SWIO: Post-Tropical Carlos

[1900hurricane]

An invest exists northeast of Madagascar. It's not much to look at currently, but guidance does allude to the possibility that 92S could become the strongest Southern Hemisphere tropical cyclone so far this season (not that it means much considering how dead the season has been thus far).

[Digital-TC-Chaser]

AWIO20 FMEE 011221
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER IN
THE SOUTHWEST INDIAN OCEAN
DATE: 2017/02/01 AT 1200 UTC
PART 1:
WARNING SUMMARY:
Nil.
PART 2 :
TROPICAL WEATHER DISCUSSION:

The SWIO basin remains in a Monsoon Trough (MT) pattern east of 50E, axed along 12S west of
75E and along 10S to the east. The convective activity remains associated with residual low of
N°03-2016-2017 and within a persistent low pressure area near Agaléga.
South of Agalega Island :
Satellite imagery shows a weak circulation, rather wide with a ill-defined center near 14.0S/55.8E at
1000Z, totally exposed in the South-East of deep convection. According with the data from
Tromelin station and the buoy n°53011603, minimal pressure is estimated at 1006 hPa. The last
partial ASCAT swath and Tromelin observations show maximal winds about 15 kt reaching locally
20 kt in the equatoward feeding. Deep convection is essentially located within the monsoon flow,
undergoing a strong south-easterly vertical wind shear.
At short term, environmental conditions are unfavorable with a moderate southeasterly vertical
windshear and especially not enough low level convergence.
From Friday, environmental conditions should improve with a increasing polerward low level
inflow and a good equatoward diffluence. Moreover, a dynamic mid-latitude upper level trough is
forecasted to shift near the Mascareignes archipelago and should provide a good upper level
divergence and a good upper level outflow up to Saturday
With these increasing conditions, the two models IFS and GFS deepen this low, but differ on the
track and the intensity:
- ECMWF tracks rapidly the system South-South-Eastwards , with a progressively intensification,
then a turn South-Westwards, so the system is expected to pass in the south-east of Mauritius then
La Reunion on Monday as a tropical storm.

- GFS suggests a slower track southwards until Sunday, but deepen it more rapidly, reaching the
storm force on Saturday. after a stationary track and evolution on Sunday, the system begin to
track South-south-westwards, deepening a little more.
It should be noted that the last ECMWF runs which have varied a lot these last days seem more
consistent. Moreover the three last runs of the ensemble forecast of IFS are more stables, and GFS
and UKMO also deepen the system. while GFS is more consistent with a deepening become more
important as the run goes.
For this reason, the likelihood of cyclogenesis become moderate to strong on Saturday.

http://www.meteo.fr/temps/domtom/La_Reu ... index.html

http://www.cyclonextreme.com/cyclonereunion.htm
Good link here for the SWIO one stop shop.

[1900hurricane]

I'm not sure I'd classify yet or not if I were in charge, but I'd certainly think long and hard about it.



Meh, who am I kidding, I'd tag it as a depression.

[1900hurricane]

JTWC Tropical Cyclone Formation Alert is up:

WTXS21 PGTW 031300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
150 NM EITHER SIDE OF A LINE FROM 13.6S 55.3E TO 17.1S 56.0E WITHIN
THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF
NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA
ARE ESTIMATED TO BE 25 TO 30 KNOTS. METSAT IMAGERY AT 031230Z
INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 14.1S 55.5E. THE
SYSTEM IS MOVING SOUTH-SOUTHEASTWARD AT 04 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 92S) PREVIOUSLY LOCATED
NEAR 13.8S 55.9E IS NOW LOCATED NEAR 14.1S 55.5E, APPROXIMATELY 405
NM NORTH OF LA REUNION. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
DEPICTS A CONSOLIDATING LOW-LEVEL CIRCULATION CENTER (LLCC) WITH
IMPROVED BANDING. RECENT MICROWAVE IMAGERY REVEALS FORMATIVE
CONVECTIVE BANDING WRAPPING INTO AN IMPROVED LLCC. UPPER-LEVEL
ANALYSIS INDICATES NEAR-RADIAL OUTFLOW WITH LOW TO MODERATE VERTICAL
WIND SHEAR. ADDITIONALLY, SST VALUES ARE FAVORABLE AT 28 TO 29C.
GLOBAL MODELS ARE IN AGREEMENT, SHOWING THE SYSTEM TRACKING SLOWLY
SOUTHWARD WHILE INTENSIFYING RAPIDLY OVER THE NEXT TWO DAYS. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. THE POTENTIAL FOR
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
041300Z.//
NNNN

[Digital-TC-Chaser]

.
cimss plot above.
Maybe TS already.
Looks a very favourable environment aloft with excellent divergence for further development and possibly a healthy RI
in the near future for this system. West of the system the atmosphere appears to be becoming more moist on vapor sat.
Red/Green=shear values
Yellow=Divergence aloft/available mass outflow exhaust chimney.

[1900hurricane]

I would not wait for anything more to classify and name this system. That F15 pass shows a tropical storm.

[Crostorm]

[1900hurricane]

Carlos looks to still be struggling with large-scale subsidence.

[Digital-TC-Chaser]

Small core,i think the ri may begin with the recurve.

[Steve820]

So we finally have something in the SHem. The SHem as a whole has been way too dead (who knows why). This looks to become the most powerful SHem storm so far this year (if it's not the most powerful already, lol), with Reunion and Madagascar in the danger zone.

[Digital-TC-Chaser]

REMARKS:
050300Z POSITION NEAR 17.5S 56.7E.
TROPICAL CYCLONE 04S (CARLOS), LOCATED APPROXIMATELY 167 NM
NORTH-NORTHWEST OF PORT LOUIS, MAURITIUS, HAS TRACKED
SOUTHEASTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED
INFRARED SATELLITE IMAGERY DEPICTS A VERY COMPACT SYSTEM WITH
FLARING CENTRAL CONVECTION AND FRAGMENTED BANDING FEATURES. A
042229Z 85 GHZ SSMI IMAGE SHOWS RELATIVELY SHALLOW CONVECTIVE
ACTIVITY WITH LITTLE IMPROVEMENT OVER THE LAST SIX HOURS. THE
INITIAL INTENSITY OF 35 KNOTS IS BASED ON THE CONSERVATIVE SIDE OF
DVORAK ESTIMATES RANGING FROM T2.0 TO T3.0 (30 TO 45 KNOTS).
ENVIRONMENTAL CONDITIONS ARE CURRENTLY VERY FAVORABLE WITH NEAR
RADIAL OUTFLOW, LOW VERTICAL WIND SHEAR, AND WARM SSTS VALUES NEAR
28 TO 29 CELSIUS. CURRENTLY TC 04S IS SLOWLY DRIFTING SOUTHWARD
GUIDED BY A WEAK RIDGE EXTENSION TO THE NORTHEAST. BY TAU 48 A
SUBTROPICAL RIDGE TO THE EAST WILL BUILD IN GUIDING THE SYSTEM ON A
SOUTHWESTWARD TRACK. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO REMAIN
FAVORABLE THROUGHOUT THE FORECAST PERIOD SUPPORTING GRADUAL
INTENSIFICATION TO A SIGNIFICANT TROPICAL CYCLONE. DYNAMIC MODEL
GUIDANCE SHOWS AGREEMENT IN THE FORECAST PHILOSOPHY BUT DIFFERS IN
THE EXACT POSITION AND TIMING OF THE TURN TO THE SOUTHWEST. OVERALL
THERE IS LOW CONFIDENCE IN THE FORECAST TRACK. MAXIMUM SIGNIFICANT
WAVE HEIGHT AT 050000Z IS 12 FEET. NEXT WARNINGS AT 051500Z AND
060300Z.//

[wxman57]

An eye is starting to appear on satellite imagery. Dvorak at 4.0.

[1900hurricane]

Looks like it might be decoupling.

[1900hurricane]

Carlos doesn't seem to be enjoying 25-35 kt of northwesterly shear.

[1900hurricane]

It's going to have to gain some distance form that upper level low if it wants to do anything intensity-wise.

[Digital-TC-Chaser]

Still given a chance @being the first shem cane this season.

[1900hurricane]

Structure still appears slightly tilted to the south with increasing height at the moment, but Carlos appears to be in the midst of a fairly decent comeback.

[Digital-TC-Chaser]

Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 08 FEB 2017 Time : 223000 UTC
Lat : 23:33:00 S Lon : 52:28:10 E


CI# /Pressure/ Vmax
3.6 / 989.3mb/ 57.0kt


Final T# Adj T# Raw T#
3.4 3.3 3.3



Nice eye feature. peaked?

[Digital-TC-Chaser]

WTIO30 FMEE 090134 RRB2017-02-09 0145Z
OVER THE PAST HOURS, CONVECTION REMAINED STRONG NEAR THE CENTER. ON
THE LAST IR IMAGES, A WARMER POINT HAS TEMPORARILY APPEARED. 2307
SSMI SWATH STILL DEPICTS A VERY TIGHT RING OF INTENSE CONVECTION, BUT
LACKING ITS WESTERN PART. ACCORDING TO CIMSS LATEST ANALYSIS, THE
VERTICAL WINDSHEAR IS INCREASING SLIGHTLY BUT REMAINS CURRENTLY WEAK.
DURING THE NEXT HOURS, CARLOS IS EXPECTED TO KEEP ON ACCELERATING
TOWARDS THE SOUTH-EAST, STEERED BY A MID-TROPOSPHERIC RIDGE IN THE
NORTH-EAST AND A TROUGH COMING FROM THE MID-LATITUDES. FROM SUNDAY,
CARLOS SHOULD BE BLOCKED BY A HIGH CELL CIRCULATING EASTWARDS IN ITS
SOUTH. THE MODEL GUIDANCE IS IN RATHER GOOD AGREEMENT EVEN IF THE GFS
MODEL REMAINS QUICKER THAN THE ECMWF ONE FRIDAY AND SATURDAY. AT THE
END OF THE TAUS, AS CARLOS SHOULD MAKE A U-TURN, THE UNCERTAINTY
BECOMES GREATER.
THE INFLUENCE OF AN UPPER TROUGH COMING FROM THE SOUTH-WEST SHOULD
GRADUALLY BECOME SIGNIFICANT TODAY. AT FIRST, THE DIVERGENCE AND
CARLOS SOUTH-EASTWARD MOVEMENT TOWARDS THE SOUTH-EAST SHOULD MITIGATE
THE EFFECTS OF THE MODERATE WESTERLY SHEAR. BUT BY FRIDAY, IT SHOULD
QUICKLY BECOME TOO STRONG, ESPECIALLY WITH THE SMALL SIZE OF CARLOS,
AS A MID-TROPOSPHERIC DRY AIR LAYER COULD ALSO SLITHER IN ITS CORE.
THE SYSTEM SHOULD THEN WEAKEN. DURING THE WEEK-END, CARLOS COULD
SHIFT UNDER THE UPPER TROUGH WHICH THEN ISOLATE ITSELF AS A CUT-OFF
LOW ABOVE THE CIRCULATION, SHIELDING IT FROM THE SHEAR. IN THIS
CONTEXT, CARLOS MAY BECOME A SUBTROPICAL SYSTEM AT THE END OF THE
TAUS, AND EVEN SLIGHTLY INTENSIFY AGAIN OVER LOW OHC WATERS.=


http://gwydir.demon.co.uk/advisories/WT ... 090134.htm

[Digital-TC-Chaser]

WTIO22 FMEE 090636
PANPAN
HURRICANE WARNING FOR METAREA VII AND METAREA VIII (S)
ISSUED BY METEO-FRANCE/TROPICAL CYCLONE CENTER/LA REUNION 09/02/2017
AT
0600 UTC.
WARNING NUMBER: 024/4 (SOUTH-WEST INDIAN OCEAN)

10 MINUTES AVERAGE WIND SPEED IN KNOTS (KT)
(WIND GUSTS AT SEA MAY BE ABOUT 40% STRONGER THAN THE AVERAGED WIND)
MINIMUM SEA LEVEL PRESSURE IN HECTOPASCAL (HPA)
(INDICATIVE FIGURE).

HURRICANE WARNING
BEGINNING OF VALIDITY: THURSDAY 09/02/2017 AT 0600 UTC.

PHENOMENON: TROPICAL CYCLONE 4 (CARLOS) 975 HPA
POSITION: WITHIN 20 NM RADIUS OF POINT 23.7 S / 53.7 E
(TWENTY THREE DECIMAL SEVEN DEGREES SOUTH AND
FIFTY THREE DECIMAL SEVEN DEGREES EAST) AT 0600 UTC
MOVEMENT: EAST-SOUTH-EAST 6 KT

THREAT AREAS:
SQUALLY WEATHER WITHIN A 60 NM RADIUS FROM THE CENTER EXTENDING UP TO
150 NM IN THE EASTERN SEMI-CIRCLE.
HURRICANE FORCE WINDS 65 KT AND VERY HIGH TO PHENOMENAL SEAS
EXTENDING UP TO 10 NM IN THE EASTERN SEMI-CIRCLE.
STORM FORCE WINDS 50/60 KT AND HIGH TO VERY HIGH SEAS WITHIN A 20 NM
RADIUS FROM THE CENTRE, EXTENDING UP TO 35 NM IN THE EASTERN
SEMI-CIRCLE.
GALE FORCE WINDS 35/45 KT AND VERY ROUGH TO HIGH SEAS WITHIN A 30 NM
RADIUS FROM THE CENTRE, EXTENDING UP TO 85 NM IN THE SOUTH-EASTERN
QUADRANT AND UP TO 90 NM IN THE NORTH-EASTERN QUADRANT.
NEAR GALE FORCE WINDS 30 KT AND ROUGH TO VERY ROUGH SEAS WITHIN A 60
NM RADIUS FROM THE CENTRE, EXTENDING UP TO 70 NM IN THE SOUTH-WESTERN
QUADRANT, UP TO 120 NM IN THE SOUTH-EASTERN QUADRANT AND UP TO 140 NM
IN THE NORTH-EASTERN QUADRANT.
STRONG GUSTS UNDER SQUALLS.

FORECAST POSITION AND INTENSITY:
12H, VALID 2017/02/09 AT 18 UTC:
25.5 S / 55.2 E, MAX WIND = 50 KT, SEVERE TROPICAL STORM
24H, VALID 2017/02/10 AT 06 UTC:
27.4 S / 57.1 E, MAX WIND = 45 KT, MODERATE TROPICAL STORM

OTHER INFORMATIONS:
NIL.=









ADT
2017FEB09 080000 4.5 973.2 77.0 4.5 4.5 3.5 MW ON OFF OFF -75.16 -68.57 UNIFRM N/A 48.7 -24.40 -53.76 FCST MET7 28.7
2017FEB09 083000 4.5 973.2 77.0 4.5 4.5 3.5 MW ON OFF OFF -77.26 -69.16 UNIFRM N/A 48.7 -24.45 -53.80 FCST MET7 28.8
2017FEB09 090000 4.6 971.2 79.6 4.6 4.6 3.5 MW ON OFF OFF -77.26 -70.13 UNIFRM N/A 48.7 -24.50 -53.84 FCST MET7 28.8