04/29/2015

Question: What Causes The Smell After Rain?

Petrichor is the scent of rain on dry earth, or the scent of dust after rain. The word is constructed from Greek, petros, meaning ‘stone’ + ichor, the fluid that flows in the veins of the gods in Greek mythology. It is defined as "the distinctive scent which accompanies the first rain after a long warm dry spell".

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Image Courtesy: Wiki

The term was coined in 1964 by two Australian researchers, Bear and Thomas, for an article in the journal Nature. In the article, the authors describe how the smell derives from an oil exuded by certain plants during dry periods, whereupon it is absorbed by clay-based soils and rocks. During rain, the oil is released into the air along with another compound, geosmin, a metabolic by-product of certain Actinobacteria, which is emitted by wet soil, producing the distinctive scent; ozone may also be present if there is lightning. In a follow-up paper, Bear and Thomas (1965) showed that the oil retards seed germination and early plant growth. This would indicate that the plants exude the oil in order to safeguard the seeds from germination under duress.

 

-Rick DeLuca

 

 

Rick

 

 

 

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04/28/2015

VIDEO: Severe Storm Blows Train Clear Off Tracks!

Severe storms Monday morning producing 70 mph winds knocked a dozen Union Pacific rail cars clear off the track yesterday morning in Jefferson Parish, Louisiana.  

 

Strong winds knock over a train in Jefferson Parish, Louisiana.  Video via WGNO in New Orleans, LA

The rail cars were empty at the time and, fortunately, there were no injuries reported in the incident.

WDRB Meteorologist Jeremy Kappell

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Vigorous Upper Storm to Bring Wet Weather for Pegasus!

While our nice stretch of weather continues for a bit longer, changes are occurring in the jet stream winds that will lead to a good chance of rain before the end of the week.  

Currently, we are tracking the formation of a trough of low pressure in the upper levels over Northern Ontario near Hudson Bay.  

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This trough is expected to dive to the south and deepen into a compact, but intense upper low pressure system and looks to swing directly over our viewing area late Wednesday night and Thursday.  

The purple/green bullseye on the map below represents a cold pocket of air aloft associated with the upper low pressure system.

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This cold air in the upper levels will likely result in the development of showers just in time for the Pegasus Parade on Thursday.

Let's time it out on AdvanceTrak...

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Although the chance of rain will be with us throughout the day, the greatest chance of rain looks to occur during the afternoon hours on Thursday with showers becoming widespread.  With so much cold air aloft, some small hail will also be possible with any heavier showers that form.

In addition to the rain, clouds and a strong north wind look to keep temperatures on the cool side with highs perhaps struggling to reach the low 60's for a high.  

Moral of the story... if you plan on attending the Pegasus Parade, be sure to dress for the wet and cool weather.

Fortunately, much nicer conditions are expected to return just in time for Derby.

Marc will have a full update on what to expect on WDRB News this evening. 

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04/27/2015

VIDEO: Deadly Avalanche Strikes Everest Base Camp

The powerful M7.8 earthquake that struck Nepal on Saturday triggered a series of avalanches on Mount Everest tragically killing and injuring many climbers.  

 

German climber Jost Kobusch filmed the footage as he and fellow trekkers surveyed the snow-covered camp site in the Himalayas

This terrifying video shows the moment an avalanche of snow hit climbers at Everset base camp after the Nepal earthquake.

German climber Jost Kobusch filmed the footage as he and fellow trekkers surveyed the snow-covered camp site in the Himalayas.

A huge cloud of snow and debris can then be seen coming towards them, and so the panicking adventurers dash inside their tents.

Mr Kobusch posted the clip on his YouTube page, on which he described himself as a former special forces member in the German Amps Mountaineering Army.

Describing the footage, he wrote: "The ground was shaking from the earthquake and as soon as we saw people running we were running ourselves to save our lives."

A number of climbers have been able to post tweets, blogs, pictures and footage from base camp following the disaster.

US climber Jon Kedrowski said in his blog from base camp that the earthquake broke off a "huge, jagged point" of ice from a ridge that slammed down, creating a hurricane force wind that blew people and tents up to a hundred feet.

Another climber said a large part of the camp looked like it was hit by a "nuclear blast."

 

A longer clip with raw sound can be seen here.  ***Warning Adult Language***

 

At least a dozen have been killed by the avalanche and many are still missing.

More than a thousand climbers were located at base camps on the mountain at the time of the quake.  

 

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04/26/2015

NASA's View Of Seaweed Farms in South Korea...

The dark squares that make up the checkerboard pattern in this image are fields of a sort—fields of seaweed. Along the south coast of South Korea, seaweed is often grown on ropes, which are held near the surface with buoys. This technique ensures that the seaweed stays close enough to the surface to get enough light during high tide but doesn’t scrape against the bottom during low tide.

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Image Credit: NASA

The Operational Land Imager (OLI) on Landsat 8 acquired this image of seaweed cultivation in the shallow waters around Sisan Island on January 31, 2014. Home to a thriving aquaculture industry, the south coast of South Korea produces about 90 percent of the country’s seaweed crop. The waters around Sisan are not the only place where aquaculture is common.

Two main types of seaweed are cultivated in South Korea: Undaria (known as miyeok in Korean, wakame in Japanese) and Pyropia (gim in Korean, nori in Japanese). Both types are used generously in traditional Korean, Japanese, and Chinese food.

Since 1970, farmed seaweed production has increased by approximately 8 percent per year. Today, about 90 percent of all the seaweed that humans consume globally is farmed. That may be good for the environment. In comparison to other types of food production, seaweed farming has a light environmental footprint because it does not require fresh water or fertilizer.

 

-Rick DeLuca

 

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04/25/2015

VIDEO: Security Video of Powerful Nepal Quake

Private security video of Nepal M7.8 earthquake from earlier today.

 

INCREDIBLE VIDEO from Kathmandu (Kishor reported)

A powerful, 7.8-magnitude earthquake shook Nepal's capital and the densely populated Kathmandu Valley before noon Saturday, collapsing houses and leveling centuries-old temples in the worst temblor in the Himalayan nation in over 80 years

Unfortunately, at least 1400 are reported dead and this figure is expected to continue to climb.

 

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Severe Thunderstorm Watch Issued!

The Storm Prediction Center has issued a Severe Thunderstorm Watch for portions of our area until 11 PM ET.  

Warnings

The watch does not include Metro Louisville, but does include much of Central and Southern Kentucky.  

E-town, Bardstown, Leitchfield, Hodgenville and Columbia are in the watch area.  

Much of Western Kentucky and Southwestern Indiana remain under a Tornado Watch.

I'll have a full update on the situation tonight on WDRB News at 10.

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Severe Thunderstorm Watch Likely...

 AREAS AFFECTED...E CNTRL MO...SRN IL...SRN INDIANA...WRN KY

   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

   PROBABILITY OF WATCH ISSUANCE...95 PERCENT

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   SUMMARY...SUPERCELLS ARE EXPECTED TO DEVELOP ACROSS FAR ERN MO INTO
   SRN IL IN THE 19-21Z TIME FRAME WITH LARGE HAIL AND A FEW TORNADOES
   POSSIBLE. TWO WATCHES ARE LIKELY...FIRST ACROSS WRN PORTIONS OF THE
   DISCUSSION AREA...THEN DOWNSTREAM INTO CENTRAL KY LATER TODAY WHERE
   A WIND THREAT MAY ALSO MATERIALIZE.

   DISCUSSION...SURFACE ANALYSIS AND VISIBLE SATELLITE IMAGERY INDICATE
   AN ALIGNMENT OF FAVORABLE FACTORS SUGGESTING A HIGH LIKELIHOOD OF
   SEVERE STORMS ACROSS A RELATIVELY NARROW CORRIDOR FROM NEAR ST.
   LOUIS SEWD ACROSS IL AND INTO WRN KY.

   STRONG HEATING IS RESULTING IN DESTABILIZATION BENEATH COOL
   TEMPERATURES ALOFT ASSOCIATED WITH THE UPPER VORT MAX. VISIBLE
   SATELLITE SHOWS CU FIELDS INCREASING ACROSS CNTRL/E-CNTRL MO WHERE
   THE WARMEST TEMPERATURES EXIST. MEANWHILE...A GRADUAL BREAKUP OF
   CLOUDS IS UNDERWAY ALONG THE WARM FRONT...AND DEWPOINTS WILL
   CONTINUE TO RISE INTO THE LOWER 60S.

   SHALLOW SHOWERS ALREADY DEVELOPING SW OF ST. LOUIS SHOULD ONLY
   INCREASE IN COVERAGE AND INTENSITY THIS AFTERNOON. MULTIPLE
   SUPERCELLS ARE THEN EXPECTED TO TREK EWD THEN SEWD WITH A COUPLE
   TORNADOES POSSIBLE IN ADDITION TO LARGE HAIL.

 

-Rick DeLuca

 

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Update: Severe Weather Likely For Some Today...

The Storm Prediction Center has expanded their "Slight Risk" for severe weather to include almost all of our viewing area with the exception of our far northeastern counties...

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Based on the latest data, I don't think the threat reaches that far north. The atmosphere will be too cool and far too stable north of the I-64 corridor. There could be a few stronger storms in Louisville with small hail and gusty winds this evening, but they should stay below severe limits. It's places like E-Town, Leitchfield, and Campbellsville that need to be on guard for severe weather later today...

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The main threat down there is the potential for large hail. Severe criteria for hail is 1" in diameter, and the ingredients are there to help it grow even larger. The strongest storms could support hail to the size of golf balls or in a rare case, baseballs! Hail this big can easily damage cars and homes and obviously it is VERY dangerous for people and pets to be outside during such an event. Another concern is the threat for powerful winds that could gust between 50 - 75 mph! As you know, the ground is already saturated and it might only take winds up to 40 mph to knock down trees. Make sure you are prepared just in case the power happens to go out. We could also see tornadoes and with so many outdoor events going on, you need to have a safe place nearby. The final threat is flash flooding. Thunderstorms may have a tendency to hit the same areas over and over again. Please don't attempt to drive across flooded roads. It only takes 2 feet of water to sweep away a car!

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Now that we have discussed the threats, let's take a look at the timing. Aside from an isolated t-shower, the steadier rain from this morning will be coming to an end.  We get a break during the early afternoon, the sun makes an appearance and winds pick up. This will quickly destabilize the atmosphere allowing storms to ignite for SOME. These are the ones that could be strong to severe. The bottom line, be on guard for nasty storms from 5 pm - 10 pm along and south of the parkways...

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Jeremy Kappell will be on WDRB tonight tracking storms and we will be the first to let you know if any watches or warning are issued. Enjoy the weekend!

 

-Rick DeLuca

 

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04/24/2015

Severe Weather Risk Saturday: Discussing Timing and Threats...

The Storm Prediction Center has placed areas along and south of I-64 in their "Slight Risk" for severe weather on Saturday...

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Based on some of the latest data, we feel a higher "Moderate" risk may be necessary in the zone painted red...

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The main threat tomorrow is the potential for large hail. Severe criteria for hail is 1" in diameter, and the ingredients are there to help it grow even larger. The strongest storms could support hail growing to the size of golfballs or in a rare case, baseballs! Hail this big can easily damage cars and homes and obviusly it is VERY dangerous for people and pets to be outside during such an event. Another concern is the threat for powerful winds that could gust between 50 - 75 mph! As you know, the ground is already saturated and it might only take winds up to 40 mph to knock down trees. Make sure you are prepared just in case the power happens to go out. We could also see tornadoes tomorrow and with so many outdoor events going on, you need to have a safe place nearby. The final threat is flash flooding. Thunderstorms may have a tendancy to hit the same areas over and over again. Please don't attempt to drive across flooded roads. It only takes 2 feet of water to sweep away a car or truck! Not that we have discussed the threats, let's take a look at the timing. Rain and maybe a couple rumbles of thunder pass through during the morning hours. We get a break during the early afternoon, the sunshine makes an appearance and winds pick up. This will quickly destabilize the atmosphere allowing storms to ignite for SOME. These are the ones that could be strong to severe. The bottom line, be on guard for nasty storms from 3 pm - 9 pm...

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Marc Weinberg will be on WDRB tonight with updates and we will be the first to let you know if any watches or warning are issued tomorrow.

 

-Rick DeLuca

 

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