SPO: ATU (11F/17P) Tropical Cyclone

[Extratropical94]

JTWC upgraded it to Tropical Storm 17P as seen in the upper left corner box of the post above.

Edit: Damn, this post started a new page

[GCANE]

PV just about on the surface.

[HURAKAN]

looks like an eye-like feature has formed

[cycloneye]

WTPS31 PGTW 182100
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 17P (SEVENTEEN) WARNING NR 001//
REF/A/MSG/NAVMARFCSTCEN PEARL HARBOR HI/180521ZFEB2011//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. TROPICAL CYCLONE 17P (SEVENTEEN) WARNING NR 001
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
181800Z --- NEAR 15.4S 169.4E
MOVEMENT PAST SIX HOURS - 205 DEGREES AT 02 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: 15.4S 169.4E
---
FORECASTS:
12 HRS, VALID AT:
190600Z --- 15.8S 169.2E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 190 DEG/ 03 KTS
---
24 HRS, VALID AT:
191800Z --- 16.4S 169.1E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
000 NM SOUTHWEST QUADRANT
000 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 170 DEG/ 04 KTS
---
36 HRS, VALID AT:
200600Z --- 17.1S 169.2E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 150 DEG/ 06 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
201800Z --- 18.1S 169.8E
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 010 NM NORTHEAST QUADRANT
010 NM SOUTHEAST QUADRANT
010 NM SOUTHWEST QUADRANT
010 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
080 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 145 DEG/ 08 KTS
---
72 HRS, VALID AT:
211800Z --- 20.6S 171.6E
MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 065 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
065 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 115 NM NORTHEAST QUADRANT
095 NM SOUTHEAST QUADRANT
100 NM SOUTHWEST QUADRANT
120 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 140 DEG/ 14 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:
221800Z --- 24.8S 175.5E
MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 120 HR POSIT: 140 DEG/ 22 KTS
---
120 HRS, VALID AT:
231800Z --- 31.3S 177.6W
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
---
REMARKS:
182100Z POSITION NEAR 15.5S 169.4E.
TROPICAL CYCLONE (TC) 17S, LOCATED APPROXIMATELY 485 NM WEST-
NORTHWEST OF NADI, FIJI, HAS TRACKED SOUTH-SOUTHWESTWARD AT 02 KNOTS
OVER THE PAST SIX HOURS. ANIMATED INFRARED IMAGERY SHOWS THAT DEEP
CONVECTION HAS FORMED OVER THE CENTER OF THE LOW LEVEL CIRCULATION
CENTER (LLCC) AND FORMATIVE BANDING IS NOW WRAPPING INTO THE CENTER
FROM THE WEST AND NORTH SIDES. AN 181753Z TRMM PASS SHOWS DEEP
CURVED CONVECTION SLIGHTLY DISPLACED TO THE NORTHWEST OF THE WELL
DEFINED, SYMMETRIC LOW LEVEL CIRCULATION. ENVIRONMENTAL ANALYSIS
INDICATES THAT THE SYSTEM IS BENEATH AN UPPER LEVEL OUTFLOW SOURCE,
IN A REGION OF LOW (15KTS) VERTICAL WIND SHEAR AND FAVORABLE SEA
SURFACE TEMPERATURES. THE SYSTEM IS CURRENTLY IN A WEAK STEERING
ENVIRONMENT BETWEEN TWO LOW TO MID-LEVEL SUBTROPICAL RIDGES (STR)
(ONE TO THE NORTHEAST AND ONE TO THE SOUTHWEST). AN APPROACHING HIGH
AMPLITUDE MIDLATITUDE TROUGH WILL START TO ERODE THE STR TO THE
SOUTHWEST, ALLOWING THE SECOND STR TO THE NORTHEAST TO TAKE OVER AS
THE PRIMARY STEERING MECHANISM. AROUND TAU 48, THE SYSTEM WILL BEGIN
TO ACCELERATE TO THE SOUTHEAST AHEAD OF THE PASSING TROUGH. WHILE
AHEAD OF THE PASSING TROUGH, POLEWARD OUTFLOW IS EXPECTED TO IMPROVE
SUBSTANTIALLY, AND THE SYSTEM IS EXPECTED TO STEADILY INTENSIFY
THROUGH THIS PERIOD UNTIL IS CROSSES INTO COOLER WATERS BY TAU 108.
BY TAU 120 THE SYSTEM IS EXPECTED TO BEGIN EXTRATROPICAL TRANSITION
UNDER THE INFLUENCES OF INCREASING VERTICAL WIND SHEAR, ENTRAINMENT
OF DRIER AIR FROM A MID-LATITUDE AIRMASS TO THE SOUTH, AND PASSAGE
OVER COOLER WATER. NOGAPS, GFS AND GFDN ARE ALL IN EXCELLENT
AGREEMENT, AND THE FORECAST IS BASED THESE MODELS. THIS WARNING
SUPERSEDES AND CANCELS REF A, NAVMARFCSTCEN 180521Z FEB 11 TROPICAL
CYCLONE FORMATION ALERT (WTPS22 PGTW 180530) MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 181800Z IS 12 FEET. NEXT WARNINGS AT 190900Z AND
192100Z.
//
NNNN

[HURAKAN]

Latest track

[cycloneye]

What name of these two (Atu or Errol) will this cyclone have?

[Extratropical94]

Atu, as it is not forecast to move west of 160°E.

And with this cyclone the basin will reach the number of 7 named cyclones and 4 severe ones.
Fiji Meteorological Service predicted 7-9 cyclones and 4 of them severe.

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Since we're still in mid-February, I expect more than two more cyclones to form and at least one of them to become a severe Cat. 3 (maybe Atu )

[P.K.]

WTPS11 NFFN 181800
TROPICAL DISTURBANCE ADVISORY NUMBER A4 ISSUED FROM RSMC NADI
Feb 18/1946 UTC 2011 UTC.

TROPICAL DEPRESSION 11F CENTRE 997 HPA WAS LOCATED NEAR 15.6S 169.6E
AT 181800 UTC.
POSITION POOR BASED ON MTSAT IR IMAGERY AND PERIPHERAL SURFACE
OBSERVATIONS. DEPRESSION SLOW MOVING. MAXIMUM 10-MINUTE AVERAGE
WINDS NEAR THE CENTRE ESTIMATED AT ABOUT 30 KNOTS.


ORGANISATION IMPROVED PAST 24 HOURS WITH PRIMARY BANDS TRYING TO WRAP
AROUND LLCC. CONVECTION HAS INCREASED PAST 12 HOURS DUE TO DIURNAL
VARIATION MAKING LLCC CLOUD FILLED. CYCLONIC CIRCULATION EXTENDS TO
500HPA. SST AROUND 30 DEGREE CELSIUS. SYSTEM LIES ALONG A SURFACE
TROUGH UNDER AN UPPER DIFFLUENT REGION IN A MODERATE SHEARED
ENVIRONMENT. SYSTEM IS BEING STEERED SOUTH-SOUTHEAST BY A WEAK
NORTHWEST DEEP LAYER MEAN REGIME. MID-LEVEL RIDGE TO SOUTH OF SYSTEM
IS EXPECTED TO WEAKEN AND RECEDE TO THE WEST AS SYSTEM MOVES SOUTH.
DVORAK ASSESMENT BASED ON 0.40 WRAP ON LOG 10 SPIRAL YIELDING DT=2.5,
MET=2.5 PT=2.5 FT BASED ON DT, THUS T2.5/2.5/D1.0/24HRS.
GLOBAL MODELS ARE GRADUALLY DEVELOPING THE DEPRESSION AND MAINTAINING
A SSE TRACK. POTENTIAL FOR THE SYSTEM TO DEVELOP INTO A TROPICAL
CYCLONE IN THE NEXT 24 HOURS IS HIGH.

FORECAST:
AT 12 HRS VALID AT 190600 UTC 16.3S 169.6E MOV S AT 04 KT WITH 35 KT
CLOSE TO CENTRE
AT 24 HRS VALID AT 191800 UTC 17.0S 169.7E MOV SSE AT 03 KT WITH 40
KT CLOSE TO CENTRE

OUTLOOK :
AT 36 HRS VALID AT 200600 UTC 17.5S 170.0E MOV SSE AT 03 KT WITH 45
KT CLOSE TO CENTRE
AT 48 HRS VALID AT 201800 UTC 18.1S 170.4E MOV SSE AT 04 KT WITH 50
KT CLOSE TO CENTRE

THE NEXT TROPICAL DISTURBANCE ADVISORY ON TD 11F WILL BE ISSUED AT
AROUND 190200 UTC OR EARLIER.

[cycloneye]

Peter,I think that by the next advisory,they will upgrade.

[Extratropical94]

That would definitely make sense because they have a Dvorak-# of 2.5 which means 35 knots already.
In addition they wrote 30-35 knots in their marine advisory.

Edit: You're right, I didn't think of the 1-minute to 10-minute conversion.

[P.K.]

A T2.5 is only about 30kts though in ten minute winds hence the lack of an upgrade so far.

Yes it does seem likely they'll upgrade at 00Z. We should find out in about 3 hours time. The SAB went to T3.0 a hour ago.

[Extratropical94]

latest IR (2100Z)

[KWT]

Don't be surprised if this is above 65kts in 12hrs time, starting to develop a very tight inner core already at this stage.

[Extratropical94]

2132Z visible

[cycloneye]

Up to 3.0/3.0.

18/2032 UTC 15.5S 169.3E T3.0/3.0 17P -- Southwest Pacific

http://www.ssd.noaa.gov/PS/TROP/tdpositions.html

[cycloneye]

Eyefeature popping out?

[P.K.]

This is clearly a TC now, T3.0 from the CPHC, JTWC and SAB.

However for some reason they've kept it the same as at 18Z.

WOPS01 NFFN 190000
GALE WARNING 008 ISSUED FROM RSMC NADI Feb 19/0103 UTC 2011 UTC.

TROPICAL DEPRESSION TD11F CENTRE 997HPA WAS LOCATED NEAR 16.0S 169.6E AT 190000
UTC SLOW MOVING. POSITION POOR.

EXPECT CLOCKWISE WINDS 30 TO 35 KNOTS WITHIN 60 TO 180 NAUTICAL MILES AWAY FROM
CENTRE IN THE SECTOR FROM NORTHWEST THROUGH EAST TO SOUTHEAST.

AREA OF GALES MOVING WITH DEPRESSION.

THIS WARNING CANCELS AND REPLACES WARNING 007.

[cycloneye]

Wow Peter. The 00:00 UTC update at NRL has it at 50kts,985 mbs.

[HURAKAN]

Latest microwave

[HURAKAN]

Latest water vapor