http://metzonesa.forumf.biz/feed/? Latest topics Thu, 26 Jun 2008 13:47:34 GMT 10 http://illiweb.com/fa/empty.gif http://metzonesa.forumf.biz/feed/? http://metzonesa.forumf.biz/preventative-measures-for-alerts-and-warnings-f6/safety-precautions-for-tornadoes-t57.htm Admin Tornado Danger Signs Learn these tornado danger signs: An approaching cloud of debris can mark the location of a tornado even if a funnel is not visible. Before a tornado hits, the wind may die down and the air may become very still. Tornadoes generally occur near the trailing edge of a thunderstorm. It is not uncommon to see clear, sunlit skies behind a tornado. During If at home: Go at once to a windowless, interior room; storm cellar; basement; or lowest level ... Preventative measures for alerts and warnings Thu, 26 Jun 2008 13:47:34 GMT http://metzonesa.forumf.biz/preventative-measures-for-alerts-and-warnings-f6/safety-precautions-for-tornadoes-t57.htm#61 http://metzonesa.forumf.biz/preventative-measures-for-alerts-and-warnings-f6/safety-precautions-for-tornadoes-t57.htm http://metzonesa.forumf.biz/preventative-measures-for-alerts-and-warnings-f6/thunderstorm-safety-t56.htm Admin Thunderstorms are easily identified by their thunder and lightning. a Storm normally last for about 30 minutes, but severe storms may last longer. There are four dangerous types of weather that can be generated by thunderstorms, namely lightning, wind gusts (squalls), hail and tornadoes. We will look at some of these types of weather separately. Precautions Before the thunderstorm season Trim back branches of trees from your house, clean and check roof gutters. Make a list of emergency ... Preventative measures for alerts and warnings Thu, 26 Jun 2008 13:40:42 GMT http://metzonesa.forumf.biz/preventative-measures-for-alerts-and-warnings-f6/thunderstorm-safety-t56.htm#60 http://metzonesa.forumf.biz/preventative-measures-for-alerts-and-warnings-f6/thunderstorm-safety-t56.htm http://metzonesa.forumf.biz/preventative-measures-for-alerts-and-warnings-f6/weather-safety-during-lightning-t55.htm Admin Lightning occurs with every thunderstorm and must be expected as soon as thunderstorms form. Lightning results from the build-up and discharge of electrical energy between positively and negatively charged areas in the atmosphere and clouds. The most lightning occurs between clouds but it is the ground strikes that are dangerous. Precautions If you live in a thatched building erect a lightning conductor near to but not touching the building. Stay indoors during a thunderstorm and if ... Preventative measures for alerts and warnings Thu, 26 Jun 2008 13:38:06 GMT http://metzonesa.forumf.biz/preventative-measures-for-alerts-and-warnings-f6/weather-safety-during-lightning-t55.htm#59 http://metzonesa.forumf.biz/preventative-measures-for-alerts-and-warnings-f6/weather-safety-during-lightning-t55.htm http://metzonesa.forumf.biz/preventative-measures-for-alerts-and-warnings-f6/safety-during-flooding-events-t54.htm Admin Flooding occurs when water overflows its normal channels such as streams and storm water drains. Floods may also occur when there is an accumulation of water by drainage into areas which are not normally submerged. Flash floods are usually associated with severe thunderstorms. However a storm may be upstream and might not be visible from your position, In the case of widespread flooding, which normally develops over several hours or even days, it is the prolonged nature of the rainy spell ... Preventative measures for alerts and warnings Thu, 26 Jun 2008 13:37:04 GMT http://metzonesa.forumf.biz/preventative-measures-for-alerts-and-warnings-f6/safety-during-flooding-events-t54.htm#58 http://metzonesa.forumf.biz/preventative-measures-for-alerts-and-warnings-f6/safety-during-flooding-events-t54.htm http://metzonesa.forumf.biz/climate-information-f26/what-are-el-nino-and-la-nina-t53.htm Admin What is El Niño? El Niño is the warming of sea-surface temperatures in the equatorial Pacific Ocean which influences atmospheric circulation, and consequently rainfall and temperature in specific areas around the world. El Niño is translated from Spanish as "the boy child". Peruvian anchovy fishermen traditionally used the term - a reference to the Christ child - to describe the appearance of a warm ocean current off the South American coast around Christmas. Over the years the term ... Climate information Thu, 26 Jun 2008 09:50:59 GMT http://metzonesa.forumf.biz/climate-information-f26/what-are-el-nino-and-la-nina-t53.htm#57 http://metzonesa.forumf.biz/climate-information-f26/what-are-el-nino-and-la-nina-t53.htm http://metzonesa.forumf.biz/climate-information-f26/what-are-the-highest-and-lowest-recorded-temperatures-rainfall-and-wind-in-the-world-and-in-south-africa-t52.htm Admin Description Location Detail Highest temperature recorded in the world Al’Aziziya, Libya 57,7 ºC on 13 September 1922 Highest temperature recorded in South Africa Dunbrody (Sundays River Valley in Eastern Cape) 50,0 ºC on 3 November 1918 The hottest place in South Africa Letaba (Limpopo Province) Mean annual temperature of 23,3 ºC Average maximum temperature 35,0 ºC Lowest temperature recorded in the world Vostok, Antarctica -89,2 ºC on 21 July 1983 Lowest temperature ... Climate information Thu, 26 Jun 2008 09:10:24 GMT http://metzonesa.forumf.biz/climate-information-f26/what-are-the-highest-and-lowest-recorded-temperatures-rainfall-and-wind-in-the-world-and-in-south-africa-t52.htm#56 http://metzonesa.forumf.biz/climate-information-f26/what-are-the-highest-and-lowest-recorded-temperatures-rainfall-and-wind-in-the-world-and-in-south-africa-t52.htm http://metzonesa.forumf.biz/climate-information-f26/a-brief-synopsis-of-droughts-in-the-summer-rainfall-regions-of-south-africa-from-1960-to-2005-t51.htm Admin Introduction The rainfall climate of South Africa is one of great variability. Seasonal rainfall percentage deviations since 1960 demonstrate wide fluctuations about the long-term average and it is in this context that large rainfall deficits must be assessed. Between July of 1960 and June of 2004, there have been 8 summer-rainfall seasons where rainfall for the entire summer-rainfall area has been less than 80% of normal. A deficit of 25% is normally regarded as a severe meteorological ... Climate information Thu, 26 Jun 2008 08:59:13 GMT http://metzonesa.forumf.biz/climate-information-f26/a-brief-synopsis-of-droughts-in-the-summer-rainfall-regions-of-south-africa-from-1960-to-2005-t51.htm#55 http://metzonesa.forumf.biz/climate-information-f26/a-brief-synopsis-of-droughts-in-the-summer-rainfall-regions-of-south-africa-from-1960-to-2005-t51.htm http://metzonesa.forumf.biz/climate-information-f26/what-is-a-drought-t50.htm Admin Drought is not easily defined and often depends on who you speak to. The South African Weather Service defines drought on the basis of the degree of dryness in comparison to normal or average amounts of rainfall for a particular area or place and the duration of the dry period. This is what is termed a meteorological drought. Less than 75% of normal rainfall is regarded as a severe meteorological drought but a shortfall of 80% of normal rainfall will cause crop and water shortages which will ... Climate information Thu, 26 Jun 2008 08:56:21 GMT http://metzonesa.forumf.biz/climate-information-f26/what-is-a-drought-t50.htm#54 http://metzonesa.forumf.biz/climate-information-f26/what-is-a-drought-t50.htm http://metzonesa.forumf.biz/climate-information-f26/what-is-global-warming-t49.htm Admin
Are Climate Change, the Greenhouse Effect and Global Warming the same thing? No they are not. However, they are linked.]]> Climate information Thu, 26 Jun 2008 08:55:07 GMT http://metzonesa.forumf.biz/climate-information-f26/what-is-global-warming-t49.htm#53 http://metzonesa.forumf.biz/climate-information-f26/what-is-global-warming-t49.htm http://metzonesa.forumf.biz/climate-information-f26/what-is-the-greenhouse-effect-t48.htm Admin The gases in our atmosphere allow the sun’s energy (shortwave radiation) to pass through and heat the earth’s surface. The earth in turn radiates the energy back to the atmosphere in the form of long-wave infrared radiation. This process causes the net warming of the earth and atmosphere and is sometimes referred to as the natural greenhouse effect. The glass of a greenhouse works in a similar way, letting in short-wave radiation but preventing long-wave radiation from escaping and thus the air ... Climate information Thu, 26 Jun 2008 08:54:40 GMT http://metzonesa.forumf.biz/climate-information-f26/what-is-the-greenhouse-effect-t48.htm#52 http://metzonesa.forumf.biz/climate-information-f26/what-is-the-greenhouse-effect-t48.htm http://metzonesa.forumf.biz/climate-information-f26/what-is-climate-change-t47.htm Admin The climate of the world varies from one decade to another, and a changing climate is natural and expected. However, there is a well-founded concern that the unprecedented human industrial and development activities of the past two centuries have caused changes over and above natural variation... What is climate change? Climate change is the natural cycle through which the earth and its atmosphere are going to accommodate the change in the amount of energy received from the sun. The ... Climate information Thu, 26 Jun 2008 08:53:03 GMT http://metzonesa.forumf.biz/climate-information-f26/what-is-climate-change-t47.htm#51 http://metzonesa.forumf.biz/climate-information-f26/what-is-climate-change-t47.htm http://metzonesa.forumf.biz/education-f31/what-library-facities-does-the-weather-service-have-t46.htm Admin The South African Weather Service library collection consists mainly of publications in the field of climatology, meteorology and related sciences. The Collection Encompasses the following materials: Monographs arranged according to the Universal Decimal Classification (UDC) system. Periodicals arranged alphabetically according to title. Approximately 255 titles are received regularly. Government Publications of South Africa Only relevant South African Government departments' annual reports, ... Education Thu, 26 Jun 2008 08:48:53 GMT http://metzonesa.forumf.biz/education-f31/what-library-facities-does-the-weather-service-have-t46.htm#50 http://metzonesa.forumf.biz/education-f31/what-library-facities-does-the-weather-service-have-t46.htm http://metzonesa.forumf.biz/education-f31/what-training-programs-do-the-weather-service-offer-t45.htm Admin Weather excellence starts with meteorological training of high standards to: Observe the weather; Provide Weather Forecasts; Collect Climatological Information; Exchange Information worldwide; Do Research Click here to download an Adobe Acrobat document detailing the Weather Observer Course Click here to view a document describing the BSc bridging course (Meteorology) for pure BSc graduates wanting to qualify in Meteorology Specific meteorological training is also provided ... Education Thu, 26 Jun 2008 08:40:59 GMT http://metzonesa.forumf.biz/education-f31/what-training-programs-do-the-weather-service-offer-t45.htm#49 http://metzonesa.forumf.biz/education-f31/what-training-programs-do-the-weather-service-offer-t45.htm http://metzonesa.forumf.biz/education-f31/what-career-paths-are-available-in-the-field-of-meteorology-t44.htm Admin Weather excellence starts with meteorological training of high standards to Observe the weather Provide Weather Forecasts Collect Climatological Information Exchange Information worldwide Do Research Meteorological Training is provided in cooperation with universities. A limited number of bursaries are advertised in the national newspapers towards April of each year for Honours students and October for the weather observer students. Private and International students are also welcome. The ... Education Thu, 26 Jun 2008 08:24:44 GMT http://metzonesa.forumf.biz/education-f31/what-career-paths-are-available-in-the-field-of-meteorology-t44.htm#48 http://metzonesa.forumf.biz/education-f31/what-career-paths-are-available-in-the-field-of-meteorology-t44.htm http://metzonesa.forumf.biz/seasonal-forecasts-f1/asdasd-werwerwer-t43.htm Tom Cruise test Seasonal Forecasts Fri, 20 Jun 2008 10:48:40 GMT http://metzonesa.forumf.biz/seasonal-forecasts-f1/asdasd-werwerwer-t43.htm#47 http://metzonesa.forumf.biz/seasonal-forecasts-f1/asdasd-werwerwer-t43.htm http://metzonesa.forumf.biz/seasonal-forecasts-f1/tesing-for-mail-t42.htm Tom Cruise Test for mail Seasonal Forecasts Fri, 20 Jun 2008 09:22:42 GMT http://metzonesa.forumf.biz/seasonal-forecasts-f1/tesing-for-mail-t42.htm#45 http://metzonesa.forumf.biz/seasonal-forecasts-f1/tesing-for-mail-t42.htm http://metzonesa.forumf.biz/questions-on-weather-f25/do-you-have-interesting-facts-on-how-wind-affects-south-africa-t41.htm Admin Which is the windiest place: Cape Town or Port Elizabeth? This is a difficult question to answer. What magnitude of wind is more noticeable than others? Possibly we can resolve the issue by referring to the Beaufort Wind Scale. If one uses the Beaufort Wind Scale, wind only really becomes felt by human beings when the wind speed exceeds 1,5 m/s. Cape Town experiences wind of 1,6 m/s or more on 95,6% of the days of the year and Port Elizabeth on 95,7% of the days of the year. The Beaufort Wind ... Questions on Weather Fri, 20 Jun 2008 08:07:33 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/do-you-have-interesting-facts-on-how-wind-affects-south-africa-t41.htm#42 http://metzonesa.forumf.biz/questions-on-weather-f25/do-you-have-interesting-facts-on-how-wind-affects-south-africa-t41.htm http://metzonesa.forumf.biz/seasonal-forecasts-f1/test-eideas4ueideas4ueideas4ueideas4u-t2.htm Tom Cruise Seasonal Forecasts Wed, 18 Jun 2008 09:50:24 GMT http://metzonesa.forumf.biz/seasonal-forecasts-f1/test-eideas4ueideas4ueideas4ueideas4u-t2.htm#3 http://metzonesa.forumf.biz/seasonal-forecasts-f1/test-eideas4ueideas4ueideas4ueideas4u-t2.htm http://metzonesa.forumf.biz/questions-on-weather-f25/which-are-the-coldest-months-of-the-year-on-the-different-continents-t40.htm Admin This is a quick summary of the average data by month for a large number of cities as found in the publication “The World Weather Guide”, E A Pearce and C G Smith, Hutchinson and CO Publishers, 1984 Continent / Country Coldest Month South Africa July Africa south of the Equator July Africa north of the Equator January Canada January followed very closely by February USA January Mexico January and December Central America January South America north of the ... Questions on Weather Fri, 20 Jun 2008 08:06:39 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/which-are-the-coldest-months-of-the-year-on-the-different-continents-t40.htm#41 http://metzonesa.forumf.biz/questions-on-weather-f25/which-are-the-coldest-months-of-the-year-on-the-different-continents-t40.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-severe-weather-warning-and-when-are-they-issued-t39.htm Admin A Severe Weather Warning is a special type of warning issued by the South African Weather Service when hazardous weather such as strong winds, slow-moving thunderstorms, tropical cyclones, very heavy rainfall conducive to flash flooding, storm tides and dangerous surf are expected to occur. The South African Weather Service, by law, is the only organization to issue severe weather warnings for South Africa. A Severe Weather Warning is issued when any of the following phenomena are observed ... Questions on Weather Fri, 20 Jun 2008 08:01:11 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-severe-weather-warning-and-when-are-they-issued-t39.htm#40 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-severe-weather-warning-and-when-are-they-issued-t39.htm http://metzonesa.forumf.biz/questions-on-weather-f25/where-can-i-get-a-complete-list-of-meteorological-terms-t38.htm Admin http://www.weathersa.co.za/References/MetTermsGlossary.jsp]]> Questions on Weather Fri, 20 Jun 2008 08:00:02 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/where-can-i-get-a-complete-list-of-meteorological-terms-t38.htm#39 http://metzonesa.forumf.biz/questions-on-weather-f25/where-can-i-get-a-complete-list-of-meteorological-terms-t38.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-the-difference-between-a-weather-forecast-and-a-weather-report-t37.htm Admin A weather forecast is given before the date in question and gives an indication of what weather conditions could be expected. Weather forecasts can be made one to two weeks in advance. The forecast skill however drops rapidly during the first week of a forecast, such that daily conditions generally become unpredictable after about a week to ten days. A weather report can only be given for a past period and gives the actual weather conditions that occurred. It can be produced for any time ... Questions on Weather Fri, 20 Jun 2008 07:58:00 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-the-difference-between-a-weather-forecast-and-a-weather-report-t37.htm#38 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-the-difference-between-a-weather-forecast-and-a-weather-report-t37.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-cold-front-and-what-weather-is-associated-with-the-passage-of-a-cold-front-t36.htm Admin A cold front occurs where a large mass of cold air meets a mass of warmer air, and the cold air advances on the warmer air. The cold air undercuts the warm air pushing it upwards. Cumulonimbus clouds form a well-defined line along the boundary between the air masses. As the cold front passes, the clouds roll by and the air temperature may become noticeably cooler, with temperatures dropping by 5 °C or more within the first hour. Rain, gusty winds, and, sometimes, thunderstorms occur with the ... Questions on Weather Fri, 20 Jun 2008 07:57:37 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-cold-front-and-what-weather-is-associated-with-the-passage-of-a-cold-front-t36.htm#37 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-cold-front-and-what-weather-is-associated-with-the-passage-of-a-cold-front-t36.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-berg-wind-t35.htm Admin A berg wind is a hot, dry wind blowing off the interior plateau of South Africa, roughly at right angles to the coast. Berg winds usually occur in winter when there is a low-pressure system along the coastal areas with a high-pressure system over the continent. Questions on Weather Fri, 20 Jun 2008 07:52:21 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-berg-wind-t35.htm#36 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-berg-wind-t35.htm http://metzonesa.forumf.biz/questions-on-weather-f25/how-is-rainfall-measured-t34.htm Admin Rainfall is measured at 08:00 SAST. The rain accumulated in the bucket of the rain gauge is poured into a specially calibrated measuring glass and the millimetre reading is recorded, whereafter the water is discarded. The rainfall measured between 08:00 SAST yesterday and 08:00 SAST today is recorded against yesterday’s date on the database. What is meant by 1 mm of rainfall is rainfall equivalent to 1 liter of water in a 1 square meter box with no runoff, infiltration or evaporation. Questions on Weather Fri, 20 Jun 2008 07:51:44 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/how-is-rainfall-measured-t34.htm#35 http://metzonesa.forumf.biz/questions-on-weather-f25/how-is-rainfall-measured-t34.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-the-meaning-of-the-temperature-shown-by-the-weather-service-t32.htm Admin Maximum temperature The maximum thermometer indicates the highest temperature reached since the thermometer was last reset. Owing to the constriction in the mercury capillary tube, the maximum thermometer is not affected when the temperature drops as this constriction prevents the mercury from returning to the bulb when it is getting colder. The maximum thermometer is only read at the time of the 08:00 SAST observation, and two readings are taken, namely the maximum temperature and ... Questions on Weather Fri, 20 Jun 2008 07:50:29 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-the-meaning-of-the-temperature-shown-by-the-weather-service-t32.htm#33 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-the-meaning-of-the-temperature-shown-by-the-weather-service-t32.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-dew-t31.htm Admin Dew forms when water vapour condenses on objects and solid surfaces on or near the ground because these have cooled during the night time below the dew-point temperature of the air around them. For dew to form, however, there must be moisture in the air and the night must be clear (cloudless) and fairly windless so that the earth can radiate its heat energy out into space. Questions on Weather Fri, 20 Jun 2008 07:48:56 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-dew-t31.htm#32 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-dew-t31.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-smog-t30.htm Admin Smog is a mixture of smoke and fog which contains large amounts of soot, sulphur dioxide and other pollutants which act as nuclei around which water condenses. Questions on Weather Fri, 20 Jun 2008 07:48:24 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-smog-t30.htm#31 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-smog-t30.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-fog-t29.htm Admin Fog is a suspension of usually very small water particles, but also sometimes ice particles, that reduces visibility at the surface to distances less than 1 km. Although fog is not usually considered to be a cloud, it has essentially the same properties. The two phenomena differ only in extend that the base of fog is at the ground, whereas clouds are above the ground. Questions on Weather Fri, 20 Jun 2008 07:48:13 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-fog-t29.htm#30 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-fog-t29.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-frost-t28.htm Admin Frost is formed in the same way as dew, but occurs when the temperature of the air in contact with the ground is below the freezing point of water (0 ºC). The water vapour changes directly from a gas to a solid state to form tiny ice crystals. Like dew, frost forms during calm, clear nights when the ground and objects near it cool rapidly because the earth’s heat is lost to space. In South Africa light frost can be expected when the minimum temperatures reach 3 ºC. This is because on a ... Questions on Weather Fri, 20 Jun 2008 07:47:42 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-frost-t28.htm#29 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-frost-t28.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-black-frost-t27.htm Admin Black frost occurs when the temperature is below zero but there is not enough moisture in the air to produce visible frost. Its name is derived from the resulting blackened appearance of affected vegetation. Questions on Weather Fri, 20 Jun 2008 07:47:39 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-black-frost-t27.htm#28 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-black-frost-t27.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-an-urban-heat-island-t26.htm Admin An urban heat island is an urban area which is significantly warmer than its surroundings. This occurs because roof and paving materials have a low reflectivity and absorb more of the sun's rays than natural surfaces, causing both surface temperature and overall ambient air temperature in an urban area to rise. In addition, there are fewer trees and other natural vegetation to shade buildings, block solar radiation and cool the air by evapotranspiration in urban areas. The urban heat island effect ... Questions on Weather Fri, 20 Jun 2008 07:46:50 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-an-urban-heat-island-t26.htm#27 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-an-urban-heat-island-t26.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-jet-stream-t25.htm Admin It is a narrow band of strong winds in the atmosphere that controls the movement of high- and low-pressure systems and associated fronts. Wind speeds can reach 380 km/h or higher in certain cases. Jet streams are usually found at 9 - 12 km (30 000 - 40 000 ft) above the surface. It owes it existence to the large temperature contrast between the polar and equatorial regions. Questions on Weather Fri, 20 Jun 2008 07:46:29 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-jet-stream-t25.htm#26 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-jet-stream-t25.htm http://metzonesa.forumf.biz/questions-on-weather-f25/are-there-other-interesting-lightning-facts-t24.htm Admin Do people who have been struck by lightning carry an electrical charge? Lightning-struck victims carry no electric charge and should be attended to immediately. What is heat lightning? Heat lightning is actually lightning from a thunderstorm too far away for thunder to be heard. However, the storm may be moving in your direction so beware. How often does lightning occur over the earth’s surface at any one time? Over the entire earth, estimates are that 100 lightning flashes ... Questions on Weather Fri, 20 Jun 2008 07:37:44 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/are-there-other-interesting-lightning-facts-t24.htm#25 http://metzonesa.forumf.biz/questions-on-weather-f25/are-there-other-interesting-lightning-facts-t24.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-are-my-chances-of-being-struck-by-lightning-t23.htm Admin Lightning occurs with every thunderstorm and must be expected as soon as thunderstorms form. Lightning results from the build-up and discharge of electrical energy between positively and negatively charged areas in the atmosphere and clouds. The most lightning occurs between clouds but it is the ground strikes that are dangerous. Your chances of being struck by lightning are estimated to be 1 in 350,000 but could be reduced by following lightning safety rules. Precautions If you live ... Questions on Weather Fri, 20 Jun 2008 07:34:58 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-are-my-chances-of-being-struck-by-lightning-t23.htm#24 http://metzonesa.forumf.biz/questions-on-weather-f25/what-are-my-chances-of-being-struck-by-lightning-t23.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-precautions-should-i-take-in-a-thunderstorm-t22.htm Admin Thunderstorms are easily identified by their thunder and lightning. a Storm normally last for about 30 minutes, but severe storms may last longer. There are four dangerous types of weather that can be generated by thunderstorms, namely lightning, wind gusts (squalls), hail and tornadoes. We these these types of weather separately in this forum. You should take the following precautions with thunder storms: If you live in a thatched building erect a lightning conductor near to but not touching ... Questions on Weather Fri, 20 Jun 2008 07:25:48 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-precautions-should-i-take-in-a-thunderstorm-t22.htm#23 http://metzonesa.forumf.biz/questions-on-weather-f25/what-precautions-should-i-take-in-a-thunderstorm-t22.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-the-difference-between-stable-and-unstable-air-t21.htm Admin
If a rising parcel of air is warmer than the surrounding atmosphere it will continue to rise. This is because warm air is less dense or lighter than cool air. This is referred to as unstable air.]]> Questions on Weather Fri, 20 Jun 2008 07:19:09 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-the-difference-between-stable-and-unstable-air-t21.htm#22 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-the-difference-between-stable-and-unstable-air-t21.htm http://metzonesa.forumf.biz/questions-on-weather-f25/which-tropical-cyclones-have-brought-devastation-to-southern-africa-in-the-last-30-years-t20.htm Admin Tropical cyclones seldom reach South Africa. However a number of tropical cyclones do move into the Mozambique Channel and have an effect on areas surrounding the channel. The following are a few of the tropical cyclone that have had some effect on southern Africa: Astrid (January 1958) – This tropical cyclone moved over Mozambique and passed north of Messina, eventually dying out over Botswana. Heavy rain fell over the Northern Province and Mpumalanga and severe flooding occurred over Wyliespoort. Claude ... Questions on Weather Fri, 20 Jun 2008 06:58:09 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/which-tropical-cyclones-have-brought-devastation-to-southern-africa-in-the-last-30-years-t20.htm#21 http://metzonesa.forumf.biz/questions-on-weather-f25/which-tropical-cyclones-have-brought-devastation-to-southern-africa-in-the-last-30-years-t20.htm http://metzonesa.forumf.biz/questions-on-weather-f25/how-are-tropical-cyclones-hurricanes-and-typhoons-named-t19.htm Admin For several hundred years many hurricanes in the West Indies were named after the particular saint's day on which the hurricane occurred. The USA meteorologists gave tropical storms women’s names. The origin of using women names is linked to the fact that satellite technology was and is still used to track tropical cyclones. Satellites were first used by the military and it is said that Air Force and Navy meteorologists, who plotted the movements of storms, named these storms after their wives ... Questions on Weather Fri, 20 Jun 2008 06:53:36 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/how-are-tropical-cyclones-hurricanes-and-typhoons-named-t19.htm#20 http://metzonesa.forumf.biz/questions-on-weather-f25/how-are-tropical-cyclones-hurricanes-and-typhoons-named-t19.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-are-the-differences-between-tropical-cyclones-hurricanes-and-typhoons-t18.htm Admin These names actually refer to the same weather phenomenon. Tropical cyclone is used in the southern Indian Ocean, hurricane in the North Atlantic and eastern North Pacific regions and typhoon in the western North Pacific. Questions on Weather Fri, 20 Jun 2008 06:52:16 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-are-the-differences-between-tropical-cyclones-hurricanes-and-typhoons-t18.htm#19 http://metzonesa.forumf.biz/questions-on-weather-f25/what-are-the-differences-between-tropical-cyclones-hurricanes-and-typhoons-t18.htm http://metzonesa.forumf.biz/questions-on-weather-f25/is-a-tropical-cyclone-and-tornado-the-same-thing-t17.htm Admin No these phenomena are not the same thing. A tropical cyclone is an intensely developed low-pressure cell that usually occurs over warm oceans. Its diameter can range between 200 and 2 000 km. Tropical cyclones can last for a few days. A tornado is a violent rotating column of air that extends from a thunderstorm and is much smaller in diameter, typically less than a few hundred meters, but some are larger than 1 km. They usually occur over land. Tornados are generally short lived and can ... Questions on Weather Thu, 19 Jun 2008 12:13:00 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/is-a-tropical-cyclone-and-tornado-the-same-thing-t17.htm#18 http://metzonesa.forumf.biz/questions-on-weather-f25/is-a-tropical-cyclone-and-tornado-the-same-thing-t17.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-tornado-t16.htm Admin Where do they come from? Characteristics and Classification When and Where? Forecasting Tornadoes. A tornado, from the Latin tornare ("to turn"), is a violent rotating column of air extending from a thunderstorm. Tornadoes are amongst the most violent and destructive of all weather phenomena, but despite the significant amount of research into the origin and prediction thereof, the phenomenon is still not fully understood or predictable. Field research on tornadoes is particularly difficult ... Questions on Weather Thu, 19 Jun 2008 12:11:06 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-tornado-t16.htm#17 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-tornado-t16.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-tropical-cyclone-t15.htm Admin A tropical cyclone is a relatively small, intensely developed low pressure cell that usually occur over warm oceans. Its diameter can range between 200 and 2 000 km. It is characterized by a warm centre, very steep pressure gradients and strong cyclonic (clockwise in the southern hemisphere) winds near the Earth's surface. Tropical cyclones with a maximum wind speed of less than 60 km/h are called tropical depressions; when the maximum wind speed ranges between 60 and 110 km/h, they are tropical ... Questions on Weather Thu, 19 Jun 2008 12:05:34 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-tropical-cyclone-t15.htm#16 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-a-tropical-cyclone-t15.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-ozone-t12.htm Admin Ozone is a nearly colourless (but faintly blue) gaseous form of oxygen, with a characteristic odour like that of weak chlorine. It is usually found in trace amounts in the atmosphere, but is primarily found at 30 000 to 150 000 feet. Its production results from photochemical process involving ultraviolet radiation. Because it absorbs harmful ultraviolet radiation at those heights, it is a beneficial gas. What is the difference between stratospheric and tropospheric Ozone? The stratosphere ... Questions on Weather Thu, 19 Jun 2008 11:58:32 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-ozone-t12.htm#13 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-ozone-t12.htm http://metzonesa.forumf.biz/general-questions-f24/what-is-the-world-meteorological-organization-wmo-t11.htm Admin The World Meteorological Organization is an intergovernmental organization with a membership of 182 Member States and 6 Territories (on 5 April 2007). It originated from the International Meteorological Organization (IMO), which was founded in 1873. The WMO was established in 1950 and became the specialized agency of the United Nations for meteorology (weather and climate), operational hydrology and related geophysical sciences. http://www.wmo.ch/pages/index_en.html General questions Thu, 19 Jun 2008 11:55:18 GMT http://metzonesa.forumf.biz/general-questions-f24/what-is-the-world-meteorological-organization-wmo-t11.htm#12 http://metzonesa.forumf.biz/general-questions-f24/what-is-the-world-meteorological-organization-wmo-t11.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-are-the-main-cloud-types-t9.htm Admin The recognition of a cloud by having a name and being in a certain class is a useful indication of the nature of a cloud and the atmospheric movements and processes which are present. Classification is based on heights, appearance, whether the cloud consists of liquid water or ice, on the processes which lead to the formation of the clouds. Clouds are classified as low, middle or high level according to their base heights. There are three cloud forms, namely stratiform, cumuliform and cirriform ... Questions on Weather Thu, 19 Jun 2008 10:32:53 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-are-the-main-cloud-types-t9.htm#10 http://metzonesa.forumf.biz/questions-on-weather-f25/what-are-the-main-cloud-types-t9.htm http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-meant-by-standard-atmosphere-t8.htm Admin The standard atmosphere is a conventional vertical structure of the atmosphere characterized by a standard sea-level pressure of 1013,25 hPa (29,92 inches of mercury) and a sea-level air temperature of 15 °C (59 °F). Questions on Weather Thu, 19 Jun 2008 10:09:12 GMT http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-meant-by-standard-atmosphere-t8.htm#9 http://metzonesa.forumf.biz/questions-on-weather-f25/what-is-meant-by-standard-atmosphere-t8.htm http://metzonesa.forumf.biz/general-questions-f24/how-are-the-dates-of-the-four-seasons-worked-out-t7.htm Admin [From Dates and Duration of the Seasons contained in WB Newsletter April 1992 by Mr. C B Archer] The Seasons Disagreements on the starting dates of the seasons exist at both the scientific and the lay level. There are however three basic ways in which starting dates may be assigned. South Africa does not really experience four distinct seasons. Throughout South Africa the transitional seasons of autumn and spring tend to be very short. Most analyses of climate are done using the assumption ... General questions Thu, 19 Jun 2008 10:07:27 GMT http://metzonesa.forumf.biz/general-questions-f24/how-are-the-dates-of-the-four-seasons-worked-out-t7.htm#8 http://metzonesa.forumf.biz/general-questions-f24/how-are-the-dates-of-the-four-seasons-worked-out-t7.htm http://metzonesa.forumf.biz/general-questions-f24/what-are-the-dates-of-the-different-seasons-t6.htm Admin Southern Hemisphere Calendar dates Northern Hemisphere Autumn 1 March to 31 May Spring Winter 1 June to 31 August Summer Spring 1 September to 30 November Autumn Summer 1 December to 28/29 February Winter General questions Thu, 19 Jun 2008 10:05:02 GMT http://metzonesa.forumf.biz/general-questions-f24/what-are-the-dates-of-the-different-seasons-t6.htm#7 http://metzonesa.forumf.biz/general-questions-f24/what-are-the-dates-of-the-different-seasons-t6.htm http://metzonesa.forumf.biz/education-f31/where-can-i-take-learners-to-see-how-a-weather-station-operates-t5.htm Admin Tours to see the operational use of weather instruments are conducted at the Irene Weather Office in Gauteng. Booking is essential and groups of up to 50 people can be accommodated at any one time. Please contact Irene Weather Office on (012) 665 1589. Groups who arrive at the Weather Office without a booking will be turned away at the gate. Education Thu, 19 Jun 2008 09:54:37 GMT http://metzonesa.forumf.biz/education-f31/where-can-i-take-learners-to-see-how-a-weather-station-operates-t5.htm#6 http://metzonesa.forumf.biz/education-f31/where-can-i-take-learners-to-see-how-a-weather-station-operates-t5.htm