ABIO10 PGTW 161100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN
/REISSUED/161100Z-161800ZDEC2019//
RMKS/
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY:
(1) AN AREA OF CONVECTION (INVEST 96S) HAS PERSISTED NEAR
11.0S 69.1E, APPROXIMATELY 292 NM SOUTHWEST OF DIEGO GARCIA.
ANIMATED INFRARED SATELLITE IMAGERY AND A 160425Z MHS METOP-A IMAGE
DEPICT A DISORGANIZED LOW LEVEL CIRCULATION WITH BROAD AREAS OF WEAK
CONVECTION. THE ENVIRONMENT FOR 96S IS FAVORABLE FOR DEVELOPMENT
WITH LOW (<15 KNOTS) VERTICAL WIND SHEAR, GOOD EQUATORWARD OUTFLOW,
AND WARM (27-28C) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE IN
GOOD AGREEMENT SHOWING LITTLE DEVELOPMENT FOR 96S. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1010 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS LOW.
(2) NO OTHER SUSPECT AREAS.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: ADDED AREA IN PARA 2.B.(1) AS LOW.//
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ABIO10 PGTW 172000
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN
/OCEAN/REISSUED/172000Z-181800ZDEC2019//
RMKS/
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF
AFRICA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
C. SUBTROPICAL SYSTEM 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 96S) PREVIOUSLY LOCATED
NEAR 11.4S 69.1E IS NOW LOCATED NEAR 13.6S 70.3E, APPROXIMATELY 398
NM SOUTH-SOUTHWEST OF DIEGO GARCIA. ANIMATED INFRARED SATELLITE
IMAGERY AND A 171225Z SSMIS 91GHZ MICROWAVE IMAGE DEPICT A BROAD
AREA WITH FLARING CONVECTION ALONG THE PERIPHERY AND CONVECTIVE
BANDING WRAPPING INTO A LOW LEVEL CIRCULATION. THE ENVIRONMENT FOR
96S IS FAVORABLE FOR DEVELOPMENT WITH LOW TO MODERATE (10-20 KNOTS)
VERTICAL WIND SHEAR, POLEWARD OUTFLOW, AND WARM (29-30C) SEA SURFACE
TEMPERATURES. GLOBAL MODELS ARE IN GOOD AGREEMENT REGARDING OVERALL
SYSTEM MOTION AND SHOW STRENGTHENING WINDS TO THE SOUTH. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 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 IS UPGRADED TO MEDIUM.
(2) NO OTHER SUSPECT AREAS.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: UPGRADED AREA IN PARA 2.B.(1) TO
MEDIUM.
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WTXS21 PGTW 190300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 96S)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
140 NM EITHER SIDE OF A LINE FROM 15.6S 71.6E TO 15.6S 67.4E
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 27 TO 32 KNOTS. METSAT
IMAGERY AT 190230Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 15.2S 70.4E. THE SYSTEM IS MOVING SOUTH-SOUTHEASTWARD AT 07
KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 96S) PREVIOUSLY LOCATED
NEAR 14.5N 70.0E IS NOW LOCATED NEAR 15.2N 70.4E, APPROXIMATELY 792
NM EAST-NORTHEAST OF MAURITIUS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS A CONSOLIDATING SYSTEM WITH LOW LEVEL CLOUDS
WRAPPING INTO A LOW LEVEL CIRCULATION CENTER (LLCC) OBSCURED BY
SIGNIFICANT CENTRAL CONVECTION. A 182049Z AMSR2 89GHZ IMAGE FURTHER
DEPICTS LOW LEVEL BANDING WITH DEEP CONVECTION NEAR THE LLCC. A
181731Z ASCAT-B IMAGE DEPICTS A WIDE SWATH OF 25 KNOT WINDS SOUTH OF
THE LLCC, WHICH ARE A RESULT FROM THE TIGHT PRESSURE GRADIENT
BETWEEN 96S AND THE STRONG HIGH PRESSURE SYSTEM LOCATED TO THE
SOUTH. INVEST 96S IS IN A MARGINAL ENVIRONMENT FOR DEVELOPMENT WITH
MODERATE (15-20 KTS) VERTICAL WIND SHEAR OFFSET BY WARM (28-29C) SEA
SURFACE TEMPERATURES AND ROBUST POLEWARD OUTFLOW ALOFT. DYNAMIC
MODELS ARE IN GOOD AGREEMENT THAT 96S WILL FURTHER CONSOLIDATE AS IT
TRACKS INITIALLY POLEWARD THROUGH TAU 12 THEN WESTWARD TOWARDS
MADAGASCAR. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 27 TO
32 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 IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
200300Z.
//
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ABIO10 PGTW 191800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN
/OCEAN/191800Z-201800ZDEC2019//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/190251DEC2019//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT CANCELLATION.//
RMKS/
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF
AFRICA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
C. SUBTROPICAL SYSTEM 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 96S) PREVIOUSLY LOCATED
NEAR 15.2S 70.4E IS NOW LOCATED NEAR 15.6S 69.8E, APPROXIMATELY 752
NM EAST-NORTHEAST OF MAURITIUS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS LOW LEVEL CLOUDS WRAPPING INTO AN EXPOSED LOW LEVEL
CIRCULATION CENTER (LLCC) WITH CONVECTION SHEARED TO THE SOUTH AND
EAST. A 191219Z MHS 89GHZ IMAGE DEPICTS THE SAME WITH FLARING
CONVECTION SOUTH AND EAST OF THE LLCC. INVEST 96S IS IN A MARGINAL
ENVIRONMENT FOR DEVELOPMENT WITH HIGH (25 KTS) VERTICAL WIND SHEAR
OFFSET BY WARM (28-29C) SEA SURFACE TEMPERATURES AND ROBUST POLEWARD
OUTFLOW ALOFT. DYNAMIC MODELS ARE IN GOOD AGREEMENT THAT 96S WILL
CONTINUE TO TRACK WESTWARD TOWARDS MADAGASCAR AND GRADUALLY WEAKEN.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 27 TO 32 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 IS DOWNGRADED TO LOW. SEE REF A (WTXS21
PGTW 191730) FOR FURTHER DETAILS.
(2) NO OTHER SUSPECT AREAS.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.//
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(1) THE AREA OF CONVECTION (INVEST 96S) PREVIOUSLY LOCATED
NEAR 12.9S 53.3E IS NOW LOCATED NEAR 11.3S 54.3E, APPROXIMATELY 569
NM NORTH-NORTHWEST OF MAURITIUS. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY AND A 262138Z AMSR2 89GHZ SATELLITE IMAGE DEPICT
CONVECTION CONSOLIDATING AROUND A BROAD LOW LEVEL CIRCULATION.
INVEST 96S IS IN A MARGINALLY FAVORABLE ENVIRONMENT FOR
DEVELOPMENT WITH MODERATE TO HIGH (20-30 KNOTS) VERTICAL WIND SHEAR
IN THE NORTHERN PERIPHERY, AND LOW (<15 KNOTS) VERTICAL WIND SHEAR
IN THE SOUTHERN PERIPHERY, WARM (29-30C) SEA SURFACE TEMPERATURES,
EQUATORWARD OUTFLOW AND A DEVELOPING POLEWARD OUTFLOW CHANNEL.
GLOBAL MODELS SUGGEST THAT 96S WILL CONSOLIDATE AND STRENGTHEN AS IT
TRACKS SOUTH-SOUTHEASTWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 15 TO 20 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 UPGRADED TO
MEDIUM.
WTXS21 PGTW 271500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 96S)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 11.5S 55.4E TO 16.8S 57.7E 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 271200Z
INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 12.1S 55.7E. THE
SYSTEM IS MOVING EAST-SOUTHEASTWARD AT 08 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 96S) PREVIOUSLY LOCATED
NEAR 11.3S 54.3E IS NOW LOCATED NEAR 12.1S 55.7E, APPROXIMATELY 508
NM NORTH-NORTHWEST OF MAURITIUS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS TROUGHING WITH SCATTERED DEEP CONVECTION WITHIN THE
TROUGH AXIS. A 271230Z SSMIS F-16 91GHZ MICROWAVE IMAGE SHOWS A
GENERAL LACK OF CONVECTIVE STRUCTURE WITH FRAGMENTED DEEP CONVECTION
TO THE EAST. A 270514Z METOP-B ASCAT PASS REVEALS TROUGHING FLANKED
BY 20 TO 25 KNOT WINDS TO THE NORTH AND SOUTH. 96S IS CURRENTLY IN A
FAVORABLE ENVIRONMENT WITH EXCELLENT POLEWARD OUTFLOW, ENHANCED BY A
TROUGH TO THE SOUTHWEST, LOW (5 TO 10 KNOT) VERTICAL WIND SHEAR, AND
WARM (29 TO 30 CELSIUS) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE
IN GOOD AGREEMENT THAT 96S WILL TRACK SOUTH-SOUTHEASTWARD AND
INTENSIFY TO THE WARNING THRESHOLD WITHIN 24-48 HOURS. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 998 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
281500Z.//
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