Depression
It involves a depressed mood or loss of pleasure or interest in activities for long periods of time
For the person on the road Depression would make him think about the health condition. For weather bloggers the mention of Depression would remind them of sleepless nights. Not even one Northeast Monsoon season goes off without one spell that tests the patience of bloggers. With 99B we will now see an inverse relationship between the pressure level over South Bay and Weather bloggers of Chennai.
Yesterday’s COMK post was put after a lot of thought considering weather models were more divergent in the approach to 99B. Today’s post is also put after a lot of consideration. Once again the primary driver of the post is to alert towards preparedness rather than panic. One of the reasons why weather models have been struggling with the Depression is the location of the initial genesis. At a very low latitude close to Equatorial bay under the influence of ER wave. This meant intensity forecasts were always expected to be slightly off in real time compared to model estimates.
Additionally over most of yesterday 99B has moved in a more westward track bringing it closer to Sri Lanka than original model estimates. This pronounced westward movement has changed the equations slightly. A burst of intensification along the coast of Sri Lanka looks less likely due to land interaction as it jogs northward. This in turn reduces the probability of a NE recurve into the open seas of Bay of Bengal. Consequently it also increases the probability of widespread heavy rains over Coastal Tamil Nadu.
The 2nd factor that complicated for models was the location of the Indo Arabian Ridge. Firmly placed to the West of Peninsular India it is expected to stay put until 28th / 29th November. This would mean any further westward movement from 99B towards Tamil Nadu coast becomes impossible once it reaches NE of Sri Lanka. With 99B expected to reach east of Delta coast around 36 to 48 hours from now we are potentially seeing a period 24 to 48 hours where 99B could remain near stationary. During this period there is also a chance it could intensify into a cyclone.
As things stand the probability of widespread heavy rains has only increased based on the events over the past 24 hours. Additionally the risk of some part of Coastal TN coming under extremely heavy rains during the near stationary period also increases. We will take one day at a time and see how things change in real time compared to model forecasts.
On the rain front with 99B now starting to climb up rainfall intensity is expected to increase over Coastal TN. South Coastal TN and delta may see widespread heavy to very heavy rains with few places seeing extremely heavy rains. Chennai and adjoining KTCC districts may see widespread moderate to heavy rains from later tonight with intensity gradually increasing from tomorrow.