Saturday, December 07, 2013

Posted Saturday Night

BB-21 is now "Madi" and a Severe Cyclone, located at 11N and 84.3E.
Studying the sub tropical ridge, we see the Southern Limit of the ridge slightly South of 10N, and of course the Northern Limit is in the North Bay. We see a sort of "absolute no upper wind direction and a sort of stagnancy " in the Western core section of the ridge.
Another HPA and ridge is located over the Indian mainland, though at a lower altitude. 
The system is located in the stagnant area of the sub tropical ridge. That is the reason why Madi is almost quasi stationary, and expected to remain with very negligible tracking next 18-24 hrs. 
Once it breaks free from the region, it will have a  steering guide, and will enter the Western edge of the sub tropical ridge and move NNE. Also the lower level ridge over the mainland can move East and push the system towards skirting the East Coast.

Some models forecast a Southerly track. It can go the SW way only if it gets "entangled" in the Southern periphery edge of the Sub Tropical ridge, and get pulled SW with the upper winds.

The HPA mentioned above is the High Pressure which was anticipated to cover the Northern and Central Indian regions from 2nd week of December.
Few places in the NCR have gone below the 24c mark (maximum temp)...we can expect a gradual fall in day and night temperatures. 
Rajastan, Gujarat and Maharashtra can expect a fall in night temperatures next few nights.
Places in Kutch may go down by 3/4c from current levels, and lowest may reach around 10c. Surat and Bharuch will have cooler nights around 15c.
Mumbai will see cooler nights, with lows around 18/19c (Scruz) and outer townships seeing a fall to 16c next few nights.
Next 2/3 nights, Pune and Nasik will be cooler around 8/9c.

Kolkat gets partly cloudy soon, so remains in the current 27- 16c range till Wednesday. After Wednesday we can expect a drop in night temperatures.

Chennai again gets avoided by another system !  Very little rains accumulating to 20 mms next 2 days.

But,the easterly wave was disrupted by Madi, and is all set to regain strength again from Wednesday off TN coast.
8:30pm, Satellite IR shows that Cyclone Madi has drifted N-E (11N , 84.5E).. slowly moving away from Tamilnadu coast.
RT @saisowsen:  #pallikaranai #Chennai at 7:15pm got good rain. Feel really chill. Good time for some hot bajji and samosa :-) 

Cyclone Madi - No movement observed during past 12hrs, #Chennai drizzle

5:30pm, Cyclone MADI has slightly intensified.
Pressure around 991mb.
Winds gusting to 105kmph.
Almost NO movement during past 12hrs.
US Navy plots Cyclone Madi at around 11N , 84.5E and with pressure at 978mb.

4:45pm, Satellite visible shot shows the massiveness, full fledged circulation and the deep convective activity... 

During past 3 hrs, N Tamilnadu coast especially #Chennai is getting drizzles with winds due to outer band of Cyclone Madi.
More expected
#Chennai - 6:34pm, Polichalur zone records 3.9mm, windy and temperature is at 22.8 C

Chennai, Polichalur zone,  3:37pm, non stop drizzle with winds for past 1.5hr

06B is now Cyclone MADI

12pm, Well established and Ominous looking Cyclone "Madi" ... 
Pressure around 991mb
Very less drift observed during past 6hrs.

Latest HWRF model predicts a Northerly movement till 12N and then a dramatic S-W re-curve towards S-E Tamilnadu coast 

12:20pm, light & moderate rain seen very near to #Chennai coast and may push into city after 1 pm.

06B - intensifies and drifts North.

At 9am, "06B" has intensified further and drifted North.
Present pressure is around 992mb.
Winds reaching to 105 kmph.

Position as of 7:40am microwave imagery is 10.4N , 83.8E ... 

But 9:30am visible reveals that 06B is well organized and may have drifted N-N-E ... 

06B, Most models suggest a Severe Cyclone in next 48hrs and slowly move in N-N-E direction upto 13th parallel, and weaken after that.
Less or almost NO rain expected for Tamilnadu coast during next 12hrs... except for a T shower over S tip and South W-ghats of Tamilnadu