South Pacific: Tropical Cyclone FUNA (TC 12P)

[Chacor]

[wyq614]

Funa may be experiencing some difficulties.
Its ADT intensity has remained unchanged for four hours and now has both weakening flag and rapid dissipation flag on.

[Pedro Fernández]

DVORAK number remains at 3.8 which means FUNA is almost reaching 1 category hurricane (Saffir Simpson Scale)... Wunderground have given that category to the cyclone (75 mph)... FIJI service keeps category 2 in the Australian Scale, with wind gusts at 65 KT...

Perhaps dry air mass is affecting the cyclone by its southwest?

I haven't seen too much intensification in the last hours...

[Chacor]

Four quick points -
1. Wunderground doesn't do warnings. They use the JTWC.
2. Dvorak ADT is not the be-all-and-end-all, and certainly should not be used alone to decipher a storm's intensity.
3. A Dvorak number of T3.8 does not mean a storm's not 65 kt.
4. There's not much dry air. Some, but probably not enough to severely restrict intensification:

[Chacor]

For what it's worth,

PHFO (CPHC) - T3.5
PGTW (JTWC) - T4.0
ABRF (BoM) - T3.5
NFFN (FMS) - T4.0
KNES (SAB) - T3.5

[Chacor]

Special Advisory Number EIGHT for Vanuatu on TC FUNA ISSUED FROM RSMC
NADI
Jan 17/1400 UTC 2008 UTC.

TROPICAL CYCLONE 10F FUNA CENTRE [970HPA] CAT 2 NEAR 15.7S 170.3E AT
171200 UTC. POSITION POOR BASED ON MTSAT EIR IMAGERY WITH ANIMATION.
CYCLONE INTENSIFYING AND MOVING EAST-SOUTHEAST AT 12 KNOTS BUT
EXPECTED TO GRADUALLY TURN SOUTHEAST THEN SOUTH IN THE NEXT 24 HOURS.
MAXIMUM 10-MINUTE AVERAGE WINDS ESTIMATED AT 60 KNOTS CLOSE TO THE
CENTRE INCREASING TO 70 KNOTS IN THE NEXT 18 HOURS. EXPECT WINDS OVER
47 KNOTS WITHIN 35 MILES OF CENTRE, AND OVER 33 KNOTS WITHIN 120
MILES OF CENTRE.

DEEP CONVECTION COOLING AND REORGANISING. COLD SPIRAL BAND TO EAST
CONSOLIDATING WHILE WRAPPING AROUND LLCC. OUTFLOW GOOD TO EAST, FAIR
TO SOUTH AND DEVELOPING ELSEWHERE. SYSTEM STILL LIES IN A DIFFLUENT
REGION WITH MINIMAL SHEAR. CIMSS MAITAINS DECREASING SHEAR OVER
SYSTEM AND ALONG FORECAST TRACK. CYCLONE STEERED TOWARDS SOUTHEAST
UNDER MID-LEVEL RIDGE TO NORTHEAST. DVORAK BASED ON 1.0 WRAP ON LOG10
SPIRAL GIVES DT3.5 PLUS DT0.5 FOR W BAND, YIELDING DT4.0. PAT AND MET
AGREE, THUS T4.0/4.0/D1.0/24HRS. GLOBAL MODELS GENERALLY AGREE ON
FURTHER INTENSIFICATION ON EAST-SOUTHEAST THEN SOUTHEAST TRACK.

AS TC FUNA IS MOVING FURTHER AWAY FROM VANUATU, WINDS ARE EXPECTED TO
DECREASE TO BELOW GALE FORCE. FURTHER RAIN, HEAVY AT TIMES, AND
SQUALLY THUNDERSTORMS. SEA FLOODING OF LOW-LYING COASTAL AREAS STILL
LIKELY EASPECIALLY ABOUT EASTERN COASTAL AREAS OF NORTHERN AND
CENTRAL VANUATU. VERY ROUGH SEAS OVER NORTHERN AND CENTRAL VANUATU
WATERS GRADUALLY ABATING. DAMAGING HEAVY SWELLS GRADUALLY ABATING.

FORECAST:
12HRS VALID AT 180000 UTC NEAR 16.8S 171.5E MOV SE 08KT WITH 65KT
CLOSE TO CENTRE. 24HRS VALID AT 181200 UTC NEAR 17.9S 172.0E MOV SSE
06KT WITH 75KT CLOSE TO CENTRE.

OUTLOOK:
36HRS VALID AT 190000 UTC NEAR 18.9S 172.1E MOV S 10KT WITH 85KT
CLOSE TO CENTRE.
48HRS VALID AT 191200 UTC NEAR 20.7S 172.1E MOV S 10KT WITH 95KT
CLOSE TO CENTRE.

AS TC FUNA IS MOVING FURTHER AWAY FROM VANUATU, THIS WILL BE THE
FINAL SPECIAL ADVISORY FOR VANUATU, UNLESS THE CYCLONE TURNS BACK TO
POSE A DIRECT THREAT TO ANY PART OF THE COUNTRY.

[Pedro Fernández]

Thanks for your clarification, Chacor. I like to learn more and more about the analysis of tropical cyclones. I try to make objective arguments.

In the case of DVORAK numbers, I have only used this table of equivalences:
http://www.ssd.noaa.gov/PS/TROP/CI-chart.html

I don't know exactly how does DVORAK technique calculate final numbers, although I understand that it is not too much accurate.

[Chacor]

Wow.

[KWT]

Does look pretty decent though I do think the convection is a little disorganised myself its still deep and therefore have cold cloud tops and you can see the convection starting to wrap around the center. Outflow looks decent in the eastern side of the system as well.
I think its got another 12-24hrs of consolidating and after that as the system starts to turn a little more to the ESE thats when it likely to have a shot at getting stronger a little more rapidly IMO.

[Crostorm]

Current Intensity Analysis




UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 2008JAN17 Time : 153000 UTC
Lat : 16:07:30 S Lon : 170:18:58 E


CI# /Pressure/ Vmax
3.8 / 981.7mb/ 61.0kt


6hr-Avg T# 3hr-Avg T# Adj T# Raw T#
3.8 3.8 3.8 3.8

Latitude bias adjustment to MSLP : +2.5mb

Center Temp : -86.8C Cloud Region Temp : -82.9C

Scene Type : UNIFORM CDO CLOUD REGION

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : WEST PACIFIC
Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

[Crostorm]

REMARKS:
170900Z POSITION NEAR 15.7S 169.4E.
TROPICAL CYCLONE (TC) 12P (FUNA) LOCATED APPROXIMATELY 505 NM
WEST-NORTHWEST OF NADI, FIJI, HAS TRACKED EAST-SOUTHEASTWARD AT
12 KNOTS OVER THE PAST 12 HOURS. THE CURRENT POSITION IS BASED ON
FIXES FROM NFFN, PGTW AND ABRF, WHICH ARE IN GOOD AGREEMENT. THE
65 KT INTENSITY IS BASED ON DVORAK VALUES OF 4.0 FROM PGTW AND NFFN.
ADDITIONALLY, AN SSMI 170540z MICROWAVE PASS SHOWS A BANDING EYE WITH
AREAS OF DEEP CONVECTION WRAPPING INTO THE CENTER. THE SYSTEM HAS
INTENSIFIED OVER THE PAST 12 HOURS DUE TO A WELL-DEVELOPED EQUATORWARD
OUTFLOW CHANNEL. TC 12P WILL SLOW SLIGHTLY NEAR TAU 24 BEFORE
ACCELERATING POLEWARD IN THE HIGH AMPLITUDE PATTERN. THE LATEST
FORECAST CALLS FOR A MORE RAPID INTENSIFICTION THAN PREVIOUSLY
FORECAST. BY TAU 24 THE SYSTEM WILL DEVELOP A STRONG POLEWARD OUTFLOW
CHANNEL DUE TO AN UPPER LEVEL TROUGH MIGRATING TO THE SOUTHEAST OF THE
SYSTEM. THIS ALIGNMENT WILL ALLOW FOR RAPID INTENSIFICATION, WHICH
IS FURTHER SUPPORTED BY STIPS. VERTICAL WIND SHEAR VALUES REMAIN LOW
AND THE SYSTEM WILL TRACK INTO EVEN HIGHER OCEAN HEAT CONTENT VALUES.
THE STORM WILL REACH ITS PEAK INTENSITY BY TAU 36. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 170600Z IS 24 FEET. NEXT WARNINGS AT 172100Z AND
180900Z.//

NNNN

[HURAKAN]

WTPS31 PGTW 172100
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 12P (FUNA) WARNING NR 004
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
171800Z --- NEAR 16.5S 171.1E
MOVEMENT PAST SIX HOURS - 120 DEGREES AT 10 KTS
POSITION ACCURATE TO WITHIN 040 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 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
040 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT
085 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
080 NM NORTHWEST QUADRANT
REPEAT POSIT: 16.5S 171.1E
---
FORECASTS:
12 HRS, VALID AT:
180600Z --- 18.0S 172.2E
MAX SUSTAINED WINDS - 080 KT, GUSTS 100 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 - 065 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 105 NM NORTHEAST QUADRANT
090 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 160 DEG/ 09 KTS
---
24 HRS, VALID AT:
181800Z --- 19.6S 172.9E
MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 045 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 065 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT
110 NM SOUTHEAST QUADRANT
080 NM SOUTHWEST QUADRANT
090 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 165 DEG/ 08 KTS
---
36 HRS, VALID AT:
190600Z --- 21.1S 173.3E
MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 050 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 115 NM NORTHEAST QUADRANT
115 NM SOUTHEAST QUADRANT
095 NM SOUTHWEST QUADRANT
095 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 175 DEG/ 13 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
191800Z --- 23.6S 173.6E
MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 045 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 075 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
055 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT
110 NM SOUTHEAST QUADRANT
090 NM SOUTHWEST QUADRANT
090 NM NORTHWEST QUADRANT
---
REMARKS:
172100Z POSITION NEAR 16.9S 171.4E.
TROPICAL CYCLONE (TC) 12P (FUNA) LOCATED APPROXIMATELY 355 NM
WEST OF NADI, FIJI, HAS TRACKED EAST-SOUTHEASTWARD AT 10 KNOTS
OVER THE PAST 12 HOURS. THE CURRENT POSITION IS BASED ON RECENT
METSAT IMAGERY AND THE PGTW FIX. THE 70 KT INITIAL INTENSITY IS
BASED ON DVORAK VALUES OF 4.0 AND 4.5 FROM PGTW AND ABRF, RESPECT-
IVELY. RECENT MICROWAVE IMAGERY SHOWS A BANDING EYE WITH AREAS OF
DEEP CONVECTION WRAPPING INTO THE CENTER. THE SYSTEM HAS CONTINUED
TO INTENSIFY OVER THE PAST 12 HOURS DUE TO WELL-DEVELOPED EQUATOR-
WARD AND POLEWARD OUTFLOW CHANNELS. TC 12P WILL CONTINUE TO CURVE
TOWARD THE SOUTH THRU THE REMAINDER OF THE FORECAST PERIOD. PRIOR
TO TAU 24, THIS TRACK WILL MOVE THE TC INTO WATERS WITH OCEAN HEAT
CONTENT HIGHER THAN THE ALREADY FAVORABLE WATERS IT IS CURRENTLY OVER.
THE CONTINUATION OF THE DUAL OUTFLOW CHANNELS AND THE INCREASE IN
AVAILABLE OCEAN HEAT CONTENT WILL ALLOW TC 12P TO CONTINUE TO INTENSIFY
AT A RAPID RATE. THE STORM IS EXPECTED TO REACH PEAK INTENSITY BY TAU
36. INCREASING VERTICAL WIND SHEAR PRIOR TO TAU 48 WILL BEGIN TO LIMIT
FURTHER DEVELOPMENT AND CAUSE THE INTENSITY TO LEVEL OFF. THE LATEST
FORECAST CALLS FOR A FASTER MOVEMENT TOWARD THE SOUTH THAN PREVIOUSLY
FORECAST. OVERALL, THE AVAILABLE DYNAMIC AIDS REMAIN IN FAIRLY GOOD
AGREEMENT THROUGHOUT THE FORECAST PERIOD. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 171800Z IS 28 FEET. NEXT WARNINGS AT 180900Z AND 182100Z.

[Coredesat]

NRL is down for site maintenance, so any images from there won't work until it comes back up (the note on the site said it should be back up later tonight).

[IceCycloon]

I don't see a eye in Funa.
And i don't think that the storm becomes a cat. 3 !

My first post

[CrazyC83]

At this point I agree this has levelled off. I'd say that it is 70 kt (1-min)/982mb right now.

[Squarethecircle]

I still think there is room for intensification, but I think that the JTWC's prediction is rather (significantly) inflated.

[Crostorm]

TROPICAL DISTURBANCE ADVISORY NUMBER A8 ISSUED FROM RSMC NADI
Jan 17/2058 UTC 2008 UTC.

***** TYPO CORRECTED
TROPICAL CYCLONE 10F FUNA CENTRE [968HPA] CAT 2 NEAR 16.6S 170.9E AT
171800 UTC. POSITION POOR BASED ON MTSAT EIR IMAGERY WITH ANIMATION.
CYCLONE INTENSIFYING, MOVING SOUTHEAST AT 10 KNOTS AND EXPECTED
CONTINUE MOVING SOUTHEAST FOR THE NEXT 24 HOURS. MAXIMUM 10-MINUTE
AVERAGE WINDS ESTIMATED AT 60 KNOTS CLOSE TO THE CENTRE INCREASING TO
70 KNOTS IN THE NEXT 12 HOURS. EXPECT WINDS OVER 47 KNOTS WITHIN 40
MILES OF CENTRE, AND OVER 33 KNOTS WITHIN 120 MILES OF CENTRE.

DEEP CONVECTION COOLING AND REORGANISING. COLD SPIRAL BAND TO EAST
CONSOLIDATING WHILE WRAPPING AROUND LLCC. OUTFLOW GOOD TO EAST, FAIR
TO SOUTH AND DEVELOPING ELSEWHERE. SYSTEM STILL LIES IN A DIFFLUENT
REGION WITH MINIMAL SHEAR. CIMSS MAITAINS DECREASING SHEAR OVER
SYSTEM AND ALONG FORECAST TRACK. CYCLONE STEERED TOWARDS SOUTHEAST
UNDER MID-LEVEL RIDGE TO NORTHEAST. DVORAK BASED ON 0.9 WRAP ON LOG10
SPIRAL GIVES DT3.5 PLUS DT0.5 FOR W BAND, YIELDING DT4.0. PAT AND MET
AGREE, THUS T4.0/4.0/D0.5/24HRS. GLOBAL MODELS GENERALLY AGREE ON
FURTHER INTENSIFICATION ON THE SOUTHEAST TRACK.

FORECAST:
12HRS VALID AT 180600 UTC NEAR 18.2S 171.9E MOV SSE 10KT WITH 70KT
CLOSE TO CENTRE.
24HRS VALID AT 181800 UTC NEAR 19.4S 172.5E MOV SSE 07KT WITH 85KT
CLOSE TO CENTRE.

OUTLOOK:
36HRS VALID AT 190600 UTC NEAR 20.8S 173.1E MOV SSE 8KT WITH 75KT
CLOSE TO CENTRE.
48HRS VALID AT 191800 UTC NEAR 23.1S 173.3E MOV S 10KT WITH 50KT
CLOSE TO CENTRE.

THE NEXT TROPICAL DISTURBANCE ADVISORY ON TC FUNA WILL BE ISSUED
AROUND 180230 UTC.

[Crostorm]

Ups

[HURAKAN]

Now we're talking!!!

[Squarethecircle]

In a few more hours the eye wall should level out. Luckily for Fiji this thing's heading south, eh?