HALS

Weather fronts of the world unite: tornadoes demand the weekend off

By Scott K. Johnson. One of the classic sci-fi doomsday machines is the weather manipulator. What better way to bend the world to your will than taking control of the weather? It seems, however, that labor regulations may have beaten mad scientists to the punch.

Past studies have identified weekly cycles in a variety of weather phenomena, including rainfall, lightning, and storm heights. It’s called the weekend effect, and it’s thought to be be linked to the industrial air pollution associated with the five-day work week, though there has been a lot of discussion about the mechanics of that connection. These aren’t global analyses—many of these studies have focused on the southeastern United States during the summer months, though similar trends have been identified in other regions, as well. There’s a good reason for this. It seems that warm, moist conditions are a pre-requisite for the effect to manifest.

A new study published recently in the Journal of Geophysical Research adds to the list, finding strong evidence for weekly cycles in tornadoes and hail storms, and discusses the most likely mechanism behind them. Continuar leyendo Weather fronts of the world unite: tornadoes demand the weekend off…

Formación bacteriana de granizo en las nubes

Se ha descubierto una alta concentración de bacterias en los núcleos de partículas de granizo, lo que sugiere que los microorganismos presentes en el aire a suficiente altitud pueden intervenir en ese y otros fenómenos meteorológicos.

Continuar leyendo Formación bacteriana de granizo en las nubes…

‘Way out of whack’ weather produces record hailstone

By Kim Hutcherson and Angela Fritz
July 30, 2010

(CNN) — A South Dakota ranch worker who found a record-setting hailstone says the chunks of ice falling from the sky sounded like “big bricks” being thrown at his house.

Leslie “Les” Scott found the record-breaker, which is almost the size of a soccer ball, last week. It’s been been officially declared the largest ever recorded in the United States, in terms of both diameter and weight. The hailstone measured 8.0 inches in diameter, had a circumference of 18.62 inches, and weighed one pound, 15 ounces, according to the NOAA National Climate Extremes Committee.

Scott says larger hailstones fell around the tiny town of Vivian, South Dakota last week. As severe thunderstorms swept through the area on July 23, Scott says he and a few friends gathered on a hilltop to watch the weather system. He abandoned his position when he saw twisters taking shape in the clouds, but continued watching the storm from his home. He told CNN that he saw hailstones that were as large or larger than the one he actually kept. In fact, Scott said the smallest hailstone he found was about the size of a tennis ball. Continuar leyendo ‘Way out of whack’ weather produces record hailstone…