BOB: HELEN

[supercane4867]

[euro6208]

AN AREA OF CONVECTION HAS PERSISTED NEAR 13.8N 89.0E,
APPROXIMATELY 405 NM SOUTHEAST OF VISAKHAPATNAM, INDIA. ANIMATED
INFRARED SATELLITE IMAGERY SHOWS SHALLOW AND FRAGMENTED FORMATIVE
BANDS FEEDING INTO A BROAD LOW LEVEL CIRCULATION CENTER FROM ALL
QUADRANTS. UPPER LEVEL ANALYSIS INDICATES THE AREA IS JUST SOUTH OF
THE RIDGE AXIS IN AN AREA OF LOW (05-10 KNOT) VERTICAL WIND SHEAR
AND GOOD RADIAL OUTFLOW. NUMERIC MODELS PROJECT VERY WEAK
DEVELOPMENT FROM THIS SYSTEM. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1006 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.

[HURAKAN]

TCFA issued, could be upgraded soon

[Alyono]

This is a clear depression. Could become a cyclone within 24 hours

[supercane4867]

TPIO10 PGTW 190016
A. TROPICAL DISTURBANCE 91B (E OF INDIA)
B. 18/2330Z
C. 15.1N
D. 86.6E
E. FIVE/MET7
F. T2.0/2.0 STT: D0.5/03HRS
G. IR/EIR
H. REMARKS: 38A/PBO SBC/ANMTN. A .35 WRAP YIELDS A DT OF 2.0,
PT AGREES WITH DT. DBO DT.
I. ADDITIONAL POSITIONS: NONE
RAPP

[Grifforzer]

Time of issue: 0830 hours IST
Dated: 19-11-2013
Bulletin No.: BOB06/2013/01

Sub: Depression over westcentral Bay of Bengal.

Latest satellite imagery and observations indicate that a depression has formed over westcentral Bay of Bengal and lay centred at 0530 hrs IST of today, the 19th November 2013 near latitude 14.5N and longitude 86.5E, about 700 km east northeast of Chennai, 600 km east-southeast of Machilipatnam and 500 km. southeast of Vishakhapatnam. The system would intensify into a deep depression and move west-northwestwards towards Andhra Pradesh Coast during next 72 hours.

Under its influence, rainfall at most places with isolated heavy to very heavy rainfall would occur over coastal Andhra Pradesh commencing from 21st November 2013 morning.

Squally winds speed reaching 45-55 kmph gusting to 65 kmph would prevail along and off Andhra Pradesh coast commencing from 21st November 2013 morning. Sea condition will be rough to very rough along and off Andhra Pradesh coasts from 21st November 2013 morning.

Fishermen are advised not to venture into Sea of off Andhra Pradesh coast. Fishermen out at sea off Andhra Pradesh coasts are advised to return to the coast.

The next bulletin will be issued at 1130 hrs IST of today, the 19th November, 2013.

ACCORDING TO SATELLITE IMAGERIES, THE INTENSITY OF THE SYSTEM IS T 1.5. ASSOCIATED BROKEN LOW/MEDIUM CLOUD EMBEDDED WITH MODERATE TO INTENSE CONVECTION IS SEEN OVER BAY OF BENGAL BETWEEN LAT 11.0N AND 18.5N LONG 84.0E AND 89.5E. THE LOWEST CLOUD TOP TEMPERATURE (CTT) IS ABOUT -80C. MAXIMUM SUSTAINED SURFACE WIND SPEED IS ESTIMATED TO BE ABOUT 25 KNOTS GUSTING TO 35 KNOTS AROUND THE SYSTEM CENTRE. THE STATE OF THE SEA IS ROUGH TO VERY ROUGH AROUND THE SYSTEM CENTRE. THE ESTIMATED CENTRAL PRESSURE IS ABOUT 1004 HPA.

REMARKS:
LATEST OCEANSAT-II DATA OF 1830 UTC OF 18TH NOVEMBER INDICATES THE CYCLONIC CIRCULATION OVER THE REGION AND ASSOCIATED WIND SPEED TO BE ABOUT 25-30 KNOTS TO THE NORTH AND SOUTHEAST SECTOR AND 15-20 KNOTS TO THE SOUTHWEST SECTOR OF THE SYSTEM. A BUOY LOCATED NEAR 14.0°N AND 87.0° E REPORTED MSLP OF 1007.1 HPA, 24 HR PRESSURE CHANGE OF -2.0 HPA AND SURFACE WIND OF 180/19 KNOTS, ANOTHER BUOY NEAR 13.5 °N AND 84.0°E REPORTED MSLP OF 1009.0 HPA, 24 HR PRESSURE CHANGE OF -1.5 HPA AND WIND OF 350/16 KNOTS AND ANOTHER BUOY NEAR 14.7 °N AND 85.8°E REPORTED MSLP OF 1007.8 HPA AND 24 HR PRESSURE CHANGE OF -4.3 HPA AT 0000 UTC OF 19TH NOVEMBER. A SHIP NEAR 15.9°N AND 86.8°E REPORTED MSLP OF 1009.6 HPA, 24 HR PRESSURE CHANGE OF -1.4 HPA AND WIND OF 100/26 KNOTS AT 0000 UTC OF 19TH NOVEMBER.

THE DEPRESSION LIES TO THE SOUTH OF THE UPPER TROPOSPHERIC RIDGE WHICH RUNS ALONG 16N. THE LOW LEVEL CONVERGENCE ALONGWITH LOW LEVEL RELATIVE VORTICITY ARE FAVOURABLE FOR INTENSIFICATION. THE SEA SURFACE TEMPERATURE IS ABOUT 28-29C. THE VERTICAL WIND SHEAR OF HORIZONTAL WIND IS LOW TO MODERATE (10-20 KNOTS). THE MADDEN JULLIAN OSCILLATION (MJO) INDEX LIES OVER PHASE 2 WITH AMPLITUDE LESS THAN 1. NWP MODELS SUGGEST THAT MJO WOULD CONTINUE IN PHASE 2 DURING NEXT 3 DAYS WITH AMPLITUDE LESS THAN I. THE CURRENT PHASE AND AMPLITUDE ARE NOT VERY SUPPORTIVE FOR INTENSIFICATION. THERE IS DIVERGENCE IN NWP MODELS GUIDANCE WITH RESPECT TO LANDFALL POINT AND TIME, AS THE TRACK FORECAST VARIES FROM WEST-SOUTHWEST TO NORTHWEST DIRECTION. WITH RESPECT TO INTENSIFICATION, THERE IS MORE CONSENSUS SUGGESTING SLOW INTENSIFICATION OR NO INTENSIFICATION. CURRENT FORECAST IS BASED ON CONSENSUS NWP AND SYNOPTIC ANALYSIS

[jaguarjace]

[euro6208]

REMARKS:
191500Z POSITION NEAR 15.0N 84.5E.
TROPICAL CYCLONE 04B (FOUR), LOCATED APPROXIMATELY 180 NM SOUTH-
SOUTHEAST OF VISAKHAPATNAM, INDIA, HAS TRACKED WESTWARD AT 08
KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY (MSI) REVEALS A DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC)
WITH FLARING CENTRAL CONVECTION AND BROKEN CONVECTIVE BANDING ALONG
THE NORTHERN SEMI-CIRCLE. A 191058Z SSMIS MICROWAVE IMAGE REVEALS A
WELL DEFINED SYSTEM WITH CURVED DEEP CONVECTIVE BANDING ALONG THE
WESTERN PERIPHERY OF THE LLCC. THE INITIAL POSITION IS BASED UPON
THE MSI LOOP ALONG WITH THE AFOREMENTIONED MICROWAVE IMAGE WITH FAIR
CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT 35 KNOTS BASED UPON
DVORAK INTENSITY ESTIMATES FROM PGTW AND KNES AND IS CONSISTENT WITH
THE CURRENT STRUCTURE OF THE SYSTEM. UPPER-LEVEL ANALYSIS INDICATES
A MODERATE ENVIRONMENT WITH LIGHT TO MODERATE (15 TO 20 KNOTS)
VERTICAL WIND SHEAR AND FAIR POLEWARD OUTFLOW. TC 04B IS EXPECTED TO
TRACK SLOWLY WEST THROUGH THE REMAINDER OF THE FORECAST IN A WEAK
BREAK BETWEEN TWO LOW- TO MID-LEVEL SUBTROPICAL RIDGES POSITIONED TO
THE EAST AND WEST OF THE SYSTEM. LANDFALL OVER INDIA IS EXPECTED TO
OCCUR AFTER TAU 48 AS THE SYSTEM TRACKS WEST. TC 04B IS EXPECTED TO
SLIGHTLY INTENSIFY TO A PEAK OF 45 KNOTS OVER THE NEXT 36 HOURS
BEFORE WEAKENING AS THE LAND EFFECTS HAMPER THE LOW LEVEL INFLOW
WHICH WILL LEAD TO THE SYSTEMS DISSIPATION BY TAU 72, AFTER
LANDFALL. AVAILABLE DYNAMIC MODEL GUIDANCE IS WIDELY SPREAD AS ECMWF
AND HWRF TAKE A SLOW TRACK TO THE NORTHWEST WHILE NAVGEM AND GFDN
TAKE A FASTER TRACK TO THE SOUTHWEST. THE JTWC TRACK IS POSITIONED
SLIGHTLY NORTH OF MULTI-MODEL CONSENSUS AND FAVORS THE GFS SOLUTION
WHICH TAKES A MORE STRAIGHT WESTWARD TRACK. THERE IS OVERALL LOW
CONFIDENCE IN THE FORECAST DUE TO THE LARGE SPREAD IN SOLUTIONS OF
THE MODELS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 191200Z IS 9 FEET.
NEXT WARNINGS AT 192100Z, 200300Z, 200900Z AND 201500Z. THIS WARNING
SUPERSEDES AND CANCELS REF A, JOINT TYPHOON WRNCEN PEARL HARBOR HI
190151Z NOV 13 TROPICAL CYCLONE FORMATION ALERT (WTIO21 PGTW
190200).//
NNNN

[Alyono]

T 1.5

seems to me IMD needs Dvorak training

[supercane4867]

TPIO10 PGTW 191807
A. TROPICAL CYCLONE 04B (E OF INDIA)
B. 19/1730Z
C. 15.3N
D. 84.2E
E. FIVE/MET7
F. T3.0/3.0/D2.0/24HRS  STT: D0.5/03HRS
G. IR/EIR
H. REMARKS: 38A/PBO SBC/ANMTN. CNVCTN WRAPS .70 ON LOG10 SPIRAL
YIELDING A DT OF 3.0. PT AGREES. MET YIELDS 2.5 BASED ON
CONSTRAINTS. DBO DT.
I. ADDITIONAL POSITIONS: NONE

   RAPP

[Grifforzer]

Time of issue: 2230 hours IST Dated: 19-11-2013
Bulletin No.: BOB06/2013/05

Sub: Deep Depression over west central Bay of Bengal

Pre-Cyclone Watch for southern Andhra Pradesh and adjoining northern Tamil Nadu coasts

The depression over west central Bay of Bengal remained practically stationary and intensified into a deep depression and lays centered at 2030 hrs IST of today, the 19th November 2013 near 15.0N 85.0E about 550 km east northeast of Chennai, 430 km east southeast of Machilipatnam, and 350 km south southeast of Vishakhapatnam.

The system would further intensify into a cyclonic storm during next 24 hrs. It would move west northwestwards for some time, then west southwestward and cross south Andhra Pradesh and adjoining north Tamil Nadu coast between Chennai and Ongole, close to Kavali around night of 21st November

[supercane4867]

Forecast to peak at 60kt

[Grifforzer]

only forecast to be about 40-45 knots from the IMD..

[Alyono]

http://www.nrlmry.navy.mil/htdocs_dyn_p ... .88pc.html

looks like an eye may be forming soon. Must be why IMD upgraded to deep depression

There total lack of understanding of the Dvorak technique is beyond mind boggling. They are totally unaware that one needs to break constraints in RI cases. Their explanation is that TCs in he NIO dont have winds as high as other basins based upon Dvorak. Their reasoning, coastal obs.

Of course... the max winds will NEVER be observed in coastal areas because of the greater friction of the land vs the water and TCs often weaken before landfall in the NIO due to land interaction

[Grifforzer]

Time of issue: 0830 hours IST Dated: 20-11-2013

Bulletin No.: BOB06/2013/07

Sub: Deep Depression over west central Bay of Bengal

Cyclone Alert for southern Andhra Pradesh and adjoining northern Tamil Nadu coasts

the deep depression over west central Bay of Bengal moved further westward and now lays center near 15.0N 84.0E, about 460 km east northeast of Chennai, 430 km east of Kavali, 330 km east southeast of Machilipatnam, and 310 km south southeast of Vishakhapatnam.

The system would further intensify into a cyclonic storm during next 6 hours and further into a severe cyclonic storm during next 24 hours. It would move west northwestwards for some time, then west southwestward and cross south Andhra Pradesh and adjoining north Tamil Nadu coast between Chennai and Ongole, close to Kavali around night of 21st November 2013.

---------
Forecast intensity is up to about 50-55 knots now.

[Grifforzer]

latest Cyclone Image from the IMD for 3:00 AM UTC shows Dvorak of T2.5 now.

Now is this still "Podul" or now Helen?

I think this is the same low that was once TS Podul

[Grifforzer]

Oh, silly me.. It's named Helen =P

Time of issue: 1030 hours IST Dated: 20-11-2013

Bulletin No.: BOB06/2013/08

Sub: Cyclonic Storm, HELEN over west central Bay of Bengal.

Cyclone Warning for south Andhra Pradesh and adjoining north
Tamilnadu coasts: Orange Message.

The deep depression over westcentral Bay of Bengal remained practically stationary during past 3 hrs, intensified into a cyclonic storm ‘HELEN’ and lay centred at 0830 hrs IST of today, the 20th
November 2013 near latitude 15.0N and longitude 84.0E, about 460 km east-northeast of Chennai, 430 km east of Kavali, 330 km east-southeast of Machilipatnam and 310 km south-southeast of Vishakhapatnam.

The system would further intensify into a severe cyclonic storm during next 24 hrs. It would move west-northwestwards for some time, then west-southwestward and cross south Andhra Pradesh coast between Sriharikota and Ongole, close to Kavali around night of 21st November 2013

[euro6208]

50 knots...


REMARKS:
201500Z POSITION NEAR 15.5N 83.9E.
TROPICAL CYCLONE 04B (HELEN), LOCATED APPROXIMATELY 499 NM SOUTH-
SOUTHWEST OF CALCUTTA, INDIA, HAS TRACKED NORTHWESTWARD AT 01
KNOT OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY DEPICTS A RESURGENCE OF DEEP CONVECTION OVER THE LOW-LEVEL
CIRCULATION CENTER (LLCC) AS THE UPPER ATMOSPHERE COOLED WITH
SUNSET. THE ONCE FORMATIVE FEEDER BAND FROM THE NORTH HAS NOW BECOME
MORE SHALLOW AND BROKEN. THE INITIAL POSITION IS BASED ON A TIMELY
201150Z SSMIS 37 GHZ PASS WITH FAIR CONFIDENCE. THE INITIAL
INTENSITY IS MAINTAINED AT 50 KNOTS BASED ON CONVECTIVE STRUCTURE
AND PERSISTENCE OF DVORAK ESTIMATES RANGING FROM 45-55 KNOTS FROM
PGTW AND KNES RESPECTIVELY. UPPER-LEVEL ANALYSIS INDICATES TC HELEN
IS LOCATED NEAR THE SUBTROPICAL RIDGE AXIS BUT VERTICAL WIND SHEAR
REMAINS MODERATE AT 15-20 KNOTS. DIVERGENCE IS CONTAINED IN THE
POLEWARD DIRECTION AS OUTFLOW INTO THE MID-LATITUDE WESTERLIES
PROVIDES THE LARGEST SOURCE OF EXHAUST. TC HELEN HAS MAINTAINED SLOW
TRACK SPEEDS DURING THE PAST 18 HOURS, AND BECOME QUASI-STATIONARY
DURING THE LAST SIX HOURS, AS IT MEANDERS NORTHWESTWARDS
UNDER A WEAKNESS IN THE MID-LEVEL RIDGE. THESE SLOW TRACK SPEEDS
ARE FORECAST TO CONTINUE AS THE CYCLONE TRACKS WITHIN
THE WEAKNESS FOR THE NEXT 24 HOURS. THE MID-LEVEL SUBTROPICAL RIDGE
SHOULD GRADUALLY BUILD IN FROM THE EAST AND STEER TC HELEN ON A MORE
WESTWARD TRACK AFTER TAU 24. GRADUAL INTENSIFICATION TO 60 KNOTS BY
TAU 12 IS EXPECTED AS POLEWARD OUTFLOW BATTLES THE MODERATE VERTICAL
WIND SHEAR. SEA SURFACE TEMPERATURES WILL REMAIN FAVORABLE AT 26-28
DEGREES CELSIUS. OCEAN HEAT CONTENT WILL BECOME LESS FAVORABLE WITH
EACH TAU, AND IN COMBINATION WITH INCREASING VERTICAL WIND SHEAR BY
TAU 36, TC HELEN WILL RAPIDLY WEAKEN BEFORE LANDFALL. THERE
CONTINUES TO BE A BIFURCATION AMONGST MODEL TRACKERS WITH THE WEAKER
VORTEX CLUSTER (ECMF, NVGM, GFDN, EGRR) TRACKING SOUTHWESTWARD AND
THE STRONGER VORTEX CLUSTER (AVNO, HWRF, CTCX) TRACKING
NORTHWESTWARD AND THEN WESTWARD. THE CURRENT FORECAST IS PRETTY MUCH
A MIRROR COPY OF THE PREVIOUS WITH A SLIGHTLY MORE NORTHWESTWARD
HUMP IN THE NEAR-TERM THAN THE PREVIOUS FORECAST BASED ON THE LATEST
BEST TRACK POSITION. DUE TO THE UNCERTAINTY AND SPREAD IN MODEL
TRACKERS, CONFIDENCE REMAINS LOW IN THE TRACK FORECAST. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 201200Z IS 16 FEET. NEXT WARNINGS AT
202100Z, 210300Z, 210900Z AND 211500Z.//
NNNN

[Grifforzer]

Time of issue: 0830 hours IST Dated: 21-11-2013
Bulletin No.: BOB06/2013/15

Sub: Severe Cyclonic Storm, HELEN over westcentral Bay of Bengal

Cyclone Warning for south Andhra Pradesh and adjoining north Tamil Nadu coasts: Orange Message

The cyclonic storm ‘HELEN’ over west central Bay of Bengal moved slightly west northwestwards and intensified into a severe cyclonic storm and lay centered at 0530 hrs IST of today, the 21st November 2013 near latitude 15.6N and longitude 83.5E, about 460 km east northeast of Chennai, 360 km east of Ongole, 260 km east southeast of Machillipatnam and 230 km south southeast of Vishakhapatnam.

It would move west-northwestwards slowly for some time, then west-southwestward and cross south Andhra Pradesh coast between Nellore and Machillipatnam, close to Ongole around afternoon of 22nd November 2013.

ACCORDING TO SATELLITE IMAGERIES, THE INTENSITY OF THE SYSTEM IS T3.5. ASSOCIATED BROKEN LOW/MEDIUM CLOUD EMBEDDED WITH INTENSE TO VERY INTENSE CONVECTION IS SEEN OVER BAY OF BENGAL BETWEEN LAT 14.5N AND 19.0N LONG 82.0E AND 85.0E. THE LOWEST CLOUD TOP TEMPERATURE (CTT) IS ABOUT -80C.CONVECTIVE BANDING IS MORE PRONOUNCED IN NORTHERN SECTOR OF THE SYSTEM. CONVECTION NEAR THE CENTRE HAS ORGANISED AND CONSOLIDATED FURTHER DURING PAST 12 HOURS.

MAXIMUM SUSTAINED SURFACE WIND SPEED IS ESTIMATED TO BE ABOUT 50 KNOTS GUSTING TO 60KNOTS AROUND THE SYSTEM CENTRE. THE STATE OF THE SEA IS VERY HIGH AROUND THE SYSTEM CENTRE. THE ESTIMATED CENTRAL PRESSURE IS ABOUT 994 HPA.

[supercane4867]

Severe Cyclonic Storm Helen