SIO: Alcide - Tropical Cyclone

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Nancy Smar
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SIO: Alcide - Tropical Cyclone

#1 Postby Nancy Smar » Sat Nov 03, 2018 8:46 am

94S INVEST 181103 1200 6.3S 73.3E SHEM 15 0
New disturbance!
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Re: SIO: INVEST 94S

#2 Postby Nancy Smar » Sat Nov 03, 2018 8:59 am

Suspect area between the Chagos and Seychelles archipelago: The NET is still as a broad and elongated area of relative low pressure without any defined surface circulation. Recent imagery however suggest that enhanced low level vorticity is located near 6.5°S / 71°E. Environmental conditions appear also favorable for some slow development although some mixed signal may interfere from Tuesday with an increase in east-north-easterly shear and a dryer mid-level environment close to the center. The system is expected to generally move westsouth-westwards or south-westwards coming nearer the Agalega islands.
Within the next 5 days, the likelihood that this system become a tropical storm becomes low from Tuesday.
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Re: SIO: INVEST 94S

#3 Postby Nancy Smar » Sat Nov 03, 2018 8:59 pm

(2) AN AREA OF CONVECTION (INVEST 94S) HAS PERSISTED NEAR 6.6S
71.0E, APPROXIMATELY 100 NM WEST-NORTHWEST OF DIEGO GARCIA. ANIMATED
ENHANCED INFRARED SATELLITE IMAGERY SHOWS PERSISTENT DEEP CONVECTION
STARTING TO TAKE ON SOME MIDLEVEL ROTATION. A 031715Z ASCAT IMAGE
SHOWS THE SYSTEM'S LLC IS CONSOLIDATING, THOUGH IT IS CURRENTLY
ELONGATED WITH 15-20 KNOT WINDS IN THE EASTERN QUADRANT. A 032255Z
89GHZ AMSU PARTIAL MICROWAVE SATELLITE IMAGE SHOWS FORMATIVE CURVED
BANDING, INDICATING THE SYSTEM HAS CONSOLIDATED SIGNIFICANTLY SINCE
THE AFOREMENTIONED ASCAT IMAGE. GOOD POLEWARD OUTFLOW IS BEING
OFFSET BY MODERATE (15-25KTS) VWS THAT INCREASES RAPIDLY TO THE
NORTHWEST. SSTS ARE WARM (27-29C) AND WILL SUPPORT FURTHER
DEVELOPMENT. GLOBAL MODELS ARE IN SOLID AGREEMENT AND AGGRESSIVELY
FORECAST DEVELOPMENT BY TAU 36-48 AS THE SYSTEM TRACKS TO THE WEST-
SOUTHWEST. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 MB.
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS MEDIUM.
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Re: SIO: INVEST 94S

#4 Postby vortextracker » Sun Nov 04, 2018 6:52 am

ImageImage
lots of cool anoms in the sio. Lower half of the intensity scale on plot 1 is likely for this disturbance.
Last edited by vortextracker on Sun Nov 04, 2018 4:04 pm, edited 1 time in total.
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Re: SIO: INVEST 94S

#5 Postby TorSkk » Sun Nov 04, 2018 7:20 am

TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER IN
THE SOUTHWEST INDIAN OCEAN

DATE: 2018/11/04 AT 1200 UTC

PART 1:
WARNING SUMMARY:
Nil.

PART 2 :
TROPICAL WEATHER DISCUSSION:

The basin remains in a Near Equatorial Trough (NET) pattern axed between 3 and 5S. Such a
configuration is also notable in the Northern Hemisphere to the east of 70°E defining a Double Near
Equatorial Trough pattern (DNET). Convective activity within this NET has been maintained for
more than 24 hours within two privileged areas. The western one occupies a large part of the area
between the Seychelles archipelago and Diego-Garcia. The second is located at the northeastern
edge of the basin.

Suspect area over the extreme Northeast of the basin (93S):

Over the past 24 hours, strong convective activity has shifted east of the clockwise low pressure
circulation. The last ASCAT swaths do not allow this clockwise circulation to be precisely located,
but it can be estimated at around 4°S/89.2°E at 0900UTC. The minimum pressure is currently
estimated at 1008 hPa and with improving low level convergence, a slow development is expected
in the next few days, while the system should move slowly in a general westerly direction.

Within the next 5 days, the likelihood that this system become a tropical storm becomes low
from Wednesday.


Zone of disturbed weather between Diego-Garcia and the Seychelles archipelago (94S):

Convective activity in this area persists, defining a zone of disturbed weather within the NET. The
0454UTC ASCAT swath of allows to define a fairly wide clockwise circulation around
6.5°S/68.5°E, with maximum winds of about 25kts in the SE part of the circulation. Unlike the
representation of some deterministic numerical models, the centre of rotation is not yet clearly
identifiable. Although the signal of a midjet development with some recent runs of numerical
models does not seem likely, environmental conditions appear favorable for development in the
coming days. The zone of disturbed weather is expected to persist and move in a general direction
towards the West-South-West. An intensification is therefore expected at the beginning of the week.

Within the next 5 days, the likelihood that this system become a tropical storm becomes
moderate from Tuesday and high from Wednesday.


Long range outlook of large scale conditions over the basin:

Under the influence of an active phase of MJO, convective activity in the basin is expected to
remain strong within the NET. The current suspect areas illustrate this conducive large scale
conditions for cyclogenesis. From mid-November, the risk of cyclogenesis should decrease with the
associated large scale subsidence and low level eastward anomaly winds less conducive for
cyclogenesis.
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Re: SIO: INVEST 94S

#6 Postby TorSkk » Sun Nov 04, 2018 10:41 am

Image
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Re: SIO: INVEST 94S

#7 Postby TorSkk » Mon Nov 05, 2018 9:45 am

TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE

BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER IN
THE SOUTHWEST INDIAN OCEAN

DATE: 2018/11/05 AT 1200 UTC

TROPICAL WEATHER DISCUSSION:

The basin remains in a Near Equatorial Trough (NET) pattern axed between 3 and 7S, on all its
length. Such a configuration is also present in the Northern Hemisphere defining a Double Near
Equatorial Trough pattern (DNET). Convective activity is moderate to severe within the NET,
especially close to the two areas monitored for several days.

Zone of Disturbed Weather east of Agalega :

Cloud pattern improved significantly over the past hours. Curved bands appeared in classic imagery
as well as in microwave data (AMSR 0910Z). However internal structure appears to be ill-defined,
with most of the convection in outer bands. This morning ASCAT swaths (0433Z) suggest a broad
elongated low level circulation with weak winds (10/15kt) close to its center. It is located near
7.5S/63.4E at 11Z, with a MSLP around 1006hPa.
Numerical guidance is in a good agreement to forecast a west-south-west track towards Agalega,
while intensifying. Wednesday seems to be the most favorable day, after the increase of the upper
divergence tomorrow evening in the southern semi-circle and before the progressive impact of the
WNW vertical wind shear ahead of a trough (from Thursday).
Guidance is still split on the intensity forecast in a rather conducive environment. Operational GFS
is among the most intense but its scenario is not privileged due to its incorrect initial analysis.
Among the other reliable,, most of them suggest a slower trend, hindered at first by the inner
structure.

From Friday, uncertainty is increasing on both track and intensity forecast due to different possible
impacts of the vertical wind shear.
Within the next 5 days, the likelihood that this system become a tropical storm becomes
moderate from Tuesday and high from Wednesday.
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Re: SIO: INVEST 94S

#8 Postby vortextracker » Mon Nov 05, 2018 6:29 pm

ABIO10 PGTW 051800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN
OCEAN/051800Z-061800ZNOV2018//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/050751ZNOV2018//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY:
(1) THE AREA OF CONVECTION (INVEST 94S) PREVIOUSLY LOCATED
NEAR 6.5S 68.3E, IS NOW LOCATED NEAR 7.8S 63.2E, APPROXIMATELY 915
NM NORTH-NORTHEAST OF LA REUNION, FRANCE. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY AND A 051315Z 91 GHZ SSMIS F-18 MICROWAVE IMAGE
SHOW FORMATIVE BANDING WRAPPING INTO THE LLCC WITH DEEP CONVECTION
PERSISTING OVER AND JUST TO THE SOUTH OF THE LLCC. THE DISTURBANCE
IS LOCATED IN AN AREA WITH FAVORABLE ENVIRONMENTAL CONDITIONS WITH
EXCELLENT POLEWARD OUTFLOW, MODERATE VERTICAL WIND SHEAR (10 TO 20
KNOTS), AND WARM SEA SURFACE TEMPERATURES (28-30 CELSIUS). GLOBAL
MODELS ARE GENERALLY IN AGREEMENT THAT THE SYSTEM WILL TRACK TO THE
WEST-SOUTHWEST OVER THE NEXT SEVERAL DAYS WITH INTENSIFICATION
VARYING FROM MODEL TO MODEL. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1002 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS HIGH.
SEE REF A (WTXS21 PGTW 050800) FOR FURTHER DETAILS.
(2) NO OTHER SUSPECT AREAS.//





Image

Image

Image

Decent anti cyclone under it. ec not thinking this will be anything other than a moderate ts atm.
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Re: SIO: 03S THREE

#9 Postby vortextracker » Mon Nov 05, 2018 8:41 pm

Best tracks
03S THREE 181106 0000 8.8S 60.7E SHEM 35 1005


Unusual pressure reading for a ts in the shem, usually just under 1000 mb as rule of thumb is a minimal tc.
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Re: SIO: 03S THREE

#10 Postby wxman57 » Mon Nov 05, 2018 9:09 pm

vortextracker wrote:Best tracks
03S THREE 181106 0000 8.8S 60.7E SHEM 35 1005


Unusual pressure reading for a ts in the shem, usually just under 1000 mb as rule of thumb is a minimal tc.


Who updates that best track file? La Reunion? They don't have any advisory out yet.
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Re: SIO: INVEST 94S

#11 Postby Grifforzer » Mon Nov 05, 2018 9:23 pm

SHIPPING BULLETIN FOR MET AREA VIII (S) METEOROLOGICAL SERVICES
MAURITIUS ISSUED ON TUESDAY 06 NOVEMBER 2018 AT 0030 UTC.

PART 1:TTT WARNING OF TROPICAL DEPRESSION
AT 0000 UTC, TROPICAL DEPRESSION 998 HPA WAS CENTERED WITHIN 20 NM OF RADIUS OF POINTS 8.2S AND 61.0E (EIGHT DECIMAL TWO DEGREES SOUTH IN
LATITUDES AND SIXTY ONE DECIMAL ZERO DEGREES EAST IN LATITUDES).
MOVEMENT: WEST SOUTHWEST 10 KNOTS.
SQUALLY WEATHER, ROUGH TO VERY ROUGH SEAS, TOGETHER WITH NEAR GALE FORCE WIND EXIST WITHIN 70 NM OF CENTER IN SOUTHERN SEMI-CIRCLE.

PART 2: GENERAL SYNOPSIS AT 0000 UTC ON TUESDAY 06 NOVEMBER 2018.
TROPICAL DEPRESSION (998 HPA) NEAR 8.2S 61.0E.
MOVEMENT: WEST SOUTHWEST 10 KNOTS.
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Re: SIO: INVEST 94S

#12 Postby vortextracker » Mon Nov 05, 2018 9:26 pm

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Re: SIO: INVEST 94S

#13 Postby wxman57 » Mon Nov 05, 2018 9:41 pm

vortextracker wrote:Its JTWC BEST TRACK DATA https://199.9.2.143/tcdat/sectors/atcf_sector_file


Ah, OK. JTWC is not the official agency of any basin, so, officially, it's a disturbance. Nothing from La Reunion yet that I can find. It does look like a TS on satellite, though.
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Re: SIO: INVEST 94S

#14 Postby vortextracker » Mon Nov 05, 2018 10:12 pm

0441Z i doubt anyone would disagree its a ts
Image

[ UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 9.0
Tropical Cyclone Intensity Algorithm


----- Current Analysis -----
Date : 06 NOV 2018 Time : 024500 UTC
Lat : 8:59:03 S Lon : 60:20:08 E


CI# /Pressure/ Vmax
2.5 /1009.9mb/ 35.0kt


Final T# Adj T# Raw T#
2.3 2.2 2.2

Center Temp : -1.4C Cloud Region Temp : -44.1C

Scene Type : CURVED BAND with 0.42 ARC in LT GRAY
Maximum CURVED BAND with 0.48 ARC in LT GRAY
at Lat: 9:34:47 S Lon: 60:55:48 E

Subtropical Adjustment : OFF

Extratropical Adjustment : OFF

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : INDIAN
Dvorak CI > MSLP Conversion Used : CKZ Method

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

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 62nmi
- Environmental MSLP : 1011mb

Satellite Name : MSG1
Satellite Viewing Angle : 24.3 degrees

Image

Image
https://imgur.com/sOpW66S
rain microwave
Last edited by vortextracker on Thu Nov 08, 2018 3:31 am, edited 1 time in total.
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Re: SIO: INVEST 94S

#15 Postby TorSkk » Tue Nov 06, 2018 11:20 am

The first name on the list is Alcide
Advisories are only issued at 6z and 12z when the system is weak

RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 2/2/20182019

1.A TROPICAL DEPRESSION 2

2.A POSITION 2018/11/06 AT 1200 UTC:
WITHIN 25 NM RADIUS OF POINT 9.5 S / 59.7 E

MOVEMENT : WEST-SOUTH-WEST 7 KT

3.A DVORAK ANALYSIS: 2.5/2.5/D 0.5/6 H]

4.A CENTRAL PRESSURE: 1000 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 30 KT
RADIUS OF MAXIMUM WINDS (RMW) :37 KM


6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: SE: 140 SW: 140 NW:

7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1011 HPA / 500 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM
1.B FORECASTS:
12H: 2018/11/07 00 UTC: 9.9 S / 57.9 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
24H: 2018/11/07 12 UTC: 10.6 S / 56.3 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
36H: 2018/11/08 00 UTC: 11.5 S / 55.3 E, MAX WIND=050 KT, SEVERE TROPICAL STORM
48H: 2018/11/08 12 UTC: 12.4 S / 54.6 E, MAX WIND=055 KT, SEVERE TROPICAL STORM
60H: 2018/11/09 00 UTC: 13.2 S / 54.3 E, MAX WIND=055 KT, SEVERE TROPICAL STORM
72H: 2018/11/09 12 UTC: 13.7 S / 54.2 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM

2.B LONGER-RANGE OUTLOOK :
96H: 2018/11/10 12 UTC: 13.9 S / 54.0 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
120H: 2018/11/11 12 UTC: 13.6 S / 53.2 E, MAX WIND=025 KT, TROPICAL DISTURBANCE

2.C ADDITIONAL INFORMATION:

T=CI=2.5-

OVER THE LAST 6 HOURS, CONVECTION DID NOT WRAP OVER THE EASTERN SEMICIRCLE,
PROBABLY BECAUSE OF A DRIER AIR INTRUSION IN THIS SECTOR.
HOWEVER, STRONG CONVECTIVE BURSTS MAINTAINED OVER THE CIRCULATION
CENTER. 89GHZ AND 36GHZ AMSR2 MW IMAGES STILL SHOW A SLIGHT WESTWARD
TILT OF THE VORTEX. THE LOW LEVEL STRUCTURE APPEARS TO BE
CONSOLIDATING.
THE WESTSOUTHWESTWARD MOTION OF TROPICAL DEPRESSION NB.2 IS
CURRENTLY STEERED BY A LOW LEVEL RIDGE LOCATED IN THE SOUTH-EAST OF
THE SYSTEM. WITH AN INTENSIFYING SYSTEM, THE MID-LEVELS PATTERNS WILL
TAKE OVER AND THE PROGRESSION OF THE STORM SHOULD BE EVENTUALLY
BLOCKED BY A HIGH GEOPOTENTIAL AREA LOCATED IN THE SOUTH-WEST. THE
TRACK WILL THUS BEGIN TO BEND SOUTHWARD THURSDAY BEFORE A
SIGNIFICANT SLOWING FRIDAY EVENING. AT LATE TAUS, THE MUCH WEAKER
SYSTEM COULD BE TAKEN AWAY BY THE TRADE WINDS FLOW. THIS TRACK
FORECAST IS BASED ON A IFS/GFS CONSENSUS. THE TWO MODELS HAVE A SIMILAR
PHILOSOPHY BUT THE LAST TWO IFS RUNS PRESENT A LITTLE NORTHWARD OFFSET.
THE UPPER-LEVEL CONDITIONS WILL IMPROVE THIS EVENING, WITH THE
DISAPPEARANCE OF THE VERTICAL WIND SHEAR AND THE GRADUAL
STRENGTHENING OF A POLEWARD OUTFLOW CHANNEL. THEREFORE, THE SYSTEM
IS FORECAST TO INTENSIFY AT A QUICKER PACE FROM TOMORROW. FROM
THURSDAY EVENING, MID-TROPOSPHERIC DRY AIR LOCATED IN THE WEST COULD
BE ADVECTED CLOSER TO THE SYSTEM'S CORE BY A STRENGTHENING SOUTHWESTERLY
WINDSHEAR ABOVE 400HPA. THEREFORE, THE STORM SHOULD BEGIN
TO WEAKEN SIGNIFICANTLY. WITH THE QUASI-COMPLETE STOP FORECAST FRIDAY
EVENING, THE UNDERLYING WATERS WILL BE COOLED QUICKLY AND PARTICIPATE
TO THE WEAKENING.
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Re: SIO: Alcide - Tropical Cyclone

#16 Postby Grifforzer » Tue Nov 06, 2018 3:38 pm

Mauritius Meteorological Services

Date and Time 6 November 2018 10 PM
Position 9.6°S 58.9°E
Estimated Central Pressure 995 hPa
Movement WSW 14 Km/h
Remark : The tropical depression has intensified into a moderate tropical storm and was named "Alcide"
Distance from Agalega (275 km ENE)
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Re: SIO: Alcide -

#17 Postby vortextracker » Tue Nov 06, 2018 3:39 pm

Image
https://imgur.com/jL8YOe0

WTIO30 FMEE 061846
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 3/2/20182019
1.A MODERATE TROPICAL STORM 2 (ALCIDE)



Image
https://imgur.com/Mb4kdHR


Image
https://imgur.com/IYnyIyg


https://severe.worldweather.wmo.int/tc/swi/


JTWC
03S THREE 181106 1800 9.8S 58.3E SHEM 45 1002
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Re: SIO: Alcide

#18 Postby vortextracker » Tue Nov 06, 2018 8:42 pm

Image

Low ocean heat appears to be keeping Alcide capped.
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Re: SIO: Alcide - Tropical Cyclone

#19 Postby Grifforzer » Wed Nov 07, 2018 2:47 am

Distance from Agalega: 55 km east

RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 5/2/20182019
1.A SEVERE TROPICAL STORM 2 (ALCIDE)
2.A POSITION 2018/11/07 AT 0600 UTC: WITHIN 20 NM RADIUS OF POINT 10.3 S / 56.9 E
MOVEMENT : WEST-SOUTH-WEST 6 KT
3.A DVORAK ANALYSIS: 4.0/4.0/D 1.0/6 H
4.A CENTRAL PRESSURE: 990 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 60 KT
1.B FORECASTS:
12H: 2018/11/07 18 UTC: 10.9 S / 55.7 E, MAX WIND=070 KT, TROPICAL CYCLONE
24H: 2018/11/08 06 UTC: 11.6 S / 54.7 E, MAX WIND=080 KT, TROPICAL CYCLONE
48H: 2018/11/09 06 UTC: 12.9 S / 54.1 E, MAX WIND=075 KT, TROPICAL CYCLONE
72H: 2018/11/10 06 UTC: 13.2 S / 54.6 E, MAX WIND=060 KT, SEVERE TROPICAL STORM

On this trajectory Severe Tropical Storm ALCIDE is dangerously approaching Agalega and is now a direct and serious threat to the island, while intensifying further. Cyclonic conditions, that is gusts of the order of 120 km/h will be experienced over the Island in the coming hours. It is very likely that the centre of Alcide will pass over the Island by mid-day. This situation may trigger an abnormal rise in sea level of about 70 cm above the normal tides causing submersion of coastal areas.

The wind will strengthen considerably from the south during the coming hours and causing cyclonic conditions, that is gusts of the order of 120 km/h over the island.
During the passage of the centre of Alcide on the island there may also be a weakening of the wind. This will be very temporary and the wind will strengthen suddenly from the opposite direction.

THE POPULATION AT AGALEGA IS STRONGLY ADVISED NOT TO VENTURE OUTDOOR DURING THE PASSAGE OF THE CENTRE OF ALCIDE OVER THE ISLAND.
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Re: SIO: Alcide - Tropical Cyclone

#20 Postby TorSkk » Wed Nov 07, 2018 2:27 pm

RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 7/2/20182019

1.A TROPICAL CYCLONE 2 (ALCIDE)

2.A POSITION 2018/11/07 AT 1800 UTC:
WITHIN 20 NM RADIUS OF POINT 10.8 S / 55.4 E

MOVEMENT : SOUTH-WEST 8 KT

3.A DVORAK ANALYSIS: 4.5/4.5/D 0.5/6 H

4.A CENTRAL PRESSURE: 980 HPA

5.A MAX AVERAGE WIND SPEED (10 MN): 70 KT

RADIUS OF MAXIMUM WINDS (RMW) :33 KM

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 140 SE: 210 SW: 210 NW: 140
34 KT NE: 90 SE: 140 SW: 140 NW: 90
48 KT NE: 70 SE: 90 SW: 90 NW: 70
64 KT NE: 50 SE: 50 SW: 50 NW: 50

7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1009 HPA / 600 KM

8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP

1.B FORECASTS:
12H: 2018/11/08 06 UTC: 11.4 S / 54.1 E, MAX WIND=080 KT, TROPICAL CYCLONE
24H: 2018/11/08 18 UTC: 12.0 S / 53.6 E, MAX WIND=085 KT, TROPICAL CYCLONE
36H: 2018/11/09 06 UTC: 12.6 S / 53.4 E, MAX WIND=075 KT, TROPICAL CYCLONE
48H: 2018/11/09 18 UTC: 13.0 S / 53.6 E, MAX WIND=065 KT, TROPICAL CYCLONE
60H: 2018/11/10 06 UTC: 13.0 S / 53.8 E, MAX WIND=055 KT, SEVERE TROPICAL STORM
72H: 2018/11/10 18 UTC: 12.7 S / 53.9 E, MAX WIND=050 KT, SEVERE TROPICAL STORM

2.B LONGER-RANGE OUTLOOK :
96H: 2018/11/11 18 UTC: 11.8 S / 53.0 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
120H: 2018/11/12 18 UTC: 10.8 S / 51.2 E, MAX WIND=040 KT, MODERATE TROPICAL
STORM

2.C ADDITIONAL INFORMATION:
T=CI=4.5+

OVER THE LAST 6 HOURS, ALCIDE'S EYE REMAINED VERY RAGGED ON THE IR SAT
ANIMATIONS. ON THE VERY LAST IMAGES, A WELL-DEFINED EYE APPEARED. THE
CURRENT DVORAK INTENSITY ESTIMATE DOES NOT YET TAKE INTO ACCOUNT THIS
LAST MINUTE IMPROVEMENT OF THE CLOUD PATTERN. THE 1430Z SSMIS MW IMAGE
WAS ALREADY SHOWING A SOLID AND WIDE CONVECTION RING. THE UPPER
DIVERGENCE REMAIN IMPRESSIVE.

ALCIDE IS CURRENTLY MOVING WESTSOUTHWESTWARD STEERED BY A WEAK MIDLEVEL
RIDGE LOCATED IN THE SOUTH. FROM TOMORROW, THE TRACK WILL BEGIN
TO BEND SOUTHWARD BEFORE A SIGNIFICANT SLOWING IN AN AREA WITHOUT ANY
SIGNIFICANT STEERING FLOW, AS THE AFOREMENTIONED RIDGE COLLAPSES.
WITHIN A RATHER NEUTRAL SYNOPTIC ENVIRONMENT, ALCIDE SHOULD NOT MOVE
MUCH. ENSEMBLE PREDICTION SHOWS THAT THE SYSTEM IS NOT LIKELY TO CROSS
15S. AT LONG RANGE, THE MODEL DISPERSION INCREASES AS THE SYSTEM COULD
BE TAKEN AWAY BY THE TRADE WINDS FLOW.

ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE WITH AN EXCELLENT UPPER
LEVEL DIVERGENCE, ESPECIALLY POLEWARD, AND ENOUGH OCEANIC POTENTIAL
NORTH OF 15S. FROM THURSDAY EVENING, VERTICAL WIND SHEAR IS FORECAST TO
STRENGTHEN IN THE MID-LEVELS AND ALTER ALCIDE'S STRUCTURE FRIDAY. EVEN
WITH A MODERATE CONSTRAINT EXPECTED, THE EFFECTS ON THIS SMALL SYSTEM
SHOULD BE SIGNIFICANT. THE WEAKENING DUE TO THE SLOW MOVEMENT AND
THE INDUCED UNDERLYING WATER COOLING SHOULD IS ALSO TAKEN INTO
ACCOUNT, MAINLY THROUGH THE ECMWF MODEL WHICH RUNS AN
OCEAN/ATMOSPHERIC COUPLING THAT SHOULD BE ABLE TO ACCURATELY
ANTICIPATE THESE EFFECTS. FROM MONDAY, WITHIN A RATHER DRY AND NEUTRAL
ENVIRONMENT, ALCIDE SHOULD CONTINUE TO WEAKEN SLOWLY WHILE DRIFTING
NORTHWESTWARD.
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