Na de "rapid intensification" tot een volwaardige cat. 5 en tevens recordzware cycloon (voor de Golf van Bengalen) is Amphan nu afgezwakt tot een forse categorie 4 cycloon met gemiddelde windsnelheden van ruim 220 km/u en windstoten tot 260 km/u. Amphan lijkt zijn oog verloren te hebben vanwege een minder gunstige shearomgeving. Echter deze omgeving zal de komende uren weer positief bijdragen aan de ontwikkeling van een nieuw oog. De eyewall replacement cyclus is dan afgerond. De ongunstige shear neemt af en het zeewater is overminderd warm (30-32C) Dit houdt in dat de afzwakking vooralsnog stopt en de storm waarschijnlijk als een cat. 4 aan land zal gaan. Nieuwe intensivering wordt niet uitgesloten alvorens landfall. Dit zal ergens tussen de 24-36 uur moeten gaan gebeuren ten zuiden van Calcutta. Los van de windschade en extreme neerslag, zal de stormvloed (tot wel 6m) veel schade aanrichten en slachtoffers eisen. Dit gezien de lage ligging van de rivierdelta in het gebied. De stormvloed kan zodoende tientallen kilometers landinwaarts komen in een gebied waar miljoenen mensen woonachtig zijn. Na 'landfall' zal Amphan snel in kracht afnemen. De neerslag en overstromingen zullen echter nog veel schade veroorzaken. Dit is een ramp in ontwikkeling, die mogelijk tienduizenden mensen het leven gaat kosten. Het is te hopen dat deze aanstaande ramp niet onder zal sneeuwen nu het nieuws volledig door corona wordt beheerst.
Hieronder de tekst en laatste beelden van het JTWC.
 Tropical Cyclone AMPHAN Forecast Track (Joint Typhoon Warning Center) |
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Tropical Cyclone AMPHAN Warning Text (JTWC)WTIO31 PGTW 190300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 01B (AMPHAN) WARNING NR 012//
RMKS/
1. TROPICAL CYCLONE 01B (AMPHAN) WARNING NR 012
01 ACTIVE TROPICAL CYCLONE IN NORTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
190000Z --- NEAR 15.6N 86.8E
MOVEMENT PAST SIX HOURS - 020 DEGREES AT 09 KTS
POSITION ACCURATE TO WITHIN 020 NM
POSITION BASED ON EYE FIXED BY A COMBINATION OF
SATELLITE AND RADAR
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 120 KT, GUSTS 145 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 065 NM NORTHEAST QUADRANT
055 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 165 NM NORTHEAST QUADRANT
165 NM SOUTHEAST QUADRANT
180 NM SOUTHWEST QUADRANT
185 NM NORTHWEST QUADRANT
REPEAT POSIT: 15.6N 86.8E
---
FORECASTS:
12 HRS, VALID AT:
191200Z --- 17.4N 87.3E
MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
080 NM SOUTHWEST QUADRANT
080 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 190 NM NORTHEAST QUADRANT
200 NM SOUTHEAST QUADRANT
160 NM SOUTHWEST QUADRANT
160 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 015 DEG/ 11 KTS
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24 HRS, VALID AT:
200000Z --- 19.5N 87.9E
MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT
190 NM SOUTHEAST QUADRANT
140 NM SOUTHWEST QUADRANT
130 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 015 DEG/ 13 KTS
---
36 HRS, VALID AT:
201200Z --- 22.0N 88.7E
MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
010 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT
160 NM SOUTHEAST QUADRANT
120 NM SOUTHWEST QUADRANT
100 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 015 DEG/ 12 KTS
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EXTENDED OUTLOOK:
48 HRS, VALID AT:
210000Z --- 24.3N 89.4E
MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
RADIUS OF 064 KT WINDS - 000 NM NORTHEAST QUADRANT
010 NM SOUTHEAST QUADRANT
000 NM SOUTHWEST QUADRANT
010 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 045 DEG/ 07 KTS
---
72 HRS, VALID AT:
220000Z --- 26.3N 91.6E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
190300Z POSITION NEAR 16.0N 86.9E.
19MAY20. TROPICAL CYCLONE 01B (AMPHAN), LOCATED APPROXIMATELY 430
NM SOUTH-SOUTHWEST OF KOLKATA, INDIA, HAS TRACKED NORTH-
NORTHEASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED
MULTISPECTRAL (MSI) AND ENHANCED INFRARED (EIR) SATELLITE IMAGERY
DEPICT A WEAKENED SYSTEM WITH A UNIFORM CENTRAL DENSE OVERCAST
(CDO) AND NO EYE, AT LEAST NOT IN THE VISIBLE OR INFRARED BANDS.
THE INITIAL POSITION IN PLACED WITH HIGH CONFIDENCE BASED ON A
182321Z DMSP 89 GHZ COLORIZED IMAGE WHICH SHOWS A NEWLY FORMED
PRIMARY EYEWALL SOLIDLY ENTRENCHED ON THE WESTERN SIDE OF THE
MICROWAVE EYE AT A RADIUS OF ABOUT 18 NM. THE EYEWALL IS OPEN ON
THE EASTERN SIDE OF THE EYE, INDICATIVE OF THE EASTERLY SHEAR AND
MID-LEVEL DRY AIR DEPICTED IN MODEL VERTICAL CROSS-SECTIONS THAT
ARE IMPACTING THE SYSTEM AND PRECLUDING MORE RAPID CONSOLIDATION
OF THE NEW EYEWALL AND COMPLETION OF THE EYEWALL REPLACEMENT CYCLE
(ERC). THE INITIAL POSITION IS ALSO SUPPORTED BY LONG-RANGE RADAR
DATA FROM INDIA WHICH CAPTURED THE INTENSE WESTERN EYEWALL. THE
INITIAL INTENSITY OF 120 KNOTS IS HELD ABOVE THE PGTW CURRENT
INTENSITY ESTIMATE OF T5.5 (102 KNOTS), HEDGED UPWARD BASED ON AN
ADVANCED DVORAK TECHNIQUE (ADT) CURRENT INTENSITY ESTIMATE OF T6.3
(122 KNOTS). ANALYSIS REVEALS THAT TC 01B IS TRACKING THROUGH A
GENERALLY FAVORABLE ENVIRONMENT WITH LOW TO MODERATE (15-20 KNOTS)
VWS, VERY WARM (31 DEG CELSIUS) SSTS AND ROBUST POLEWARD AND
MODERATE EQUATORWARD OUTFLOW. THE VWS AND MID-LEVEL DRY AIR
MENTIONED EARLIER ARE THE PRIMARY CONSTRAINTS ON THE SYSTEM AT THE
MOMENT WITH CIMSS SHEAR ESTIMATES CURRENTLY 17.8 KNOTS FROM 150
DEG. TC 01B IS TRACKING NORTH-NORTHEASTWARD ALONG THE WESTERN
PERIPHERY OF A DEEP-LAYER NER TO THE EAST AND IS EXPECTED TO
CONTINUE THIS MOTION THROUGH THE DURATION OF THE FORECAST PERIOD.
WITH THE ERC NEARING COMPLETION AND THE EYEWALL BEGINNING TO
REESTABLISH ITSELF IT IS EXPECTED THAT THE SYSTEM WILL EXPERIENCE
SOME ADDITIONAL WEAKENING THROUGH TAU 12 BEFORE THE NEW EYE FULLY
CONSOLIDATES. ONCE THE EYE BECOMES FULLY ESTABLISHED THE SYSTEM
WILL MAINTAIN INTENSITY THROUGH TAU 24 AS THE NEW CORE BECOMES
MORE ROBUST AND THE SHEAR VECTOR BECOMES MORE ALIGNED WITH THE
STORM MOTION, RESULTING IN LOWER EFFECTIVE SHEAR. AFTER MAKING
LANDFALL SOUTH OF KOLKATA NEAR TAU 36 THE SYSTEM WILL RAPIDLY
WEAKEN AND THEN DISSIPATE JUST SOUTH OF BHUTAN DUE TO RAPIDLY
INCREASING WESTERLY VWS AND TERRAIN INTERACTION. TRACK GUIDANCE
REMAINS IN VERY GOOD AGREEMENT THROUGH TAU 48 WITH ONLY MINIMAL
SPREAD (25 NM) AT LANDFALL, WITH INCREASING UNCERTAINTY THEREAFTER
AS MODELS HAVE DIFFICULTY IN TRACKING THE VORTEX. WITH THE VERY
TIGHT PACKING IN THE TRACK GUIDANCE, THERE IS HIGH CONFIDENCE IN
THE JTWC TRACK FORECAST. INTENSITY GUIDANCE MOSTLY SHOWS A STEADY
WEAKENING TREND THROUGH THE ENTIRE FORECAST, WITH THE EXCEPTION OF
COAMPS-TC AND HWRF, BOTH OF WHICH INDICATE A NEAR-TERM STEADY
INTENSITY OR EVEN SLIGHT INTENSIFICATION. THE JTWC INTENSITY
FORECAST IS HIGHER THAN THE MULTI-MODEL CONSENSUS BUT BELOW THE
HWRF THROUGH TAU 24, THEN TRACKS THE HWRF THROUGH THE REMAINDER OF
THE FORECAST. DUE TO THE UNCERTAINTY IN THE EVOLUTION OF THE ERC
AND THE SHEAR ENVIRONMENT THERE IS LOW CONFIDENCE IN THE JTWC
INTENSITY FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 190000Z IS
50 FEET. NEXT WARNINGS AT 190900Z, 191500Z, 192100Z AND 200300Z.//
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