Sciency Thoughts: Weather

Showing posts with label Weather. Show all posts

Saturday, 8 June 2019

Cloud of Ladybird Beetles, confuse US Weather Radar.

A United States National Weather Service station in San Diego was briefly confused by the apparent sudden appearance of a large cloud over San Bernardino County, California. The cloud appeared without warning on the San Diego CA Radar system on Wednesday 5 June 2019, and appeared to be about 130 km across, far larger than would usually be expected to form rapidly over a fairly dry part of Southern California in June. This prompted the weather station to contact ground observers in the area, who reported a large cloud of the Beetles travelling at between 1500 and 2750 m, with the densest part of the cloud less than 20 km across.

Large cloud of Ladybird Beetles detected over Southern California by a weather radar system. National Weather Service.

Ladybird Beetles, Coccinellidae, are primarily carnivorous Beetles, many species targeting agricultural pests such as Aphids or Scale Insects, so that they are widely used as biological controls. though most species will eat some plant matter, and some are minor pests in their own right. Most species are red or orange in colour, often with conspicuous spots; the name 'Ladybird' refers to the apparent resemblance of the colour of the Beetles to the cloak of the Virgin Mary, which by convention was always depicted as red in classical European art, although many species have less conspicuous colouration, making them harder to identify as part of the group. Large clouds of Ladybirds are an uncommon phenomenon. usually associated with droughts, which can lead to shortages of prey items, causing large numbers of the Beetles to take to the air at the same time.

Sunday, 26 June 2016

Flooding kills 26 in West Virginia.

Twenty six people have been confirmed dead in West Virginia after the state suffered its worst flooding in a century this week. 250 mm or rain was recored in parts of West Virginia on Thursday 23 June 2016, roughly a quater of the expected annual rainfall for the state, and leading to flash floods that swept away many houses and other buildings. The worst hit areas are reported to be in the southeast of the state, notably Greenbrier County, where sixteen people are reported to have died and Kanahwa County, where another six fatalities occured.

Floodwaters near White Sulphur Springs in Greenbrier County, West Virginia, on 24 June 2016. AP.

At least a hundred homes are thought to have been destroyed, while across the state about 32 000 homes and businesses are thought to be without electricity. A State of Emergency has been declared by President Barack Obama following a request from State Governor Earl Ray Tomblin, meaning that residents of the worst affected areas will be able to apply for federal aid to help them rebuild.

Flooding in Richwood in Nicholas County, West Virginia, on 23 June 2016. Jeremy Rose/Charleston Gazette-Mail.

Richwood

West Virginia has a warm subtropical climate with rainfall largely driven by evaporation in the North Pacific rather than the (nearer) Atlantic, with prevailing winds predominantly carrying moist air from the West that is pushed upwards by the Appalachian Mountains, causing it to cool and lose its capacity to cary as much water, resulting in rainfall. However Atlantic storms can reverse this process, bringing warm moist air from the Atlantic, which also tends to deposit its water content on encountering the Appalachians.

Saturday, 25 June 2016

Ninety-eight confirmed deaths as storms batter Jiangsu Province, China.

Ninety-eight people have been confirmed dead and around 800 injured following a series of storms that battered coastal areas of Jiangsu Province, China, on Friday 24 June 2016. Windspeeds of 125 kilometers per hour were recored in Funing County, and witnesses reported seeing a tornado near the city of Yancheng. A factory belonging to GCL System Integration Technology Co Ltd has also been partially destroyed, including a store for hazardous chemicals, leading to concerns that water supplies could be contaminated.

Storm damage in Funing County following the storms that battered Jiangsu Province on 24 June 2016. AP.

Ocean storms form due to heating of air over the sea in tropical zones. As the air is heated the the air pressure drops and the air rises, causing new air to rush in from outside the forming storm zone. If this zone is sufficiently large, then it will be influenced by the Coriolis Effect, which loosely speaking means the winds closer to the equator will be faster than those further away, causing the storm to rotate, clockwise in the northern hemisphere and anticlockwise in the southern hemisphere.

Storm damaged buildings in Yangcheng following the storms that battered Jiangsu Province on 24 June 2016. AP.

Tropical storms are common in South China, but Jiangsu Provinc is in the northeast of the country and does not usually suffer such storms. Meteorologists in China have suggested the storms may be conneted to last year's El Niño conditions, which has brought unusual weather conditions around the Pacific and Indian oceans.

Movements of air masses and changes in precipitation in an El Niño weather system. Fiona Martin/NOAA.

The El Niño is the warm phase of a long-term climatic oscillation affecting the southern Pacific, which can influence the climate around the world. The onset of El Niño conditions is marked by a sharp rise in temperature and pressure over the southern Indian Ocean, which then moves eastward over the southern Pacific. This pulls rainfall with it, leading to higher rainfall over the Pacific and lower rainfall over South Asia. This reduced rainfall during the already hot and dry summer leads to soaring temperatures in southern Asia, followed by a rise in rainfall that often causes flooding in the Americas and sometimes Africa. Worryingly climatic predictions for the next century suggest that global warming could lead to more frequent and severe El Niño conditions, extreme weather conditions a common occurrence.

See also...

http://sciencythoughts.blogspot.co.uk/2016/05/landslide-kills-six-in-zhejiang.html

Landslide kills six in Zhejiang Province, China. Six people have been confirmed dead following a landslide in the city of Jiande in Zhejiang...

http://sciencythoughts.blogspot.co.uk/2015/11/multiple-deaths-following-landslide-in.html

Multiple deaths following landslide in Zhejiang Province, China. Eleven people have been confirmed dead and another 26 are still missing following a landslide that buried about 27 houses in the village of Lidong in the Llandu District of Zhejiang Province at about 10.50 pm local time on Friday 13 November 2015. The...

http://sciencythoughts.blogspot.co.uk/2015/03/earthquake-in-anhui-province-china.html

Earthquake in Anhui Province, China, kills at least two. Two people are known to have died and at least twelve more have been injured following an Earthquake close to the city of Fuyang in Anhui Province slightly before 2.15 pm local time (slightly before 6.15 am GMT) on Saturday 14 March 2015, which was recorded by the...

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Monday, 2 June 2014

13 killed by lightning in West Bengal.

At least thirteen people have been killed by lightning in West Bengal during the last week, and over twenty more have been injured as the annual kalboishakhi storms swept across the state. Most of those who have died were farm workers caught in the open in the Murshidabad, Burdwan and North Parganas Districts. The kalboishaki storms occur around the beginning of the monsoon season each year, as cool dry air masses moving southwest from Iran and Turkmenistan interact with warmer wetter air sweeping up from the Indian Ocean.

The location of West Bengal. Google Maps.

Thunderstorms occur when warm, moist bodies of air encounter cooler, drier air packages. The warm air rises over the cooler air until it rises above its dew point (the point where it cools to far to retain its water content as vapor), and the water precipitates out, falling as rain, sleet or hail.

Warm moist air passing over the surface of the Earth acts as an electrical generator, creating a negative charge in the cloud tops and a positive charge at the ground (or occasionally in a second cloud layer). The atmosphere acts as an electrical insulator, allowing this potential to build up, until water begins to precipitate out. This allows a channel of ionized air to form, carrying a current between the clouds and the ground, which we perceive as lightning.