Menu

TS 27W(NYATOH) intensity to peak(CAT 3) within 36h then will decay (dry air and shear)//Invest 92S: TCFA(High),Invest 94W still Medium



JTWC IS ISSUING 6HOURLY WARNINGS ON 27W(NYATOH). 3HOURLY SATELLITE BULLETINS ARE ISSUED FOR BOTH 27W AND INVEST 92S.
JTWC IS ISSUING 6HOURLY WARNINGS ON 27W(NYATOH). 3HOURLY SATELLITE BULLETINS ARE ISSUED FOR BOTH 27W AND INVEST 92S.
JTWC PH
ILES SOEURS
Joint Typhoon Warning Center
JTWC BIS

WESTERN NORTH PACIFIC: TS 27W(NYATOH). WARNING 7 ISSUED AT 01/03UTC

3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: DURING THE NEXT 36 HOURS, TROPICAL STORM 27W WILL ROUND THE RIDGE AND REACH ITS MAXIMUM INTENSITY, TAKING ADVANTAGE OF A NEARLY IDEAL OUTFLOW SITUATION WHILE STILL REMAINING IN A REGION OF LOW VERTICAL WINDSHEAR AND HIGH OCEAN HEAT CONTENT. A COMBINATION OF THREE NEGATIVE FACTORS WILL BEGIN WEARING ON THE STORM AFTER IT PEAKS NEAR THE 18TH LATITUDE AT ABOUT 36H. VERTICAL WINDSHEAR ASSOCIATED WITH A DEEP MID-LATITUDE TROUGH WILL BE THE FIRST TO WEAR ON THE STORM, BEGINNING NEAR 30H AND EXCEEDING 30KNOTS BY 48H. DRY AIR ENTRAINMENT WILL BEGIN WORKING ITS MISERY SHORTLY THEREAFTER AND BY 60H THE CORE WILL BE COMPLETELY CONSTRICTED BY A WALL OF DRY, MODIFIED CONTINENTAL POLAR AIR. AND TO ADD THE COUP DE GRACE, THE SYSTEM WILL MOVE OUT OF FAVORABLE OCEAN HEAT CONTENT AND INTO DESTRUCTIVELY COOL WATERS BY THE TIME IT REACHES THE 20TH LATITUDE, NEAR 48H. FOR THE 36 HOURS AFTER THAT, TS 27W WILL WEAKEN AND ACCELERATE TOWARDS THE MID-LATITUDES, BUT BY THE TIME IT CROSSES THE TROPIC OF CANCER THE UPPER LEVELS WILL HAVE DECOUPLED FROM THE LOW LEVEL VORTEX, WHERE WHAT REMAINS OF THE LLCC WILL DRIFT UNTIL THE NEWLY EXTENDED SUBTROICAL RIDGE BUILDING OFF THE CONTINENT PICK IT UP AND DRIVES IT BACK TO THE WEST.
3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: DURING THE NEXT 36 HOURS, TROPICAL STORM 27W WILL ROUND THE RIDGE AND REACH ITS MAXIMUM INTENSITY, TAKING ADVANTAGE OF A NEARLY IDEAL OUTFLOW SITUATION WHILE STILL REMAINING IN A REGION OF LOW VERTICAL WINDSHEAR AND HIGH OCEAN HEAT CONTENT. A COMBINATION OF THREE NEGATIVE FACTORS WILL BEGIN WEARING ON THE STORM AFTER IT PEAKS NEAR THE 18TH LATITUDE AT ABOUT 36H. VERTICAL WINDSHEAR ASSOCIATED WITH A DEEP MID-LATITUDE TROUGH WILL BE THE FIRST TO WEAR ON THE STORM, BEGINNING NEAR 30H AND EXCEEDING 30KNOTS BY 48H. DRY AIR ENTRAINMENT WILL BEGIN WORKING ITS MISERY SHORTLY THEREAFTER AND BY 60H THE CORE WILL BE COMPLETELY CONSTRICTED BY A WALL OF DRY, MODIFIED CONTINENTAL POLAR AIR. AND TO ADD THE COUP DE GRACE, THE SYSTEM WILL MOVE OUT OF FAVORABLE OCEAN HEAT CONTENT AND INTO DESTRUCTIVELY COOL WATERS BY THE TIME IT REACHES THE 20TH LATITUDE, NEAR 48H. FOR THE 36 HOURS AFTER THAT, TS 27W WILL WEAKEN AND ACCELERATE TOWARDS THE MID-LATITUDES, BUT BY THE TIME IT CROSSES THE TROPIC OF CANCER THE UPPER LEVELS WILL HAVE DECOUPLED FROM THE LOW LEVEL VORTEX, WHERE WHAT REMAINS OF THE LLCC WILL DRIFT UNTIL THE NEWLY EXTENDED SUBTROICAL RIDGE BUILDING OFF THE CONTINENT PICK IT UP AND DRIVES IT BACK TO THE WEST.
2721112618  68N1550E  20
2721112700  71N1535E  20
2721112706  76N1516E  20
2721112712  83N1500E  20
2721112718  92N1484E  20
2721112800  99N1467E  20
2721112806 104N1456E  20
2721112812 111N1446E  20
2721112818 115N1437E  20
2721112900 117N1429E  20
2721112906 117N1423E  25
2721112912 123N1416E  30
2721112918 126N1403E  35
2721113000 128N1391E  35
2721113006 130N1380E  40
2721113012 130N1376E  40
2721113018 132N1370E  50
2721120100 138N1364E  60

TS 27W(NYATOH) intensity to peak(CAT 3) within 36h then will decay (dry air and shear)//Invest 92S: TCFA(High),Invest 94W still Medium


IF NEEDED CLICK ON THE IMAGERY TO GET IT ANIMATED AND TO ENLARGE IT

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED VISUAL IMAGERY OVER THE PAST SIX HOURS SHOWS INTENSE BURSTS OF CONVECTION AND TIGHTENING AROUND THE CORE OF THE STORM. ALTHOUGH NO EYE IS PRESENT YET, AN ARC OF ESPECIALLY DEEP CONVECTIVE BANDING IS NOW EXTENDING FROM THE NORTHWEST QUADRANT ALL THE WAY AROUND TO THE SOUTHEASTERN QUADRANT. CONVECTIVE BURSTS ARE ALSO OBSERVABLE DIRECTLY OVER THE CORE. THE EFFECTS OF DRY AIR ENTRAINMENT MAY ALREADY BE WORKING ON THE SYSTEM, AS A DRY SLOT SURGING FROM THE NORTHERLIES WEST OF THE STORM IS BEGINNING TO WRAP ALL THE WAY AROUND THE CORE AND INTO THE NORTHWESTERN QUADRANT, CREATING SEPARATION BETWEEN THE CORE AND THE BANDING THAT WILL LIKELY BECOME THE EYEWALL. TROPICAL CYCLONE NYATOH IS TRACKING THROUGH A NEARLY IDEAL ENVIRONMENT FOR INTENSIFICATION, WITH EXCEPTIONALLY HIGH OCEAN HEAT CONTENT (OHC) AND LOW VERTICAL WINDSHEAR (VWS). ANIMATED WATER VAPOR IMAGERY SHOWS A BLOOM OF OUTFLOW IN ALL DIRECTIONS THAT BEGAN ABOUT TWELVE HOURS AGO AND CONTINUES TO EXPAND, APPEARING AS A ZONE OF ANTICYCLONIC EXHAUST THAT EXTENDS OVER 10 DEGREES OF LATITUDE. BOTH OBJECTIVE AND SUBJECTIVE DVORAKS ARE COMING INTO ALIGNMENT, AND THE CURRENT INTENSITY ASSESSMENT IS BARELY ON THE HIGH SIDE OF A CONSENSUS OF AGENCY DVORAKS, ADT, AND SATCON. THE SYSTEM IS ENTERING THE ZONE OF MAXIMUM INTENSIFICATION, BEGINNING A POLEWARD BEND AS IT ROUNDS THE SUBTROPICAL RIDGE.
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED VISUAL IMAGERY OVER THE PAST SIX HOURS SHOWS INTENSE BURSTS OF CONVECTION AND TIGHTENING AROUND THE CORE OF THE STORM. ALTHOUGH NO EYE IS PRESENT YET, AN ARC OF ESPECIALLY DEEP CONVECTIVE BANDING IS NOW EXTENDING FROM THE NORTHWEST QUADRANT ALL THE WAY AROUND TO THE SOUTHEASTERN QUADRANT. CONVECTIVE BURSTS ARE ALSO OBSERVABLE DIRECTLY OVER THE CORE. THE EFFECTS OF DRY AIR ENTRAINMENT MAY ALREADY BE WORKING ON THE SYSTEM, AS A DRY SLOT SURGING FROM THE NORTHERLIES WEST OF THE STORM IS BEGINNING TO WRAP ALL THE WAY AROUND THE CORE AND INTO THE NORTHWESTERN QUADRANT, CREATING SEPARATION BETWEEN THE CORE AND THE BANDING THAT WILL LIKELY BECOME THE EYEWALL. TROPICAL CYCLONE NYATOH IS TRACKING THROUGH A NEARLY IDEAL ENVIRONMENT FOR INTENSIFICATION, WITH EXCEPTIONALLY HIGH OCEAN HEAT CONTENT (OHC) AND LOW VERTICAL WINDSHEAR (VWS). ANIMATED WATER VAPOR IMAGERY SHOWS A BLOOM OF OUTFLOW IN ALL DIRECTIONS THAT BEGAN ABOUT TWELVE HOURS AGO AND CONTINUES TO EXPAND, APPEARING AS A ZONE OF ANTICYCLONIC EXHAUST THAT EXTENDS OVER 10 DEGREES OF LATITUDE. BOTH OBJECTIVE AND SUBJECTIVE DVORAKS ARE COMING INTO ALIGNMENT, AND THE CURRENT INTENSITY ASSESSMENT IS BARELY ON THE HIGH SIDE OF A CONSENSUS OF AGENCY DVORAKS, ADT, AND SATCON. THE SYSTEM IS ENTERING THE ZONE OF MAXIMUM INTENSIFICATION, BEGINNING A POLEWARD BEND AS IT ROUNDS THE SUBTROPICAL RIDGE.


MODEL DISCUSSION: INTENSITY GUIDANCE IS IN EXCELLENT AGREEMENT ON THE TIMING OF THE RAMP-UP, SHOWING A CLEAR PEAK AT AND JUST AFTER 36H. THERE IS, HOWEVER, A WIDE ENVELOPE OF POSSIBILITES, RANGING FROM 75 TO 115KNOTS. THE JTWC FORECAST LIES ON THE HIGH SIDE OF THE GUIDANCE PACKAGE BUT CONFIDENCE IN A PEAK INTENSITY OF AROUND 100KNOTS (NEAR THE 18TH LATITUDE) IS INCREASING. AS WOULD BE EXPECTED, THE ALONG-TRACK SPREAD BEGINS TO INCREASE DURING THE PERIOD WHEN THE SYSTEM ACCELERATES TOWARDS THE MID-LATITUDES (BETWEEN 24H AND 72H), BUT THE CROSS TRACK SPREAD IS REASONABLY TIGHT. AFTER 72H, THE DECOUPLING PERIOD BEGINS, TRACK GUIDANCE IS SPREAD WILDLY AND CONFIDENCE IN THE TRACK DECREASES SHARPLY. OVER THE PAST 48 HOURS, GUIDANCE HAS BEEN CONSISTENT IN BOTH TRACK AND INTENSITY AND IS PLAYING OUT ACCURATELY, WITH THE ENSEMBLES BEING PARTICULARLY CONSISTENT IN PREDICTING A DECOUPLING SCENARIO. NONETHELESS, THERE IS ESPECIALLY LOW CONFIDENCE IN THE FORECAST AFTER 72H DUE TO THE WIDE POSSIBILITES IN HOW THE DECOUPLING PROCESS PLAYS OUT AND WHERE THE LOW LEVEL VORTEX WINDS UP WHEN THE DECOUPLING IS COMPLETE.
MODEL DISCUSSION: INTENSITY GUIDANCE IS IN EXCELLENT AGREEMENT ON THE TIMING OF THE RAMP-UP, SHOWING A CLEAR PEAK AT AND JUST AFTER 36H. THERE IS, HOWEVER, A WIDE ENVELOPE OF POSSIBILITES, RANGING FROM 75 TO 115KNOTS. THE JTWC FORECAST LIES ON THE HIGH SIDE OF THE GUIDANCE PACKAGE BUT CONFIDENCE IN A PEAK INTENSITY OF AROUND 100KNOTS (NEAR THE 18TH LATITUDE) IS INCREASING. AS WOULD BE EXPECTED, THE ALONG-TRACK SPREAD BEGINS TO INCREASE DURING THE PERIOD WHEN THE SYSTEM ACCELERATES TOWARDS THE MID-LATITUDES (BETWEEN 24H AND 72H), BUT THE CROSS TRACK SPREAD IS REASONABLY TIGHT. AFTER 72H, THE DECOUPLING PERIOD BEGINS, TRACK GUIDANCE IS SPREAD WILDLY AND CONFIDENCE IN THE TRACK DECREASES SHARPLY. OVER THE PAST 48 HOURS, GUIDANCE HAS BEEN CONSISTENT IN BOTH TRACK AND INTENSITY AND IS PLAYING OUT ACCURATELY, WITH THE ENSEMBLES BEING PARTICULARLY CONSISTENT IN PREDICTING A DECOUPLING SCENARIO. NONETHELESS, THERE IS ESPECIALLY LOW CONFIDENCE IN THE FORECAST AFTER 72H DUE TO THE WIDE POSSIBILITES IN HOW THE DECOUPLING PROCESS PLAYS OUT AND WHERE THE LOW LEVEL VORTEX WINDS UP WHEN THE DECOUPLING IS COMPLETE.


HWRF: 130KNOTS AT +54H

TS 27W(NYATOH) intensity to peak(CAT 3) within 36h then will decay (dry air and shear)//Invest 92S: TCFA(High),Invest 94W still Medium

 

ANIMATED WATER VAPOR IMAGERY SHOWS A BLOOM OF OUTFLOW IN ALL DIRECTIONS THAT BEGAN ABOUT TWELVE HOURS AGO AND CONTINUES TO EXPAND, APPEARING AS A ZONE OF ANTICYCLONIC EXHAUST THAT EXTENDS OVER 10 DEGREES OF LATITUDE.


27W TRACKING OVER A POOL OF HIGH OCEAN HEAT CONTENT


01/0210UTC.
01/0210UTC.


SOUTHERN HEMISPHERE/SOUTH INDIAN OCEAN: INVEST 92S. TROPICAL CYCLONE FORMATION ALERT ISSUED AT 30/23UTC

THE AREA OF CONVECTION (INVEST 92S) PREVIOUSLY LOCATED NEAR 7.2S 102.6E IS NOW LOCATED NEAR 7.8S 102.9E, APPROXIMATELY 252NM WEST-SOUTHWEST OF JAKARTA, INDONESIA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS INCREASING ORGANIZATION OF THE CONVECTIVE BANDING WRAPPING INTO THE LOW LEVEL CIRCULATION (LLC). A 301902Z ASMR2 SERIES SHOWS DEEP CONVECTION SURROUNDING MOST OF THE LLC. ENVIRONMENTAL ANALYSIS INDICATES THAT THE SYSTEM IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH STRONG POLEWARD OUTFLOW ALOFT, MODERATE (15-20KT) VERTICAL WIND SHEAR, AND WARM (28-29C) SEA SURFACE TEMPERATURES. GLOBAL MODELS AGREE THAT 92S WILL TRACK SOUTH SOUTHWESTWARD OVER THE NEXT 24 HOURS. HOWEVER, THEY ARE SPLIT ON INTENSIFICATION WITH ONLY GFS REACHING WARNING CRITERIA. 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 IS UPGRADED TO HIGH.
THE AREA OF CONVECTION (INVEST 92S) PREVIOUSLY LOCATED NEAR 7.2S 102.6E IS NOW LOCATED NEAR 7.8S 102.9E, APPROXIMATELY 252NM WEST-SOUTHWEST OF JAKARTA, INDONESIA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS INCREASING ORGANIZATION OF THE CONVECTIVE BANDING WRAPPING INTO THE LOW LEVEL CIRCULATION (LLC). A 301902Z ASMR2 SERIES SHOWS DEEP CONVECTION SURROUNDING MOST OF THE LLC. ENVIRONMENTAL ANALYSIS INDICATES THAT THE SYSTEM IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH STRONG POLEWARD OUTFLOW ALOFT, MODERATE (15-20KT) VERTICAL WIND SHEAR, AND WARM (28-29C) SEA SURFACE TEMPERATURES. GLOBAL MODELS AGREE THAT 92S WILL TRACK SOUTH SOUTHWESTWARD OVER THE NEXT 24 HOURS. HOWEVER, THEY ARE SPLIT ON INTENSIFICATION WITH ONLY GFS REACHING WARNING CRITERIA. 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 IS UPGRADED TO HIGH.
9221112912  67S1009E  15
9221112918  67S1012E  15
9221113000  68S1017E  20
9221113006  69S1021E  15
9221113012  72S1026E  20
9221113018  78S1029E  25
9221120100  90S1030E  30
NNNN


GLOBAL MODELS AGREE THAT 92S WILL TRACK SOUTH SOUTHWESTWARD OVER THE NEXT 24 HOURS. HOWEVER, THEY ARE SPLIT ON INTENSIFICATION WITH ONLY GFS REACHING WARNING CRITERIA.
GLOBAL MODELS AGREE THAT 92S WILL TRACK SOUTH SOUTHWESTWARD OVER THE NEXT 24 HOURS. HOWEVER, THEY ARE SPLIT ON INTENSIFICATION WITH ONLY GFS REACHING WARNING CRITERIA.


NORTH INDIAN OCEAN/ANDAMAN SEA: INVEST 94W. MEDIUM. 01/09UTC UPDATE

THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED NEAR 9.3N 101.0E IS NOW LOCATED NEAR 8.6N 92.6E, APPROXIMATELY 630 KM WEST OF PHUKET, THAILAND. ANIMATED ENHANCED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND A 010724Z AMSR2 89GHZ MICROWAVE IMAGE DEPICT DEEP FLARING CONVECTION OBSCURING A LOW LEVEL CIRCULATION. ENVIRONMENTAL ANALYSIS INDICATES THAT SYSTEM IS IN A FAVORABLE ENVIRONMENT CHARACTERIZED BY STRONG OUTFLOW ALOFT, MODERATE (15- 20KT) VERTICAL WIND SHEAR, AND VERY WARM (29-30C) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT INVEST 94W WILL CONTINUE TO INTENSIFY AS IT TRACKS WEST-NORTHWESTWARD IN THE BAY OF BENGAL BEFORE RECURVING TO THE NORTH NEAR THE EASTERN COAST OF INDIA. 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 REMAINS MEDIUM.
THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED NEAR 9.3N 101.0E IS NOW LOCATED NEAR 8.6N 92.6E, APPROXIMATELY 630 KM WEST OF PHUKET, THAILAND. ANIMATED ENHANCED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND A 010724Z AMSR2 89GHZ MICROWAVE IMAGE DEPICT DEEP FLARING CONVECTION OBSCURING A LOW LEVEL CIRCULATION. ENVIRONMENTAL ANALYSIS INDICATES THAT SYSTEM IS IN A FAVORABLE ENVIRONMENT CHARACTERIZED BY STRONG OUTFLOW ALOFT, MODERATE (15- 20KT) VERTICAL WIND SHEAR, AND VERY WARM (29-30C) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT INVEST 94W WILL CONTINUE TO INTENSIFY AS IT TRACKS WEST-NORTHWESTWARD IN THE BAY OF BENGAL BEFORE RECURVING TO THE NORTH NEAR THE EASTERN COAST OF INDIA. 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 REMAINS MEDIUM.


GLOBAL MODELS ARE IN GOOD AGREEMENT THAT INVEST 94W WILL CONTINUE TO INTENSIFY AS IT TRACKS WEST-NORTHWESTWARD IN THE BAY OF BENGAL BEFORE RECURVING TO THE NORTH NEAR THE EASTERN COAST OF INDIA.
GLOBAL MODELS ARE IN GOOD AGREEMENT THAT INVEST 94W WILL CONTINUE TO INTENSIFY AS IT TRACKS WEST-NORTHWESTWARD IN THE BAY OF BENGAL BEFORE RECURVING TO THE NORTH NEAR THE EASTERN COAST OF INDIA.



TS 27W(NYATOH) intensity to peak(CAT 3) within 36h then will decay (dry air and shear)//Invest 92S: TCFA(High),Invest 94W still Medium


Rédigé par PATRICK HOAREAU le Wednesday, December 1st 2021 à 07:40
Les News
Liens utiles
Joint Typhoon Warning Center

TC 22P(PAUL)// Remnants of TC 21S(OLGA)// ECMWF 10 Day Storm Tracks// 1103utc

TC 21S(OLGA) SAR reveals still a bit stronger than expected// INVEST 97P// ECMWF 10 Day Storm Traccks// 0903utc

TC 21S(OLGA) peaked as a powerful CAT 4 US// ECMWF 10 Day Storm Tracks// 0803utc

TC 21S(OLGA) reaches CAT 3 US still intensifying// ECMWF 10 Day Storm Tracks// 0709utc

TC 21S(OLGA) intensifying and peaking within 24H may reach CAT 2 US// ECMWF 10 Day Storm Tracks, 0615utc