SIO: OLWYN - Post-Tropical

[jaguarjace]

96S INVEST 150309 1200 16.0S 114.0E SHEM 15 1010

[jaguarjace]

96S INVEST 150310 1800 14.9S 116.5E SHEM 30 1000

[jaguarjace]

AUSTRALIAN GOVERNMENT BUREAU OF METEOROLOGY
TROPICAL CYCLONE WARNING CENTRE PERTH

TROPICAL CYCLONE FORECAST TRACK MAP
Tropical Low
Issued at 8:55 am WST Wednesday 11 March 2015.



96S INVEST 150311 0000 15.8S 116.3E SHEM 30 1000

[jaguarjace]

AUSTRALIAN GOVERNMENT BUREAU OF METEOROLOGY
TROPICAL CYCLONE WARNING CENTRE PERTH

TROPICAL CYCLONE FORECAST TRACK MAP
Tropical Cyclone Olwyn
Issued at 2:54 pm WST Wednesday 11 March 2015.



Details of Tropical Cyclone Olwyn at 2:00 pm WST:

Intensity: category 1, sustained winds near the centre of 65 kilometres per hour with wind gusts to 95 kilometres per hour.
Location: within 75 kilometres of 16.3 degrees South, 116.1 degrees East , 500 kilometres north of Karratha and 660 kilometres north northeast of Exmouth .
Movement: south at 9 kilometres per hour .

The system has rapidly developed in the last few hours. Tropical Cyclone Olwyn will to continue to develop as it moves in a south to southwest direction over the next 48 hours, reaching the west Pilbara coastline Friday morning.

[talkon]

19S OLWYN 150311 1200 17.3S 116.0E SHEM 45 989

12Z BT upped this to 45 knots.

[jaguarjace]

Olwyn reminds me of Elia 2006.

[CrazyC83]

If this tracks west and misses the NW coast, it could hit a more populated area?

[Yellow Evan]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 12 MAR 2015 Time : 013000 UTC
Lat : 18:52:03 S Lon : 114:47:21 E


CI# /Pressure/ Vmax
3.2 / 994.5mb/ 49.0kt


Final T# Adj T# Raw T#
2.8 2.6 2.6

Center Temp : +3.5C Cloud Region Temp : -55.3C

Scene Type : CURVED BAND with 0.58 ARC in LT GRAY
Maximum CURVED BAND with 0.64 ARC in LT GRAY
at Lat: 18:15:36 S Lon: 114:10:48 E

Positioning Method : FORECAST INTERPOLATION

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

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

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 100km
- Environmental MSLP : 1009mb

Satellite Name : MTSAT2

[Yellow Evan]

ADt thinks its weakening since it's not recognizing the eye

[CrazyC83]

Learmonth reporting a 971mb pressure and a 10-min sustained wind of 72 kt in the eyewall, gusting to 97 kt.

SPECI YPLM 121730Z AUTO 05072G97KT 0200 +RA BKN006 OVC012 26/25 Q0971

http://www.wunderground.com/cgi-bin/fin ... 58&sp=YPLM

Based on that information, I would estimate the landfall pressure was 963mb, and the (1-min sustained) intensity was 90 kt.

[CrazyC83]

SPECI YPLM 121757Z AUTO 03072G93KT 0250 +RA BKN003 OVC006 26/22 Q0970

Pressure ticked down to 970 but clearly still in the eyewall. Central pressure appears to have actually been about 961mb?

[Alyono]

with the track shift to the east, this won't be moving inland.

Could have a very strong cyclone moving into Perth in a little more than 24 hours.

[CrazyC83]

with the track shift to the east, this won't be moving inland.

Could have a very strong cyclone moving into Perth in a little more than 24 hours.

Indeed, and that is always one of the more problematic situations. Even a Category 1 hitting them would be really bad.

Olwyn definitely made a first landfall west of Learmonth, but has re-emerged over water. I'd put the intensity right now at 85 kt thinking it weakened slightly over land.

[CrazyC83]

I thought the Learmonth observations were 10-min sustained? That would support an intensity of 85 kt at least. Also those same observations suggest the central pressure is around 961mb.

WTXS31 PGTW 122100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 19S (OLWYN) WARNING NR 007//
RMKS/
1. TROPICAL CYCLONE 19S (OLWYN) WARNING NR 007
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
121800Z --- NEAR 22.3S 113.8E
MOVEMENT PAST SIX HOURS - 195 DEGREES AT 10 KTS
POSITION ACCURATE TO WITHIN 025 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
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 - 060 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 105 NM NORTHEAST QUADRANT
110 NM SOUTHEAST QUADRANT
100 NM SOUTHWEST QUADRANT
095 NM NORTHWEST QUADRANT
REPEAT POSIT: 22.3S 113.8E
---
FORECASTS:
12 HRS, VALID AT:
130600Z --- 25.1S 113.6E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
VECTOR TO 24 HR POSIT: 165 DEG/ 19 KTS
---
24 HRS, VALID AT:
131800Z --- 28.7S 114.8E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
VECTOR TO 36 HR POSIT: 155 DEG/ 24 KTS
---
36 HRS, VALID AT:
140600Z --- 33.1S 117.0E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
EXTRATROPICAL
---
REMARKS:
122100Z POSITION NEAR 23.0S 113.7E.
TROPICAL CYCLONE 19S (OLWYN), LOCATED APPROXIMATELY 17 NM WEST OF
LEARMONTH, AUSTRALIA, HAS TRACKED SOUTH-SOUTHWESTWARD AT 10 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE
IMAGERY DEPICTS AN INTENSE AND WELL ORGANIZED SYSTEM WITH AN
APPARENT 25 NM RAGGED EYE FEATURE. THE 121826Z GPM MICROWAVE IMAGE
REVEALS A SHARPLY DEFINED MICROWAVE EYE JUST WEST OF LEARMONTH. THE
INITIAL POSITION IS BASED ON THE EYE FEATURE IN THE EIR ANIMATION
AND SUPPORTED BY THE AFOREMENTIONED MICROWAVE IMAGE. THE INITIAL
INTENSITY IS BASED ON THE 121430 PGTW FIX, SATCON ESTIMATES, AS WELL
AS OBSERVATIONS REPORTED AT LEARMONTH. UPPER LEVEL ANALYSIS
INDICATES AN ENVIRONMENT CHARACTERIZED BY LOW TO MODERATE (10-20
KNOTS) VERTICAL WIND SHEAR AND STRONG POLEWARD OUTFLOW. TC 19S IS
CURRENT TRACKING ALONG THE WESTERN PERIPHERY OF THE DEEP LAYERED
SUBTROPICAL RIDGE TO THE EAST. THE CYCLONE IS EXPECTED TO CREST THE
RIDGE AXIS WITHIN THE NEXT 12 HOURS, BEGIN TO WEAKEN DUE TO LAND
INTERACTION, AND THEN BEGIN TO SLIGHTLY RECURVE TO THE SOUTHEAST.
EXTRATROPICAL TRANSITION IS EXPECTED TO BEGIN NEAR TAU 12 WITH
COMPLETION OF THE TRANSITION BY TAU 36 AS A SHORTWAVE TROUGH
PROPAGATES INTO THE AREA AND INTERACTS WITH TC 15S. DYNAMIC MODEL
GUIDANCE REMAINS IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE TO THE
JTWC FORECAST TRACK WHICH IS PLACED CLOSE TO THE MULTI-MODEL
CONSENSUS. NEXT WARNINGS AT 130300Z, 130900Z, 131500Z AND 132100Z.
//

[Yellow Evan]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 12 MAR 2015 Time : 223000 UTC
Lat : 23:23:48 S Lon : 113:42:11 E


CI# /Pressure/ Vmax
6.0 / 943.8mb/115.0kt


Final T# Adj T# Raw T#
6.0 6.0 6.0

Estimated radius of max. wind based on IR : 18 km

Center Temp : -10.6C Cloud Region Temp : -70.9C

Scene Type : EYE

Positioning Method : RING/SPIRAL COMBINATION

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

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

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 102km
- Environmental MSLP : 1009mb

Satellite Name : MTSAT2
Satellite Viewing Angle : 44.4 degrees

[Yellow Evan]

TPXS12 PGTW 122127

A. TROPICAL CYCLONE 19S (OLWYN)

B. 12/2032Z

C. 23.15S

D. 113.69E

E. FIVE/MTSAT

F. T4.5/4.5/D1.0/24HRS STT: S0.0/06HRS

G. IR/EIR

H. REMARKS: 38A/PBO SBC/ANMTN. CNVCTN WRAPS 1.1 ON LOG10 SPIRAL
YIELDING A DT OF 4.0. PT AND MET YIELD A 4.5. DBO PT.

I. ADDITIONAL POSITIONS:
12/1648Z 21.98S 113.77E AMS2
12/1813Z 22.35S 113.83E MMHS
12/1826Z 22.25S 113.75E GPMI


LEMBKE

Wrong pattern IMO.

[Yellow Evan]

Not to mention Cat 2 surface winds.

[talkon]

TXXS27 KNES 130019
TCSSIO

A. 19S (OLWYN)

B. 12/2332Z

C. 23.7S

D. 113.6E

E. ONE/MTSAT

F. T5.5/5.5/D1.5/24HRS

G. IR/EIR/VIS

H. REMARKS...DT=5.5 BASED ON LG RING WITH 0W EYE EMBEDDED BY
FL. PT=5.5. MET=5.5. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...SCHWARTZ

[talkon]

19S OLWYN 150313 0000 23.6S 113.6E SHEM 85 959

[HurricaneBill]

Learmonth Airport elevation is listed as 5m. So those observations were ground level.

Highest sustained wind (10-min): 74KT
Highest gust: 97KT
Lowest pressure: 969mb