WPAC : TROPICAL STORM CHOI-WAN (15W)

[dowdavek]

Keeping an eye on this on Guam. Anyone have any ideas?

[Typhoon Hunter]

It's looking pretty good today. ECMWF develops this and takes it over Guam as a tropical storm and then it intensifies into a strong typhoon further to the north. Certainly something to keep a close eye on if you're in Guam.

[dowdavek]

Thanks for your reply. Yes, it is certainly something we're watching here in Guam. Nothing in the local news yet but I'm sure they will step up their game once NWS or JTWC comments on it.

[HURAKAN]

ABPW10 PGTW 111430
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND
/SOUTH PACIFIC OCEANS REISSUED/111430Z-120600ZSEP2009//
REF/A/MSG/NAVMARFCSTCEN PEARL HARBOR HI/111352ZSEP2009//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.//
RMKS/
1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA):
A. TROPICAL CYCLONE SUMMARY:
(1) AT 111200Z, TROPICAL DEPRESSION 14W (MUJIGAE) WAS LOCATED
NEAR 19.7N 107.3E, APPROXIMATELY 115 NM SOUTHEAST OF HANOI VIETNAM,
AND HAD TRACKED WESTWARD AT 08 KNOTS OVER THE PAST SIX HOURS.
MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 30 KNOTS GUSTING
TO 40 KNOTS. SEE REF A (WTPN32 PGTW 111500) FOR FURTHER DETAILS.
(2) NO OTHER TROPICAL CYCLONES.
B. TROPICAL DISTURBANCE SUMMARY:
(1) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 12.6N
128.9E, IS NOW LOCATED NEAR 13.4N 127.4E, APPROXIMATELY 380 NM EAST
OF MANILA, PHILIPPINES. ANIMATED INFRARED IMAGERY DEPICTS CONTINUED
DEVELOPMENT OF THE LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP
CONVECTION PERSISTING NEAR THE LLCC. A 110914Z QUIKSCAT PASS
REVEALED THAT THE LLCC WAS SOMEWHAT ELONGATED FROM EAST TO WEST, AND
HAD UNFLAGGED WINDS NEAR THE CENTER AT 10 TO 15 KNOTS WITH A FEW 15
TO 20 KNOTS ON THE EASTERN SIDE. UPPER LEVEL ANALYSIS SHOWS A
DECREASE IN VERTICAL WIND SHEAR OVER THE PAST 12 HOURS WITH UPPER
LEVEL EASTERLY FLOW PROVIDING THE ONLY OUTFLOW FOR THE LLCC.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS REMAINS FAIR.
(2) AN AREA OF CONVECTION HAS PERSISTED NEAR 13.3N 155.2E,
APPROXIMATELY 600 NM EAST OF GUAM. ANIMATED INFRARED IMAGERY DEPICTS
A CONSOLIDATING LLCC, WITH CONVECTION BEGINNING TO DEVELOP AND WRAP
TOWARD THE CENTER. AN 110733Z QUIKSCAT PASS SHOWS A BROAD REGION OF
TURNING WITH AND ELONGATED LLCC. UPPER LEVEL ANALYSIS INDICATES THE
LLCC IS LOCATED UNDER AN UPPER LEVEL ANTICYCLONE AXIS, HELPING TO
ENHANCE OUTFLOW, AND CREATE A LOW VERTICAL WIND SHEAR ENVIRONMENT.
THE AREA HAS QUICKLY ORGANIZED OVER THE PAST 12 HOURS, AND IS IN A
FAVORABLE ENVIRONMENT FOR FURTHER DEVELOPMENT. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS FAIR.
(3) NO OTHER SUSPECT AREAS.
2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: ADDED AREA IN PARA 1.B.(2) AS A FAIR.
FORECAST TEAM: BRAVO//
NNNN

[HURAKAN]

Looking good

[HURAKAN]

Continues to organize

[HURAKAN]

WTPN21 PGTW 112230
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
150 NM EITHER SIDE OF A LINE FROM 13.5N 154.5E TO 15.3N 149.5E
WITHIN THE NEXT 03 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 17 TO 22 KNOTS. METSAT IM-
AGERY AT 112130Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 13.4N 154.4E. THE SYSTEM IS MOVING WESTWARD AT 06 KNOTS.
2. REMARKS:
A COMBINATION OF RECENT ANIMATED INFRARED AND MULTISPECTRAL IMAGERY
INDICATES THAT DEEP CONVECTION IS RAPIDLY CONSOLIDATING ABOUT A
DEVELOPING LOW LEVEL CIRCULATION CENTER (LLCC) EMBEDDED WITHIN THE
EASTERN END OF THE MONSOON TROUGH. THE DEVELOPING LLCC IS EVIDENT IN
THE 110914Z QUIKSCAT PASS, THE 111128Z ASCAT PASS, AND VARIOUS
MICROWAVE IMAGES. THE RAPID CONSOLIDATION OF CONVECTION IS BEING
ENHANCED BY INCREASING POLEWARD OUTFLOW INTO THE TROPICAL UPPER
TROPOSPHERIC TROUGH (TUTT) TO THE NORTH AND EQUATORWARD OUTFLOW AS
THE SYSTEM SITS UNDERNEATH THE AXIS OF THE UPPER-LEVEL NEAR-
EQUATORIAL RIDGE. THE SYSTEM WILL TRACK IN A GENERAL NORTHWESTWARD
DIRECTION UNDER THE STEERING INFLUENCE OF THE SOUTHERN PERIPHERY OF
THE SUBTROPICAL RIDGE. THE CURRENT POSITION IS SUPPORTED BY THE PGTW
112030 FIX AND ANIMATED SATELLITE IMAGERY.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
122230Z.//
NNNN

[HURAKAN]

LOW PRESSURE AREA 1010 HPA NEAR 15N 153E WNW 10 KT.

[HURAKAN]

Looking great

[HURAKAN]

WTPN31 PGTW 120300
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
REF/A/MSG/NAVMARFCSTCEN PEARL HARBOR HI/112221ZSEP09//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. TROPICAL DEPRESSION 15W (FIFTEEN) WARNING NR 001
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
120000Z --- NEAR 14.3N 153.3E
MOVEMENT PAST SIX HOURS - 310 DEGREES AT 11 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: 14.3N 153.3E
---
FORECASTS:
12 HRS, VALID AT:
121200Z --- 14.6N 151.4E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 275 DEG/ 08 KTS
---
24 HRS, VALID AT:
130000Z --- 14.8N 149.7E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 275 DEG/ 06 KTS
---
36 HRS, VALID AT:
131200Z --- 14.9N 148.4E
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 - 080 NM NORTHEAST QUADRANT
075 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 280 DEG/ 07 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
140000Z --- 15.1N 147.0E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 105 NM NORTHEAST QUADRANT
095 NM SOUTHEAST QUADRANT
095 NM SOUTHWEST QUADRANT
105 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 280 DEG/ 06 KTS
---
72 HRS, VALID AT:
150000Z --- 15.5N 144.7E
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
045 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 115 NM NORTHEAST QUADRANT
105 NM SOUTHEAST QUADRANT
110 NM SOUTHWEST QUADRANT
120 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 280 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:
160000Z --- 16.0N 141.6E
MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 280 DEG/ 08 KTS
---
120 HRS, VALID AT:
170000Z --- 16.6N 138.5E
MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
120300Z POSITION NEAR 14.4N 152.8E.
TROPICAL DEPRESSION (TD) 15W (FIFTEEN), LOCATED APPROXIMATELY 410 NM
EAST OF SAIPAN, HAS TRACKED NORTHWESTWARD AT 11 KNOTS OVER THE PAST
SIX HOURS. THIS WARNING SUPERSEDES AND CANCELS REF A (WTPN21 PGTW
112230 ). MAXIMUM SIGNIFICANT WAVE HEIGHT AT 120000Z IS 7 FEET.
NEXT WARNINGS AT 120900Z, 121500Z, 122100Z AND 130300Z. REFER TO
(WTPN32 PGTW 120300) FOR FINAL WARNING ON TROPICAL DEPRESSION 14W
(MUJIGAE).//
NNNN

[HURAKAN]

TROPICAL DEPRESSION 1008 HPA
AT 14.3N 153.5E TRUKS MOVING WEST 13 KNOTS.
POSITION POOR.
MAX WINDS 30 KNOTS NEAR CENTER.

[dowdavek]

Thanks again for your posts. Any idea of the effects we will experience on guam as far as wind? The rain is ok because we are used to getting torrential ammounts this time of year.

[HURAKAN]

000
WWMY80 PGUM 112230
SPSMY

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TIYAN GU
830 AM CHST SAT SEP 12 2009

GUZ001>004-PMZ151>154-130000-
GUAM-ROTA-TINIAN-SAIPAN-MARIANAS COASTAL WATERS-
830 AM CHST SAT SEP 12 2009

...DEVELOPING TROPICAL DISTURBANCE HEADED TOWARD THE MARIANAS...

A TROPICAL DISTURBANCE CURRENTLY LOCATED ABOUT 500 MILES EAST OF THE
MARIANA ISLANDS NEAR 14N153E IS STEADILY DEVELOPING AND MAY INTENSIFY
INTO A TROPICAL DEPRESSION WITHIN THE NEXT 24 TO 36 HOURS. APPARENT
MOVEMENT AT THIS TIME IS AROUND 10 MPH TO THE WEST. MAXIMUM WINDS
NEAR THE CENTER ARE ESTIMATED TO BE 20 TO 25 MPH.

WEATHER FORECAST MODEL GUIDANCE INDICATES THIS SYSTEM WILL CONTINUE
MOVING WEST OVER THE NEXT 2 TO 3 DAYS TOWARD THE CNMI. SINCE THIS IS
NEAR THE PEAK OF THE TROPICAL CYCLONE SEASON IN THE WESTERN PACIFIC
RESIDENTS OF THE MARIANAS ARE ADVISED TO BE WARY OF THIS TROPICAL
DISTURBANCE AND CLOSELY MONITOR ITS DEVELOPMENT OVER THE NEXT COUPLE
OF DAYS. WEAK DISTURBANCES CAN QUICKLY INTENSIFY DURING LATE SUMMER
OR EARLY FALL IN THIS PART OF THE PACIFIC CALLED TYPHOON ALLEY.

IT HAS BEEN SEVERAL YEARS SINCE THE MARIANAS HAVE BEEN THREATENED BY
A TYPHOON. NOW IS A GOOD TIME TO REVIEW YOUR PREPAREDNESS PROCEDURES
AND RESTOCK YOUR TYPHOON EMERGENCY KITS WELL BEFORE A TROPICAL STORM
WATCH OR WARNING IS DECLARED.

THE NATIONAL WEATHER SERVICE WILL UPDATE THIS INFORMATION AS NEEDED
BASED ON FORECAST INFORMATION FROM THE JOINT TYPHOON WARNING CENTER.

$$

MUNDELL

[HURAKAN]

Continous to get better organized

[cycloneye]

This one could be the strongest one in 2009 and become the first super-typhoon at the WPAC.

[HURAKAN]

000
WTPQ31 PGUM 120340
TCPPQ1

BULLETIN
TROPICAL DEPRESSION 15W ADVISORY NUMBER 1
NATIONAL WEATHER SERVICE TIYAN GU WP132009
200 PM CHST SAT SEP 12 2009

...A TYPHOON WATCH IS NOW IN EFFECT FOR TINIAN AND SAIPAN...
...A TROPICAL STORM WATCH IS NOW IN EFFECT FOR GUAM AND ROTA...

A TYPHOON WATCH MEANS TYPHOON CONDITIONS...INCLUDING TYPHOON-FORCE
WINDS OF 74 MPH OR MORE...ARE POSSIBLE WITHIN 48 HOURS.

A TROPICAL STORM WATCH MEANS TROPICAL STORM-FORCE WINDS OF 39 MPH OR
MORE ARE POSSIBLE WITHIN 48 HOURS.

AT 100 PM CHST...0300Z...TROPICAL DEPRESSION 15W WAS CENTERED NEAR
LATITUDE 14.4 DEGREES NORTH AND LONGITUDE 152.8 DEGREES EAST.

THIS IS ABOUT 415 MILES EAST OF TINIAN AND SAIPAN
440 MILES EAST OF ROTA
470 MILES EAST OF GUAM

DEPRESSION 15W IS MOVING WEST AT 13 MPH. IT IS EXPECTED TO CONTINUE
MOVING WEST...AT 5 TO 10 MPH...OVER THE NEXT 24 HOURS.

MAXIMUM SUSTAINED WINDS ARE 30 MPH. THE DEPRESSION IS EXPECTED TO
INTENSIFY...AND BECOME A TROPICAL STORM IN THE NEXT 12 TO 24 HOURS.

REPEATING THE 100 PM CHST POSITION...LATITUDE 14.4 DEGREES NORTH AND
LONGITUDE 152.8 DEGREES EAST...MOVING WEST AT 13 MPH WITH MAXIMUM
SUSTAINED WINDS OF 30 MPH.

AN INTERMEDIATE ADVISORY WILL BE ISSUED BY THE NATIONAL WEATHER
SERVICE AT 5 PM...FOLLOWED BY THE NEXT SCHEDULED ADVISORY AT 8 PM.

$$

MUNDELL

[HurricaneBill]

I think Choi-Wan is the next name.

[Macrocane]

This one could be the strongest one in 2009 and become the first super-typhoon at the WPAC.

I agree with you, I find very interesting tracking the strongest tropical cyclones of this world: the super-typhoons. Hopefully it won't affect land at that strength that wouldn't be nice. Euro depicts a very strong typhoon on the long range, let's see if it verifies.

[StormingB81]

This storm looks good for only just forming wow!

[beaufort12]

Initial forecast track.