Tropical Cyclones Winston & Tatiana

Manukau heads obs · Fri 19/02/2016 21:16

http://rammb.cira.colostate.edu/ramsdis ... display=24

Manukau heads obs · Fri 19/02/2016 21:44

and still nothing in the main stream media here..and yet currently Fiji is staring down the barrel of a destructive Cat 5 TC

jamie · Unread post by **jamie** » Fri 19/02/2016 21:56

Don't worry Brian. It will start "trending" online which then we will see NZ media pick it up. That seems to be all the media reports on these days.

Doesn't look good for Fiji. Wonder if the serious chasers will be heading to Suva. Could be the perfect place to be.

ScottyD · Unread post by **ScottyD** » Fri 19/02/2016 22:08

Latest info from jtwc does not bode well for those in Fiji. Id link to the page but unfortunately im having arguments with my phone.

Nev · Unread post by **Nev** » Fri 19/02/2016 22:13

Winstone has become very symmetrical in the last few hours, with a very well-defined eye and convection has deepened.

Still looks to me like Winstone's eye will pass between Fiji's two main islands. What makes it even worse is that it looks like he may pass through overnight tomorrow night.

WTPS31 PGTW 190900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 11P (WINSTON) WARNING NR 025//
RMKS/
1. TROPICAL CYCLONE 11P (WINSTON) WARNING NR 025
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
190600Z --- NEAR 17.5S 175.9W
MOVEMENT PAST SIX HOURS - 270 DEGREES AT 12 KTS
POSITION ACCURATE TO WITHIN 020 NM
POSITION BASED ON EYE FIXED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 125 KT, GUSTS 150 KT
…
REMARKS:
190900Z POSITION NEAR 17.5S 176.4W.
TROPICAL CYCLONE (TC) 11P (WINSTON), LOCATED APPROXIMATELY 330 NM
EAST OF SUVA, FIJI, HAS TRACKED WESTWARD AT 12 KNOTS OVER THE PAST
SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A
190405Z SSMIS 91 GHZ IMAGE REVEAL A SYMMETRIC EYEWALL SURROUNDING A
15 NM EYE, WITH CLOUD-TOP COOLING OBSERVED OVER THE PAST 6-HOURS.
THE INITIAL INTENSITY IS ASSESSED AT 125 KNOTS BASED UPON DVORAK
CURRENT INTENSITY ESTIMATES OF T6.5 (127 KNOTS) FROM MULTIPLE
AGENCIES. UPPER LEVEL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT FOR
DEVELOPMENT WITH DUAL CHANNEL OUTFLOW AND WEAK (5 TO 10 KNOTS)
VERTICAL WIND SHEAR (VWS). TC 11P IS CURRENTLY TRACKING ALONG THE
NORTHERN PERIPHERY OF A BUILDING RIDGE TO THE SOUTH. AFTER TAU 48,
THE SYSTEM WILL RECURVE SHARPLY SOUTHWARD, AS THE RIDGE RE-ORIENTS
POLEWARD AND A TROUGH APPROACHES FROM THE WEST. TC 11P IS FORECAST
TO STRENGTHEN SLIGHTLY OVER THE NEXT 24 HOURS, AS VWS REMAINS WEAK,
SSTS REMAIN ABOVE 30C, AND UPPER LEVEL OUTFLOW REMAINS FAVORABLE.
THE SYSTEM IS CURRENTLY FORECAST TO MAKE LANDFALL ALONG THE EAST
COAST OF FIJI AROUND TAU 36, WITH AN INTENSITY BETWEEN 130 AND 135
KNOTS. AFTER TAU 48, THE SYSTEM WILL BEGIN TO WEAKEN DUE TO LAND
INTERACTIONS. AFTER TAU 72, TC WINSTON IS FORECAST TO WEAKEN RAPIDLY
AS IT TRACKS OVER COLDER SSTS, AND ENCOUNTERS HIGHER VWS AS IT
BECOMES EMBEDDED WITHIN THE TROUGH. DYNAMIC MODEL GUIDANCE CONTINUES
TO CONSOLIDATE ON THE OVERALL SYNOPTIC STEERING PATTERN. THEREFORE,
THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 190600Z IS 35 FEET. NEXT WARNINGS AT
191500Z, 192100Z, 200300Z AND 200900Z.//

Nev · Unread post by **Nev** » Sat 20/02/2016 06:51

Winston continues to strengthen as he nears Fiji. Earlier this morning central pressure was 925 hPa, max winds about 215 km/h. Eye now visible on Fiji's rain-radar.

TROPICAL DISTURBANCE ADVISORY NUMBER A38 ISSUED FROM RSMC NADI
Feb 191408 UTC.

SEVERE TROPICAL CYCLONE WINSTON CENTRE 925HPA WAS LOCATED NEAR 17.3S
177.4W AT 191200 UTC. POSITION GOOD BASED ON HR MTSAT EIR AND
PERIPHERAL SURFACE REPORTS. CYCLONE MOVING WEST AT ABOUT 12 KNOTS.
MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT ABOUT
115 KNOTS.
…
EYE WELL DEFINED. DEEP CONVECTION REMAINS PERSISTENT. EYE WARMING AND
CLOUD TOPS COOLING PAST 6 HOURS. ORGANIZATION REMAINS GOOD. SST
AROUND 29-30 DEGREES CELSIUS. SYSTEM LIES IN LOW SHEARED ENVIRONMENT.
OUTFLOW GOOD TO THE SOUTH AND WEST. DVORAK ANALYSIS BASED ON OW EYE
SURROUNDED BY W IN CMG RING WITH EYE ADJUSTMENT YIELDS DT=6.5, MET
AND PT AGREE, FT BASED ON DT. THUS YIELDING T6.5/6.5/D1.0/24HRS.

FORECASTS :
AT 12 HRS VALID AT 200000 UTC 17.3S 179.5W MOV W AT 10KT WITH 120 KT
CLOSE TO CENTRE
AT 24 HRS VALID AT 201200 UTC 17.5S 178.7E MOV W AT 09KT WITH 115 KT
CLOSE TO CENTRE

OUTLOOK :
AT 36 HRS VALID AT 210000 UTC 17.7S 177.2E MOV W AT 08KT WITH 105 KT
CLOSE TO CENTRE
AT 48 HRS VALID AT 211200 UTC 18.1S 176.3E MOV WSW AT 06KT WITH 105
KT CLOSE TO CENTRE

WTPS31 PGTW 191500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 11P (WINSTON) WARNING NR 026//
RMKS/
1. TROPICAL CYCLONE 11P (WINSTON) WARNING NR 026
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
191200Z --- NEAR 17.3S 177.5W
MOVEMENT PAST SIX HOURS - 275 DEGREES AT 15 KTS
POSITION ACCURATE TO WITHIN 020 NM
POSITION BASED ON EYE FIXED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 125 KT, GUSTS 150 KT
…
REMARKS:
191500Z POSITION NEAR 17.3S 178.0W.
TROPICAL CYCLONE (TC) 11P (WINSTON), LOCATED APPROXIMATELY 239 NM
EAST OF SUVA, FIJI, HAS TRACKED WESTWARD AT 15 KNOTS OVER THE PAST
SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A
190928Z AMSU-B 89 GHZ IMAGE CONTINUE TO REVEAL A SYMMETRIC EYEWALL
SURROUNDING A 15 NM EYE, AND THE MAINTENANCE OF DEEP CONVECTION OVER
THE PAST 6-HOURS. THE INITIAL INTENSITY IS ASSESSED AT 125 KNOTS
BASED UPON DVORAK CURRENT INTENSITY ESTIMATES OF T6.5 (127 KNOTS)
FROM MULTIPLE AGENCIES. UPPER LEVEL ANALYSIS INDICATES A FAVORABLE
ENVIRONMENT WITH DUAL CHANNEL OUTFLOW AND WEAK (5 TO 10 KNOTS)
VERTICAL WIND SHEAR (VWS). TC 11P IS CURRENTLY TRACKING ALONG THE
NORTHERN PERIPHERY OF A STRONG STEERING RIDGE TO THE SOUTH. AFTER
TAU 48, THE SYSTEM WILL RECURVE SHARPLY SOUTHWARD, AS THE RIDGE RE-
ORIENTS POLEWARD AND A TROUGH APPROACHES FROM THE WEST. TC 11P IS
FORECAST TO STRENGTHEN SLIGHTLY OVER THE NEXT 24 HOURS, AS UPPER
LEVEL CONDITIONS AND SSTS REMAIN EXTREMELY FAVORABLE. THE SYSTEM IS
CURRENTLY FORECAST TO MAKE LANDFALL ALONG THE EAST COAST OF FIJI
AROUND TAU 24, WITH AN INTENSITY BETWEEN 125 AND 130 KNOTS. AFTER
TAU 24, THE SYSTEM WILL BEGIN TO WEAKEN DUE TO LAND INTERACTIONS.
AFTER TAU 72, TC WINSTON IS FORECAST TO WEAKEN RAPIDLY AS IT TRACKS
OVER COLDER SSTS, AND ENCOUNTERS HIGHER VWS AS IT BECOMES EMBEDDED
WITHIN THE TROUGH. DYNAMIC MODEL GUIDANCE CONTINUES TO CONSOLIDATE
ON THE OVERALL SYNOPTIC STEERING PATTERN. THEREFORE, THERE IS HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 191200Z IS 38 FEET. NEXT WARNINGS AT 192100Z, 200300Z,
200900Z AND 201500Z.//

Manukau heads obs · Sat 20/02/2016 06:57

how come a bunch of arm chair guys can better work out where this thing was going to go .....by just watching its movement on the sat image...instead of using (out of date..as slow to react models)

Manukau heads obs · Sat 20/02/2016 07:03

the sat image at the bottom of the M/S web site:
http://www.metservice.com/warnings/trop ... e-activity
is great as its really up to date

Its gonna pass between the 2 main islands by the looks...

Nev · Unread post by **Nev** » Sat 20/02/2016 08:57

Central pressure now down to 920 hPa, with max winds about 220 km/h.

I think this may be the strongest TC on record to ever affect Fiji's main island of Viti Levu.

TROPICAL DISTURBANCE ADVISORY NUMBER A39 ISSUED FROM RSMC NADI
Feb 191947 UTC.

SEVERE TROPICAL CYCLONE WINSTON CENTRE 920HPA WAS LOCATED NEAR 17.1S
178.9W AT 191800 UTC. POSITION GOOD BASED ON HR MTSAT EIR AND
PERIPHERAL SURFACE REPORTS. CYCLONE MOVING WEST AT ABOUT 13 KNOTS.
MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT ABOUT
120 KNOTS.
…
EYE WELL DEFINED. DEEP CONVECTION REMAINS PERSISTENT. EYE WARMING AND
CLOUD TOPS COOLING PAST 6 HOURS. ORGANIZATION REMAINS GOOD. SST
AROUND 29-30 DEGREES CELSIUS. SYSTEM LIES IN LOW SHEARED ENVIRONMENT.
OUTFLOW GOOD TO THE SOUTH AND WEST. DVORAK ANALYSIS BASED ON OW EYE
IN CMG SURROUND YIELDS DT=7.0, MET AND PT AGREE, FT BASED ON DT. THUS
YIELDING T7.0/7.0/D1.0/24HRS.

FORECASTS :
AT 12 HRS VALID AT 200600 UTC 17.1S 179.1E MOV W AT 09KT WITH 120 KT
CLOSE TO CENTRE
AT 24 HRS VALID AT 201800 UTC 17.3S 177.5E MOV W AT 08KT WITH 115 KT
CLOSE TO CENTRE

OUTLOOK :
AT 36 HRS VALID AT 210600 UTC 17.6S 176.3E MOV WSW AT 06KT WITH 110
KT CLOSE TO CENTRE
AT 48 HRS VALID AT 211800 UTC 17.9S 175.6E MOV WSW AT 04KT WITH 105
KT CLOSE TO CENTRE

THE NEXT TROPICAL DISTURBANCE ADVISORY ON WINSTON WILL BE ISSUED
AROUND 200200 UTC.

Manukau heads obs · Sat 20/02/2016 09:18

http://fiji.intercontinental.com/home/live-video-feed

http://denaraumarina.com/port-denarau-weather-webcam/

Nev · Unread post by **Nev** » Sat 20/02/2016 09:42

JTWC still expect Winston strengthen more over the next 12 hours under very favourable conditions…

WTPS31 PGTW 192100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
RMKS/
1. TROPICAL CYCLONE 11P (WINSTON) WARNING NR 027
01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
191800Z --- NEAR 17.2S 178.9W
MOVEMENT PAST SIX HOURS - 275 DEGREES AT 13 KTS
POSITION ACCURATE TO WITHIN 010 NM
POSITION BASED ON EYE FIXED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 145 KT, GUSTS 175 KT
...
REMARKS:
192100Z POSITION NEAR 17.1S 179.5W.
TROPICAL CYCLONE 11P (WINSTON), LOCATED APPROXIMATELY 164 NM
EAST-NORTHEAST OF SUVA, FIJI, HAS TRACKED WESTWARD AT 13 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY, CURRENT RADAR IMAGERY FROM LABASA, FIJI AND A 191815Z SSMIS
91 GHZ MICROWAVE IMAGE CONTINUE TO REVEAL A SYMMETRIC EYEWALL
SURROUNDING A 15 NM EYE AND THE MAINTENANCE OF DEEP CONVECTION OVER
THE PAST 6-HOURS, PROVIDING HIGH CONFIDENCE IN THE INITIAL POSITION.
THE INITIAL INTENSITY IS ASSESSED AT 145 KNOTS BASED ON ANALYSIS OF
ALL AVAILABLE SUBJECTIVE AND OBJECTIVE DVORAK INTENSITY ESTIMATES.
UPPER LEVEL ANALYSIS SHOWS THAT TC WINSTON REMAINS IN A FAVORABLE
ENVIRONMENT WITH STRONG RADIAL OUTFLOW, LOW (10 TO 15 KNOTS)
VERTICAL WIND SHEAR (VWS) AND VERY HIGH SEA SURFACE TEMPERATURES
(SSTS) OVER 31 CELSIUS. TC 11P IS CURRENTLY TRACKING WESTWARD UNDER
THE INFLUENCE OF A DEEP-LAYER SUB-TROPICAL RIDGE (STR) TO THE SOUTH.
BY TAU 36, TC WINSTON WILL BEGIN SLOWING, BECOMING NEARLY QUASI-
STATIONARY BEFORE TURNING MORE SHARPLY TOWARDS THE SOUTH AFTER TAU
48 IN RESPONSE TO WEAKENING OF THE STEERING RIDGE AND CONCURRENT
DEVELOPMENT OF AN UPPER-LEVEL CUTOFF LOW TO THE SOUTHWEST. TC
WINSTON IS FORECAST TO CONTINUE TO STRENGTHEN OVER THE NEXT 12 HOURS
AS UPPER LEVEL CONDITIONS AND SSTS REMAIN EXTREMELY FAVORABLE,
PEAKING AT 160 KNOTS JUST PRIOR TO MAKING LANDFALL ALONG THE EAST
COAST OF THE NORTHERN FIJI ISLANDS. AFTER TAU 12, TC WINSTON WILL
WEAKEN SOMEWHAT AFTER LANDFALL DUE TO LAND INTERACTION. ONCE OVER
OPEN WATERS BY TAU 36, TC WINSTON WILL MAINTAIN INTENSITY AS A
SIGNIFICANT TROPICAL CYCLONE, BEFORE BEGINNING A SLOW WEAKENING
TREND AFTER TAU 96 AS IT TRACKS OVER COLDER SSTS AND ENCOUNTERS
HIGHER VWS AS IT BECOMES EMBEDDED WITHIN THE TROUGH. DYNAMIC MODEL
GUIDANCE CONTINUES TO CONSOLIDATE ON THE OVERALL SYNOPTIC STEERING
PATTERN AND IS IN GOOD AGREEMENT THROUGH TAU 72, LEADING TO HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 191800Z IS 40 FEET. NEXT WARNINGS AT 200300Z, 200900Z,
201500Z AND 202100Z.//

ScottyD · Unread post by **ScottyD** » Sat 20/02/2016 09:45

That is some serious forecast wind speed! I hope everyone remains safe.

David · Unread post by **David** » Sat 20/02/2016 10:01

Wow, that is about 295 km/h with gusts to 360 km/h. Certainly would make it a high-end Cat 5

jamie · Unread post by **jamie** » Sat 20/02/2016 10:09

Wow so many beautiful little islands between the two main islands. I hope they are prepared.

Manukau heads obs · Sat 20/02/2016 10:14

http://www.met.gov.fj/latest_synoptic.php

Nev · Unread post by **Nev** » Sat 20/02/2016 10:17

David wrote:Wow, that is about 295 km/h with gusts to 360 km/h. Certainly would make it a high-end Cat 5

Don't forget that JTWC use US 1-minute mean-winds, while most of the rest of the world use 10-minute mean-winds, as recommended by the WMO.

So, 1-minute mean-winds of 160 kt (296 km/h) = 10-minute mean-winds of about 141 kts (261 km/h).

However, even with the convertion, JTWC often tends to overestimate winds. MetService says that a WS on the small island of Vanua Balavu recorded mean-winds of 170 km/h when the eye more or less passed over earlier this morning.

Manukau heads obs · Sat 20/02/2016 12:25

the Fiji Met rain radar shows TC Winston has now done the slight turn more to the WSW
and so it will get very close to the northern parts of the Main Island now...

Manukau heads obs · Sat 20/02/2016 12:50

I see people are asking the question, will it affect NZ
and Met Service are saying no...citing the current model runs...but every day the model runs are very different...
currently some models have it to move into the north tasman (which actually could mean it directs a moist NE airflow onto northern NZ)

Nev · Unread post by **Nev** » Sat 20/02/2016 13:28

Can't see any change in Winston's westward track going by the latest rain-radar imagery?

Manukau heads obs · Sat 20/02/2016 13:33

the southern portion of the eye is now straddling over the 300 line whereas a few hours ago it was only just touching that line
compare with the one you posted earlier

Nev · Unread post by **Nev** » Sat 20/02/2016 13:45

Comparing several images over the last 5 hours, I think that's within tolerance of the eye's distortion. May have to wait another hour or two before I'm convinced...

Manukau heads obs · Sat 20/02/2016 13:51

well, that's what the Fiji Met projected path was for it to do, and that looks like what it is doing
i.e its eye is going to along just north of the Main island at this rate...not good

Manukau heads obs · Sat 20/02/2016 13:52

you can see that slightly south of W movement with the rain radar animation
http://www.met.gov.fj/aifs_prods/fijico ... ed_fij.gif
(which struggles to load under the demand)

Nev · Unread post by **Nev** » Sat 20/02/2016 14:06

Meant to post this last track-map earlier. Nadi has Winston passing between the 2 main islands marginally further north than before.

Manukau heads obs · Sat 20/02/2016 14:10

It looks like it end up between that latest and the earlier forecast map runs
i.e just a bit further south of that latest forecast track
nervous times for people in the forecast track zone...as because its relatively small and very compact TC, just a slight wobble or slight change in direction could mean the difference between catastrophic destruction and just desctruction

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