching mid-latitude trough..."

Yes, I see that trough, but I think it's digging a little too late to safe the Philippines. Yes, it will influence the subtropical ridge and, yes, it will eventually shift Butchoy northward and then northeastward, but I still feel Samar may still be under the gun. Will Samar and the easternmost Visayas (Leyte?) get hit? Maybe not, but it's still too early, in my opinion, to say so.


Some of the strike probabilities at T+72hr show a 1/5 chance of being brushed affected by Butchoy. Still worth monitoring.




BTW, The PAGASA bulletin

Severe Weather Bulletin Number TWO
Tropical Cyclone Alert: Tropical Storm "BUTCHOY"
Issued at 11:00 p.m., Wednesday, 07 May 2008 "Butchoy" has intensified into a tropical storm as it continues to move in a west northwest direction.
Location of Center: (as of 10:00 p.m.) 610 kms East of Mindanao
Coordinates: 07.8°N, 132.3°E
Strength: Maximum sustained winds of 65 kph near the center and gustiness of up to 80 kph
Movement: West Northwest at 13 kph
Forecast Positions / Outlook:
Thursday evening: 460 kms East of Northern Mindanao
Friday evening: 480 kms Northeast of Northern Mindanao
Saturday evening: 530 kms Northeast of Eastern Visayas

It is expected to induce the southwest monsoon and bring rains over Visayas and Mindanao.

Residents in low lying areas and living near mountain slopes over areas are advised to take all the necessary precautions against possible flashflood and landslides.

The public and the disaster coordinating councils concerned are advised to take appropriate actions and watch for the next bulletin to be issued at 11 AM tomorrow.

[P.K.]

T2.5 at 1800 from RSMC Tokyo so this will be named shortly.

[P.K.]

WTPQ20 RJTD 071800
RSMC TROPICAL CYCLONE ADVISORY
NAME TS 0802 RAMMASUN (0802) UPGRADED FROM TD
ANALYSIS
PSTN 071800UTC 08.2N 130.6E FAIR
MOVE WNW 10KT
PRES 996HPA
MXWD 035KT
GUST 050KT
30KT 120NM
FORECAST
24HF 081800UTC 10.0N 129.7E 90NM 70%
MOVE NNW 06KT
PRES 990HPA
MXWD 045KT
GUST 065KT
48HF 091800UTC 12.9N 128.9E 150NM 70%
MOVE NNW 08KT
PRES 975HPA
MXWD 060KT
GUST 085KT
72HF 101800UTC 16.5N 128.5E 220NM 70%
MOVE N 09KT
PRES 960HPA
MXWD 075KT
GUST 105KT =