Warm, Humid weekend ahead

A low level circulation in Central India and the Line of Wind Discontinuity extending from South Madhya Pradesh to South Tamilnadu, brings rains along the LWD and to N- NW Karnataka Thursday and Friday.

This signals the end of clear days and nights being experienced in Goa since Sunday April 13. See this blog post

As a result the minimum temperatures are expected to rise again to 26C with humidity in the region of 75-80%. Maximum temperatures in the range 34-35C, with mid level cloud cover are expected.

The above INSAT image shows cloud cover for Goa at around 19:15 hrs on April and rains in Orrisa, along the LWD in south India and north and central India.

Mid April Cool Times

Goa has been experiencing a welcome drop in Minimum and Max temperatures since Sunday 13th continuing into the week. This is attributed to dry and cool winds blowing from north - northwest. The days and nights have been clear, contributing to a lower temperature regime.

April 13 - Min 21.8C ( 3C below normal) RH 66% at 8:30 am

             - Max 33.7C ( 1C above normal) RH 46% at 5:30 pm

April 14 - Min 22.5C . RH 65% at 8:30 am

            - Max 33.9C . RH 53% at 5:30 pm

Elsewhere, Pune was 14.7C and Mahabaleshwar 19.2C on Sunday April 13 morning.

On April 6, 2014, the minimum in Goa had reached 26.4C with RH 79% and max temp on that day had climbed to 34.6C.

With central and north west India beginning to heat up, temperatures in Goa could again climb to normal 25-35C region by the weekend.

El Niño CPC/NCEP predicts 50% chance for Summer/Fall of 2014

In its latest update of April 7, 2014, Climate Prediction Center / NCEP  (NOAA), has updated the status of ENSO to a probability of 50% for onset of El Niño in Summer or Fall in 2014.

This has ofcourse far reaching implications for the performance of the Monsoons in India and else where, going by past observations.

Storm and Hails in North east corner of Goa - April 4, 2014 - Update April 6

Update April 6 - Margao and surrounding areas got first drizzle of the year on the intervening night of April 5-6. The drizzle for about 30 minutes around midnight left puddles of water on the city roads, but failed to bring down the humidity or the temperature. Minimum temperature recorded by Panaji IMD on the morning of April 6 was 26.4C the highest minimum recorded this year, so far!

 

A localized, intense but highly destructive storm with hails lashed the north eastern corner of Goa for nearly an hour, affecting parts of Bicholim and Satari talukas and towns and villages like Sanquelim, Keri, Honda, Salelim, Harvalem, Thane etc, claiming one life, uprooting tens of trees, electricity poles, damaging houses, shops and road and telecommunications network. Power was disrupted for hours at many places. Industrial estates at Honda and Pissurlem.

The storm was the result of a cyclonic disturbance off the coast of Goa and a trough in North Interior Karnataka. The intense updraft created due to the mountains of Salelim and Vagheri on Goa - Karnataka border in the north east corner of Goa, along with a vertical wind shear and moisture laden winds blowing from the coast, could have contributed to the hailstorm experienced at Honda and Keri and the rains over a 20 km radius from the base of these mountains. The Chorla Ghat and the villages on the Karnataka side of the border must have suffered extensive damage too.

Reports indicated that hails were seen in this part of Goa after nearly 20 years!

The brief phenomenon was captured by EUMETSAT over 3 - 4 hours with yellow and blue at around 15.3N and 74E indicating the storm developing, peaking and dissipating:

Hails recorded at Honda, Satari measured upto 4 inches.

Coastal Goa was dry though overcast, and did not experience the storm.

Panaji recorded Max Temp of 34.7C, which was 2C above normal and Min Temp of 25.8C which was 1C above normal. Humidity was between 75 - 77%.

The Heat is On!

As is usual at this time of the year, Goa has started to feel the hot, humid sultry weather truly setting in beginning March! Coinciding with the northward march of the Sun, the temperatures across the Indian sub continent will only move northwards, fulfilling one of the major requirements for setting in of the Monsoons in May - June.

The chill which was felt towards February end, continued into March. But the Minimum temperatures experienced continued to rise steadily, from the sub 20 C in early March to a maximum of 26.2 in the early hours of the morning on the last day of the month, March 31st. The warm winds blowing from south - south east being a major factor contributing! Relative Humidity of 86% (+ 08 above normal) on March 31 morning, meant a hazy, warm and humid day to end the month! The coolest day in March on 2nd day of the month, was soon a distant memory!

The month of March ended with the following statistics:

Max High Temperature: 37.3 C March 13
Min High Temoerature: 30.6 C March 02

Max Low Temperature: 26.2 C March 31
Min Low Temperature: 17.6 C March 02

The Maximum High of 37.3 C was lower than the recent all time high of 39 C reached in March 1979! Last year the maximum high in March of 35.6 C was also recorded on March 13!

The precipitation recorded was NIL in March, considering that traces were experienced in the interior areas of Goa mid March,

Parts of South, East and Central India are already experiencing max temperatures around 40 C, and the summer is just beginning!

The graphs of the Average temperatures over India in February 2014 and the Maximum temperatures in the last week of March 2014, dramatically bring out the increase in temperatures.

Plenty to ponder on what's in store for the coming summer months!

Take care, Stay cool!!

And stay connected to this blog on Facebook at www.facebook.com/weatheringoa for the latest!

El Niño and its effects on the South West Monsoon - Reproduced article from "Vagaries of the Weather" Blog

The red flags are out! Meteorologists from all over the world are eagerly watching the enfolding of El Niño  phenomenon in the Pacific. According to some estimates, El Niño may develop fully by July - August, this year. The last time there was El Niño in 2009, India faced deficient monsoons.

So how do the El Niño  and La Niña phenomena affect the South West Monsoon?

The noted weather enthusiast Rajesh Kapadia who runs the very popular blog "Vagaries of the Weather" has written an excellent post on  his blog on the topic and is being reproduced below with his permission. the post can also be accessed on his blog at http://www.vagaries.in/2014/03/enso-and-its-effect-on-south-west.html

The main takeaways from the post are:

1. The parameters which influence the advance of South West Monsoon in June are different and not affected by El Niño.

2. In the last 130 years not all El Niño years have been bad for the South West Monsoons

The blog also has a post on ENSO development for 2014, which you may access if you want background reading on ENSO at 

http://www.vagaries.in/2014/03/el-nino-is-spanish-for-boy-and-term-el.html

ENSO and its effect on the South West Monsoon - From "Vagaries of the Weather" Blog

Basically, the South West Monsoon advances and covers the entire Sub Continent region in June and completes its advance around early July.
Now, these advancing parameters and criteria are not linked or affected by the El Nino or the La Nina.                            
The advancing parameters are initiated from the South Indian Ocean, and are largely influenced by the Mascrene Highs between Madagascar and Australia.
Other parameters, which largely influence the advance is the seasonal low over the sub continent and the pressure gradient thus created. Many of the initial parameters are discussed in the Vagaries' Monsoon Watch Series, which are found in the Archives Page of this blog.
                                                                                                                     
The ENSO factors affect the subsequent performance of the Monsoon rains.

In an El -Nino year, the waters of the Pacific Ocean off the Peru Coast in South American Continent heats up by 2/4c. Now, as a result, the Central Pacific Ocean , roughly where the "tongue" of the heated waters end, rise, and form rain bearing clouds, and precipitation in the Central Pacific Region. 
El- Nino induced warm zones in the Pacific cause the warm air over them to rise and initiate circulation cells. Such cells along northern Australia, Indonesia and the eastern edge of the Indian Ocean could have their down draft sides over a nascent monsoon circulation cell in the Indian Ocean, which would disrupt Monsoon Depression  formation, causing poor monsoon rains over the subcontinent.
Thus, there is a marked reduction in Typhoons and Depressions forming. Consequently, in an El Nino year, we would expect lesser depressions and lows forming in the Bay. This sequence  implies that El Nino years should coincide with deficient monsoon rains.
  

                             
Normally, when in a neutral or La Nina year, the waters normally heat up towards the far West of the Pacific Ocean, rain bearing clouds are formed much to the West and near the Philippines.

Now, Typhoons and Lows forming from these regions travel West, and send Low pulses into the Bay. These are the "life giving" depressions in the Bay which criss- cross across the Indian regions.

But, that does not mean lower rainfall all over the Sub Continent. Absence of Lows from the Bay will keep the WDs active, and may increase the number of WDs crossing the Northern Regions even till July/August. This has happened, when the Lows from the Bay do not "interfere" and WDs are given a "free hand".

But, the above sequence may not necessarily happen, and sometimes, even in an El Nino year, the Central Regions of India get good rains from Line of Wind Discontinuity forming from localised heat developments. Deeps troughs in the jet streams could bring or create UAC in the Gujarat regions, even in an El Nino year.
                                  
So, all El -Nino years are not bad for Monsoons.This Graphical Plotting from IITM, shows  the inconsistency of 130  years..

Polar Vortex and the Frigid Cold that gripped the US

The biggest International weather news this week has been the Frigid Cold that engulfed almost the whole of contiguous United States on January 5, 6 and 7th with minimum temperatures in Metro cities like Chicago dropping to -32C! It was even colder due to wind chill factor, with feel of -52C!

Naturally headlines like "US colder than Mars" appeared around the globe, forgetting for a while that the Mars temperatures being compared were from the equatorial belt of Mars, and actually Mars is actually much more colder at the latitude of US, year round!!

We heard a lot  also about the 'Polar Vortex', which was the cause of the cold arctic wind spilling down southward, riding the jet streams and also various other dynamics of weather.

A clip from PBS Newshour with Andrew Freedman of Climate Central explaining about Polar Vortex and the reason for the Frigid Cold is embedded below and provides a good explanation of the Polar Vortex.

With my visit to Chicago in October 2013, still fresh in my mind, compare the  photo I clicked of the lake view from my Uncle's backyard in Oak Brook, Illinois, USA on October 21, with the one of the same area sent by my cousin on January 5, 2014

 



Next time around, I'm going to Chicago in January for sure! I only hope the Polar Vortex gets stirred too!