WPAC: Sonamu - Severe Tropical Storm

[supercane4867]

SUBJ/TROPICAL CYCLONE FORMATION ALERT//
WTPN21 PGTW 022130
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
200 NM EITHER SIDE OF A LINE FROM 7.8N 126.7E TO 7.9N 115.0E
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 15 TO 20 KNOTS. METSAT IM-
AGERY AT 022100Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 7.9N 125.8E. THE SYSTEM IS MOVING WESTWARD AT 23 KNOTS.
2. REMARKS:
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 032130Z.
//

[euro6208]

2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 7.5N
128.1E IS NOW LOCATED NEAR 7.9N 125.8E, APPROXIMATELY 230 NM EAST-
NORTHEAST OF ZAMBOANGA, PHILIPPINES. ANIMATED INFRARED SATELLITE
IMAGERY DEPICTS A CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC)
WITH IMPROVED DEEP CONVECTIVE BANDING. A 021741Z AMSU IMAGE
INDICATES THAT THE LLCC IS LOCATED OVER MINDANAO BUT HAS MAINTAINED
CURVED, DEEP CONVECTIVE BANDING OVER THE WESTERN SEMI-CIRCLE. UPPER-
LEVEL ANALYSIS SHOWS A MARGINAL ENVIRONMENT WITH MODERATE, EASTERLY
VERTICAL WIND SHEAR OFFSET BY STRONG DIFFLUENCE. DYNAMIC MODEL
GUIDANCE INDICATES THAT THE SYSTEM WILL RE-STRENGTHEN AS IT TRACKS
BACK OVER WATER BY TAU 12. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1004 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
032130Z.//
NNNN

[euro6208]

barely at TD status...


TPPN10 PGTW 030017

A. TROPICAL DISTURBANCE 93W (NW OF MINDANAO)

B. 02/2332Z

C. 8.7N

D. 124.1E

E. FIVE/MTSAT

F. T1.0/1.0

G. IR/EIR

H. REMARKS: 38A/PBO SBC/ANMTN. A .20 WRAP ON THE LOG10 SPIRAL
YIELDS A DT OF 1.0. PT AGREES. DBO DT.

I. ADDITIONAL POSITIONS: NONE


NEWCOMER

20130102 2032 7.8 -125.8 Overland 92W 92W

[dexterlabio]

This time though it's different and it's likely to be a named tropical cyclone. And I think it will get stronger once in the SCS. Impressive CDO right now. IMO this is the real earliest start of a WPAC tropical cyclone season that I know so far. Well last year we also started quite early with Pakhar developing in March.

[Meow]

This time though it's different and it's likely to be a named tropical cyclone. And I think it will get stronger once in the SCS. Impressive CDO right now. IMO this is the real earliest start of a WPAC tropical cyclone season that I know so far. Well last year we also started quite early with Pakhar developing in March.

Soulik was a typhoon in both 2000 and 2001.

[RobWESTPACWX]

I just made a video update specifically on this storm, although been talking about it for 4 days now, very disappointing that now just upgraded to a TD by PAGASA.

[youtube]http://www.youtube.com/watch?v=6VOrQ_uIXpU[/youtube]

[RobWESTPACWX]

JMA now holds this as a Tropical Storm. I think its appropriate, given the on the ground wind reports we have been seeing across the Philippines. I try to use those before Dvorak if a storm is over land. Would only make sense. Looks like JMA saw some winds over 35kts in Palawan.

http://www.jma.go.jp/en/typh/1301.html

[Meow]

JMA now holds this as a Tropical Storm. I think its appropriate, given the on the ground wind reports we have been seeing across the Philippines. I try to use those before Dvorak if a storm is over land. Would only make sense. Looks like JMA saw some winds over 35kts in Palawan.

http://www.jma.go.jp/en/typh/1301.html

What a historical moment right now, and you only post a few sentence? There has been no tropical storm in the Northwestern Pacific in January since 2005! And the link will not work when Sonamu dissipated.





TS 1301 (SONAMU)
Issued at 13:05 UTC, 3 January 2013

<Analyses at 03/12 UTC>
Scale -
Intensity -
Center position N8°35'(8.6°)
E119°35'(119.6°)
Direction and speed of movement W 35km/h(20kt)
Central pressure 1002hPa
Maximum wind speed near the center 18m/s(35kt)
Maximum wind gust speed 25m/s(50kt)
Area of 30kt winds or more ALL170km(90NM)

<Forecast for 04/00 UTC>
Intensity -
Center position of probability circle N8°30'(8.5°)
E116°35'(116.6°)
Direction and speed of movement W 30km/h(15kt)
Central pressure 998hPa
Maximum wind speed near the center 18m/s(35kt)
Maximum wind gust speed 25m/s(50kt)
Radius of probability circle 90km(50NM)

<Forecast for 04/12 UTC>
Intensity -
Center position of probability circle N8°20'(8.3°)
E114°05'(114.1°)
Direction and speed of movement W 20km/h(12kt)
Central pressure 994hPa
Maximum wind speed near the center 20m/s(40kt)
Maximum wind gust speed 30m/s(60kt)
Radius of probability circle 140km(75NM)

<Forecast for 05/12 UTC>
Intensity -
Center position of probability circle N7°50'(7.8°)
E110°50'(110.8°)
Direction and speed of movement W 15km/h(8kt)
Central pressure 990hPa
Maximum wind speed near the center 23m/s(45kt)
Maximum wind gust speed 35m/s(65kt)
Radius of probability circle 200km(110NM)

<Forecast for 06/12 UTC>
Intensity -
Center position of probability circle N7°30'(7.5°)
E108°20'(108.3°)
Direction and speed of movement W 10km/h(6kt)
Central pressure 990hPa
Maximum wind speed near the center 23m/s(45kt)
Maximum wind gust speed 35m/s(65kt)
Radius of probability circle 300km(160NM)

<Forecast for 07/12 UTC>
Center position of probability circle N7°05'(7.1°)
E107°00'(107.0°)
Direction and speed of movement WSW Slowly
Radius of probability circle 370km(200NM)

<Forecast for 08/12 UTC>
Center position of probability circle N6°35'(6.6°)
E105°50'(105.8°)
Direction and speed of movement WSW Slowly
Radius of probability circle 480km(260NM)

[Meow]

How can the JTWC estimate that Sonamu will intensify when approaching Malaysia?



WTPN31 PGTW 031500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/022121Z JAN 13//
AMPN/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. TROPICAL DEPRESSION 01W (ONE) WARNING NR 001
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
031200Z --- NEAR 8.7N 119.4E
MOVEMENT PAST SIX HOURS - 260 DEGREES AT 17 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 8.7N 119.4E
---
FORECASTS:
12 HRS, VALID AT:
040000Z --- 8.4N 116.3E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 265 DEG/ 13 KTS
---
24 HRS, VALID AT:
041200Z --- 8.2N 113.7E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 36 HR POSIT: 260 DEG/ 10 KTS
---
36 HRS, VALID AT:
050000Z --- 7.9N 111.7E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 48 HR POSIT: 260 DEG/ 10 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
051200Z --- 7.6N 109.8E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 72 HR POSIT: 265 DEG/ 06 KTS
---
72 HRS, VALID AT:
061200Z --- 7.4N 107.5E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 96 HR POSIT: 240 DEG/ 04 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
071200Z --- 6.6N 106.1E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 225 DEG/ 05 KTS
---
120 HRS, VALID AT:
081200Z --- 5.3N 104.8E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
031500Z POSITION NEAR 8.6N 118.6E.
TROPICAL DEPRESSION (TD) 01W (ONE), LOCATED APPROXIMATELY 185 NM
NORTHWEST OF ZAMBOANGA, PHILIPPINES, HAS TRACKED WESTWARD AT 17
KNOTS OVER THE PAST SIX HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
031200Z IS 7 FEET. NEXT WARNINGS AT 032100Z, 040300Z, 040900Z AND
041500Z. THIS WARNING SUPERSEDES AND CANCELS REF A, JOINT TYPHOON
WRNCEN PEARL HARBOR HI 022121Z JAN 13 TROPICAL CYCLONE FORMATION
ALERT (WTPN21 PGTW 022130).//
NNNN

[mrbagyo]

early start... and models are showing a twin... 2013 definitely looks exciting...
what's the current status of the MJO???

[xtyphooncyclonex]

Another disturbance west-southwest of Chuuk.

[P.K.]

There has been no tropical storm in the Northwestern Pacific in January since 2005!

Earliest forming tropical storm since Alice in 1979 as well. You mentioned Soulik from 2000 previously but that actually formed in December and crossed over into Jan as did Norris in 1986.

[euro6208]

Tropical storm Sonamu with 35 knots winds but little strengthening is forecast before weakening...

1. TROPICAL STORM 01W (SONAMU) WARNING NR 003
UPGRADED FROM TROPICAL DEPRESSION 01W
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
040000Z --- NEAR 8.5N 116.5E
MOVEMENT PAST SIX HOURS - 270 DEGREES AT 13 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
REPEAT POSIT: 8.5N 116.5E


REMARKS:
040300Z POSITION NEAR 8.4N 115.9E.
TROPICAL STORM 01W (SONAMU), LOCATED APPROXIMATELY 595 NM EAST-
SOUTHEAST OF HO CHI MINH CITY, VIETNAM, HAS TRACKED WESTWARD AT 13
KNOTS OVER THE PAST SIX HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
040000Z IS 11 FEET. NEXT WARNINGS AT 040900Z, 041500Z, 042100Z AND
050300Z.//
NNNN

[supercane4867]

Up to 40kt

TS 1301 (SONAMU)
Issued at 06:45 UTC, 4 January 2013
<Analyses at 04/06 UTC>
Scale -
Intensity -
Center position N8°25'(8.4°)
E115°25'(115.4°)
Direction and speed of movement W 15km/h(8kt)
Central pressure 998hPa
Maximum wind speed near the center 20m/s(40kt)
Maximum wind gust speed 30m/s(60kt)
Area of 30kt winds or more ALL170km(90NM)

[euro6208]

JMA now holds this as a Tropical Storm. I think its appropriate, given the on the ground wind reports we have been seeing across the Philippines. I try to use those before Dvorak if a storm is over land. Would only make sense. Looks like JMA saw some winds over 35kts in Palawan.

http://www.jma.go.jp/en/typh/1301.html

What a historical moment right now, and you only post a few sentence? There has been no tropical storm in the Northwestern Pacific in January since 2005! And the link will not work when Sonamu dissipated.

what's so historical about this? this isn't the atlantic/epac/cpac...january storms happen every other year...

[euro6208]

Tropical Storm Sonamu maintaning low end TS strength...

WDPN31 PGTW 041500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 01W (SONAMU) WARNING NR
05//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 01W (SONAMU), LOCATED APPROXIMATELY 430 NM
EAST-SOUTHEAST OF HO CHI MINH CITY, VIETNAM, HAS TRACKED WESTWARD AT
14 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED (IR) SATELLITE
IMAGERY SHOWS CENTRAL CONVECTION PERSISTING OVER THE LOW LEVEL
CIRCULATION CENTER AND SOME FRAGMENTED FORMATIVE BANDING OVER THE
NORTHERN SEMI-CIRCLE. THE INITIAL POSITION IS BASED UPON THE IR LOOP
AND IS EXTRAPOLATED FROM A 041011Z SSMIS 37 GHZ MICROWAVE IMAGE WITH
FAIR CONFIDENCE. THE INITIAL INTENSITY IS BASED UPON CONGRUENT
DVORAK INTENSITY ESTIMATES OF 35 KNOTS FROM PGTW, KNES AND RJTD.
UPPER-LEVEL ANALYSIS REVEALS TS 01W IS WITHIN A MARGINAL UPPER-LEVEL
ENVIRONMENT WITH MODERATE TO STRONG (20 TO 30 KNOTS) EASTERLY
VERTICAL WIND SHEAR (VWS) OFFSET BY STRONG DIFFLUENCE AND GOOD
POLEWARD OUTFLOW INTO THE UPPER-LEVEL WESTERLIES. TS 01W IS
CURRENTLY TRACKING WESTWARD UNDER THE DEEP-LAYERED SUBTROPICAL RIDGE
(STR) THAT IS ENTRENCHED OVER THE WESTERN PACIFIC AND SOUTH CHINA
SEA.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TS 01W WILL CONTINUE TO TRACK WESTWARD THROUGH TAU 48 UNDER
THE STEERING INFLUENCE OF THE STR POSITIONED OVER THE NORTHERN SOUTH
CHINA SEA. TS 01W IS FORECAST TO INTENSIFY TO A PEAK OF 45 KNOTS BY
TAU 24 AND THEN WEAKEN AS HIGHER VWS IS ENCOUNTERED DUE TO A
FORECAST NORTHEAST SURGE. DYNAMIC MODEL GUIDANCE IS IN GOOD
AGREEMENT WITH SOLUTIONS VARYING FROM A WESTWARD TRACK TO A WEST-
SOUTHWESTWARD TRACK WITH THE DIFFERENCES DUE TO THE INTERACTION WITH
THE NORTHEAST SURGE FLOW AND THE INTENSITIES AS THE SYSTEM CROSSES
THE SOUTH CHINA SEA. THE JTWC FORECAST IS POSITIONED CLOSE TO THE
MODEL CONSENSUS, FAVORING THE ECMWF AND GFS SOLUTIONS. DUE TO THE
GOOD AGREEMENT AMONG THE MODEL SOLUTIONS, THERE IS HIGH CONFIDENCE
IN THIS PORTION OF THE FORECAST.
C. IN THE EXTENDED TAUS, TS 01W WILL TURN SOUTHWESTWARD UNDER THE
STEERING INFLUENCE OF A NEAR-EQUATORIAL RIDGE (NER), FORECAST TO
BUILD IN OVER INDONESIA. TS 01W WILL CONTINUE TO WEAKEN UNDER THE
UNFAVORABLE UPPER-LEVEL ENVIRONMENT AND DISSIPATE BY TAU 96 AS THE
SYSTEM APPROACHES THE COAST OF MALAYSIA. DYNAMIC MODEL GUIDANCE
DIVERGES IN THE EXTENDED TAUS WITH NOGAPS, AND GFDN TAKING A FASTER
AND STRAIGHT TRACK, WHILE GFS, ECMWF, AND JGSM TAKE A SLOWER TRACK
WITH A SOUTHWESTERN TURN. THE JTWC FAVORS THE LATTER SOLUTIONS BASED
UPON THE EXPECTED WEAKENING AND THE STEERING INFLUENCE FROM THE NER
AND THE NORTHEAST FLOW. DUE TO UNCERTAINTIES IN THE DIFFERENCES IN
THE MODEL TRACK SOLUTIONS, THERE IS LOW CONFIDENCE IN THE EXTENDED
PORTION OF THE JTWC FORECAST TRACK.//
NNNN

[euro6208]

early start... and models are showing a twin... 2013 definitely looks exciting...
what's the current status of the MJO???

a strong mjo strengthening over the maritime continent and moving to our area...

[Meow]

what's so historical about this? this isn't the atlantic/epac/cpac...january storms happen every other year...

Also the earliest formation in the Northwestern Pacific Ocean since 1979. It is the first January tropical storm since 2005, this could prove:

http://agora.ex.nii.ac.jp/cgi-bin/dt/se ... p&mtype=se

Please be aware that the current RSMC is established by the JMA.

[euro6208]

what's so historical about this? this isn't the atlantic/epac/cpac...january storms happen every other year...

Also the earliest formation in the Northwestern Pacific Ocean since 1979. It is the first January tropical storm since 2005, this could prove:

http://agora.ex.nii.ac.jp/cgi-bin/dt/se ... p&mtype=se

Please be aware that the current RSMC is established by the JMA.

using 1 min for winds, sonamu is the third tropical storm in january since 2000...there are countless of other storms forming in this month but for earliest, i have yet to check...

[Meow]

using 1 min for winds, sonamu is the third tropical storm in january since 2000...there are countless of other storms forming in this month but for earliest, i have yet to check...

Only the JTWC in this basin using 1-min sustained winds.

Anyway, the JMA reported that Somanu has intensified a little.



TS 1301 (SONAMU)
Issued at 18:45 UTC, 4 January 2013

<Analyses at 04/18 UTC>
Scale -
Intensity -
Center position N8°10'(8.2°)
E113°25'(113.4°)
Direction and speed of movement W 20km/h(10kt)
Central pressure 992hPa
Maximum wind speed near the center 23m/s(45kt)
Maximum wind gust speed 35m/s(65kt)
Area of 30kt winds or more NW220km(120NM)
SE170km(90NM)

<Forecast for 05/06 UTC>
Intensity -
Center position of probability circle N8°05'(8.1°)
E111°25'(111.4°)
Direction and speed of movement W 20km/h(10kt)
Central pressure 992hPa
Maximum wind speed near the center 23m/s(45kt)
Maximum wind gust speed 35m/s(65kt)
Radius of probability circle 90km(50NM)

<Forecast for 05/18 UTC>
Intensity -
Center position of probability circle N7°50'(7.8°)
E109°50'(109.8°)
Direction and speed of movement W 15km/h(8kt)
Central pressure 992hPa
Maximum wind speed near the center 23m/s(45kt)
Maximum wind gust speed 35m/s(65kt)
Radius of probability circle 130km(70NM)

<Forecast for 06/18 UTC>
Intensity -
Center position of probability circle N7°10'(7.2°)
E108°05'(108.1°)
Direction and speed of movement WSW Slowly
Central pressure 1000hPa
Maximum wind speed near the center 18m/s(35kt)
Maximum wind gust speed 25m/s(50kt)
Radius of probability circle 300km(160NM)

<Forecast for 07/18 UTC>
Intensity -
TD
Center position of probability circle N6°25'(6.4°)
E107°00'(107.0°)
Direction and speed of movement SW Slowly
Central pressure 1004hPa
Radius of probability circle 410km(220NM)