Tuesday, August 16, 2016

Posted Tuesday 16th Aug Night:

1. BB-8 ( Depression) has shown very little movement since last report, and is located in North Bay, at 20.5N south of Kolkata. Expected to track W/NW into North Odisha.

2. Wednesday 17th, heavy rains likely in North Odisha, North Chattisgarh and East M.P.( Shahdol). Gangetic West Bengal can expect heavy showers in some regions.Inflow of moist West winds can bring scattered rains to parts of Saurashtra. Interior Peninsula continues to get subdued rains.

3. Thursday 18th, BB-8 strengthens and tracks NW into North Chattisgarh, with strong associated convection in SW and West segments. Heavy rains many regions of East M.P.

Kolkata: Next 2 days will see windy conditions. Sharp showers will be frequent on Wednesday.
Mumbai: Wednesday will be cloudy. Passing showers with chances of a few of them being heavy.

ENSO Status:

1.ENSO-neutral conditions are present.

2.Equatorial sea surface temperatures (SST) are near or below average in the east-central and eastern Pacific Ocean.

3.La Niña is slightly favoured to develop during August-October 2016, with chances of stronger La Niña during winter 2016-17.

4.The latest weekly SST
departures are:
Niño 4 -0.1ºC
Niño 3.4 -0.6ºC
Niño 3 -0.7ºC
Niño 1+2 0.1ºC

5.The most recent ONI value (May-June-July 2016) is 0.2ºC. Down from 0.6 in April-May-June

(El Niño: characterised by a positive ONI greater than or equal to +0.5ºC.
La Niña: characterised by a negative ONI less than or equal to -0.5ºC.
By historical standards, to be classified as a full-fledged El Niño or La Niña episode,
these thresholds must be exceeded for a period of at least 5 consecutive overlapping
3-month seasons).


Cumulus arjun said...

La Niña WATCH remains; negative Indian Ocean Dipole weakens

The tropical Pacific Ocean persists at neutral El Niño—Southern Oscillation levels. However, the possibility of a weak La Niña in 2016 remains. In the Indian Ocean, a negative Indian Ocean Dipole (IOD) continues, but has weakened in recent weeks. The current event peaked in July as the strongest negative IOD event recorded in at least 50 years of record.

Climate models indicate the negative IOD will continue to steadily weaken over the southern hemisphere spring. This means its influence on Australian rainfall may lessen in the coming months. Rainfall has been well above average for large parts of Australia since May 2016 – which is a typical rainfall pattern observed during negative IOD events. During negative IOD events, southern Australia typically experiences above average winter and spring rainfall and cooler than average daytime temperatures. Northern Australia often experiences warmer than usual day and night-time temperatures.

In the Pacific Ocean, only two of eight international climate models monitored by the Bureau indicate La Niña is likely to develop during the austral spring, with two more indicating a possible late-forming event in summer. The remaining models suggest neutral or near-La Niña conditions. A La Niña WATCH remains in place, but if La Niña does develop it is likely be weak.

During La Niña, eastern Australia typically experiences above average spring rainfall, with the first rains of the wet season often arriving earlier than normal in northern Australia. Some La Niña-like effects can still occur even if thresholds are not met.

Source : BOM

NilaY Wankawala said...

ENSO-neutral conditions are present- you had very well caught the same in MW-4 and MW-5 somewhere in month of May 2016 - La Nina may develop August- October 2016, few models suggesting now this development -2 to 4 against 6 out of eight models earlier as written by BOM Austarlian Government, Too early to say , but your views on extended monsoon for SWM 2016 Indian subcontinent, of course other factors being present and one more surprising factor was behaviour of negative IOD with quantum of rainfall received till date- Thanks.

Vinod Desai said...

We have not got any substantial rains in mumbai/maharashtra from last 10 days. Sir when will this break monsoon condition end.

Unknown said...

Rajesh sir,whats the relation between fog(dew) and rain?Is it when there's dew on leaves or fog it doesn't rain?Can you explain me?

Rajesh said...

abizer: Dew is water in the form of liquid droplets that appears on thin, exposed objects in the morning or evening due to condensation. As the exposed surface cools by radiating its heat, atmospheric moisture condenses at a rate greater than that at which it can evaporate, resulting in the formation of water droplets.Basically heat radiation needs a clear sky.
Dew forms when temp drops below the dew point, and that is related to the humidity in the atmosphere. So, dew can occur after rains also.

Weather outlook till Friday 31st March - As we calculated in mid March after the Heat spell,  remaining days of March stayed below 40c in In...