t02436

JTWC 06Z直接發出FW....


IMD 06Z降格低壓，不再看好命名

** WTIN20 DEMS 110711 ***
SPECIAL TROPICAL WEATHER OUTLOOK


DEMS-RSMC SPECIAL TROPICAL CYCLONES NEW DELHI DATED   11-10-2015

TROPICAL WEATHER OUTLOOK FOR NORTH INDIAN OCEAN (THE BAY OF BENGAL
AND ARABIAN SEA) VALID FOR NEXT 72 HOURS ISSUED AT 0600 UTC OF
11TH OCTOBER 2015 BASED ON 0300 UTC OF 11TH OCTOBER 2015



THE DEEP DEPRESSION OVER EASTCENTRAL ARABIAN SEA MOVED SLIGHTLY
NORTHWARDS WITH A SPEED OF 05 KM PER HOUR DURING PAST 6 HOURS,
WEAKENED INTO A DEPRESSION AND LAY CENTRED AT 0300 UTC OF TODAY,
THE 11TH OCTOBER, 2015 OVER EASTCENTRAL ARABIAN SEA NEAR LATITUDE
15.70N AND LONGITUDE 69.20E, ABOUT 490 KM WEST OF GOA (43192) AND
520 KM SOUTH-SOUTHWEST OF MUMBAI (43057). IT WOULD MOVE NORTH-
NORTHWESTWARDS DURING NEXT 24 HOURS AND WEST-NORTHWESTWARDS
THEREAFTER. DUE TO DRY AIR INTRUSION FROM NORTHWEST TOWARDS
THE SYSTEM CENTRE AND SLOW MOTION OF THE SYSTEM, IT WOULD WEAKEN
GRADUALLY.



ACCORDING TO SATELLITE IMAGERY, INTENSITY IS C.I. 2.0.  CONVECTION
HAS DISORGANISED DURING PAST 12 HOURS.  MOST OF THE CONVECTION
LIES TO THE NORTHWEST OF THE SYSTEM CENTRE. ASSOCIATED BROKEN LOW
AND MEDIUM CLOUDS WITH EMBEDDED INTENSE TO VERY INTENSE CONVECTION
LIE OVER AREA BETWEEN LATITUDE 14.00N TO 19.50N AND LONGITUDE
64.00E TO 70.50E. LOWEST CLOUD TOP TEMPERATURE ASSOCIATED WITH THE
SYSTEM IS -770C.



THE ESTIMATED CENTRAL PRESSURE IS ABOUT 1004 HPA AND MAXIMUM
SUSTAINED WIND SPEED IS ABOUT 25 KNOTS GUSTING TO 35 KNOTS NEAR
THE SYSTEM CENTRE. WINDS ARE HIGHER OVER THE NORTHEASTERN SECTOR.
SEA CONDITION IS ROUGH TO VERY ROUGH AROUND THE SYSTEM CENTRE.



FORECAST TRACK AND INTENSITY OF THE SYSTEM ARE GIVEN IN THE TABLE
BELOW:



DATE/TIME(UTC)POSITION MAXIMUM SUSTAINED SURFACE CATEGORY OF CYCLONIC
          (LAT.ON/LONG.0E) WIND SPEED (KMPH)      DISTURBANCE


11-10-2015/0300 15.7/69.2 45-55 GUSTING TO 65    DEPRESSION

11-10-2015/0600  15.8/69.2 45-55 GUSTING TO 65   DEPRESSION

11-10-2015/1200 16.0/69.0 40-50 GUSTING TO 60    DEPRESSION

11-10-2015/1800 16.2/68.7  40-50 GUSTING TO 60   DEPRESSION

12-10-2015/0000  16.5/68.2 40-50 GUSTING TO 60   DEPRESSION

12-10-2015/1200  17.1/67.0 35-45 GUSTING TO 55   DEPRESSION

13-10-2015/0000  17.7/65.6 25-35 GUSTING TO 45 WELL MARKED LOW





THE DEEP DEPRESSION WEAKENED INTO A DEPRESSION UNDER THE INFLUENCE
OF DRY AIR INTRUDING INTO THE SYSTEM FROM THE NORTHWEST AND SLOW
MOVEMENT OF THE SYSTEM ACCOMPANIED WITH REDUCED OUTFLOW AND HENCE
UPPER LEVEL DIVERGENCE. ANIMATION OF TOTAL PRECIPITABLE WATER
VAPOUR INDICATES DRY AIR INTRUSION AROUND THE SYSTEM FROM THE
NORTHWEST. AS A RESULT, THE DEPTH OF CONVECTION HAS REDUCED DURING
PAST 12 HOURS. THE LOW LEVEL RELATIVE VORTICITY IS 100 X 10-5 S-1,
UPPER LEVEL DIVERGENCE IS 5-10 X 10-5 S-1 AROUND THE SYSTEM CENTRE
AND LOW LEVEL CONVERGENCE IS 5-10 X 10-5 S-1. THE UPPER TROPOSPHERIC
RIDGE AT 200 HPA LEVEL RUNS ALONG 170N. HOWEVER, THE VERTICAL WIND
SHEAR IS ABOUT 10-20 KNOTS (MODERATE) AROUND THE SYSTEM CENTRE AND
IS 5-10 KNOTS TO THE NORTH. AS THE SYSTEM IS EXPECTED TO CONTINUE
ITS NORTH-NORTHWESTWARD MOVEMENT FOR SOME MORE TIME, IT MAY
EXPERIENCE THE DECREASED WIND SHEAR DURING THIS PERIOD. FURTHER,
THE SYSTEM WOULD MOVE AWAY FROM THE ANTICYCLONIC CIRCULATION
LOCATED CLOSE TO THE NORTHEAST OF THE SYSTEM CENTRE, IT MAY HELP
IN IMPROVING THE OUTFLOW IN UPPER TROPOSPHERIC LEVEL. THE SEA
SURFACE TEMPERATURE AROUND THE REGION OF DEPRESSION IS 28-290C.
THE OCEAN THERMAL ENERGY IS ABOUT 60-80 KJ/CM2. HOWEVER, IT
DECREASES TOWARDS THE WEST.

THUS THE DEPRESSION IS EXPECTED TO MAINTAIN ITS INTENSITY DURING
NEXT 24 HOURS AND WEAKEN THEREAFTER WHILE MOVING NORTH-
NORTHWESTWARDS INITIALLY AND THEN WEST-NORTHWESTWARDS.=

風力明顯不足....