WPAC: NESAT - Tropical Storm (20W)

[Typhoon Hunter]

Keeping a side eye on this whilst in Japan shooting volcano. Nice typhoon in HK to wash away the ash from my hair would be good

[dexterlabio]

TPPN11 PGTW 231208

A. TROPICAL DISTURBANCE 98W (SW OF GUAM)

B. 23/1132Z

C. 13.6N

D. 138.0E

E. FIVE/MTSAT

F. T2.0/2.0/D1.0/24HRS STT: D0.5/06HRS

G. IR/EIR

H. REMARKS: 38A/PBO SBC/ANMTN. CONVECTIVE WRAP OF .35 ON LOG 10
SPIRAL YIELDS A 2.0 DT. MET AND PT AGREE. DBO DT.

I. ADDITIONAL POSITIONS:
23/0851Z 13.4N 138.6E SSMS


BELMONDO


1st bulletin from JTWC highly certain.

[StormingB81]

Off the NRL site my Guess is it is being upgraded to a depression

[Extratropical94]

Now showing 20W.TWENTY

[dexterlabio]

First warning from JTWC, guys...

WTPN31 PGTW 231500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL DEPRESSION 20W (TWENTY) 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:
231200Z --- NEAR 13.6N 138.0E
MOVEMENT PAST SIX HOURS - 305 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: 13.6N 138.0E
---
FORECASTS:
12 HRS, VALID AT:
240000Z --- 14.3N 136.6E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 285 DEG/ 09 KTS
---
24 HRS, VALID AT:
241200Z --- 14.8N 134.9E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 280 DEG/ 10 KTS
---
36 HRS, VALID AT:
250000Z --- 15.1N 132.9E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 095 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
090 NM SOUTHWEST QUADRANT
095 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 275 DEG/ 10 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
251200Z --- 15.2N 130.8E
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT
100 NM SOUTHEAST QUADRANT
105 NM SOUTHWEST QUADRANT
115 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 275 DEG/ 09 KTS
---
72 HRS, VALID AT:
261200Z --- 15.6N 127.2E
MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 125 NM NORTHEAST QUADRANT
115 NM SOUTHEAST QUADRANT
115 NM SOUTHWEST QUADRANT
125 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 290 DEG/ 08 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
271200Z --- 16.7N 123.9E
MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 300 DEG/ 08 KTS
---
120 HRS, VALID AT:
281200Z --- 18.3N 120.8E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
231500Z POSITION NEAR 13.8N 137.7E.
TROPICAL DEPRESSION 20W (TWENTY) LOCATED APPROXIMATELY 990 NM EAST
OF MANILA, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD AT 08 KNOTS
OVER THE PAST SIX HOURS. THIS WARNING SUPERSEDES AND CANCELS REF A,
NAVMARFCSTCEN 222000Z SEP 11 TROPICAL CYCLONE FORMATION ALERT
(WTPN21 PGTW 222000) MAXIMUM SIGNIFICANT WAVE HEIGHT AT 231200Z IS
10 FEET. NEXT WARNINGS AT 232100Z, 240300Z, 240900Z AND 241500Z.//
NNNN

[StormingB81]

JMA:

TD
Issued at 13:10 UTC, 23 September 2011
<Analyses at 23/12 UTC>
Scale -
Intensity -
TD
Center position N13°35'(13.6°)
E138°20'(138.3°)
Direction and speed of movement WNW 10km/h(6kt)
Central pressure 1004hPa
Maximum wind speed near the center 15m/s(30kt)
Maximum wind gust speed 23m/s(45kt)

<Forecast for 24/12 UTC>
Intensity -
Center position of probability circle N14°10'(14.2°)
E136°10'(136.2°)
Direction and speed of movement WNW 10km/h(6kt)
Central pressure 1000hPa
Maximum wind speed near the center 18m/s(35kt)
Maximum wind gust speed 25m/s(50kt)
Radius of probability circle 220km(120NM)

[RobWESTPACWX]

Warning #1 from JTWC

[Extratropical94]

Consolidating pretty quickly now, intense convection with cold cloud tops and spiral banding forming.

IR:

[Extratropical94]

23/1432 UTC 13.7N 137.5E T2.5/2.5 20W -- West Pacific

Supporting TS strength

[RobWESTPACWX]

Situations looking more and more Grim for the PI on this one, already seeing the rapid intensification with it and overall guidance looks like it is will track towards Luzon.

[RobWESTPACWX]

Very little change in the most recent track from JTWC outside of the expected upgrade to TS.

[RobWESTPACWX]

WEATHER ADVISORY
Weather Advisory No. 1
For: Tropical Depression
*FROM PAGASA*

Issued at 5:00 p.m., 23 September 2011
At 2 p.m. today, the Tropical Depression located North of the Caroline Islands was estimated at 1,310 km East of Visayas (13.0°N 138.9°E) with maximum sustained winds of 55 kph. It is forecast to move North Northwest slowly.

This Tropical Depression is expected to enter the Philippine Area of Responsibility (PAR) within the next 24 - 48 hours.

The next update will be incorporated in the 5 a.m. public weather forecast tomorrow.

The next advisory will be issued at 11 a.m. tomorrow.

[Extratropical94]

Very little change in the most recent track from JTWC outside of the expected upgrade to TS.

But a HUGE change in intensity. Max speeds were supposed to be 90 knots gusting to 110, now 130 gusting to 160.

[RobWESTPACWX]

Good point, I overlooked that ET. Did read the prog reasoning though, they stated it was above the model output but due to the rapid increase in intensity and also the very favorable conditions.

In other words it seems likely.

[RobWESTPACWX]

First vis images coming in this morning.

[ManilaTC]

JMA is taking some time to release its 8am 00z warning, probably they're gonna name it.
really looking good.

Just hoping it doesnt make its West turn early or we are toast.

Also, The days of September 25-30 have been historically devastating for Luzon.

Xangsane/Bebinca of '05 hit September 28
Ketsana/Ondoy of '09 hit September 29

[dexterlabio]

Eerie prognostics from JTWC. Now it's confirmed to me that this system is a large one.

REMARKS:
232100Z POSITION NEAR 14.1N 136.7E.
TROPICAL STORM (TS) 20W, LOCATED APPROXIMATELY 270 NM NORTH OF YAP,
MICRONESIA, HAS TRACKED WEST-NORTHWESTWARD AT 08 KNOTS OVER THE PAST
SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS SIGNIFICANT
DEVELOPMENT AND CONSOLIDATION AROUND THE LOW LEVEL CIRCULATION
CENTER. CONVECTION IS DEEPENING AND NOW EXTENDS OVER ALL QUADRANTS.
A 231821Z TRMM IMAGE SHOWS CURVED CONVECTIVE BANDING IN ALL
QUADRANTS AND INDICATES THAT TS 20W IS AN EXPANSIVE SYSTEM. THE
LARGE SIZE OF TS 20W DOES NOT APPEAR TO BE SLOWING DEVELOPMENT. THAT
MAY BE DUE TO EXCELLENT RADIAL OUTFLOW AROUND THE SYSTEM, AS
REVEALED ON ANIMATED WATER VAPOR IMAGERY. THE SYNOPTIC PATTERN
DICTATES THAT TS 20W WILL BE A STRAIGHT RUNNER. THE 231200Z PGTW
UPPER LEVEL STREAMLINE ANALYSIS DEPICTS A DEVELOPING ANTICYCLONE
BETWEEN TAIWAN AND LUZON, WHICH IS BUILDING INTO THE PHILIPPINE SEA
IN THE WAKE OF A LONG WAVE TROUGH THAT IS NOW CLEARING THE AREA. THE
TROUGH WAS CREATING A WEAKNESS IN THE SUBTROPICAL RIDGE BETWEEN THE
130TH AND 135TH MERIDIANS, BUT AS THE ANTICYCLONE SURGES INTO THE
PHILIPPINE SEA, THAT WEAKNESS WILL FILL AND THE STORM WILL BE
PREVENTED FROM ANY SIGNIFICANT POLEWARD MOVEMENT. A FRAGMENTED
TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) EXTENDS ALONG THE 20TH
LATITUDE. VENTING INTO THE TUTT WILL PROVIDE INTERMITTENT
ENHANCEMENT TO OUTFLOW AS TS 20W STEERS A STEADY WEST-NORTHWESTERLY
COURSE. AVAILABLE MODEL GUIDANCE IS IN GOOD AGREEMENT REGARDING
TRACK AND SPEED AND THE JTWC TRACK FORECAST STAYS VERY CLOSE TO
CONSENSUS. THE FORECAST IS WELL ABOVE INTENSITY GUIDANCE DUE TO THE
OBSERVED DEVELOPMENT OF TS 20W THUS FAR, THE RADIAL OUTFLOW OBSERVED
ON WATER VAPOR ANIMATION, THE WARM ALONG TRACK SEA SURFACE
TEMPERATURES, AND THE HISTORICALLY FERTILE GROUNDS OF THE PHILIPPINE
SEA. THE CURRENT INTENSITY IS BASED ON PGTW AND KNES DVORAK
ESTIMATES OF 35 KNOTS. THE INTENSITY FORECAST IS BASED ON A SIMPLE
CLIMATOLOGICAL RATE OF DEVELOPMENT FOR A SYSTEM OF THIS TYPE, TRACK,
REGION, AND SEASON.MAXIMUM SIGNIFICANT WAVE HEIGHT AT 231800Z IS 11
FEET. NEXT WARNINGS AT 240300Z, 240900Z, 241500Z AND 242100Z.//
NNNN

[windysocks]

It's been a quiet summer in Hong Kong for typhoons - I wonder if this one will come and change all that?

[euro6208]

WTPN31 PGTW 232100
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL STORM 20W (TWENTY) WARNING NR 002
UPGRADED FROM TROPICAL DEPRESSION 20W
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
231800Z --- NEAR 13.9N 137.2E
MOVEMENT PAST SIX HOURS - 290 DEGREES AT 08 KTS
POSITION ACCURATE TO WITHIN 060 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: 13.9N 137.2E
---
FORECASTS:
12 HRS, VALID AT:
240600Z --- 14.7N 135.4E
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 24 HR POSIT: 290 DEG/ 11 KTS
---
24 HRS, VALID AT:
241800Z --- 15.4N 133.2E
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 - 075 NM NORTHEAST QUADRANT
075 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
075 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 275 DEG/ 11 KTS
---
36 HRS, VALID AT:
250600Z --- 15.6N 131.0E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT
100 NM SOUTHEAST QUADRANT
100 NM SOUTHWEST QUADRANT
120 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 275 DEG/ 11 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
251800Z --- 15.7N 128.8E
MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT
120 NM SOUTHEAST QUADRANT
120 NM SOUTHWEST QUADRANT
150 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 280 DEG/ 08 KTS
---
72 HRS, VALID AT:
261800Z --- 16.1N 125.7E
MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT
120 NM SOUTHEAST QUADRANT
120 NM SOUTHWEST QUADRANT
150 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 290 DEG/ 07 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
271800Z --- 17.0N 123.1E
MAX SUSTAINED WINDS - 130 KT, GUSTS 160 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 310 DEG/ 08 KTS
---
120 HRS, VALID AT:
281800Z --- 18.9N 120.6E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
232100Z POSITION NEAR 14.1N 136.7E.
TROPICAL STORM (TS) 20W, LOCATED APPROXIMATELY 270 NM NORTH OF YAP,
MICRONESIA, HAS TRACKED WEST-NORTHWESTWARD AT 08 KNOTS OVER THE PAST
SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS SIGNIFICANT
DEVELOPMENT AND CONSOLIDATION AROUND THE LOW LEVEL CIRCULATION
CENTER. CONVECTION IS DEEPENING AND NOW EXTENDS OVER ALL QUADRANTS.
A 231821Z TRMM IMAGE SHOWS CURVED CONVECTIVE BANDING IN ALL
QUADRANTS AND INDICATES THAT TS 20W IS AN EXPANSIVE SYSTEM. THE
LARGE SIZE OF TS 20W DOES NOT APPEAR TO BE SLOWING DEVELOPMENT. THAT
MAY BE DUE TO EXCELLENT RADIAL OUTFLOW AROUND THE SYSTEM, AS
REVEALED ON ANIMATED WATER VAPOR IMAGERY. THE SYNOPTIC PATTERN
DICTATES THAT TS 20W WILL BE A STRAIGHT RUNNER. THE 231200Z PGTW
UPPER LEVEL STREAMLINE ANALYSIS DEPICTS A DEVELOPING ANTICYCLONE
BETWEEN TAIWAN AND LUZON, WHICH IS BUILDING INTO THE PHILIPPINE SEA
IN THE WAKE OF A LONG WAVE TROUGH THAT IS NOW CLEARING THE AREA. THE
TROUGH WAS CREATING A WEAKNESS IN THE SUBTROPICAL RIDGE BETWEEN THE
130TH AND 135TH MERIDIANS, BUT AS THE ANTICYCLONE SURGES INTO THE
PHILIPPINE SEA, THAT WEAKNESS WILL FILL AND THE STORM WILL BE
PREVENTED FROM ANY SIGNIFICANT POLEWARD MOVEMENT. A FRAGMENTED
TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) EXTENDS ALONG THE 20TH
LATITUDE. VENTING INTO THE TUTT WILL PROVIDE INTERMITTENT
ENHANCEMENT TO OUTFLOW AS TS 20W STEERS A STEADY WEST-NORTHWESTERLY
COURSE. AVAILABLE MODEL GUIDANCE IS IN GOOD AGREEMENT REGARDING
TRACK AND SPEED AND THE JTWC TRACK FORECAST STAYS VERY CLOSE TO
CONSENSUS. THE FORECAST IS WELL ABOVE INTENSITY GUIDANCE DUE TO THE
OBSERVED DEVELOPMENT OF TS 20W THUS FAR, THE RADIAL OUTFLOW OBSERVED
ON WATER VAPOR ANIMATION, THE WARM ALONG TRACK SEA SURFACE
TEMPERATURES, AND THE HISTORICALLY FERTILE GROUNDS OF THE PHILIPPINE
SEA. THE CURRENT INTENSITY IS BASED ON PGTW AND KNES DVORAK
ESTIMATES OF 35 KNOTS. THE INTENSITY FORECAST IS BASED ON A SIMPLE
CLIMATOLOGICAL RATE OF DEVELOPMENT FOR A SYSTEM OF THIS TYPE, TRACK,
REGION, AND SEASON.MAXIMUM SIGNIFICANT WAVE HEIGHT AT 231800Z IS 11
FEET. NEXT WARNINGS AT 240300Z, 240900Z, 241500Z AND 242100Z.//
NNNN

130 knots sustained Landfall!!

[cycloneye]

JMA is taking some time to release its 8am 00z warning, probably they're gonna name it.
really looking good.

Just hoping it doesnt make its West turn early or we are toast.

Also, The days of September 25-30 have been historically devastating for Luzon.

Xangsane/Bebinca of '05 hit September 28
Ketsana/Ondoy of '09 hit September 29

And they did name it NESAT.

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

TS 1117 (NESAT)
Issued at 01:10 UTC, 24 September 2011
<Analyses at 24/00 UTC>
Scale -
Intensity -
Center position N14°00'(14.0°)
E136°25'(136.4°)
Direction and speed of movement WNW 15km/h(8kt)
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 ALL130km(70NM