SIO: JERUTO - Post-Tropical

[cycloneye]

93S INVEST 200411 1200 10.1S 91.8E SHEM 20 1007

[cycloneye]

93S INVEST 200411 1800 10.0S 91.3E SHEM 20 1007

[cycloneye]

93S INVEST 200412 0000 10.1S 90.8E SHEM 20 1007

[Nancy Smar]

A wide clockwise circulation remains located East of the border of the basin, within the Australian area of responsibility. This morning ASCAT-C and ASCAT-B swaths reveal a still elongated structure, with max winds of about 15/20kt and a center near 10.8S/91.8E. Convective activity is significant over the area, thanks to a good poleward divergence and a strong surface convergence fueled by moderate trade winds. Over the next days, upper conditions remain favorable to a cyclogenesis. However, the lack of equatorward convergence should most likely prevent the consolidation of the low-level circulation, or at least slow it down. Thus, some deterministic Euro runs forecast a cyclogenesis occurring next week but the analysis of the available ensemble prediction suggest a low probability for this scenario.

The risk of formation of a moderate tropical storm east of the basin becomes low from next Tuesday.

[cycloneye]

93S INVEST 200412 1200 11.3S 92.1E SHEM 20 1007

AN AREA OF CONVECTION (INVEST 93S) HAS PERSISTED NEAR
11.2S 92.2E, APPROXIMATELY 284 NM WEST OF COCOS ISLAND, AUSTRALIA.
ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS FLARING CONVECTION
OVER A POORLY ORGANIZED AND OBSCURED LOW LEVEL CIRCULATION. A RECENT
120204Z ASCAT-A PASS REVEALED SPARSE 15- TO 20-KNOT WINDS ALONG THE
NORTHEASTERN QUADRANT WITH A BROAD 20-25 KNOT WIND FIELD ALONG THE
SOUTHERN AND WESTERN PERIPHERY OF THE LOW-LEVEL CIRCULATION. INVEST
93S IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH GOOD POLEWARD
OUTFLOW, LOW (<15KTS) VERTICAL WIND SHEAR, AND WARM (29-31C) SEA
SURFACE TEMERATURES. GLOBAL MODELS ARE IN GENERAL AGREEMENT THAT
INVEST 93S WILL CONTINUE TO CONSOLIDATE AS IT TRACKS WEST-
SOUTHWESTWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15
TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007
MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.
(2) NO OTHER SUSPECT AREAS.

[cycloneye]

93S INVEST 200412 1800 10.5S 91.4E SHEM 25 1004

[cycloneye]

AN AREA OF CONVECTION (INVEST 93S) PREVIOUSLY LOCATED NEAR
11.2S 92.2E IS NOW LOCATED NEAR 10.7S 92.0E, APPROXIMATELY 298 NM
WEST-NORTHWEST OF COCOS ISLAND, AUSTRALIA. ANIMATED ENHANCED
INFRARED SATELLITE IMAGERY AND A 121248Z SSMIS 91GHZ SATELLITE IMAGE
DEPICT FLARING CONVECTION OVER A POORLY ORGANIZED AND OBSCURED LOW
LEVEL CIRCULATION. A 121503z ASCAT-C PASS AMB REVEALS WINDS SPEEDS
15-20KT >30NM FROM LLCC, WRAPPING AROUND WESTERN HALF. INVEST 93S IS
IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH GOOD POLEWARD
OUTFLOW, LOW TO MODERATE (15-20KTS) VERTICAL WIND SHEAR, AND WARM
(29-31C) SEA SURFACE TEMERATURES. GLOBAL MODELS ARE IN GENERAL
AGREEMENT THAT INVEST 93S WILL CONTINUE TO CONSOLIDATE AS IT TRACKS
WEST-SOUTHWESTWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT
20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR
1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.

[NotSparta]

Looks like a TD, or at least close to it. Pretty obvious LLC near the edge of convection due to NE shear

[cycloneye]

93S INVEST 200413 0000 11.0S 90.5E SHEM 25 1004

[cycloneye]

93S INVEST 200413 1200 11.4S 90.4E SHEM 30 1006

[cycloneye]

THE AREA OF CONVECTION (INVEST 93S) PREVIOUSLY LOCATED
NEAR 11.2S 92.2E IS NOW LOCATED NEAR 12.5S 90.5E, APPROXIMATELY
375NM WEST-SOUTHWEST OF THE COCOS ISLANDS. ANIMATED ENHANCED
INFRARED SATELLITE IMAGERY AND A 131234Z SSMIS 91GHZ MICROWAVE IMAGE
DEPICT FLARING CONVECTION OVER A POORLY ORGANIZED AND OBSCURED LOW
LEVEL CIRCULATION. INVEST 93S IS IN A FAVORABLE ENVIRONMENT FOR
DEVELOPMENT WITH GOOD POLEWARD OUTFLOW, LOW TO MODERATE (15-20KTS)
VERTICAL WIND SHEAR, AND WARM (29-31C) SEA SURFACE TEMPERATURES.
GLOBAL MODELS ARE IN GENERAL AGREEMENT THAT INVEST 93S WILL CONTINUE
TO CONSOLIDATE AS IT TRACKS WEST-SOUTHWESTWARD. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS REMAINS LOW.

[cycloneye]

93S INVEST 200414 0000 13.5S 89.0E SHEM 30 1004

[cycloneye]

Upgraded to medium.

THE AREA OF CONVECTION (INVEST 93S) PREVIOUSLY LOCATED
NEAR 12.5S 90.5E IS NOW LOCATED NEAR 13.5S 89.0E, APPROXIMATELY 471
NM WEST-SOUTHWEST OF COCOS ISLAND. ENHANCED INFRARED SATELLITE
IMAGERY AND A 132224Z SSMIS 91 GHZ MICROWAVE IMAGE REVEAL FORMATIVE
BANDING WRAPPING UNDER AN AREA OF DEEP CONVECTION, WHICH IS
OBSCURING THE LOW LEVEL CIRCULATION. SUPPORTED BY ESTABLISHED
POLEWARD OUTFLOW, LOW (10-15 KTS) VERTICAL WIND SHEAR, AND WARM (29-
31 CELSIUS) SEA SURFACE TEMPERATURES, INVEST 93S REMAINS IN AN
OVERALL FAVORABLE ENVIRONMENT FOR DEVELOPMENT. GLOBAL MODELS ARE IN
GOOD AGREEMENT THAT INVEST 93S WILL CONTINUE TO CONSOLIDATE AS IT
TRACKS WEST-SOUTHWESTWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1004 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO
MEDIUM.
(2) N

[cycloneye]

93S INVEST 200414 1200 14.1S 87.3E SHEM 25 1006

[cycloneye]

TCFA issued

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 93S)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 13.9S 87.7E TO 16.9S 82.0E
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 141200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 14.1S 87.3E. THE SYSTEM IS MOVING WEST-SOUTHWESTWARD AT 06
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 93S) PREVIOUSLY LOCATED
NEAR 12.5S 90.5E IS NOW LOCATED NEAR 14.1S 87.3E, APPROXIMATELY 575
NM WEST-SOUTHWEST OF COCOS ISLAND. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY AND A 141101Z F-15 SSMIS 91GHZ MICROWAVE IMAGE DEPICT DEEP
CONVECTION ON THE SOUTHERN HALF OF A TIGHT LOW LEVEL CIRCULATION
CENTER (LLCC) AND BANDING WRAPPING IN FROM THE EAST. A 140303Z METOP-
A ASCAT PASS REVEALS AN ASYMMETRIC WIND FIELD AROUND A TIGHT LLCC
WITH 25 TO 30 KNOT WINDS IN THE SOUTHWESTERN QUADRANT AND 15-20 KTS
TO THE NORTH. 93S IS CURRENTLY IN A FAVORABLE ENVIRONMENT WITH GOOD
POLEWARD OUTFLOW, MODERATE (20 TO 25 KNOT) VERTICAL WIND SHEAR
(VWS), AND WARM (28 TO 29 CELSIUS) SEA SURFACE TEMPERATURES. GLOBAL
MODELS ARE IN GOOD AGREEMENT THAT 93S WILL CONTINUE TO TRACK
GENERALLY SOUTHWESTWARD WITH SLIGHT INTENSIFICATION, POTENTIALLY
REACHING WARNING THRESHOLD WITHIN 24 HOURS, BEFORE BEGINNING TO
DISSIPATE UNDER UNFAVORABLE VWS. 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
151500Z.//
NNNN

[wxman57]

Official RSMC of the basin in La Reunion has classified this disturbance as a tropical depression:

[cycloneye]

[Nancy Smar]

FKIO20 FMEE 150630
TC ADVISORY
DTG: 20200415/0630Z
TCAC: REUNION
TC: JERUTO
ADVISORY NR: 2020/01
OBS PSN: 15/0600Z S1549 E08432
CB: WI 200NM OF TC CENTRE TOP FL530
MOV: WSW 10KT
C: 1000HPA
MAX WIND: 35KT
FCST PSN +6 HR: 15/1200Z S1622 E08352
FCST MAX WIND +6 HR: 33KT
FCST PSN +12 HR: 15/1800Z S1658 E08310
FCST MAX WIND +12 HR: 30KT
FCST PSN +18 HR: 16/0000Z S1739 E08223
FCST MAX WIND +18 HR: 30KT
FCST PSN +24 HR: 16/0600Z S1812 E08139
FCST MAX WIND +24 HR: 30KT
RMK: NIL
NXT MSG: 20200415/1200Z=

[wxman57]

Looks like Meteo France upgraded the storm after it weakened below TS strength. Latest ASCAT indicates winds now below 35kts and dropping.

[cycloneye]

TROPICAL CYCLONE 26S (JERUTO) WARNING NR 003
01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
151800Z --- NEAR 16.2S 83.1E
MOVEMENT PAST SIX HOURS - 255 DEGREES AT 07 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
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
000 NM NORTHWEST QUADRANT
REPEAT POSIT: 16.2S 83.1E
---
FORECASTS:
12 HRS, VALID AT:
160600Z --- 17.0S 81.7E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---