|
|
機構普遍預料NIvar會逐漸增強，稍後逐漸靠近印度東南部一帶沿海WTIO32 PGTW 240900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 04B (NIVAR) WARNING NR 004//
RMKS/
1. TROPICAL CYCLONE 04B (NIVAR) WARNING NR 004
02 ACTIVE TROPICAL CYCLONES IN NORTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
240600Z --- NEAR 9.5N 82.8E
MOVEMENT PAST SIX HOURS - 270 DEGREES AT 05 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
065 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
REPEAT POSIT: 9.5N 82.8E
---
FORECASTS:
12 HRS, VALID AT:
241800Z --- 9.8N 82.0E
MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 000 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
010 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
080 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 305 DEG/ 06 KTS
---
24 HRS, VALID AT:
250600Z --- 10.5N 80.9E
MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 010 NM NORTHEAST QUADRANT
020 NM SOUTHEAST QUADRANT
000 NM SOUTHWEST QUADRANT
000 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 010 NM NORTHEAST QUADRANT
010 NM SOUTHEAST QUADRANT
010 NM SOUTHWEST QUADRANT
010 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
060 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 310 DEG/ 06 KTS
---
36 HRS, VALID AT:
251800Z --- 11.3N 79.9E
MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 010 NM NORTHEAST QUADRANT
010 NM SOUTHEAST QUADRANT
000 NM SOUTHWEST QUADRANT
000 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 010 NM NORTHEAST QUADRANT
010 NM SOUTHEAST QUADRANT
010 NM SOUTHWEST QUADRANT
010 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 305 DEG/ 06 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
260600Z --- 12.0N 78.9E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
000 NM SOUTHWEST QUADRANT
010 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 310 DEG/ 05 KTS
---
72 HRS, VALID AT:
270600Z --- 13.2N 77.3E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
240900Z POSITION NEAR 9.6N 82.6E.
24NOV20. TROPICAL CYCLONE 04B (NIVAR), LOCATED APPROXIMATELY 849
NM SOUTH-SOUTHWEST OF KOLKATA, INDIA, HAS TRACKED WESTWARD AT 05
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) DEPICTS AN ASYMMETRIC SYSTEM WITH CONVECTION DISPLACED
WEST OF THE LOW-LEVEL CIRCULATION CENTER (LLCC), HOWEVER SIGNIFICANT
CONSOLIDATION OF THE CONVECTION HAS BEEN NOTED OVER THE PAST 6
HOURS. THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON
THE BANDING FEATURES PRESENT IN THE MSI LOOP AS WELL AS THE LOW
LEVEL CONVECTIVE BANDS THAT ARE EVIDENT IN A 240336Z METOP-B 89GHZ
IMAGE. THE INITIAL INTENSITY IS ASSESSED AT 45 KNOTS AND IS IN
AGREEMENT WITH A PGTW DVORAK INTENSITY ESTIMATE OF T3.0 (45 KNOTS),
A 240335Z SATCON INTENSITY ESTIMATE OF 46 KNOTS AND THE 40 KTS WINDS
PRESENT IN A 240336Z ASCAT-B PASS. THE SYSTEM IS TRACKING ALONG THE
SOUTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) POSITIONED TO
THE NORTHEAST AND THROUGH A FAVORABLE ENVIRONMENT WITH LOW VERTICAL
WIND SHEAR, ROBUST POLEWARD OUTFLOW AND WARM 929-30 CELSIUS) SEA
SURFACE TEMPERATURES (SST). TC NIVAR IS FORECAST TO BEGIN A
GENERALLY NORTHWESTWARD TRACK IN THE NEAR TERM AS A MID-LATITUDE
TROUGH APPROACHING FROM THE NORTHWEST DIGS INTO AND WEAKENS THE
AFOREMENTIONED STR. OF NOTE, THIS WEAKENING OF THE RIDGE MAY ALLOW
FOR INCREASED POLEWARD OUTFLOW AND SUBSEQUENT RAPID INTENSIFICATION.
THIS INCREASED OUTFLOW, COUPLED WITH FAVORABLE VWS AND SST, WILL
ALLOW THE SYSTEM TO FURTHER INTENSIFY THROUGH TAU 24 AT WHICH TIME IT
WILL REACH AN INTENSITY OF 70 KTS. SLIGHTLY HIGHER VERTICAL WIND
SHEAR AND COOLER SST THEREAFTER WILL SUPPORT GRADUAL INTENSIFICATION
TO 75 KTS BY TAU 36. SHORTLY THEREAFTER THE SYSTEM WILL MAKE
LANDFALL ALONG THE EASTERN COAST OF INDIA, SOUTH OF CHENNAI.
INTERACTION WITH THE UNDERLYING TERRAIN WILL LEAD TO RAPID WEAKENING
TO 45 KTS BY TAU 48 AS THE SYSTEM BEGINS DISSIPATION OVER LAND AND
FULL DISSIPATION OVER LAND BY TAU 72. THE REMNANTS OF TC 04B MAY
TRACK OVER THE ARABIAN SEA, HOWEVER, THERE IS LOW PROBABILITY OF
REGENERATION. NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT WITH A
SPREAD OF 93 NAUTICAL MILES AT LANDFALL, HOWEVER THIS AGREEMENT
BECOMES POOR THEREAFTER AS THE SPREAD INCREASES TO 364 NAUTICAL
MILES BY TAU 72. THIS WIDER SPREAD IS LARGELY DUE TO UKMET MODEL
SOLUTIONS WHICH TURN THE SYSTEM SHARPLY TO THE RIGHT AT LANDFALL.
OVERALL, MODEL GUIDANCE LENDS ONLY FAIR CONFIDENCE IN THE JTWC
FORECAST TRACK WHICH IS PLACED JUST SOUTH OF THE MULTI-MODEL
CONSENSUS TO OFFSET THE UKMET TRACKS. MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 240600Z IS 17 FEET. NEXT WARNINGS AT 241500Z, 242100Z,
250300Z AND 250900Z.//
NNNN
|
|
