Wednesday, August 19, 2009

Mesocyclonic Waterspout, Gloria platform, Black Sea

High resolution - VIS, EUMETSAT

Waterspout over the Black Sea, 18 August 2009, produced by a splitting supercell, initated in a horizontal roll clouds PBL environmnet.

A non-mesocyclonic waterspout still requires a convective cloud.

Tuesday, July 7, 2009

Bow echo

A reflectivity image with a bow echo, C band, and a sattelite image, visible low resolution, with the clear spot behind the bowecho where the rear inflow jet is, red arrow, and a lot of rolls in the southern part or Romania, nice to act as local enhancers.
Last evening Bucharest had a severe storm with 40 mm in less than one hour, the fears are if again the storms will be severe for Bucharest or not.

Wednesday, May 20, 2009

Birds on radar

While satellite in visible (EUMETSAT) shows clear skies (top image), radar shows plenty of echoes from birds and insects after the Sun rise (bottom); no, it wasn't dust. The south-eastern radar of Romania, with big lakes and the Danube Delta, has a lot of "noise" during summer, but sometimes we can easily monitor low level circulations due to these tracers. Well, sometimes birds can mislead the forecaster !

Tuesday, May 12, 2009

Gust front

The red arrow points toward an outflow from a convective cell. The thin line is the leading edge of the diverging outflow, it is called "gust front".

(visible channel, satellite images, 15 minutes apart - EUMETSAT- northern part of Moldova - Romania)

Sunday, April 26, 2009

Cloud streets

I am reading now some papers on horizontal convective roll clouds, street clouds and other similar shallow structures and how they can interact with other phenomena like the sea breeze.
The first image is about what an ignorant could think about a cloud street; the second image is what radar iamges show very often but people do not know what they are looking at (convective rolls) , the third one is a nice one from satellite Terra, with streets over the Black Sea, the last one is an airplane view of the street structure, maybe the closer to our sense of Nature. True. Meteorology is a lucky science where concepts get to a structure that can be "seen".

I struggle to find a language that can ease the process of learning, to avoid difficult math and to build concepts beyond equations. But... there are concepts that reveal only with hard work and math.
The two last days I have advanced only two pages in my reading and my conclusion is that many forecasters might have only "cartoons" and nice images in their minds... and do their jobs in the same way a gipsy "musicant" can play violin without ever seeing scores. In the same way, there are composers that never played a piece. But art and science have a different consequence of "amateurism". Art is gentle with amateurism and kitsch.
How deep do we want to go in our profession depends on how much we need a "profession" or we just want to remain "amateurs". Is the difference between a "profession" and a "job".
Of course, amateurs can be much better payed, jobs can have a role in society, but... the real advance of our society has been done through the long effort of people conceptualizing, working hard, creating new theories for days and years in a row.
There is a "natural" selection among professionals: the real ones remain for research at any price, the amateurs go for better "jobs".
I remember a cross moment in my life when I had to choose between arts and physics, and I understand now that arts wouldn't have been enough for me, that I am a better artist now, as an amateur artist, than the professional artist I would have been without my professional work in science.

Saturday, April 4, 2009

Education in Radar Meteorology

I am reading now a radar monography book, a collection of essays in honor of David Atlas. Leaving apart the joy of reading a book in nice format and good paper, it has some great overviews that really help understanding where we are in radar. My favourite is a paper on Some Educational Innovation in Radar Meteorology, by Steven Rutledge and V. Chandrasekar (I do not know why one is listed with the whole first name and the other only with initial, maybe because the very known name of the second author is simply, the great "Chandra").

Reading this paper a lot of ideas come into my mind to improve my training in radar. Is that kind of work that gives you real hints on what you can do, if you REALLY want to change something in good. "There is no replacement for direct experience when it comes to radar meteorological education" is one of the ... conclusions they start with after a survey among students. Of course there is a lot we can do via internet to simulate "hands on" experience.

I was thinking to bring a mobile radar during the pre-conference ERAD 2010 course in Sibiu, and organize few sessions of real experience.

I was thinking at the enthousiasm that is always coming out from the field work of radar people (in the image, Rita Roberts and Jim Wilson on high resolution refractivity (moisture) data), how they present their results "hot", just taken out from fresh fiels data, and how could I develop a serial sessions that could be held in different universities in Romania, a real radar on wheels from door to door.

Well, maybe if I buy a mobile radar for the met service and organize it, or if I buy my own radar and travel with it around... well, I do not drive, but I could arrange it with students that drive.
Well, look what a good paper can do !

Tuesday, March 31, 2009

Looking back at previous ERAD conferences, I found a very nice video with images from ERAD 2006 in Barcelona, here. Barcelona was celebrating a famous fiesta, la Merce, in that period so we had the chance to build a real ERAD castle. It was a very touching moment in ERAD's life, getting us closer, feeling we can build something together.

I will try to uopload it also on the site.

Tuesday, February 17, 2009

ERAD 2010, 6-10 September Sibiu, Romania

The Romanian National Meteorological Administration will host the sixth European Conference on Radar in Meteorology and Hydrology, ERAD 2010.

The city will be Sibiu (Hermanstadt) in Transylvania, Romania. The dates are from 6 to 10 of September 2010, with a pre-course in radar.
The site is with a backup at and we will provide soon more details.
Some information is also available at in Romanian and English.

Thursday, February 12, 2009

Wave perturbation

The last two images are a rough analysis of almost the same moment, seen on radar and satellite, as a sinoptician would do: a classical wave-like perturbation.

On top, in the first image, you can see my analysis, where I am more interested on the banded character of precipitation.

What is nice to observe is that strong echoes develop around the occlusion and in the warm air mass, and not around the cold front as we would be temped to think.

Sunday, January 18, 2009

A tornado witness, in 1928's Romanian literature

"Over Moldova, beyond the Bolandars hills, the sky was moving and bending as it was turning against the earth ; and a roar beyond measure, one never heard before, filled the valleys as it was getting near; and all those present, turning their faces and staring around saw the dragon coming in a spiralling whirlwind at a great speed. I saw it with my own eyes and I trembled. It was coming straight towards us. With a thin tail like a black scroll, it was touching the ground and its body was high up in the air and its mouth was gaping like that of a lioness in the clouds.
It was coming roaring and swinging its tail; its very breath was sucking throwing into the sky haystacks, house roofs and uprooted trees. Beneath the roar, a downpour of hail and water was unleashed as if the whole Moldova riverbed was taken to the sky and then knocked down on us.”

Mihail Sadoveanu, Excerpt from “The Dragon” (from Ancuta’s Inn, collection of short stories)

Tuesday, January 6, 2009 - web site

The web site of the National Meteorological Administration, is presenting information in a new and attractive way at this link.

You can find forecasts, warnings, animated radar images, detailed products, very useful and information about more specific products, road maintenance and conditions, etnometeorolgy, nivometeorology.

Behind this page is a very talented person, Darius Popa, that found a way to merge the interests of a private company with public needs. He has been close to the meteorology over the last 10 years and struggled to find ways on a wild land (private business with public benefits). He managed to work with professionals outside and inside the institute and to develop meteorologic products.

I am happy that my institute found a way to convey better service to the public.

Congratulations and go on!

Friday, January 2, 2009

Gliding into a storm

A champion paraglider described on 16 February 2007 how she was caught in a massive thunderstorm over Australia, hurled to a height greater than Mount Everest and encased in ice before managing to descend safely to earth.
Ewa Wisnerska, 35, was sucked 32,000 ft into the air — so high that she lost consciousness from lack of oxygen and ice formed over her body. Hospital staff say the paraglider suffered severe frostbite from which she almost lost her ears.
The adventurer said it was a miracle that she survived: "You can't imagine the power. You feel like nothing, like a leaf from a tree going up," she said. "I can't do anything. It's raining and hailing and I'm still climbing — I'm lost." "I was climbing and climbing and the air was starting to freeze my sunglasses and then it was dark."
Miss Wisnerska, from Germany, was preparing for the 10th World Paragliding Championships above the town of Manilla in New South Wales when the storm struck on Wednesday.
After launching as usual from a hill, she appears to have flown under a black storm cloud and then, with terrifying speed, the wind whisked her upwards. She climbed from 2,500ft to an estimated 32,000ft in about 15 minutes.
A 42-year-old Chinese para-glider, He Zhongpin, was sucked into the same storm and died, apparently from lack of oxygen and cold. His body was found nearly 50 miles from where he took off.
Miss Wisnerska said she encountered hailstones the size of oranges as the temperature dropped to minus 58 degrees Fahrenheit. "I was shaking all the time. The last thing I remember is that it was dark. I could hear lightning all around me," she said. She regained consciousness mid-air about one hour later. "I wanted to fly around the clouds but I got sucked up 20 metres (67ft) per second into it and spiralled," she told The Sydney Morning Herald.

"After 40 minutes or an hour, I woke up and I was at 6,900 metres (23,000ft). I was still flying but I realised I didn't have the brakes in my hand. I saw my hands and the gloves were frozen, I didn't have the brakes, and the glider was still flying on its own.

"I was thinking 'I can't do anything so I only have to wait and hope that the clouds are bringing me out somewhere'. Then I woke up and was thinking that I was maybe unconscious for about one minute. I didn't know I was unconscious for so long."

Her ordeal was recorded by a global positioning beacon and a radio attached to her equipment. The swirling clouds released Miss Wisnerska from their grasp and she landed safely 40 miles from her launch, suffering frostbite to her face and with ice inside her lightweight flying suit — but otherwise unharmed.
Godfrey Wenness, the president of the Manilla Sky Sailors club and organiser of the Paragliding World Championship, said Miss Wisnerska's tale was unprecedented.
"It's like winning the Lotto 10 times in a row," he said, adding that the previous altitude survival record for a paraglider pilot was 24,000ft.
Mr Wenness, one of Australia's most experienced paraglider pilots, said the chances of surviving such an experience were negligible.
"There's no oxygen. She could have suffered brain damage. But she came to at a height of 6,900 metres with ice all over her body and slowly descended herself."

The German said she felt like an astronaut returning from the Moon as the ground loomed beneath her. "I could see the Earth coming — wow, like Apollo 13," she said.
Miss Wisnerska spent one hour in the local district hospital for observation and she hopes to compete in the biennial paragliding championships which begin on Feb 24.
(Sydney Morning Herald, Reuters )

Thursday, January 1, 2009

First radar hook echo ever recorded !

Scientists from the Illinois State Water Survey recorded in April 53 the first hook echo with a war radar (photo above is taken from their web site). The movie is here and is impressive (youtube).

The presence of a hook echo on a radar image in US is enough to issue a tornado warning. If you don't, you get in trouble. The warnings get to the Police. If the Police officer doesn't push the sirene button once he got the warning, he gets in big trouble.

The hook echo is a consequence of rotation in the storm (the mesocyclone), is a wrapped column of air in strong rotation, and the storms that have a mesocyclone can be very dangerous, with hail, flashfloods and strong winds; only 60% of the supercells are tornadic.
The first conference in Europe where have been presented cases with Tornado in Europe was Eurotornado, in February 2000, in France, Toulouse, but tornadoes have been reported and studied long ago and actually before they have been studied in US !