NIO: Cyclonic Storm Nisha (TS 06B) - Discussion

[wyq614]

24/0230 UTC 8.5N 82.9E T1.0/1.0 93B -- Bay of Bengal

According to the latest ECWMF, 92A may be annexed by 93B and then the system will develop into a fishy storm and make landfall on the coast of Tamil Nadu..

[Chacor]

Looks pretty good.

[RattleMan]

ABIO10 PGTW 241230
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN
/OCEAN REISSUED/241230Z-241800ZNOV2008//
RMKS/
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY:
(1) A BROAD AREA OF CONVECTION IS LOCATED NEAR 8.7N 81.7E, APPROXI-
MATELY 25 NM EAST OF SRI LANKA. ANIMATED MULTISPECTRAL IMAGERY DEPICTS
CONVECTIVE BANDS AROUND THE CENTER HAVE BECOME MORE SYMMETRIC THE PAST
24 HOURS. UPPER LEVEL ANALYSIS SHOWS THE SYSTEM IS UNDER THE SOUTHERN
PERIPHERY OF A RIDGE AXIS WITH LOW TO MODERATE VERTICAL WIND SHEAR. WATER
VAPOR ANIMATION INDICATES GOOD POLEWARD AND EQUATORWARD OUTFLOW. SURFACE
OBSERVATION AT COLOMBO INTERNATIONAL AIRPORT AT 241110Z SHOWS NORTHWES-
TERLY WINDS AT 11 KNOTS AND A SEA LEVEL PRESSURE OF 1006 MB. 24-HR PRESSURE
TREND INDICATES A DROP OF 1 MB. MAXIMUM SUSTAINED WINDS NEAR THE CENTER
ARE ESTIMATED AT 15 TO 20 KNOTS AND MINIMUM SEA LEVEL PRESSURE IS NEAR
1004 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS IS POOR.
(2) NO OTHER SUSPECT AREAS.
2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: ADDED POOR AREA IN PARA 1.B.(1).
FORECAST TEAM: CHARLIE//
NNNN

-------------------

ABIO10 PGTW 241800
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN
/OCEAN/241800Z-251800ZNOV2008//
RMKS/
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY:
(1) A BROAD AREA OF CONVECTION PREVIOUSLY LOCATED NEAR NEAR 8.7N
81.7E, IS NOW LOCATED NEAR 8.8N 81.3E APPROXIMATELY 140 NM NORTHEAST OF
COLOMBO, SRI LANKA. ANIMATED MULTISPECTRAL IMAGERY DEPICTS DEEP
CONVECTION FLANKING THE NORTHERN AND SOUTHERN OUTER-PERIPHERIES OF THE
SYSTEM. CONVECTION HAS REMAINED MINIMAL NEAR THE LOW LEVEL CIRCULATION
CENTER THAT HAS MORE RECENTLY BEGUN TO DETERIORATE DUE TO INTERACTION
WITH SRI LANKA. RECENT OBSERVATIONS NEAR COLOMBO SHOW SEA LEVEL
PRESSURES RANGING FROM 1006 TO 1009 MB WITH MINOR PRESSURE FALLS OVER
THE PAST 24 HOURS. UPPER LEVEL ANALYSIS SHOWS THE SYSTEM IS UNDER THE
SOUTHERN PERIPHERY OF A RIDGE AXIS WITH LOW TO MODERATE VERTICAL WIND
SHEAR. WATER VAPOR ANIMATION INDICATES GOOD POLEWARD AND EQUATORWARD
OUTFLOW. MAXIMUM SUSTAINED WINDS NEAR THE CENTER ARE ESTIMATED AT 15
TO 20 KNOTS AND MINIMUM SEA LEVEL PRESSURE IS NEAR 1005 MB. THE POTENTIAL
FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS REMAINS POOR.
(2) NO OTHER SUSPECT AREAS.
2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA):
A. TROPICAL CYCLONE SUMMARY: NONE.
B. TROPICAL DISTURBANCE SUMMARY: NONE.
FORECAST TEAM: BRAVO//
NNNN

[CrazyC83]

I really do not like the looks of this one. Lots of water ahead.

[HURAKAN]

[HURAKAN]

A BROAD AREA OF CONVECTION PREVIOUSLY LOCATED NEAR NEAR 8.7N
81.7E, IS NOW LOCATED NEAR 8.8N 81.3E APPROXIMATELY 140 NM NORTHEAST OF
COLOMBO, SRI LANKA. ANIMATED MULTISPECTRAL IMAGERY DEPICTS DEEP
CONVECTION FLANKING THE NORTHERN AND SOUTHERN OUTER-PERIPHERIES OF THE
SYSTEM. CONVECTION HAS REMAINED MINIMAL NEAR THE LOW LEVEL CIRCULATION
CENTER THAT HAS MORE RECENTLY BEGUN TO DETERIORATE DUE TO INTERACTION
WITH SRI LANKA. RECENT OBSERVATIONS NEAR COLOMBO SHOW SEA LEVEL
PRESSURES RANGING FROM 1006 TO 1009 MB WITH MINOR PRESSURE FALLS OVER
THE PAST 24 HOURS. UPPER LEVEL ANALYSIS SHOWS THE SYSTEM IS UNDER THE
SOUTHERN PERIPHERY OF A RIDGE AXIS WITH LOW TO MODERATE VERTICAL WIND
SHEAR. WATER VAPOR ANIMATION INDICATES GOOD POLEWARD AND EQUATORWARD
OUTFLOW. MAXIMUM SUSTAINED WINDS NEAR THE CENTER ARE ESTIMATED AT 15
TO 20 KNOTS AND MINIMUM SEA LEVEL PRESSURE IS NEAR 1005 MB. THE POTENTIAL
FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS REMAINS POOR.

[HURAKAN]

Floater: http://www.ssd.noaa.gov/PS/TROP/mtsatfloat1.html

[HurricaneBill]

As we head towards December, the cyclone threat in the NIO shifts to southern India and Sri Lanka.

[Chacor]

DEMS–RSMC TROPICAL CYCLONES NEW DELHI 25-11-2008



Tropical weather outlook for north Indian ocean (The bay of Bengal and Arabian sea) valid for next 24 hours issued at 0600 utc (.)





YESTERDAY’S LOW PRESSURE AREA OVER SRI LANKA AND NEIGHBOURHOOD NOW LIES AS A WELL MARKED LOW PRESSURE AREA OVER NORTH SRI LANKA AND ADJOINING SOUTHWEST BAY OF BENGAL. THE SYSTEM IS LIKELY TO CONCENTRATE INTO A DEPRESSION OVER SOUTHWEST BAY OF BENGAL BY TOMORROW.

[Chacor]

WTIO21 PGTW 250730
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
A 090 NM RADIUS OF 9.7N 80.5E WITHIN THE NEXT 06 TO 24 HOURS.
AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL CY-
CLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO
BE 30 TO 35 KNOTS. METSAT IMAGERY AT 250600Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 9.6N 80.7E. THE SYSTEM IS
QUASI-STATIONARY AT 03 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 8.8N 81.3E,
IS NOW LOCATED NEAR 10.1N 81.0E, APPROXIMATELY 170 NM NORTH-NORTHEAST
OF KOTTE, SRI LANKA. RECENT ANIMATED MULTISPECTRAL IMAGERY REVEALS A
RAPIDLY CONSOLIDATING LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP
CONVECTION BEGINNING TO MOVE OVER WATER FROM NORTHERN SRI LANKA.
UPPER LEVEL ANALYSIS SHOWS THE SYSTEM IS UNDER THE SOUTHERN PERIPHERY
OF A RIDGE AXIS WITH LOW TO MODERATE VERTICAL WIND SHEAR. WATER VAPOR
ANIMATION INDICATES GOOD POLEWARD AND EQUATORWARD OUTFLOW. MAXIMUM
SUSTAINED WINDS NEAR THE CENTER ARE ESTIMATED AT 30 TO 35 KNOTS AND
MINIMUM SEA LEVEL PRESSURE IS NEAR 1000 MB. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS UPGRADED TO GOOD.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
260730Z.//

[Chacor]

[HURAKAN]

25/0830 UTC 9.7N 80.7E T2.5/2.5 93B -- Bay of Bengal

[Chacor]

Depression BOB07:

BOB 07/2008/01 Dated: 25 November 2008



Time of issue: 1730 hours IST



Sub: Depression over Sri Lanka – Pre-cyclone watch for Tamil Nadu coast



Latest satellite imageries and surface observations from Sri Lanka and coastal stations of Tamil Nadu indicate that a depression has formed over Sri Lanka and it lay centred at 1430 hours IST of today, the 25th November 2008 near lat. 8.50 N and Long. 81.00 E, about 200 km southeast of Pamban, about 300 km south-southeast of Nagapattinam close to the southwest of Trincomalee (Srilanka). The system is likely to intensify further and move slowly in a northwesterly direction and cross Tamil Nadu coast between Pamban and Nagapattinam by tomorrow, the 26th November 2008 night.



Under its influence, rainfall at most places with heavy to very heavy falls at a few places and isolated extremely heavy falls is likely over coastal Tamil Nadu during next 48 hrs. Rainfall at many places with isolated heavy to very heavy falls is also likely over interior Tamil Nadu and Kerala during the same period.

Squally winds speed reaching 45-55 kmph gusting to 65 kmph are likely along and off Tamilnadu & Puducherry coasts during next 48 hours. Sea condition is rough to very rough along and off these coasts. Fishermen are advised not to venture into the sea.

[Chacor]

WTIN20 DEMS 251420

SPECIAL TROPICAL WEATHER OUTLOOK
----------------------------------
DEMS-RSMC TROPICAL CYCLONE NEW DELHI 25-11-2008 (.)

TROPICAL WEATHER OUTLOOK FOR NORTH INDIAN OCEAN (THE
BAY OF BENGAL AND THE ARABIAN SEA) VALID FOR NEXT 24
HOURS ISSUED AT 1200 UTC OF 25 NOVEMBER,2008 BASED ON
0900 UTC OF 25 NOVEMBER,2008 (.)

MORNING"S WELL MARKED LOW PRESSURE AREA OVER NORTH SRILANKA
AND ADJOINING SOUTHWEST BAY OF BENGAL CONCENTRATED INTO A
DEPRESSION OVER THE SAME REGION AND LAY CENTRED AT 0900 UTC OF
TODAY,THE 25TH NOVEMBER 2008 NEAR LAT.8.5 DEG N AND LONG.81.0
DEG.E, CLOSE TO THE SOUTHWEST OF TRINCOMALEE(43418),SRILANKA,
ABOUT 200 KM SOUTHEAST OF PAMBAN(43363),AND 300 KM SOUTH-SOUTH
EAST OF NAGAPATTINAM(43347).

SATELLITE IMAGERY INDICATES GRADUAL ORGANISATION OF CONVECTION
DURING PAST SIX HOURS IN ASSOCIATED WITH THE SYSTEM. ASSOCIATED
BROKEN INTENSE CONVECTION OBSERVED OVER SOUTHWEST BAY ADJOINING
NORTH SRI LANKA,PALK STRAIT,TAMILNADU,GULF OF MANNAR AND COMRAIN.


SUSTAINED MAXIMUM WINDS 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 1001 HPA.THE
LOWEST CLOUD TOP TEMPERATURE(CTT)DUE TO CONVECTION IS AROUND -65
DEG C. VERTICAL WIND SHEAR OF HORIZONTAL WIND OVER THE REGION IS
15 TO 20 KNOTS. SHEAR TENDENCY IS -10 TO -20 KNOTS TO NORTH OF
THE SYSTEM.THE SYSTEM LIES TO THE SOUTH OF THE UPPER
TROPOSPHERIC RIDGE,WHICH ROUGHLY RUNS ALONG 14 DEG.N. THE SEA
SURFACE TEMPERATURE OVER THE REGION IS ABOUT 29 DEG C.

CONSIDERING ALL THE ABOVE, THE SYSTEM IS LIKELY TO INTENSIFY
FURTHER AND MOVE SLOWLY IN A NORTHWESTERLY DIRECTION AND CROSS
TAMILNADU COAST BETWEEN PAMBAN AND NAGAPATINAM BETWEEN 1500 UTC
TO 1900 UTC OF TOMORROW,THE 26TH NOVEMBER,2008.

[RattleMan]

BOB 07/2008/02 Dated: 25 November 2008



Time of issue: 2130 hours IST



Sub: Depression over Sri Lanka – Cyclone alert for Tamil Nadu coast



The depression over Sri Lanka remained practically stationary, intensified into a deep depression and lay centred at 1730 hours IST of today, the 25th November 2008 near lat. 8.50 N and Long. 81.00 E, about 200 km southeast of Pamban, about 300 km south-southeast of Nagapattinam close to the southwest of Trincomalee (Sri Lanka). The system is likely to intensify further and move slowly in a northwesterly direction and cross Tamil Nadu coast between Pamban and Nagapattinam by tomorrow, the 26th November 2008 night.



Under its influence, rainfall at most places with heavy to very heavy falls at a few places and isolated extremely heavy falls is likely over coastal Tamil Nadu during next 48 hrs. Rainfall at many places with isolated heavy to very heavy falls is also likely over interior Tamil Nadu and Kerala during the same period.

Squally winds speed reaching 55-65 kmph gusting to 75 kmph are likely along and off Tamil Nadu & Puducherry coasts during next 48 hours. Sea condition is very rough to high along and off these coasts. Fishermen are advised not to venture into the sea.

[HURAKAN]

25/1430 UTC 9.9N 80.3E T3.0/3.0 93B -- Bay of Bengal



Very well organized system.

[P.K.]

The IMD are still at T2.0. PGTW are at T3.0/3.0 as well.

BOB 07/2008/03 Dated: 25 November 2008

Time of issue: 2330 hours IST

Sub: Deep Depression over Sri Lanka coast & adjoining southwest Bay of

Bengal – Cyclone alert for Tamil Nadu coast (Yellow)

The deep depression over Sri Lanka moved northwards and lay centred at 2030 hours IST of today, the 25th November 2008 over Sri Lanka coast & adjoining southwest Bay of Bengal near lat. 9.00 N and Long. 81.00 E, about 200 km east-southeast of Pamban, about 240 km south-southeast of Nagapattinam and close to the northwest of Trincomalee (Sri Lanka). The system is likely to intensify into a cyclonic storm and move slowly in a northwesterly direction and cross Tamil Nadu coast between Pamban and Nagapattinam by tomorrow, the 26th November 2008 night.

Under its influence, rainfall at most places with heavy to very heavy falls at a few places and isolated extremely heavy falls is likely over coastal Tamil Nadu during next 48 hrs. Rainfall at many places with isolated heavy to very heavy falls is also likely over interior Tamil Nadu and Kerala during the same period.

Squally winds speed reaching 55-65 kmph gusting to 75 kmph are likely along and off Tamil Nadu & Puducherry coasts during next 48 hours. Sea condition is very rough to high along and off these coasts. Fishermen are advised not to venture into the sea.

[HURAKAN]

40 knots.

[HURAKAN]

WTIO31 PGTW 252100
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE WARNING//
REF/A/NAVMARFCSTCEN PEARL HARBOR HI/250730Z NOV 08//
AMPN/TROPICAL CYCLONE FORMATION ALERT//
1. TROPICAL CYCLONE 06B (SIX) WARNING NR 001
01 ACTIVE TROPICAL CYCLONE IN NORTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
251800Z --- NEAR 9.7N 80.4E
MOVEMENT PAST SIX HOURS - 340 DEGREES AT 03 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
045 NM NORTHWEST QUADRANT
REPEAT POSIT: 9.7N 80.4E
---
FORECASTS:
12 HRS, VALID AT:
260600Z --- 10.1N 79.9E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
035 NM SOUTHWEST QUADRANT
030 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 300 DEG/ 03 KTS
---
24 HRS, VALID AT:
261800Z --- 10.4N 79.4E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
VECTOR TO 36 HR POSIT: 295 DEG/ 03 KTS
---
36 HRS, VALID AT:
270600Z --- 10.7N 78.8E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
VECTOR TO 48 HR POSIT: 290 DEG/ 04 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
271800Z --- 11.0N 78.0E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
252100Z POSITION NEAR 9.8N 80.3E.
TROPICAL CYCLONE (TC) 06B, LOCATED APPROXIMATELY 245 NM EAST
COCHIN, INDIA, HAS TRACKED NORTH-NORTHWESTWARD AT 03 KNOTS OVER
THE PAST 06 HOURS. RECENT ANIMATED MULTISPECTRAL SATELLITE
IMAGERY AND A 251415Z SSMIS MICROWAVE IMAGE SHOW DEEP CONVECTION
WRAPPING INTO A WELL-DEFINED LOW LEVEL CIRCULATION CENTER, ESPECIALLY
WITHIN THE NORTHERN SEMICIRCLE. THE INITIAL INTENSITY OF 40 KNOTS IS
CONSISTENT WITH DVORAK SATELLITE INTENSITY ESTIMATES FROM PGTW AND
KNES, THE SATELLITE PRESENTATION, AND TOPOGRAPHICAL INFLUENCES.
UPPER LEVEL DYNAMICS ARE FAVORABLE FOR CONTINUED INTENSIFICATION WITH
EXCELLENT RADIAL OUTFLOW AND LOW VERTICAL WIND SHEAR, HOWEVER,
CONTINUED LAND INTERACTION WILL PREVENT SIGNIFICANT INTENSIFICATION
PRIOR TO MAKING LANDFALL. THE CYCLONE IS FORECAST TO TRACK SLOWLY
NORTHWESTWARD THROUGH THE PALK STRAIT AND WILL MAKE LANDFALL WITH THE
EASTERN COAST OF INDIA WITHIN 24 HOURS. THE CYCLONE WILL THEN WEAKEN
SIGNIFICANTLY AS IT TRANSITS ACROSS SOUTHERN INDIA. CURRENT LIMITED
MODEL GUIDANCE SUGGESTS THAT A WEAKENED LOW LEVEL CIRCULATION CENTER
WILL TRACK INTO THE ARABIAN SEA, THOUGH THIS SCENARIO SEEMS LESS
LIKELY GIVEN THIS FORECAST TRACK/DURATION OVER LAND. THIS WARNING
SUPERSEDES AND CANCELS REF A, NAVMARFCSTCEN 250730Z NOV 08 TROPICAL
CYCLONE FORMATION ALERT (WTIO21 PGTW 250730). MAXIMUM SIGNIFICANT WAVE
HEIGHT AT 251800Z IS 11 FEET. NEXT WARNINGS AT 260300Z, 260900Z,
261500Z AND 262100Z.//

[HURAKAN]