SHEM: 23P(NIRAN) 55knots gradually intensifying over the Coral Sea// 22S(MARIAN) 90knots set on a weakening trend, 02/15utc updates


22S(MARIAN). 02/1017UTC. DMSP VISIBLE.


22S(MARIAN). 02/1017UTC. DMSP VISIBLE.
22S(MARIAN). 02/1017UTC. DMSP VISIBLE.
2021 MAR 02 15UTC #SOUTHERNHEMISPHERE
TC #23P  #SOUTHPACIFICOCEAN #CORALSEA
WARNING 7
As of 12:00 UTC Mar 02, 2021:
Location: 14.8°S 148.2°E
Maximum Winds: 55 kt ( 100km/h)
Gusts: 70 kt ( 130km/h)
Minimum Central Pressure: 986mb
INTENSIFYING
LOCATED AT 02/12UTC  APPROXIMATELY 345 KM NORTHEAST OF CAIRNS, AUSTRALIA, HAS TRACKED EASTWARD AT 04 KM/H
OVER THE PAST SIX HOURS.
 Satellite bulletins are to be found in the comments of this post on JTWC BIS
----------------------------------------------------------------------------------------------------------------------
TC #22S #MARIAN  #SOUTHINDIANOCEAN
WARNING 10
As of 12:00 UTC Mar 02, 2021:
Location: 18.7°S 89.8°E
Maximum Winds: 90 kt (170km/h)
Gusts: 110 kt ( 205km/h)
Minimum Central Pressure: 956 mb
CATEGORY US : 2
WEAKENING
LOCATED AT 02/12UTC APPROXIMATELY 1045 KM SOUTHWEST OF COCOS ISLAND, AUSTRALIA, HAS TRACKED EAST-SOUTHEASTWARD AT 04 KM/H OVER THE PAST SIX HOURS.
Satellite bulletins are to be found in the comments of this post on JTWC BIS

Cheers,
Patrick Hoareau
 Météo974
M974World
Cyclone Class 4
 Cheers,PH.

Joint Typhoon Warning Center

23P(NIRAN). WARNING 7 ISSUED AT 02/15UTC.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) EXTENDED 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 24H, DRIVE IT  SOUTHEASTWARD, PASSING JUST SOUTH OF NEW CALEDONIA BEFORE AROUND 78H, AND BY 120H, SHOULD BE TO THE NORTHEAST OF NEW ZEALAND. THE  MARGINALLY FAVORABLE ENVIRONMENT WILL PROMOTE A SLOW INTENSIFICATION  TO A PEAK OF 80KNOTS/US CATEGORY 1 BY 96H AS THE SYSTEM TAPS INTO INCREASED  POLEWARD OUTFLOW AS IT APPROACHES THE MIDLATITUDE WESTERLIES.  AFTERWARD, INCREASING WIND SHEAR AND COOLING SEAS WILL BEGIN TO ERODE THE  CYCLONE DOWN TO 65KNOTS BY 120H. CONCURRENTLY, IT WILL ENTER THE  BAROCLINIC ZONE AND BEGIN EXTRA-TROPICAL TRANSITION.
23P(NIRAN). WARNING 7 ISSUED AT 02/15UTC.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) EXTENDED 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 24H, DRIVE IT SOUTHEASTWARD, PASSING JUST SOUTH OF NEW CALEDONIA BEFORE AROUND 78H, AND BY 120H, SHOULD BE TO THE NORTHEAST OF NEW ZEALAND. THE MARGINALLY FAVORABLE ENVIRONMENT WILL PROMOTE A SLOW INTENSIFICATION TO A PEAK OF 80KNOTS/US CATEGORY 1 BY 96H AS THE SYSTEM TAPS INTO INCREASED POLEWARD OUTFLOW AS IT APPROACHES THE MIDLATITUDE WESTERLIES. AFTERWARD, INCREASING WIND SHEAR AND COOLING SEAS WILL BEGIN TO ERODE THE CYCLONE DOWN TO 65KNOTS BY 120H. CONCURRENTLY, IT WILL ENTER THE BAROCLINIC ZONE AND BEGIN EXTRA-TROPICAL TRANSITION.

23P(NIRAN). NUMERICAL MODELS ARE IN GENERAL AGREEMENT WITH THE TRACK FORECAST WITH  SIGNIFICANT VARIATIONS IN ALONG TRACK SPEED IN THE NEAR-TERM AS THE  TC TRANSITIONS FROM THE COL AND ACROSS TRACK SPREAD TO OVER 1850KM BY 120H, 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 WITH SIGNIFICANT VARIATIONS IN ALONG TRACK SPEED IN THE NEAR-TERM AS THE TC TRANSITIONS FROM THE COL AND ACROSS TRACK SPREAD TO OVER 1850KM BY 120H, LENDING LOW CONFIDENCE IN THE JTWC TRACK FORECAST THAT IS LAID CLOSE TO THE MODEL CONSENSUS.


23P(NIRAN). 02/1410UTC. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS THE CENTRAL DENSE OVERCAST CONTINUED TO DEEPEN AND  EXPAND. ADDITIONALLY, A 020830UTC MULTISPECTRAL SATELLITE SUNSET  IMAGE, SHOWED OVERSHOOTING CLOUD TOPS AND A DIMPLE FEATURE NEAR THE  CENTER.
23P(NIRAN). 02/1410UTC. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS THE CENTRAL DENSE OVERCAST CONTINUED TO DEEPEN AND EXPAND. ADDITIONALLY, A 020830UTC MULTISPECTRAL SATELLITE SUNSET IMAGE, SHOWED OVERSHOOTING CLOUD TOPS AND A DIMPLE FEATURE NEAR THE CENTER.

22S(MARIAN). WARNING 10 ISSUED AT 02/15UTC.THE SYSTEM IS IN A MARGINAL ENVIRONMENT WITH LOW (10-15KT) VERTICAL WIND SHEAR  AND GOOD RADIAL OUTFLOW THAT ARE OFFSET BY SUBSIDENCE ALONG THE  SOUTHWEST QUADRANT CAUSED BY THE MID-LATITUDE TROUGH TO THE  SOUTHWEST AND TEPID (26C) SEA SURFACE TEMPERATURE (SST). TC 22S IS  QUASI-STATIONARY AND SLOWLY MOVING OUT OF A COL BETWEEN THE NEAR  EQUATORIAL RIDGE (NER) TO THE NORTH-NORTHEAST AND A SUBTROPICAL  RIDGE (STR) TO THE SOUTH. THE STR TO THE SOUTH IS EXPECTED TO  WEAKEN, ALLOWING FOR A SECONDARY STR BUILDING IN FROM THE EAST TO  ASSUME STEERING AND EVENTUALLY DRIVE THE CYCLONE SOUTH- SOUTHEASTWARD. THE MARGINAL ENVIRONMENT IS EXPECTED TO GET WORSE  WITH INCREASING WIND SHEAR AND COOLING SEAS, LEADING TO GRADUAL WEAKENING  WITH INTENSITY FALLING BELOW 35KNOTS BY 120H.
22S(MARIAN). WARNING 10 ISSUED AT 02/15UTC.THE SYSTEM IS IN A MARGINAL ENVIRONMENT WITH LOW (10-15KT) VERTICAL WIND SHEAR AND GOOD RADIAL OUTFLOW THAT ARE OFFSET BY SUBSIDENCE ALONG THE SOUTHWEST QUADRANT CAUSED BY THE MID-LATITUDE TROUGH TO THE SOUTHWEST AND TEPID (26C) SEA SURFACE TEMPERATURE (SST). TC 22S IS QUASI-STATIONARY AND SLOWLY MOVING OUT OF A COL BETWEEN THE NEAR EQUATORIAL RIDGE (NER) TO THE NORTH-NORTHEAST AND A SUBTROPICAL RIDGE (STR) TO THE SOUTH. THE STR TO THE SOUTH IS EXPECTED TO WEAKEN, ALLOWING FOR A SECONDARY STR BUILDING IN FROM THE EAST TO ASSUME STEERING AND EVENTUALLY DRIVE THE CYCLONE SOUTH- SOUTHEASTWARD. THE MARGINAL ENVIRONMENT IS EXPECTED TO GET WORSE WITH INCREASING WIND SHEAR AND COOLING SEAS, LEADING TO GRADUAL WEAKENING WITH INTENSITY FALLING BELOW 35KNOTS BY 120H.

22S(MARIAN). NUMERICAL MODELS ARE IN A TIGHT PACK, HOWEVER, THERE ARE DIFFERENCES IN THE TIMING ON THE STEERING  TRANSITION AND EVENTUAL SOUTH-SOUTHEASTWARD TRACK, LENDING FAIR  CONFIDENCE IN THE JTWC TRACK FORECAST.
22S(MARIAN). NUMERICAL MODELS ARE IN A TIGHT PACK, HOWEVER, THERE ARE DIFFERENCES IN THE TIMING ON THE STEERING TRANSITION AND EVENTUAL SOUTH-SOUTHEASTWARD TRACK, LENDING FAIR CONFIDENCE IN THE JTWC TRACK FORECAST.


22S(MARIAN). 02/1415UTC.ANIMATED 12-HR ENHANCED INFRARED SATELLITE IMAGERY SHOWS THE SYSTEM HAS MAINTAINED DEEP  CONVECTIVE SIGNATURE AND A RAGGED 55-KM EYE, ALBEIT WITH WARMING  CLOUD TOPS IN THE CENTRAL DENSE OVERCAST..
22S(MARIAN). 02/1415UTC.ANIMATED 12-HR ENHANCED INFRARED SATELLITE IMAGERY SHOWS THE SYSTEM HAS MAINTAINED DEEP CONVECTIVE SIGNATURE AND A RAGGED 55-KM EYE, ALBEIT WITH WARMING CLOUD TOPS IN THE CENTRAL DENSE OVERCAST..

22S(MARIAN). 02/1205UTC. SMAP(NASA) READ 67KNOT WINDS(10 MINUTES). IT SUGGESTS A CURRENT INTENSITY SLIGHTLY LOWER THAN THE 12UTC JTWC ESTIMATE, 75/80KNOTS(1 MINUTE) INSTEAD OF 90KNOTS.
22S(MARIAN). 02/1205UTC. SMAP(NASA) READ 67KNOT WINDS(10 MINUTES). IT SUGGESTS A CURRENT INTENSITY SLIGHTLY LOWER THAN THE 12UTC JTWC ESTIMATE, 75/80KNOTS(1 MINUTE) INSTEAD OF 90KNOTS.

02/15UTC.  JTWC IS ISSUING 3HOURLY WARNING ON TC 23P(NIRAN) AND 12HOURLY WARNINGS ON TC 22S(MARIAN). 3 HOURLY SATELLITE BULLETINS ARE ISSUED FOR BOTH SYSTEMS.
02/15UTC. JTWC IS ISSUING 3HOURLY WARNING ON TC 23P(NIRAN) AND 12HOURLY WARNINGS ON TC 22S(MARIAN). 3 HOURLY SATELLITE BULLETINS ARE ISSUED FOR BOTH SYSTEMS.
Rédigé par PATRICK HOAREAU le Mardi 2 Mars 2021 à 19:25