BOB: 03B - Tropical Cyclone

[euro6208]

16/2100 UTC 14.4N 89.7E T1.5/1.5 98B -- Bay of Bengal

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 14.7N
90.7E, IS NOW LOCATED NEAR 14.5N 90.1E, APPROXIMATELY 580 NM EAST
OF CHENNAI, INDIA. RECENT ANIMATED INFRARED SATELLITE IMAGERY SHOWS
A CONSOLIDATING LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP
CONVECTION PERSISTING OVER THE EASTERN PERIPHERY. A 162204Z SSMI
85GHZ MICROWAVE IMAGE DEPICTS A LOOSELY ORGANIZED SYSTEM WITH
CONVECTION BEGINNING TO BUILD OVER THE LLCC. UPPER-LEVEL ANALYSIS
DEPICTS THE DISTURBANCE IS UNDERNEATH A SUBTROPICAL RIDGE (STR)
AXIS WITH EXCELLENT DIVERGENCE ALOFT, WHICH IS BEING ENHANCED BY
THE WESTERLIES TO THE NORTH AND IS NOW IN AN AREA OF LOW (05-10
KNOT) VERTICAL WIND SHEAR (VWS). SEA SURFACE TEMPERATURES ARE
FAVORABLE FOR TROPICAL CYCLOGENESIS AT 28 TO 30 DEGREES CELSIUS.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. DUE TO
THE INCREASE IN ORGANIZATION AND A MORE FAVORABLE UPPER LEVEL
ENVIRONMENT, THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT
TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.

[Hurricane_Luis]

Tropical Cyclone Formation Alert



WTIO21 PGTW 170800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN A
230 NM RADIUS OF 16.1N 88.6E WITHIN THE NEXT 12 TO 24 HOURS.
AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL
CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO BE
27 TO 32 KNOTS. METSAT IMAGERY AT 170530Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 15.7N 89.2E. THE SYSTEM IS MOVING
NORTH-NORTHWESTWARD AT 04 KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 14.5N
90.1E, IS NOW LOCATED NEAR 15.7N 89.2E, APPROXIMATELY 410 NM SOUTH
OF KOLKATA, INDIA. RECENT ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) SHOWS CONTINUED CONSOLIDATION OF THE LOW LEVEL CIRCULATION
CENTER (LLCC) WITH STEADY IMPROVEMENT IN THE DEEP CONVECTIVE BANDING
WRAPPING INTO THE CENTER. A 170423Z ASCAT PASS SHOWING A BAND OF 20
TO 25 KNOT WINDS BEGINNING TO BUILD INTO THE LLCC ALONG THE SOUTHERN
PERIPHERY OF THE SYSTEM. MSI SUGGESTS THAT THE STRONGER WINDS ARE
LOCATED ALONG THE EASTERN HALF OF THE AREA BETWEEN 25 TO 30 KNOTS.
UPPER LEVEL ANALYSIS INDICATES THE LLCC IS LOCATED UNDER THE AXIS OF
A SUBTROPICAL RIDGE, WHICH IS PROVIDING AMPLE POLEWARD OUTFLOW AND A
LOW VERTICAL WIND SHEAR ENVIRONMENT (05 TO 10 KNOTS). ANIMATED TOTAL
PRECIPITABLE WATER IMAGERY SHOWS A DEVELOPING BAND OF DRY COOL AIR
ATTEMPTING TO WRAP ALONG THE SOUTHERN PERIPHERY INTO THE SYSTEM,
HOWEVER THE CENTRAL WARM CORE REMAINS ISOLATED FROM THIS BAND AND IS
BEING SUPPORTED BY THE WARM TROPICAL AIR MASS LOCATED IN THE
SOUTHEASTERN QUADRANT OF LLCC. SEA SURFACE TEMPERATURES REMAIN
FAVORABLE (28 TO 30 CELSIUS) FOR FURTHER DEVELOPMENT. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 27 TO 32 KNOTS. MINIMUM
SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. DUE TO THE
INCREASE IN ORGANIZATION AND A MORE FAVORABLE UPPER LEVEL
ENVIRONMENT, THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT
TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
180800Z.//
NNNN

[wxman57]

It appears to already be a TS.

[euro6208]

It appears to already be a TS.

17/1430 UTC 16.1N 88.3E T2.5/2.5 98B -- Bay of Bengal

[supercane4867]

we now have 03B according to NRL

[somethingfunny]

I don't see any serious dry air for this system to deal with, but it is underneath some southwesterly shear:



IMD is forecasting for this to peak at around 35 or 45 kt.

This is the current forecast track from the Indian Meteorological Department:

[somethingfunny]

A few more images:

Infrared:


Microwave:


Wide-shot visible:

[supercane4867]

Center becoming exposed

[euro6208]

1.TROPICAL CYCLONE 03B (THREE) WARNING NR 004
01 ACTIVE TROPICAL CYCLONE IN NORTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
181200Z --- NEAR 15.9N 87.7E
MOVEMENT PAST SIX HOURS - 235 DEGREES AT 04 KTS
POSITION ACCURATE TO WITHIN 020 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 15.9N 87.7E


REMARKS:
181500Z POSITION NEAR 15.8N 87.5E.
TROPICAL CYCLONE (TC) 03B LOCATED APPROXIMATELY 465 NM EAST-
NORTHEAST OF CHENNAI, INDIA HAS TRACKED SOUTHWESTWARD AT 04 KNOTS
OVER THE PAST SIX HOURS. RECENT ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) SHOWS THE DEEP CENTRAL CONVECTION HAS NEARLY BEEN
COMPLETELY SHEARED FROM THE NOW FULLY EXPOSED LOW LEVEL CIRCULATION
CENTER (LLCC). AN OLDER 180628Z OSCAT PASS SHOWED A SIGNIFICANT
REGION OF 35 KNOT WINDS WITHIN THE NORTHEASTERN QUADRANT OF THE
LLCC. THE SOUTHWESTERN QUADRANT INDICATED MUCH LIGHTER WINDS BETWEEN
15 TO 20 KNOTS. ANIMATED TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE
DRY AIR CONTINUES TO WRAP TOWARDS THE CENTER OF THE SYSTEM AND HAS
STEADILY DIMINISHED THE INFLOW OF THE WARMER MOIST TROPICAL AIR MASS
IN THE SOUTHEASTERN QUADRANT. UPPER LEVEL ANALYSIS INDICATES TC 03B
IS LOCATED TO THE NORTH OF A SUBTROPICAL RIDGE (STR) AXIS. OVER THE
PAST FEW HOURS THE VERTICAL WIND SHEAR (VWS) HAS INCREASED TO
MODERATELY HIGH LEVELS (20 TO 30 KNOTS) WHICH IS RESPONSIBLE FOR THE
OBSERVED SHEARING OF THE CONVECTION TO THE NORTHEAST OF THE LLCC.
DVORAK ESTIMATES FROM PGTW INDICATE A NOTICEABLE WEAKENING TREND
OVER THE PAST 12 HOURS. INTENSITY HAS BEEN MAINTAINED AT 35 KNOTS
BASED ON THE PREVIOUSLY MENTIONED OSCAT PASS AND THE OBSERVED
STRUCTURE OF THE LLCC IN MSI. MODEL GUIDANCE HAS BEEN STEADY OVER
THE PAST 12 HOURS WITH THE WEST-SOUTHWEST TRACK, EXCLUDING WBAR
WHICH CONTINUES TO SHOW A NORTHWARD TRACK. BASED ON THE INCREASE IN
VWS, THE FORECASTED INTENSITY HAS BEEN DECREASED OVER THE NEXT 24
HOURS TO A STEADY STATE FORECAST, WITH DISSIPATION BY TAU 48. BASED
ON CONSISTENT MODEL GUIDANCE AND THE RECENT INCREASE IN TRACK SPEED
TO THE SOUTHWEST, THERE IS NOW HIGH CONFIDENCE IN THE FORECAST TRACK.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 181200Z IS 14 FEET. NEXT WARNINGS
AT 182100Z, 190300Z, 190900Z AND 191500Z.//
NNNN

[Meow]

It is Deep Depression BOB 03.

[P.K.]

It is Deep Depression BOB 03.

As of 12Z they are no longer forecasting this to get to Cyclonic Storm strength.

[supercane4867]

It's now a naked swirl, should die off soon

[RL3AO]

Looks like it was likely at storm strength at the peak, but what can you do, its the IMD.

[supercane4867]

Final Warning from the JTWC

SUBJ: TROPICAL CYCLONE 03B (THREE) WARNING NR 006
WTIO31 PGTW 190300
1. TROPICAL CYCLONE 03B (THREE) WARNING NR 006
01 ACTIVE TROPICAL CYCLONE IN NORTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
190000Z --- NEAR 15.2N 86.7E
MOVEMENT PAST SIX HOURS - 225 DEGREES AT 03 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
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
REPEAT POSIT: 15.2N 86.7E
---
FORECASTS:
12 HRS, VALID AT:
191200Z --- 15.0N 85.9E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER
---
REMARKS:
190300Z POSITION NEAR 15.2N 86.5E.

THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON
WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR
SIGNS OF REGENERATION.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 190000Z IS 12 FEET.
//
BT
#0001
NNNN

[Meow]

Beautiful...

[euro6208]

Looks like it was likely at storm strength at the peak, but what can you do, its the IMD.

i agree...3.0 dvorak and a very impressive circulation, i doubt this was only a deep depression.....

[wxman57]

Sure looked like a TS. The IMD quite often underestimates intensity.

[supercane4867]

Last advisory from IMD

India Meteorological Department
Tropical Cyclone Advisory #14
WELL MARKED LOW PRESSURE AREA, FORMER DEPRESSION BOB03-2012
8:30 AM IST November 20 2012
=================================

At 3:00 AM UTC, The well marked low pressure area over west central Bay of Bengal persists over the same region.

The system would move west southwestwards towards southern Andhra Pradesh and northern Tamil Nadu coasts and weaken further during next 48 hours.

This is the final tropical cyclone bulletin from the India Meteorological Department

[supercane4867]

Comes back to life!

Let's see if the convection can be presistent