SIO: IRVING - Post-Tropical

[Digital-TC-Chaser]

95S INVEST
As of 00:00 UTC Jan 05, 2018:

Location: 10.7°S 94.0°E
Maximum Winds: 20 kt
Minimum Central Pressure: 1007 mb

[Digital-TC-Chaser]

AXAU01 APRF 050724
IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0724 UTC 05/01/2018
Name: Tropical Low
Identifier: 08U
Data At: 0600 UTC
Latitude: 11.1S
Longitude: 94.1E
Location Accuracy: within 45 nm [85 km]
Movement Towards: southwest [224 deg]
Speed of Movement: 8 knots [16 km/h]
Maximum 10-Minute Wind: 40 knots [75 km/h]
Maximum 3-Second Wind Gust: 55 knots [100 km/h]
Central Pressure: 1000 hPa
Radius of 34-knot winds NE quadrant:
Radius of 34-knot winds SE quadrant:
Radius of 34-knot winds SW quadrant: 90 nm [165 km]
Radius of 34-knot winds NW quadrant: 90 nm [165 km]
Radius of 48-knot winds NE quadrant:
Radius of 48-knot winds SE quadrant:
Radius of 48-knot winds SW quadrant:
Radius of 48-knot winds NW quadrant:
Radius of 64-knot winds:
Radius of Maximum Winds: 40 nm [75 km]
Dvorak Intensity Code: T2.5/2.5/D1.5/24HRS STT:D0.5/24HRS
Pressure of outermost isobar: 1006 hPa
Radius of outermost closed isobar: 180 nm [335 km]
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+06: 05/1200: 11.8S 93.7E: 055 [105]: 040 [075]: 998
+12: 05/1800: 12.2S 92.8E: 070 [130]: 040 [075]: 997
+18: 06/0000: 12.5S 91.6E: 080 [150]: 040 [075]: 997
+24: 06/0600: 12.9S 90.2E: 095 [175]: 040 [075]: 997
+36: 06/1800: 13.5S 87.8E: 115 [210]: 040 [075]: 997
+48: 07/0600: 14.4S 85.3E: 135 [245]: 045 [085]: 994
+60: 07/1800: 15.8S 82.7E: 150 [280]: 045 [085]: 994
+72: 08/0600: 17.7S 80.3E: 170 [320]: 050 [095]: 991
+96: 09/0600: 22.2S 75.6E: 215 [400]: 045 [085]: 992
+120: 10/0600: 26.9S 71.2E: 300 [560]: 030 [055]: 1000
REMARKS:
Tropical low 08U has developed over the past 24 hours. T1.0 was assigned at 04
0600 UTC.

The system was located using visible and microwave imagery.

TC_SSMIS at 2350 UTC showed deep convection to the west and southwest of the
centre. A partial ASCAT pass at 0253 UTC showed 25/30 knot winds to the west of
the centre.

Dvorak: Over the past 6 hours a curved band on VIS/EIR of 0.4 to 0.5 yielded a
DT of 2.5. 24 trend is D with MET/PAT of 2.0. FT/CI set to 2.5. Intensity set to
40 knots with gales in the NW and SW quadrants.

Most recent imagery showed some deep convection just to the west of the centre.

UW-CIMSS at 05 0300 UTC indicated E'ly shear between 30 and 40 knots. There is
some equatorward outflow and good poleward outflow. SSTs in the area are about
28C with TC Heat Potential not particularly favourable.

08U is expected to gradually develop and may become a tropical cyclone overnight
or during Saturday as wind shear decreases.

08U is being steered by a mid level ridge to the southeast. The majority of NWP
indicates consistent west to southwest motion with the system crossing 90E [La
Reunion Area of Responsibility] around 06 0600 UTC.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 05/1330 UTC by Perth TCWC.

[Digital-TC-Chaser]

Tropical Storm 08U
UW-CIMSS Automated Satellite-Based
Advanced Dvorak Technique (ADT)
Version 8.2.1
Tropical Cyclone Intensity Estimation Algorithm
RSMC Initialized


Current Intensity Analysis



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

----- Current Analysis -----
Date : 05 JAN 2018 Time : 072000 UTC
Lat : 11:17:30 S Lon : 94:04:05 E


CI# /Pressure/ Vmax
3.0 / 991.0mb/ 45.0kt


Final T# Adj T# Raw T#
3.0 3.0 3.0

Latitude bias adjustment to MSLP : +0.0mb

Center Temp : -19.3C Cloud Region Temp : -22.7C

Scene Type : IRREGULAR CDO*

Positioning Method : FORECAST INTERPOLATION

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

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

Satellite Name : HIM-8
Satellite Viewing Angle : 55.0 degrees

[Digital-TC-Chaser]

NHC/JTWC storms in GREEN / RSMC/TCWC storms in YELLOW
Regional Responsibility
South-East Indian Ocean:
TCWC-Perth/Bureau of Meteorology (Western Australia region), Australia

[Digital-TC-Chaser]

IDW24000
Australian Government Bureau of Meteorology
Western Australia

TROPICAL CYCLONE INFORMATION BULLETIN
Issued at 8:40 am WST on Saturday 6 January 2018
BY THE BUREAU OF METEOROLOGY
TROPICAL CYCLONE WARNING CENTRE PERTH

Tropical Cyclone Irving (Category 1) was located at 8:00 am AWST near 12.6S
92.3E, that is 495 km west of Cocos Island and moving west southwest at 13
kilometres per hour. The system is not expected to directly impact the Cocos
(Keeling) Islands.

The next Information Bulletin will be issued at 3 pm AWST

[Digital-TC-Chaser]

AXAU01 APRF 060700
IDW27600
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by PERTH TROPICAL CYCLONE WARNING CENTRE
at: 0700 UTC 06/01/2018
Name: Tropical Cyclone Irving
Identifier: 08U
Data At: 0600 UTC
Latitude: 12.7S
Longitude: 90.6E
Location Accuracy: within 30 nm [55 km]
Movement Towards: west southwest [257 deg]
Speed of Movement: 11 knots [20 km/h]
Maximum 10-Minute Wind: 40 knots [75 km/h]
Maximum 3-Second Wind Gust: 55 knots [100 km/h]
Central Pressure: 994 hPa
Radius of 34-knot winds NE quadrant: 90 nm [165 km]
Radius of 34-knot winds SE quadrant: 90 nm [165 km]
Radius of 34-knot winds SW quadrant: 90 nm [165 km]
Radius of 34-knot winds NW quadrant: 90 nm [165 km]
Radius of 48-knot winds NE quadrant:
Radius of 48-knot winds SE quadrant:
Radius of 48-knot winds SW quadrant:
Radius of 48-knot winds NW quadrant:
Radius of 64-knot winds:
Radius of Maximum Winds: 30 nm [55 km]
Dvorak Intensity Code: T3.0/3.0/D0.5/24HRS
Pressure of outermost isobar: 1004 hPa
Radius of outermost closed isobar: 180 nm [335 km]
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+06: 06/1200: 13.1S 89.3E: 055 [105]: 040 [075]: 994
+12: 06/1800: 13.5S 87.9E: 070 [130]: 040 [075]: 995
+18: 07/0000: 13.8S 86.5E: 080 [150]: 045 [085]: 992
+24: 07/0600: 14.3S 85.3E: 095 [175]: 045 [085]: 992
+36: 07/1800: 15.7S 82.6E: 115 [210]: 045 [085]: 992
+48: 08/0600: 17.6S 80.0E: 135 [245]: 050 [095]: 989
+60: 08/1800: 19.8S 77.3E: 150 [280]: 050 [095]: 988
+72: 09/0600: 22.0S 74.1E: 170 [320]: 045 [085]: 991
+96: 10/0600: 27.3S 68.5E: 215 [400]: 030 [055]: 998
+120: 11/0600: 37.5S 74.1E: 300 [560]: 030 [055]: 996
REMARKS:
Tropical Cyclone Irving has shown little sign of development over the past six
hours displaying a partially exposed low level centre.

A Shear Pattern on IR imagery has the centre approximately 10 nautical miles
from the strong T gradient yielding a DT3.0. Development is D- which gives a MET
of 2.5, PAT is also 2.5. FT of 3.0 based on DT. ADT at 06 0545 UTC is 3.0.

UW-CIMSS at 05 1700 UTC indicated E'ly shear of around 30 knots. Though
convection is located in only western quadrants this estimate seems a little
high given the proximity of the estimated location of the centre to the
convection.

SSTs in the area are about 28C with TC Heat Potential not particularly
favourable.

Irving is being steered by a mid level ridge to the southeast. The majority of
NWP indicates consistent west to southwest motion with the system crossing 90E
[La Reunion Area of Responsibility] between 06 0600 and 06 1200 UTC.

Copyright Commonwealth of Australia
==
There will be no further bulletins issued for this system by Perth TCWC. Please
refer to La Reunion RSMC for subsequent updates.

[Digital-TC-Chaser]

WTXS32 PGTW 060900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 04S (IRVING) WARNING NR 002//
RMKS/
1. TROPICAL CYCLONE 04S (IRVING) WARNING NR 002
02 ACTIVE TROPICAL CYCLONES IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
060600Z --- NEAR 12.6S 90.4E
MOVEMENT PAST SIX HOURS - 265 DEGREES AT 12 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
RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT
095 NM SOUTHEAST QUADRANT
095 NM SOUTHWEST QUADRANT
135 NM NORTHWEST QUADRANT
REPEAT POSIT: 12.6S 90.4E
---
FORECASTS:
12 HRS, VALID AT:
061800Z --- 13.2S 87.9E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 115 NM NORTHEAST QUADRANT
135 NM SOUTHEAST QUADRANT
120 NM SOUTHWEST QUADRANT
125 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 250 DEG/ 14 KTS
---
24 HRS, VALID AT:
070600Z --- 14.2S 85.1E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 000 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
010 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT
200 NM SOUTHEAST QUADRANT
160 NM SOUTHWEST QUADRANT
095 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 245 DEG/ 16 KTS
---
36 HRS, VALID AT:
071800Z --- 15.6S 82.1E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 010 NM NORTHEAST QUADRANT
045 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT
215 NM SOUTHEAST QUADRANT
165 NM SOUTHWEST QUADRANT
075 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 235 DEG/ 17 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
080600Z --- 17.6S 79.3E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 005 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
000 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
055 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 160 NM NORTHEAST QUADRANT
225 NM SOUTHEAST QUADRANT
175 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 225 DEG/ 20 KTS
---
72 HRS, VALID AT:
090600Z --- 22.9S 73.1E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT
065 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
010 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT
110 NM SOUTHEAST QUADRANT
080 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 215 NM NORTHEAST QUADRANT
230 NM SOUTHEAST QUADRANT
190 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 210 DEG/ 18 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
100600Z --- 29.2S 69.1E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 075 NM NORTHEAST QUADRANT
095 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
005 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 200 NM NORTHEAST QUADRANT
220 NM SOUTHEAST QUADRANT
150 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 120 HR POSIT: 165 DEG/ 28 KTS
---
120 HRS, VALID AT:
110600Z --- 40.1S 73.1E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
BECOMING EXTRATROPICAL
RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT
250 NM SOUTHEAST QUADRANT
130 NM SOUTHWEST QUADRANT
180 NM NORTHWEST QUADRANT
---
REMARKS:
060900Z POSITION NEAR 12.7S 89.8E.
TROPICAL CYCLONE (TC) 04S (IRVING), LOCATED APPROXIMATELY 1108 NM
EAST-SOUTHEAST OF DIEGO GARCIA, HAS TRACKED WESTWARD AT 12 KNOTS
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS PERSISTENT CONVECTION, MAINLY TO THE WEST OF THE LOW LEVEL
CIRCULATION CENTER (LLCC) ASSOCIATED WITH TC 04S. THE INITIAL
POSITION IS BASED ON A 060550Z HIMAWARI VISIBLE SATELLITE IMAGE
SHOWING THE AFOREMENTIONED CONVECTION WEST OF THE LLCC. THE INITIAL
INTENSITY IS 35 KNOTS BASED ON A DVORAK ESTIMATE OF T2.5 (35 KNOTS)
FROM PGTW AND KNES. UPPER LEVEL ANALYSIS SHOWS MODERATE TO STRONG
VERTICAL WIND SHEAR VALUES OF 20 TO 25 KNOTS. BOTH POLEWARD AND
EQUATORWARD OUTFLOW CHANNELS ARE BEGINNING TO DEVELOP. SEA SURFACE
TEMPERATURES ARE FAVORABLE FOR DEVELOPMENT (27 TO 28 DEGREES
CELSIUS). TC 04S IS TRACKING WESTWARD ALONG THE NORTHERN PERIPHERY
OF A SUBTROPICAL RIDGE (STR) LOCATED TO THE SOUTH. AFTER TAU 12,
THE SYSTEM WILL GRADUALLY TURN SOUTHWESTWARD AS IT ROUNDS THE
WESTERN EDGE OF THE STR. TC 04S WILL STEADILY INTENSIFY UNDER
FAVORABLE ENVIRONMENTAL CONDITIONS TO A PEAK OF 65 KNOTS BY TAU 48.
AFTER TAU 72, TC 04S WILL BEGIN TO RE-CURVE AND ACCELERATE AS IT
BEGINS TO INTERACT WITH THE MIDLATITUDE WESTERLIES, BEGINNING
EXTRA-TROPICAL TRANSITION NEAR TAU 120. DYNAMIC MODEL GUIDANCE IS
IN GOOD AGREEMENT THROUGH TAU 120, THEREFORE, THERE IS HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 060600Z IS 12 FEET. NEXT WARNINGS AT 061500Z, 062100Z,
070300Z AND 070900Z. REFER TO TROPICAL CYCLONE 03S (AVA) WARNINGS
(WTXS31 PGTW) FOR SIX-HOURLY UPDATES.//
NNNN

[cycloneye]

15:00 UTC JTWC warning at 40 kts and Is forecast to peak at 70 kts.

[cycloneye]

21:00 UTC warning from JTWC at 45 kts.

[1900hurricane]

Since it has now crossed 90ºE, MFr has begun issuing advisories in BoM's stead. They're classifying it as a moderate tropical storm.

WTIO30 FMEE 061851
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 2/2/20172018
1.A MODERATE TROPICAL STORM 2 (IRVING)
2.A POSITION 2018/01/06 AT 1800 UTC:
WITHIN 30 NM RADIUS OF POINT 13.1 S / 88.5 E
(THIRTEEN DECIMAL ONE DEGREES SOUTH AND EIGHTY EIGHT DECIMAL FIVE
DEGREES EAST)
MOVEMENT : WEST-SOUTH-WEST 10 KT
3.A DVORAK ANALYSIS: 3.0/3.0/D 0.5/6 H
4.A CENTRAL PRESSURE: 992 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 40 KT
RADIUS OF MAXIMUM WINDS (RMW) :37 KM
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 150 SE: 260 SW: 260 NW: 150
34 KT NE: 110 SE: 70 SW: 70 NW: 70
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 1000 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP
1.B FORECASTS:
12H: 2018/01/07 06 UTC: 14.5 S / 85.3 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
24H: 2018/01/07 18 UTC: 16.5 S / 82.0 E, MAX WIND=050 KT, SEVERE TROPICAL STORM
36H: 2018/01/08 06 UTC: 18.6 S / 79.0 E, MAX WIND=060 KT, SEVERE TROPICAL STORM
48H: 2018/01/08 18 UTC: 21.0 S / 76.6 E, MAX WIND=060 KT, SEVERE TROPICAL STORM
60H: 2018/01/09 06 UTC: 23.8 S / 73.8 E, MAX WIND=050 KT, SEVERE TROPICAL STORM
72H: 2018/01/09 18 UTC: 27.0 S / 70.6 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
2.B LONGER-RANGE OUTLOOK :
96H: 2018/01/10 18 UTC: 35.0 S / 70.1 E, MAX WIND=035 KT, EXTRATROPICAL
DEPRESSION
120H: 2018/01/11 18 UTC: 44.8 S / 78.0 E, MAX WIND=035 KT, EXTRATROPICAL
DEPRESSION
2.C ADDITIONAL INFORMATION:
T=CI=3.0+
AS ANNOUNCED DURING THE PAST 6 HOURS DURING THE PREVIOUS RMSC
WARNING, THE CONVECTIVE BURSTS ARE STRONG AND REMAIN WELL AXED OVER
THE CIRCULATION CENTER.
IRVING'S TRACK IS STEERED BY A STRONG RIDGE IN THE SOUTH-EAST. ALL
NUMERICAL MODELS ARE IN AGREEMENT WITH THIS SITUATION, DEFINING THEN A
GOOD CONFIDENCE IN THE FORECAST. FROM WEDNESDAY, IRVING SHOULD BE
ATTRACTED TOWARDS THE MID-LATITUDES BY A TROUGH ARRIVING FROM THE
SOUTH-WEST WHOSE FORECAST IS ALSO WELL APPREHENDED.
THE UPPER ATMOSPHERIC DYNAMICS IS SUITABLE FOR A SHEAR ENVIRONMENT
NEAR THE SYSTEM. HOWEVER THE SIGNIFICANT SPEED OF DISPLACEMENT OF
IRVING SHOULD ALLOW IT TO COMPENSATE THE NEGATIVE EFFECTS OF THE SHEAR
AND TO INTENSIFY UNTIL THE MAXIMUM STAGE OF SEVERE TROPICAL STORM,
RESTRICTED BY THE OCEANIC POTENTIAL TO THESE LATITUDES AND THE
INFLUENCE OF THE UPPER TROUGH STRONGER. IRVING SHOULD THEN BEGIN TO
WEAKEN WHILE BEGINNING AN EXTRATROPICAL TRANSITION.

However, I think it may be stronger than that based on microwave imagery.

[Digital-TC-Chaser]

yeah me to.earlier 941z it appeared to be intensifying.

[Digital-TC-Chaser]

50/50 chance of later going annular tropical cyclone?

[wxman57]

This is no 45kt TS. Eyewall is nearly complete.

[cycloneye]

JTWC 03:00 UTC warning is up to 55 kts and it peaks at 90 kts.

[Digital-TC-Chaser]

[cycloneye]

JTWC up to 65 kts.

[cycloneye]

[cycloneye]

Up to 90 kts.

[doomhaMwx]

04S IRVING 180108 0600 17.6S 79.8E SHEM 90 956

[cycloneye]

90 kts has been the peak by JTWC for a few warnings so is going down in intensity from here.