Southern Hemisphere cyclonic trio: 10S(DIANE), 11S(ESAMI), 12P: updates



TC 10S(DIANE): WARNING 3. PEAK INTENSITY NEAR 50KT FORECAST WITHIN 24H.

TC 10S(DIANE) SOUTH INDIAN
As of 18:00 UTC Jan 25, 2020:
Location: 22.0°S 64.0°E
Maximum Winds: 50 kt ( 95km/h)
Gusts: 65 kt ( 120km/h)

Minimum Central Pressure: 996 mb
REMARKS:
252100Z POSITION NEAR 22.2S 64.7E.
25JAN20. TROPICAL CYCLONE (TC) 10S (DIANE), LOCATED APPROXIMATELY 392
NM EAST-SOUTHEAST OF PORT LOUIS, MAURITIUS, HAS TRACKED EAST-
SOUTHEASTWARD AT 20 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED
INFRARED SATELLITE IMAGERY DEPICTS AN ELONGATED AREA OF DEEP
CONVECTION PERSISTING OVER THE NORTHERN SEMICIRCLE OF THE SYSTEM. A
251459Z SSMIS IMAGE INDICATES AN ILL-DEFINED LOW-LEVEL CIRCULATION
CENTER WITH LIMITED CURVED BANDING OVER THE NORTHERN SEMICIRCLE. A
TIMELY 251745Z ASCAT IMAGE PROVIDES GOOD CONFIDENCE IN BOTH THE
INITIAL POSITION AND INITIAL INTENSITY, AND SHOWS 45 KNOT WINDS OVER
THE NORTHEAST QUADRANT OF THE CIRCULATION. TC 10S HAS MAINTAINED
INTENSITY AND STRUCTURE DUE TO MARGINALLY-FAVORABLE CONDITIONS.
SPECIFICALLY, THE SYSTEM IS LOCATED UNDER THE NORTHERN PERIPHERY OF
A BROAD UPPER-LEVEL TROUGH AND IS UNDER MODERATE VERTICAL WIND SHEAR
(20 KNOTS). FAIR OUTFLOW ALOFT AND WARM SST VALUES (27-28C) HAVE
ALLOWED THE SYSTEM TO VENT AND MAINTAIN FORMATIVE BANDING. TC 10S IS
CURRENTLY TRACKING ALONG THE SOUTHERN PERIPHERY OF THE NEAR-
EQUATORIAL RIDGE AND IS FORECAST TO GRADUALLY TURN SOUTHWARD AFTER
TAU 36 AS THE SUBTROPICAL RIDGE BUILDS TO THE EAST. ENVIRONMENTAL
CONDITIONS ARE FORECAST TO DEGRADE WITH INCREASING VERTICAL WIND
SHEAR (30-45 KNOTS) AND COOLER SST VALUES (24-26C). THEREFORE, TC
10S WILL DISSIPATE BETWEEN TAU 48 AND TAU 72 AS IT ABSORBS A RAPIDLY
WEAKENING TC 11S. NUMERICAL MODEL GUIDANCE REMAINS IN GOOD AGREEMENT
WITH A 105NM SPREAD IN SOLUTIONS AT TAU 72, THEREFORE, THERE IS HIGH
CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 251800Z IS 18 FEET. NEXT WARNINGS AT 260900Z AND 262100Z.
REFER TO TROPICAL CYCLONE 11S (ESAMI) WARNINGS (WTXS32 PGTW) FOR
UPDATES.//
NNNN

TC 12P SOUTH PACIFIC
As of 18:00 UTC Jan 25, 2020:
Location: 21.1°S 167.4°W
Maximum Winds: 35 kt ( 65km/h)
Gusts: 45 kt ( 85km/h)
Minimum Central Pressure: 1000 mb

REMARKS:
252100Z POSITION NEAR 21.4S 167.3W.
25JAN20. TROPICAL CYCLONE (TC) 12P (TWELVE), LOCATED APPROXIMATELY
185 NM SOUTHEAST OF NIUE, HAS TRACKED SOUTHEASTWARD AT 10 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI)
DEPICTS AN EXPOSED, WELL-DEFINED LOW-LEVEL CIRCULATION CENTER WITH
LIMITED DEEP CONVECTIVE BANDING OVER THE EASTERN SEMICIRCLE. THERE
IS GOOD CONFIDENCE IN THE INITIAL POSITION BASED ON THE MSI. A
251744Z SSMIS 91GHZ IMAGE INDICATES CURVED, FRAGMENTED DEEP
CONVECTIVE BANDING OVER THE EASTERN SEMICIRCLE ASSOCIATED WITH
STRONG LOW-LEVEL CONVERGENT FLOW. RECENT ASCAT DATA INDICATES 30-35
KNOT WINDS ASSOCIATED WITH THIS PERSISTENT BANDING, WHICH SUPPORTS
THE INITIAL INTENSITY ASSESSMENT OF 35 KNOTS. TC 12P IS FORECAST TO
TRACK SOUTHWARD UNDER THE STEERING INFLUENCE OF A LOW-LEVEL
SUBTROPICAL RIDGE POSITIONED TO THE EAST BUT IS EXPECTED TO TURN
SOUTHWESTWARD AS A LOW-LEVEL HIGH BUILDS SOUTH OF THE SYSTEM AFTER
TAU 24. TC 12P IS STRUGGLING TO CONSOLIDATE UNDER A MARGINALLY-
FAVORABLE ENVIRONMENT BUT SHOULD MAINTAIN 35 KNOTS THROUGH TAU 24.
HOWEVER, THE SYSTEM WILL TRACK UNDER INCREASING VERTICAL WIND SHEAR
AND ENCOUNTER SLIGHTLY COOLER SST (25-26C), WHICH WILL LEAD TO
DISSIPATION BY TAU 36. OVERALL, THERE IS MODERATE CONFIDENCE IN THE
JTWC FORECAST TRACK WITH NUMERICAL MODELS IN FAIR AGREEMENT. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 251800Z IS 12 FEET. NEXT
WARNINGS AT 260300Z, 260900Z, 261500Z AND 262100Z.//
NNNN

TC 11S(ESAMI) SOUTH INDIAN
As of 18:00 UTC Jan 25, 2020:
Location: 25.6°S 74.6°E
Maximum Winds: 40 kt ( 75km/h)
Gusts: 50 kt ( 95km/h)

Minimum Central Pressure: 998 mb
REMARKS:
252100Z POSITION NEAR 25.9S 74.8E.
25JAN20. TROPICAL CYCLONE (TC) 11S (ESAMI), LOCATED APPROXIMATELY
1011 NM EAST-SOUTHEAST OF PORT LOUIS, MAURITIUS, HAS TRACKED
SOUTHEASTWARD AT 11 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED
INFRARED (EIR) SATELLITE IMAGERY DEPICTS A LOW LEVEL CIRCULATION
WITH INTENSE CONVECTION SHEARED TO THE NORTHEAST. THE INITIAL
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A 251816Z GMI 36GHZ
IMAGE THAT DEPICTS A WELL DEFINED LOW LEVEL CIRCULATION CENTER
(LLCC) WITH SHALLOW BANDS OF CONVECTION IN THE NORTH AND SOUTH
QUADRANTS. THE INITIAL INTENSITY IS ALSO PLACED WITH HIGH CONFIDENCE
HEDGED ABOVE A PGTW DVORAK INTENSITY ESTIMATE OF T2.5 (35 KTS) BASED
ON A 251816Z ASCAT-A DATA THAT REFLECTS 40KT WINDS TO THE EAST OF
THE CIRCULATION. ESAMI IS TRACKING ALONG THE PERIPHERY OF WEAK
EQUATORIAL RIDGING TO THE NORTH AS IT CONTINUES TO TRAVERSE THROUGH
AN INCREASINGLY MARGINAL ENVIRONMENT. MARGINAL (15-20 KTS) VERTICAL
WIND SHEAR (VWS) WILL CONTINUE TO INCREASE, SURPASSING 30 KTS BY TAU
12. ADDITIONALLY, MARGINAL SEA SURFACE TEMPERATURES ARE NOTABLY
COOLER (25-26C) AND WILL CONTINUE TO DROP BELOW 24C BY TAU 24,
HINDERING FURTHER DEVELOPMENT. THESE INCREASINGLY UNFAVORABLE
CONDITIONS WILL CAUSE ESAMI TO BEGIN DISSIPATING AT TAU 36 AS IT
BEGINS TO CURVE SOUTHWESTWARD DUE TO INTERACTION WITH A BUILDING
RIDGE TO THE SOUTH. ESAMI WILL THEN DISSIPATE OVER WATER BY TAU 48  
AS IT GETS ABSORBED INTO THE OUTER PERIPHERY OF TC DIANE APPROACHING
FROM THE NORTHWEST (380 NM DISTANCE BETWEEN SYSTEMS AT TAU 48).
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 251800Z IS 12 FEET. NEXT WARNINGS
AT 260900Z AND 262100Z. REFER TO TROPICAL CYCLONE 10S (DIANE)
WARNINGS (WTXS31 PGTW) FOR UPDATES.//
NNNN
                  

TC 12P: WARNING 2. NEAR PEAK INTENSITY


TC 11S(ESAMI): WARNING 3. WEAKENING GRADUALLY.


TC 10S: TRACK AND INTENSITY GUIDANCE


TC 12P: TRACK AND INTENSITY GUIDANCE


TC 11S: TRACK AND INTENSITY GUIDANCE


01/25 2230UTC


01/25 15UTC

Rédigé par PATRICK HOAREAU le Dimanche 26 Janvier 2020 à 03:11