Maharashtra, Karnataka and parts of AP are experiencing a cold wave on Sunday, 18th November. Partly due to an anti-cyclone over central India. The greatest departure was in the Vidharbha/Rayalseema region.
Temperatures as on 18th November with departures:
Chennai Ap was 17.2c a departure of 5.5c from the normal, and City at 17.6c was 5.3c below.  

Hyderabad 12.4, 4.8c below.In AP. Anantpur at 11c was 9c below normal.

Mumbai Scruz was 15.2c, 6c below the normal. Ahmadnagar at 7.8c was the lowset in Mahrashtra and was 7c below normal. Highest departure was in Yeotmal which saw 10c and was 8c below normal. Nagpur saw 10.5c, 4.9c below.

In Karnataka, Bijapur and Raichur which were at 9c was 10c below the normal and Belgaum at 7.7c was 9c below. Gadag was 12.9c again 5.1c below.

For update on cyclone ..now a depression see vagaries..

#chennai - temp. now 10:34pm is 25 deg C and going down slowly. City can expect a cloudy morning with medium high cloud cover & DRY.

"03B" - Becoming DRY and Weakening now, crawling S-W

"03B" - Becoming DRY and Weakening now.
A dry Deep Depression, crawling S-W and showing signs of weakening.
9pm Satellite IR shows convection along E,S-E and N-E.. almost nothing over the rest of the system.
Medium level clouding seen over S-W periphery may reach Chennai, S.Andhra coast by early morning tomorrow.

Latest position plot on map.

JTWC warning at 8:30pm
----------------------------------------------------

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.

Colourful forecasts and very frequent changes in track forecasts have cast a shadow on the reliability and accuracy of model forecasts. True, all models go as per their computers, fed with the current parameters, but all including popular US model computers are in no position to accurately estimate the possible changes in the parameters they depend on. All judge from the possible computed estimates of wind shear, SST, pressure ridges, winds aloft and surrounding conditions.

Course of Events:...check article in vagaries....and the latest Update

4:30pm, Latest satellite IR shows that convective activity around "03B" is getting less.. A Dry Depression !!.. http://ow.ly/i/18NHE 

Present W.D over Kashmir is slowly moving away into East.. but Snow/Rain to prevail for next 24hrs.

NOGAPS and COLA model suggest a landfall near Chennai on 20/21-Nov

COLA model suggests a S-W drift from today (it's happening now) and hit S.Andhra, Chennai and N.Tamilnadu coast as a Depression on 20/21-Nov.

NOGAPS model also predicts it to drift S-W and hit along S.Andhra coast and N.Tamilnadu coast as Depression on 21-Nov.

#chennai - had a COLD morning today.. Airport records 17.2 deg C.. "a record for November in recent years".

"98B" is now "03B" - Deep Depression now! Moving S-W

"98B" is now "03B" - Deep Depression now! Moving S-W
As expected by GFS models the system is now moving S-W. Still a deep depression.
Pressure at 996mb.
Winds upto 60km/hr.
1:30pm, latest satellite.

Latest position plot on map.
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IMD warning at 1pm.
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The deep depression over eastcentral Bay of Bengal moved westwards and lay centred at 1130 hrs IST of 

today 18

th

 November 2012 near latitude 16.0

0

N and longitude 88.0

0

E, about 900 km east-northeast of Chennai, 550

km east-southeast of Visakhapatnam and 500 km southeast of Paradip. The system would intensify further into a 

cyclonic storm and move slowly westwards during next 12 hrs and west-southwestwards towards south Andhra

Pradesh and north Tamil Nadu coasts during subsequent 72 hrs.

JTWC warning at 2:30pm
--------------------------------------------

TROPICAL CYCLONE (TC) 03B LOCATED APPROXIMATELY 385 NM SOUTH OF 
KOLKATA, INDIA HAS TRACKED WEST-SOUTHWESTWARD AT 02 KNOTS OVER THE 
PAST SIX HOURS. RECENT ANIMATED MULTISPECTRAL SATELLITE IMAGERY 
SHOWS THE DEEP CENTRAL CONVECTION HAS DIMINISHED SLIGHTLY SINCE THE 
PREVIOUS FORECAST, WITH THE LOW LEVEL CIRCULATION CENTER (LLCC) 
SHOWING A SMALL AMOUNT OF ELONGATION IN THE NORTHWESTERN QUADRANT. 
ANIMATED TOTAL PRECIPITABLE WATER SHOWS THE DRY AIR ALONG THE 
WESTERN HALF OF THE SYSTEM CONTINUES TO WRAP TOWARD THE CENTER OF 
THE SYSTEM. THE DRY AIR HAS ALMOST COMPLETELY ISOLATED THE LLCC FROM 
THE INFLOW OF THE WARMER MOIST TROPICAL AIR MASS IN THE SOUTHEASTERN 
QUADRANT. THIS WEAKENING OBSERVED IN THE CONVECTION IS LIKELY DUE IN 
GREAT PART TO THIS INFLUX OF DRY AIR. UPPER LEVEL ANALYSIS INDICATES 
TC 03B IS LOCATED UNDER THE AXIS OF A SUBTROPICAL RIDGE (STR) AND IS 
IN THE DIVERGENT QUADRANT OF A SUBTROPICAL JET MAX TO THE NORTHEAST, 
WHICH IS PROVIDING AMPLE POLEWARD OUTFLOW. THE VERY FAVORABLE 
OUTFLOW IN ASSOCIATION WITH CONSOLIDATION OF THE LLCC WITHIN THE 
NEXT 36 HOURS WILL CAUSE A WEAK INTENSIFICATION, BUT WILL QUICKLY BE 
OVERCOME BY INCREASING VERTICAL WIND SHEAR AND DRY AIR ENTRAINMENT. 
WITH THE EXCEPTION OF WBAR, MODEL GUIDANCE HAS COME INTO GOOD 
ALIGNMENT INDICATING A WEST TO WEST-SOUTHWEST TRACK. TC 03B IS 
CURRENTLY TRACKING SLOWLY IN A WEAK STEERING ENVIRONMENT, BUT AS A 
STR LOCATED OVER INDIA BUILDS, THE SYSTEM IS EXPECTED TO TRACK MORE 
QUICKLY TO THE WEST-SOUTHWEST. EVEN WITH THE INCREASED CONSOLIDATION 
OF MODEL GUIDANCE, THE SYSTEM BEING IN A POOR STEERING ENVIRONMENT 
LENDS TO LOW CONFIDENCE IN THE FORECAST TRACK. MAXIMUM SIGNIFICANT 
WAVE HEIGHT AT 180600Z IS 14 FEET.

'98B' stagnant at the same position and seems to be losing strength.. report after 3pm

"98B" - New path prediction ! Amazing !

At present "98B" is slowly crawling N-W.
Latest COLA GFS model has come up with a new path prediction for "98B" .
The system is expected to move N-W for next 12hrs and then start drifting S-W and end up near Chennai, S.Andhra coast on 21/22-Nov.

And IMD warning at 8pm was somewhat based on this model.
Here's the IMD warning at 8pm...


The depression over eastcentral Bay of Bengal moved west-nothwestwards, intensified into a deep
depression and lay centred at 1730 hrs IST of today, the 17th November 2012 over eastcentral Bay of Bengal near latitude 16.00N and longitude 89.00E, about 1000 km east-northeast of Chennai, 650 km east-southeast of Visakhapatnam and 550 km southeast of Paradip. The system would intensify further into a cyclonic storm and move slowly west-northwestwards during next 12 hrs. It would move west/west-southwestwards towards south Andhra Pradesh and north Tamil Nadu coasts during subsequent 72 hrs.


Opinion #1 --> This S-W drift may not be the case, because the 200hpa Jet is from S-W or S above 13th parallel. This will steer the system North, N-W or N-E.
Opinion #2 --> COLA model expects a Anti-cyclone is expected to move in from Myanmar into N-E Bay during next 3 days.. so this may make the present system "98B" to drift S-W.