Eñ jTWC lanza alerta de formación tropical. Los modelos no le dan mucho margen, aunque debería moverse en dirección N-NW camino de Filipinas, o desviarse sin desarrollarse en dirección N

WTPN31 PGTW 081500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL DEPRESSION 21W (TWENTYONE) WARNING NR 001   
   03 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   081200Z --- NEAR 16.7N 143.0E
     MOVEMENT PAST SIX HOURS - 355 DEGREES AT 08 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: 16.7N 143.0E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   090000Z --- 18.4N 142.6E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 24 HR POSIT: 345 DEG/ 10 KTS
    ---
   24 HRS, VALID AT:
   091200Z --- 20.4N 142.1E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 36 HR POSIT: 355 DEG/ 10 KTS
    ---
   36 HRS, VALID AT:
   100000Z --- 22.3N 142.0E
   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
                            035 NM SOUTHWEST QUADRANT
                            035 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 005 DEG/ 11 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   101200Z --- 24.4N 142.3E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 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: 025 DEG/ 12 KTS
    ---
   72 HRS, VALID AT:
   111200Z --- 28.9N 144.5E
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 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 - 100 NM NORTHEAST QUADRANT
                            100 NM SOUTHEAST QUADRANT
                            095 NM SOUTHWEST QUADRANT
                            095 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 030 DEG/ 13 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:
   121200Z --- 33.4N 147.8E
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING EXTRATROPICAL
   VECTOR TO 120 HR POSIT: 040 DEG/ 21 KTS
    ---
   120 HRS, VALID AT:
   131200Z --- 39.9N 154.7E
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   EXTRATROPICAL
    ---
REMARKS:
081500Z POSITION NEAR 17.1N 142.9E.
TROPICAL DEPRESSION (TD) 21W (TWENTYONE), LOCATED APPROXIMATELY 235
NM NORTH-NORTHWEST OF GUAM, HAS TRACKED NORTHWARD AT 08 KNOTS OVER
THE PAST SIX HOURS. THIS WARNING SUPERSEDES AND CANCELS REF A,
NAVMARFCSTCEN 080221Z OCT 09 TROPICAL CYCLONE FORMATION ALERT
(WTPN21 PGTW 080230) MAXIMUM SIGNIFICANT WAVE HEIGHT AT 081200Z
IS 9 FEET. NEXT WARNINGS AT 082100Z, 090300Z, 090900Z AND 091500Z.
REFER TO TROPICAL DEPRESSION 19W (PARMA) WARNINGS (WTPN33 PGTW) FOR
SIX-HOURLY UPDATES. REFER TO TROPICAL STORM 20W (MELOR) WARNINGS
(WTPN34 PGTW) FOR SIX-HOURLY UPDATES.//
NNNN

JTWC reporto nr.1

25kts-1004mb

Como decía por la mañana, si va en dirección N, no tiene mucho margen. El JTWC parece que se salió de madre en el parte de la tarde, porque en el de esta noche, tiene más coherencia





De todas maneras, sube de fuerza a 30kt

No debería de tardar en adquirir denominación de Tormenta Tropical. Dvorak ya otorga vientos de dicha categoría, y empieza a aglutinar bastante convección tapando el LLCC

El JMA actualiza datos, nace NEPARTAK. Y le da bastante chance

TS 0919 (Nepartak)
Issued at 07:20 UTC, 9 October 2009
<Analyses at 09/06 UTC>
Scale -
Intensity -
Center position N19°25'(19.4°)
E142°40'(142.7°)
Direction and speed of movement NNW 15km/h(9kt)
Central pressure 1000hPa
Maximum wind speed near the center 18m/s(35kt)
Maximum wind gust speed 25m/s(50kt)
Area of 30kt winds or more Wide 150km(80NM)

<Forecast for 10/06 UTC>
Intensity -
Center position of probability circle N21°10'(21.2°)
E141°55'(141.9°)
Direction and speed of movement NNW Slowly
Central pressure 998hPa
Maximum wind speed near the center 18m/s(35kt)
Maximum wind gust speed 25m/s(50kt)
Radius of probability circle 130km(70NM)

<Forecast for 11/06 UTC>
Intensity -
Center position of probability circle N21°55'(21.9°)
E141°35'(141.6°)
Direction and speed of movement STR 
Central pressure 992hPa
Maximum wind speed near the center 23m/s(45kt)
Maximum wind gust speed 35m/s(65kt)
Radius of probability circle 200km(110NM)

<Forecast for 12/06 UTC>
Intensity -
Center position of probability circle N22°00'(22.0°)
E141°05'(141.1°)
Direction and speed of movement STR 
Central pressure 985hPa
Maximum wind speed near the center 25m/s(50kt)
Maximum wind gust speed 35m/s(70kt)
Radius of probability circle 300km(160NM)

http://www.jma.go.jp/en/typh/0919.html

Recordar que las mediciones japonesas, son diezminutales... Es decir, que en Saffir-Simpson estaríamos hablando de un Tormenta Tropical intensa, y porque no, de un Tifón Cat. 1...

Sin embargo, el JTWC mantiene datos sensiblemente inferiores

WARNING POSITION:
   090600Z --- NEAR 19.6N 142.6E
     MOVEMENT PAST SIX HOURS - 345 DEGREES AT 08 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: 19.6N 142.6E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   091800Z --- 20.7N 142.1E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 24 HR POSIT: 350 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   100600Z --- 21.7N 141.9E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 36 HR POSIT: 005 DEG/ 05 KTS
    ---
   36 HRS, VALID AT:
   101800Z --- 22.7N 142.0E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 48 HR POSIT: 030 DEG/ 10 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   110600Z --- 24.5N 143.1E
   MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
   VECTOR TO 72 HR POSIT: 035 DEG/ 12 KTS
    ---
   72 HRS, VALID AT:
   120600Z --- 28.6N 146.3E
   MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER

Ya existe aún más discrepancia entre los pronósticos emitidos por varias agencias. A las 6 UTC hoy, JTWC lo tiene 45kts en 72 horas, JMA lo intensifica hasta una tormenta tropical severa...

SIN EMBARGO, Nuestra AGENCIA METEOROLÓGICA DE CHINA (CMA) pronostica que lo denegere y se convirtiera en una DEPRESION tropical en 72 horas....

El pronóstico chino

SUBJECTIVE FORECAST   
TS NEPARTAK 0919 (0919) INITIAL TIME 100600 UTC   
00HR 21.3N 142.6E 998HPA 18M/S   
30KTS 100KM 
P12HR NNW 10KM/H
P+24HR 22.0N 142.3E 998HPA 18M/S
P+48HR 23.0N 142.2E 998HPA 18M/S 
P+72HR 24.4N 142.6E 1000HPA 16M/S

 

El "fish" NEPARTAK se mantiene por debajo del status de Typhoon... con 50Kt y 985mb, aunque ha llegado a consolidar los 55Kt de viento sostenido...

- ATCF:

WP, 21, 2009101200,   , BEST,   0, 237N, 1445E,  55,  982, TS
WP, 21, 2009101206,   , BEST,   0, 247N, 1454E,  50,  985, TS

- "Fish" porque no afectará a tierra... y con poca vida por delante al encontrar aire seco que erosiona la convección por los cuadrantes 2º y 3º, mientras que por el Norte los vientos de Oeste y la zona Baroclina hacen su trabajo de extratropicalización.

ANIMATED MULTISPECTRAL IMAGERY IS STARTING TO SHOW SOME DRY AIR ENTRAINMENT AND THE EROSION OF DEEP CONVECTION IN THE SOUTHERN SEMI-CIRCLE. DESPITE THE SIGNS OF A WEAK- ENING CONVECTIVE STRUCTURE, A 120333Z AMSRE MICROWAVE IMAGE DEPICTS THE CONTINUED PRESENCE OF A MICROWAVE EYE AND DVORAK ESTIMATES FROM KNES, PGTW AND RJTD ARE STILL IN THE T3.O TO T3.5 RANGE.
THEREFORE, THE CURRENT INTENSITY HAS ONLY DROPPED BY 05 KNOTS, TO 50 KNOTS, OVER THE LAST SIX HOURS. ADDITIONALLY, THE AMSRE IMAGE ALSO REVEALS
THAT THE BULK OF DEEP CONVECTION HAS STARTED TO SHIFT TO THE NORTH-
EAST OF THE LOW LEVEL CIRCULATION CENTER (LLCC), INDICATING THAT THE
NORTHERN PORTION OF THE SYSTEM MAY FINALLY BE STARTING TO ENCOUNTER
THE UNFAVORABLE VERTICAL WIND SHEAR ASSOCIATED WITH THE BAROCLINIC
ZONE AND STRONG MID-LATITUDE WESTERLIES.

otro ..aparte de melor ...cuyos restos llegaran a estados unidos