Wednesday, May 05, 2010

International Weather

 Some Rare Cold Weather from France and Mexico !!
(reproduced from e-mails to'' Ice age now''.) 
Snow in the south of France... in May ! ! ! !
4 May 10 - An E mail fromToulouse
"Today temps dived to 1°C in Carcassonne, with big flakes à noon ! ! IN MAY ! !
Here in Toulouse it is very, very cold too (5°C), it may snow tomorrow, but it is not sure."
See details here: 

 "Very rare" snow in 18 municipalities in Mexico  
2 May 10- Email from Mexico
" Carlos Rosan, from northern Mexico. I want to inform you about a very rare May snowfall in many municipalities of the State of Chihuahua (18 to be exact, in a territory bigger than the U.K.) including the capital city of Chihuahua, where more than 15 centimetres of snow and sleet fell. That is something so rare and has been happening with more frequency. This winter we had the coldest temperature in my city since 1996; the thermometre dropped all the way to -5C. And in the city of Saltillo, Coahuila, just a few hours south it dropped to -7C with snow. 
Where I  live is a city called Laredo, Tamaulipas, about 250 kms from the gulf and just 150 metres above sea level, and snow is sporadically common across many parts of northern Mexico during the months of December and January, but not in the middle of Spring (almost Summer) and not at elevations as low as the capital city of the state of Chihuahua."
 Here are some links...
9:30pm, ... massive showers over kashmir, N. punjab, and Himachal. isolated rain over Trichy - tamilnadu.
@_anamus >> Is it rainin there? Pls upload a snap shot from there. LAtest satellite shot of Kolkata rain..
RT @PallabDv: Summer Clouds over kolkata ... make me go back to the days of green field,Football, rain and mud ....
RT @ashishmohta: its raining here in Kolkata every evening. Where else ?
RT @jainavinash: want more of western disturbances to disturb us ,!#rain delhi .. YES, its coming..
RT @Rustagi007: Delhi hot again after rain last week !!
RT @sultanmohideenk: looks like its gonna rain getting pleasant here in Bangalore : ) love it :) (3:53pm)
RT @rajesh_desai: everyday evening rain in Bangalore, spoiling party
RT @prerit_jain: I thought Rain got upset with Bangalore.. but now.. its again raining.. Enjoy this season of raining!!
5pm, Lonely thunder cell S-W of Madurai and over Tirunelveli in Tamilnadu..
5pm, Thunder cells over Orissa, N-E Andhra, central Karnataka, W.Ghats of Karnataka, Tamilnadu, Kerala..
5pm, Isolated thunder cells along Chatisgarh and M.P border..
5pm, Stormy west bengal.. heavy showers reported ..
5pm, Super showers over Kashmir and Himachal due to fresh Western disturbance..
Rains Won't Water Down India's Prices ..
2pm, showers erupt over N-E states again, isolated thunder cell along S-S-E coast of Tamilnadu, and over N-E Andhra..
2pm, Showers engulfing most of Western Bengal ..
2pm, Heavy showers along Pakistan and Punjab & kashmir border ..
Chennai - "Dog days" ahead .. What are dog days ?? ..
Chennai - After touching 38.9°C , now 2:26pm its at 36 deg C
1:30pm, Heavy thunder storms all along Western bengal ..
Chennai - now 1:58pm is at 38.8°C
Chennai - 38.3°C (1:40pm)
Rain map of 4-May, shows showers over Tamilnadu and N-E states ..
Duststorm/thunderstorms with squalls would occur over Punjab, Haryana, Delhi, Isolated over Rajasthan, Uttar Pradesh and N-W Madhya Pradesh
western disturbance will affect western Himalayan region during next 3-4 days. It may affect adjoining plains of northwest India from today.
Chennai - Touched a super temp. of 38.1°C at 1:37pm and still rising.
Trough from northwest Jharkhand, to south Tamilnadu coast now runs from north Marathwada to south Tamilnadu coast across Karnataka.
Severe heat wave conditions are prevailing over extreme north Rajasthan
On 4-May, highest maximum temperature of 47.4°C has been recorded at Sriganganagar (Rajasthan) .. Anyone alive there ??
ECMWF is of the view that concentrated heating would engulf west and southwest Rajasthan and adjoining south and East Pakistan from May 14.
NCEP : a weather system developing over south-central & southwest Bay of Bengal, tracking southwest to hit Sri Lanka first and Kerala later
Bay of Bengal may flare-up during May 12 to 20
Activity in the Arabian Sea would peak around May 25 ..
Chennai - WoW !! just now 1:24pm touched a max. temp. of 37.9°C and still going up.
N-E states are having a calm day so far ..
12:30pm, Except kashmir rest of India is getting ready to host another round of Afternoon showers..
12:30pm, Heavy showers over west Kashmir. Due to W.D Rajasthan, Punjab and Himachal are getting cloudy ..
Western disturbance has started affecting over Kashmir ..
Morning sat. shot shows a heavy activity over Bay continues from South to North..
Chennai - Temp. now 12:13pm is 36.4°C and going up.
Chennai - Had a mild start to the day with cloud cover.. Just now touched a max. temp of 36.3°C (12:07pm)
Arabian Sea seen mirroring Bay activity with a lag ...
South west Monsoon watch - 5 ...

A comment on "Monsoon Watch"

Monsoon watch is one of the component of weather watch. You may watch it from Mumbai. Some may watch it from Karnataka and even some may from Mauritius {I am referring to Indian Summer monsoon only] However it is an interesting study. During the month of May generally Bay will be active with transitional pressure, repeat pressure pattern. Winds, accordingly vary in Bay. Recent developments show the wind discontinutity is prominent from Bihar to Tamilnadu coast via Jarkand, Orissa and AP. This underlies one thing that this year SW monsoon will be faily good in the eastern side of Western ghats. Western side of Western ghat may not be as good as to its eastern counterparts. Sometime Mumbai may be getting lesser rain too.
Suuuper rain accompanied by strong winds lashed Nagapattinam today at 6:30 AM
On 4-May, "Heavy rains for more than one hour drenched Srirangam (Trichy) "

Arabian Sea seen mirroring Bay activity with a lag

An experimental US ocean forecast model has hinted that the Arabian Sea might whip up some action around May 25.

It is forecast to take place in the east-central and adjoining east Arabian Sea (north of the Lakshadweep islands) oriented in a west-to-east trajectory.

The west-to-east orientation would seem to rule out an away-going system that causes incoming monsoon winds to falter and unsettle a concurrent monsoon.

Such away-going systems have triggered the formation of rogue weather systems in both the Arabian Sea and the Bay of Bengal during the onset period in the past, diverting precious moisture and rains away from mainland India.

The US model suggests that the activity in the Arabian Sea would peak around May 25 before petering out over the next two days, likely after ‘transferring the energy' to the west coast of India.

But meteorologists are of the view that it is too early still to take a call on the onset of monsoon, although the emerging pattern from the May 17 as depicted by various models is strikingly similar.

The US National Centres for Environmental Prediction (NCEP) has retained the outlook that the Arabian Sea shake-up could be preceded by similar activity in the Bay of Bengal during May 12 to 20.

On Tuesday, India Meteorological Department (IMD) traced out a crucial north-south trough running all the way down from Bihar to southwest Bay of Bengal.

This would be monitored for any signs of triggering activity in the Bay.

The NCEP sees the weather system developing over south-central and adjoining southwest Bay of Bengal, tracking southwest to hit Sri Lanka first and Kerala later.

Wet MJO phase

The European Centre for Medium-Range Weather Forecasts (ECMWF) is of the view that southeast Arabian Sea would get impacted by a weather-driving wet phase of a Madden-Julian Oscillation (MJO) wave from May 12.

MJO wave travels periodically from west to east in the higher levels and can set up weather on ground in the form of monsoon onsets, low-pressure areas and even cyclones.

The alternating dry phase has been blamed for ‘break-monsoon' and other forms of interferences that give rise to intra-season droughts during monsoon.

Meanwhile, heating of the land over northwest India, crucial for setting up the monsoon-driving temperature and pressure gradients, was apace during the 24 hours ending Tuesday morning.

The ECMWF is of the view that concentrated heating would engulf west and southwest Rajasthan and adjoining south and East Pakistan from May 14.

An IMD update said that heat wave conditions have developed over some parts of Rajasthan overnight on Tuesday. The highest maximum temperature of 45.6 deg Celsius was recorded at Barmer.

Still, it maintained the outlook for the arrival of a fresh western disturbance, with its calming impact on heat, over the next few days.

The system will affect western Himalayan region and even the adjoining plains of northwest India from Wednesday.

Satellite imagery revealed the presence of convective (thundershower-causing) clouds over parts of Arunachal Pradesh and southeast and central Bay of Bengal. Low to medium clouds (partly clouded conditions) were seen over parts of the Andaman Sea, and central, east, northeast and peninsular India.

Weather-making troughs tracked south-southeast down from Bihar to Assam across sub Himalayan West Bengal. Another trough ran north-south from Bihar to south west Bay of Bengal across Jharkhand, Orissa and west central Bay of Bengal.

Monsoon Watch - 5

The parameter of utmost concern to me now is the Bay factor. The consistently -ve factor from the very first MW.

The latest winds in the Bay continues to show strong winds rushing Northwards along the East coast of India, into the trough lined up in the North-East. The North-West flow of winds into the Myanmar coast also exists.

Also, the SST in the Bay is now very conducive to host a low anytime now.

In fact, on comparing the Bay SST on this date last year,(Maps from NOAA) we can see how much hotter the waters are this year.( Last year, 2 cyclones had cooled the waters of the Bay). A low, according to me, should have normally formed by 15th. April.

Now, the delay in the formatiion of the wanted Bay low is due to non active movements of MJO towards the East from western Indian Ocean..

Also, according to ECMWF forecasts, and other models,no low is predicted in the Bay till the 11th.May at least.

Indicator :-ve

The 200 hpa jet stream. Normally, they should be Easterlies right upto 20N by May end to facilitate the Northward movement of the Monsoon Current. Today, the jet stream is developed upto the Equator, but is stationary. These jet winds need to get organised soon, and come upto 8N by 2nd.week of May at least, and then move upto 10N before 20th.May, to be in time for the Andaman Sea Monsoon arrival.

With the heat continuing in the Northern regions,the Seasonal Low in the Thar Desert is deepening, with a core pressure now at 998mb, and spread over a wider area. (See Thai Met Dept Map). And this is perfectly forming as per schedule.

Moisture inflow into Kerala and South Karnataka has now lessened. As mentioned in my MW previously, this is absolutely necessary for the creation of a good gradiant between Kerala pressure and Rajasthan/Sindh pressure. And that is a must for creating a pull Northwards for the Monsoon. Overall position in this parameter is much improved since MW-4.

A north-south trough from Madhya Pradesh to the Tamil Nadu coast across east Vidarbha, Andhra Pradesh, south interior Karnataka and Tamil Nadu indicates the line of wind dis-continuity has also formed in the Peninsula region.This is a pre monsoon formation, and is a fore-runner for the seasonal low to stretch its presence over central India.

Indicator: +ve

Conclusion: There continues to be a doubt on the timely arrival of the Monsoon in the Bay branch. The Arabian Sea branch, may not be affected by the temporary "dis-organisation " in the equatorial winds at the equator. ( Provided they regroup fast as predicted). Rains have also tapered down a bit on the South-West coast, as required now. Arrival date should be around 1st. June for Kerala.

posted by Rajesh Kapadia (
3-May, Nagercoil: Heavy rain ..
Chennai - sat shot at 11:30pm shows the thunder cell over western chennai ..
chennai - now 12:40am , the thunder cell has become strong & we can hear the thunder. Its over W-N-W of chennai.
chennai - a lone thunder cell was seen blinking it's way up from west at 10pm.