BOB: DEEP DEPRESSION (TC 07B) - Discussion

[HURAKAN]

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 6.4N 91.3E,
HAS REMAINED QUASI-STATIONARY OVER THE PAST 06 HOURS, APPROXIMATELY
700 NM EAST OF COLOMBO, SRI LANKA. RECENT ANIMATED INFRARED IMAGERY
AND A 021219Z SSMI MICROWAVE IMAGE DEPICT A SLOWLY CONSOLIDATING
LOW-LEVEL CIRCULATION CENTER (LLCC) WITH WEAK CONVECTIVE BANDING.
A 021153Z QUIKSCAT IMAGE SUPPORTS THE PRESENCE OF AN ELONGATED LLCC
WITH 20-25 KNOT UNFLAGGED WINDS NEAR THE CENTER. THE SYSTEM
REMAINS IN A GENERALLY FAVORABLE ENVIRONMENT WITH LOW VERTICAL
WIND SHEAR AND STRONG DIFFLUENCE ALOFT FUELING PERSISTENT DEEP
CONVECTION. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO
25 KNOTS AND MINIMUM SEA LEVEL PRESSURE AT 1008 MB. DUE TO THE
PRESENCE OF A DEVELOPING LLCC WITH CONVECTIVE BANDING BEGINNING
TO WRAP INTO THE CENTER, THE POTENTIAL FOR THE DEVELOPMENT OF
A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS
FAIR.

[HURAKAN]

[HURAKAN]

DEMS-RSMC TROPICAL CYCLONES, NEW DELHI 03-12-2008

TROPICAL WEATHER OUTLOOK FOR INDIAN OCEAN (THE BAY OF BENGAL AND ARABIAN SEA) VALID FOR NEXT 24 HOURS ISSUED AT 0600 UTC (.)

CONVECTIVE CLOUDS ARE SEEN OVER SOUTH ANDAMAN SEA, SOUTHEAST BAY OF BENGAL, PARTS OF SOUTHEAST ARABIAN SEA(.)

RIDGE LINE AT 200 hPa PASSES THROUGH LATITUDE 10.0 DEG. NORTH OVER INDIAN REGION(.)

[Chacor]

WTIO21 PGTW 032230
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 6.7N 91.0E TO 8.1N 86.6E WITHIN
THE NEXT 06 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSU-
ANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS
IN THE AREA ARE ESTIMATED TO BE 20 TO 25 KNOTS. METSAT IMAGERY
AND SYNOPTIC DATA AT 032100Z INDICATE THAT A CIRCULATION CENTER
IS LOCATED NEAR 6.4N 90.2E. THE SYSTEM IS MOVING WESTWARD AT 05
KNOTS.
2. REMARKS: THE AREA OF CONVECTION LOCATED NEAR 6.4N 90.2E, APPROX-
IMATELY 495 NM EAST OF SRI LANKA HAS SIGNIFICANTLY INTENSIFIED OVER
THE PAST 06 HOURS. RECENT ANIMATED INFRARED IMAGERY AND A 031607Z
AMSU-B MICROWAVE IMAGE DEPICT A CONSOLIDATING LOW-LEVEL CIRCULATION
CENTER (LLCC). UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS SOUTH OF
THE SUBROPICAL RIDGE AXIS IN A FAVORABLE ENVIRONMENT WITH LOW VERTICAL
WIND SHEAR AND STRONG DIFFLUENCE ALOFT. ANIMATED INFRARED WATER VAPOR
IMAGERY SHOWS STRONG POLEWARD OUTLFOW AND DEEPENING BANDS OF
CONVECTION AND THE APPEARANCE OF A CENTRAL DENSE OVERCAST. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS AND MINIMUM
SEA LEVEL PRESSURE AT 1005 MB. THE POTENTIAL FOR THE DEVELOPMENT OF
A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS GOOD.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
042230Z.//

[HURAKAN]

[HURAKAN]

Looks to be becoming very well organized.

[HURAKAN]

TC 07B is here.

[HURAKAN]

WTIO31 PGTW 040300
MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
REF/A/NAVMARFCSTCEN PEARL HARBOR HI/032151Z DEC 08//
AMPN/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. TROPICAL CYCLONE 07B (SEVEN) WARNING NR 001
01 ACTIVE TROPICAL CYCLONE IN NORTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
040000Z --- NEAR 6.7N 90.2E
MOVEMENT PAST SIX HOURS - 280 DEGREES AT 05 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 6.7N 90.2E
---
FORECASTS:
12 HRS, VALID AT:
041200Z --- 6.8N 89.0E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 280 DEG/ 07 KTS
---
24 HRS, VALID AT:
050000Z --- 7.0N 87.7E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
080 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 275 DEG/ 09 KTS
---
36 HRS, VALID AT:
051200Z --- 7.2N 85.9E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT
075 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 280 DEG/ 11 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
060000Z --- 7.5N 83.7E
MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT
075 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
085 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 275 DEG/ 08 KTS
---
72 HRS, VALID AT:
070000Z --- 7.8N 80.5E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
---
REMARKS:
040300Z POSITION NEAR 6.7N 89.9E.
TROPICAL CYCLONE 07B, LOCATED NEAR 6.7N 90.2E, APPROXIMATELY 500 NM
EAST OF SRI LANKA HAS TRACKED WESTWARD AT 05 KTS OVER THE PAST
O6 HOURS, AND HAS RAPIDLY INTENSIFIED. RECENT ANIMATED INFRARED
IMAGERY AND A 040044Z SSMI MICROWAVE IMAGE DEPICT A CONSOLIDATING
LOW-LEVEL CIRCULATION CENTER (LLCC). UPPER LEVEL ANALYSIS INDICATES
THE SYSTEM IS SOUTH OF THE SUBROPICAL RIDGE AXIS IN A FAVORABLE
ENVIRONMENT WITH LOW VERTICAL WIND SHEAR AND STRONG DIFFLUENCE ALOFT.
ANIMATED INFRARED WATER VAPOR IMAGERY SHOWS STRONG OUTLFOW AND
DEEPENING BANDS OF CONVECTION. THIS WARNING SUPERCEDES AND CANCELS
REF A, NAVMARFCSTCEN 032151Z DEC 08 TROPICAL CYCLONE FORMATION
ALERT (WTIO21 PGTW 032200 ) MAXIMUM SIGNIFICANT WAVE HEIGHT
AT 040000Z IS 10 FEET. NEXT WARNINGS AT 041500Z AND 050300Z.

[HURAKAN]

[HURAKAN]

[Sanibel]

A follow up on the last one. The area must be tropically "hot".

[Crostorm]

[Chacor]

WTIN20 DEMS 040710

SPECIAL TROPICAL WEATHER OUTLOOK
------------------------------------
DEMS-RSMC TROPICAL CYCLONES NEW DELHI 04-12-2008 (.)
TROPICAL WEATHER OUTLOOK FOR NORTH INDIAN OCEAN (THE
BAY OF BENGAL AND THE ARABIAN SEA) VALID FOR NEXT 24
HOURS ISSUED AT 0600 UTC OF 04 DECEMBER,2008 BASED
ON 0300 UTC OF 04 DECEMBER 2008(.)

A DEPRESSION HAS FORMED OVER SOUTHEAST BAY OF BENGAL AND LAY
CENTRED AT 0300 UTC OF TODAY,THE 04 TH DECEMBER 2008 NEAR LAT.
6.5 DEG N AND LONG.90.0 DEG E,ABOUT 650 KM SOUTH-SOUTHWEST OF
PORT BLAIR (43333),1300 KM SOUTHEAST OF CHENNAI (43279) AND 1000
KM EAST-SOUTHEAST OF TRINCOMALEE (43418),SRILANKA.

SATELLITE IMAGERY INDICATES GRADUAL ORGANISATION OF CONVECTION
DURING PAST TWELVE HOURS.THE SYSTEM SHOWS THE CURVED BAND PATTERN
WITH INTENSITY T1.5.ASSOCIATED BROKEN INTENSE CONVECTION OBSERVED
OVER SOUTH BAY OF BENGAL AND ADJOINING INDIAN OCEAN BETWEEN LAT.4.5
DEG N AND 10.0 DEG N AND LONG.86.0 DEG E AND 91.0 DEG E.

SUSTAINED MAXIMUM SURFACE WIND SPEED IS ESTIMATED TO BE ABOUT 25
KNOTS .THE STATE OF THE SEA IS ROUGH TO VERY ROUGH AROUND THE SYSTEM
CENTRE.THE ESTIMATED CENTRAL PRESSURE IS ABOUT 1006 HPA.THE LOWEST
CLOUD TOP TEMPERATURE (CTT) DUE TO CONVECTION IS AROUND -40 DEG C
TO -50 DEG C.VERTICAL WIND SHEAR OF HORIZONTAL WIND OVER THE REGION
IS 15 TO 20 KNOTS.WIND SHEAR TENDENCY SHOWS NO SIGNIFICANT CHANGE
DURING PAST 24 HOURS.THE SYSTEM LIES TO THE SOUTH OF THE UPPER
TROPOSPHERIC RIDGE,WHICH ROUGHLY RUNS ALONG 11 DEG N.

CONSIDERING ALL THE ABOUVE,THE SYSTEM IS LIKELY TO INTENSIFY FURTHER
AND MOVE IN A WEST-NORTHWESTERLY DIRECTION.

[Sanibel]

Could be a December limit to tropical potential involved here.

[HURAKAN]

04/2100 UTC 7.5N 88.9E T2.5/2.5 07B -- Bay of Bengal

[HURAKAN]

Shear is clearly not letting up.

[HURAKAN]

[HURAKAN]

BOB 08/2008/05 Dated: 05 December 2008

Time of issue: 0800 hours IST

Sub: Deep depression over southeast Bay of Bengal

The depression over southeast Bay of Bengal has moved northwestwards, concentrated into a deep depression and lay centred at 0530 hours IST of today, the 05th December 2008 near lat. 7.50 N and long. 88.50 E, about 650 km southwest of Port Blair, 1100 km southeast of Chennai and about 800 km east-southeast of Trincomalee (Sri Lanka). The system is likely to intensify further and move in a west-northwesterly direction.

Under its influence, rainfall at many places with isolated heavy falls is likely over Nicobar Islands during next 12 hrs.

Squally winds speed reaching 45-55 kmph gusting to 65 kmph are likely over Nicobar Islands and adjoining Sea areas during next 12 hours. Sea condition is rough to very rough along and off Nicobar Islands. Fishermen are advised not to venture into the sea.

[Chacor]

WTIN20 DEMS 050720

SPECIAL TROPICAL WEATHER OUTLOOK
=================================================
DEMS-RSMC TROPICAL CYCLONES NEW DELHI 05-12-2008

TROPICAL WEATHER OUTLOOK FOR NORTH INDIAN OCEAN (THE BAY OF BENGAL
AND ARABIAN SEA) VALID FOR NEXT 24 HOURS ISSUED AT 0600 UTC OF 05
DECEMBER, 2008 BASED ON 0300 UTC OF 05 DECEMBER, 2008 (.)

THE DEEP DEPRESSION OVER SOUTHEAST BAY OF BENGAL REMAINED
PRACTICALLY STATIONARY AND LAY CENTRED AT 0300 UTC TODAY, THE 05TH
DECEMBER 2008 NEAR LAT. 7.50 N AND LONG. 88.50 E, ABOUT 650 KM
SOUTHWEST OF PORT BLAIR (43333), 1100 KM SOUTHEAST OF CHENNAI (43279)
AND 800 KM EAST-SOUTHEAST OF TRINCOMALEE (43418), SRI LANKA.

SATELLITE IMAGERY INDICATES MORE ORGANISED CONVECTION DURING PAST
TWELVE HOURS. THE SYSTEM SHOWS THE CURVED BAND PATTERN WITH INTENSITY
T2.0. ASSOCIATED BROKEN TO SOLID INTENSE TO VERY INTENSE CONVECTION
OBSERVED OVER AREA BETWEEN LAT. 5.50 N AND 10.00 N AND LONG. 83.00 E
AND 89.00 E.


SUSTAINED MAXIMUM SURFACE WIND SPEED IS ESTIMATED TO BE ABOUT 30
KNOTS GUSTING TO 40 KNOTS. THE STATE OF THE SEA IS VERY ROUGH AROUND
THE SYSTEM CENTRE. THE ESTIMATED CENTRAL PRESSURE IS ABOUT 1004 HPA.
THE LOWEST CLOUD TOP TEMPERATURE (CTT) DUE TO CONVECTION IS AROUND
-600C. VERTICAL WIND SHEAR OF HORIZONTAL WIND OVER THE REGION IS 15
TO 20 KNOTS. WIND SHEAR TENDENCY SHOWS NO SIGNIFICANT CHANGE DURING
PAST 24 HOURS. THE SYSTEM LIES TO THE SOUTH OF THE UPPER TROPOSPHERIC
RIDGE, WHICH ROUGHLY RUNS ALONG 120N. HENCE, THE SYSTEM LIES IN
FAVOURABLE UPPER LEVEL DIVERGENCE ZONE FOR INTENSIFICATION.



CONSIDERING ALL THE ABOVE, THE SYSTEM IS LIKELY TO INTENSIFY FURTHER
AND MOVE IN A WEST-NORTHWESTERLY DIRECTION TOWARDS NORTH SRI LANKA,
TAMIL NADU & PUDUCHERRY COASTS DURING NEXT 72 HOURS.



DATE/TIME(IST) POSITION (LAT. N/LONG. E) SUSTAINED MAXIMUM SURFACE
WIND SPEED (KNOTS)

05/0830 7.5/88.5 30 GUSTING TO 40
06/0830 8.5/86.5 35 GUSTING TO 45
07/0830 9.0/84.5 40 GUSTING TO 50
08/0830 9.5/82.5 40 GUSTING TO 50

[HURAKAN]

Looks like shear is winning or won!