SHEM: 23P(NIRAN) forecast to peak as a strong US/Cat 3 in 36h, 22S(MARIAN) is weakening. Invest 90S now on the map, 03/15utc updates


03/18UTC. JTWC HAS BEEN ISSUING 6HOURLY WARNINGS ON 23P(NIRAN) AND 12HOURLY WARNINGS ON 22S(MARIAN). 3 HOURLY SATELLITE BULLETINS ARE ISSUED FOR BOTH SYSTEMS. INVEST 90S IS NOW ON THE MAP WITH CURRENTLY MEDIUM CHANCES OF REACHING 35KNOTS WITHIN 24HOURS. REFER TO THE CHART BELOW.


03/18UTC. JTWC HAS BEEN ISSUING 6HOURLY WARNINGS ON 23P(NIRAN) AND 12HOURLY WARNINGS ON 22S(MARIAN). 3 HOURLY SATELLITE BULLETINS ARE ISSUED FOR BOTH SYSTEMS. INVEST 90S IS NOW ON THE MAP WITH CURRENTLY MEDIUM CHANCES OF REACHING 35KNOTS WITHIN 24HOURS. REFER TO THE CHART BELOW.
03/18UTC. JTWC HAS BEEN ISSUING 6HOURLY WARNINGS ON 23P(NIRAN) AND 12HOURLY WARNINGS ON 22S(MARIAN). 3 HOURLY SATELLITE BULLETINS ARE ISSUED FOR BOTH SYSTEMS. INVEST 90S IS NOW ON THE MAP WITH CURRENTLY MEDIUM CHANCES OF REACHING 35KNOTS WITHIN 24HOURS. REFER TO THE CHART BELOW.
2021 MAR 03 15UTC #SOUTHERNHEMISPHERE
TC #23P #NIRAN  #SOUTHPACIFICOCEAN #CORALSEA
WARNING 11
As of 12:00 UTC Mar 03, 2021:
Location: 14.8°S 148.3°E
Maximum Winds: 70 kt ( 130km/h)
Gusts: 85 kt ( 160km/h)
Minimum Central Pressure: 970mb
INTENSIFYING
CATEGORY US: 1
LOCATED AT 03/12UTC  APPROXIMATELY 355 KM NORTHEAST OF CAIRNS, AUSTRALIA, HAS TRACKED EASTWARD AT 07 KM/H OVER
THE PAST SIX HOURS.
 Satellite bulletins are to be found in the comments of this post on JTWC BIS
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TC #22S #MARIAN  #SOUTHINDIANOCEAN
WARNING 12
As of 12:00 UTC Mar 03, 2021:
Location: 19.3°S 92.1°E
Maximum Winds: 50 kt (95km/h)
Gusts: 65 kt ( 120km/h)
Minimum Central Pressure: 985 mb
WEAKENING
LOCATED AT 03/12UTC APPROXIMATELY 2290 KM WEST OF LEARMONTH, AUSTRALIA, HAS TRACKED EAST-SOUTHEASTWARD  AT 13 KM/H OVER THE PAST SIX HOURS.
Satellite bulletins are to be found in the comments of this post on JTWC BIS
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INVEST #90S  #SOUTHINDIANOCEAN
UPDATE
As of 12:00 UTC Mar 03, 2021:
Location: 15.2°S 66.2°E
Maximum Winds: 20 kt
Minimum Central Pressure: 1001 mb
LOCATED AT 03/12UTC APPROXIMATELY 580KM TO THE NORTHEAST OF RODRIGUES ISLAND.
CURRENT POTENTIAL FOR THE NEXT 24HOURS: UP-GRADED TO MEDIUM.
 
Cheers,
Patrick Hoareau
 Météo974
M974World
Cyclone Class 4
 Cheers,PH.

Joint Typhoon Warning Center

23P(NIRAN). WARNING 11 ISSUED AT 03/15UTC.THE ENVIRONMENT IS OVERALL FAVORABLE WITH LOW (10-15KT) VERTICAL WIND SHEAR, VERY WARM  (29-30C) SSTS PARTLY OFFSET BY LIMITED OUTFLOW ALOFT. TC 23P IS  QUASI-STATIONARY IN A COL BETWEEN THE NEAR EQUATORIAL RIDGE (NER),  EXTENDING FROM THE NORTH TO SOUTHEAST OF THE SYSTEM, AND THE  SUBTROPICAL RIDGE TO THE WEST OVER AUSTRALIA. THE NER IS EXPECTED TO  BUILD AND BECOME THE DOMINANT STEERING MECHANISM AND SLOWLY NUDGE  THE SYSTEM OUT OF THE COL, AND BY 12H, DRIVE IT SOUTHEASTWARD,  PASSING JUST SOUTH OF NEW CALEDONIA AROUND 60H, AND BY 96H,  SHOULD BE APPROXIMATELY 815KM NORTH-NORTHEAST OF AUCKLAND, NEW  ZEALAND. THE MARGINALLY FAVORABLE ENVIRONMENT WILL IMPROVE AS THE  CYCLONE TRACKS POLEWARD INTO IMPROVED UPPER LEVEL OUTFLOW AND HELP  FUEL A STEADY INTENSIFICATION TO A PEAK OF 105KNOTS/US CATEGORY 3 BY 36H.  AFTERWARD, INCREASING VERTICAL WIND SHEAR AND COOLING SEAS WILL GRADUALLY ERODE THE  CYCLONE DOWN TO 70KNOTS/CATEGORY 1 BY 96H. CONCURRENTLY, BY 72H, IT WILL  BEGIN SUBTROPICAL TRANSITION AS IT APPROACHES THE COLD BAROCLINIC  ZONE, AND BY 96H, WILL TRANSFORM INTO A SUBTROPICAL SYSTEM.
23P(NIRAN). WARNING 11 ISSUED AT 03/15UTC.THE ENVIRONMENT IS OVERALL FAVORABLE WITH LOW (10-15KT) VERTICAL WIND SHEAR, VERY WARM (29-30C) SSTS PARTLY OFFSET BY LIMITED OUTFLOW ALOFT. TC 23P IS QUASI-STATIONARY IN A COL BETWEEN THE NEAR EQUATORIAL RIDGE (NER), EXTENDING FROM THE NORTH TO SOUTHEAST OF THE SYSTEM, AND THE SUBTROPICAL RIDGE TO THE WEST OVER AUSTRALIA. THE NER IS EXPECTED TO BUILD AND BECOME THE DOMINANT STEERING MECHANISM AND SLOWLY NUDGE THE SYSTEM OUT OF THE COL, AND BY 12H, DRIVE IT SOUTHEASTWARD, PASSING JUST SOUTH OF NEW CALEDONIA AROUND 60H, AND BY 96H, SHOULD BE APPROXIMATELY 815KM NORTH-NORTHEAST OF AUCKLAND, NEW ZEALAND. THE MARGINALLY FAVORABLE ENVIRONMENT WILL IMPROVE AS THE CYCLONE TRACKS POLEWARD INTO IMPROVED UPPER LEVEL OUTFLOW AND HELP FUEL A STEADY INTENSIFICATION TO A PEAK OF 105KNOTS/US CATEGORY 3 BY 36H. AFTERWARD, INCREASING VERTICAL WIND SHEAR AND COOLING SEAS WILL GRADUALLY ERODE THE CYCLONE DOWN TO 70KNOTS/CATEGORY 1 BY 96H. CONCURRENTLY, BY 72H, IT WILL BEGIN SUBTROPICAL TRANSITION AS IT APPROACHES THE COLD BAROCLINIC ZONE, AND BY 96H, WILL TRANSFORM INTO A SUBTROPICAL SYSTEM.

23P(NIRAN).NUMERICAL MODELS ARE IN GENERAL AGREEMENT WITH THE TRACK FORECAST  BUT WITH SIGNIFICANT VARIATIONS IN ALONG TRACK SPEED IN THE NEAR- TERM AS THE TC EXITS FROM THE COL. ALSO, ACROSS TRACK SPREADS TO  OVER 1330KM BY 96H, LENDING LOW CONFIDENCE IN THE JTWC TRACK  FORECAST THAT IS LAID CLOSE TO THE MODEL CONSENSUS.
23P(NIRAN).NUMERICAL MODELS ARE IN GENERAL AGREEMENT WITH THE TRACK FORECAST BUT WITH SIGNIFICANT VARIATIONS IN ALONG TRACK SPEED IN THE NEAR- TERM AS THE TC EXITS FROM THE COL. ALSO, ACROSS TRACK SPREADS TO OVER 1330KM BY 96H, LENDING LOW CONFIDENCE IN THE JTWC TRACK FORECAST THAT IS LAID CLOSE TO THE MODEL CONSENSUS.

23P(NIRAN). 03/1430UTC.ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS THE SYSTEM HAS MAINTAINED OVERALL CONVECTIVE SIGNATURE WITH THE MAIN FEEDER BAND WRAPPING IN FROM THE NORTH INTO AN OBSCURED LOW LEVEL CIRCULATION THAT IS UNDER COLD OVERSHOOTING CLOUD TOPS.
23P(NIRAN). 03/1430UTC.ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS THE SYSTEM HAS MAINTAINED OVERALL CONVECTIVE SIGNATURE WITH THE MAIN FEEDER BAND WRAPPING IN FROM THE NORTH INTO AN OBSCURED LOW LEVEL CIRCULATION THAT IS UNDER COLD OVERSHOOTING CLOUD TOPS.

23P(NIRAN). 03/1204UTC.ASCAT PASS CORROBORATES THE   QUASI-STATIONARY MOTION OF THE CYCLONE.
23P(NIRAN). 03/1204UTC.ASCAT PASS CORROBORATES THE QUASI-STATIONARY MOTION OF THE CYCLONE.

22S(MARIAN). WARNING 12 ISSUED AT 03/15UTC.THE SYSTEM IS IN A DETERIORATING ENVIRONMENT WITH INCREASING VERTICAL WIND SHEAR  (15KTS+) AND COOLING SSTS (25C). TC 22S HAS MOVED OUT OF THE COL  BETWEEN THE NEAR EQUATORIAL RIDGE (NER)TO THE NORTH-NORTHEAST AND A  SUBTROPICAL RIDGE (STR) TO THE SOUTH WHICH HAS WEAKENED AND ALLOWED  A SECONDARY STR TO BUILD IN FROM THE EAST AND ASSUME STEERING. THIS  NEW STR WILL DRIVE THE CYCLONE SOUTH-SOUTHEASTWARD FOR THE WHOLE  DURATION OF THE FORECAST. THE HARSH ENVIRONMENT WILL CONTINUE THE  GRADUAL WEAKENING AND EVENTUALLY THE INTENSITY FALLING BELOW 35KNOTS BY 96H,  POSSIBLY SOONER.
22S(MARIAN). WARNING 12 ISSUED AT 03/15UTC.THE SYSTEM IS IN A DETERIORATING ENVIRONMENT WITH INCREASING VERTICAL WIND SHEAR (15KTS+) AND COOLING SSTS (25C). TC 22S HAS MOVED OUT OF THE COL BETWEEN THE NEAR EQUATORIAL RIDGE (NER)TO THE NORTH-NORTHEAST AND A SUBTROPICAL RIDGE (STR) TO THE SOUTH WHICH HAS WEAKENED AND ALLOWED A SECONDARY STR TO BUILD IN FROM THE EAST AND ASSUME STEERING. THIS NEW STR WILL DRIVE THE CYCLONE SOUTH-SOUTHEASTWARD FOR THE WHOLE DURATION OF THE FORECAST. THE HARSH ENVIRONMENT WILL CONTINUE THE GRADUAL WEAKENING AND EVENTUALLY THE INTENSITY FALLING BELOW 35KNOTS BY 96H, POSSIBLY SOONER.

22S(MARIAN). NUMERICAL MODELS ARE IN TIGHT AGREEMENT, LENDING  HIGH CONFIDENCE IN THE JTWC TRACK FORECAST.
22S(MARIAN). NUMERICAL MODELS ARE IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE IN THE JTWC TRACK FORECAST.


22S(MARIAN). 03/1430UTC.ANIMATED 12-HR ENHANCED  INFRARED SATELLITE IMAGERY SHOWS THE SYSTEM HAS GREATLY WEAKENED AS  EVIDENCED BY WARMING CLOUD TOPS IN THE CENTRAL DENSE OVERCAST AND  UNRAVELING RAIN BANDS..
22S(MARIAN). 03/1430UTC.ANIMATED 12-HR ENHANCED INFRARED SATELLITE IMAGERY SHOWS THE SYSTEM HAS GREATLY WEAKENED AS EVIDENCED BY WARMING CLOUD TOPS IN THE CENTRAL DENSE OVERCAST AND UNRAVELING RAIN BANDS..

INVEST 90S. ANIMATED ENHANCED INFRARED SATELLITE  IMAGERY AND A 031428Z SSMIS 91GHZ MICROWAVE IMAGE DEPICT FRAGMENTED  FORMATIVE BANDING WRAPPING INTO AN ELONGATED LOW LEVEL CIRCULATION  CENTER (LLCC) WITH FLARING CONVECTION IN THE EASTERN SEMICIRCLE.  INVEST 90S IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH GOOD  OUTFLOW ALOFT, LOW (
INVEST 90S. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 031428Z SSMIS 91GHZ MICROWAVE IMAGE DEPICT FRAGMENTED FORMATIVE BANDING WRAPPING INTO AN ELONGATED LOW LEVEL CIRCULATION CENTER (LLCC) WITH FLARING CONVECTION IN THE EASTERN SEMICIRCLE. INVEST 90S IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH GOOD OUTFLOW ALOFT, LOW (
Rédigé par PATRICK HOAREAU le Mercredi 3 Mars 2021 à 19:50