Modern weather predictions aid in timely evacuations and potentially save lives and property damage

Human beings have attempted to predict the weather since time immemorial. Today, weather forecasts are made by collecting quantitative data about the current state of the atmosphere and using scientific understanding of atmospheric processes to project how the atmosphere will evolve. The chaotic nature of the atmosphere, the massive computational power required to solve the equations that describe the atmosphere, and incomplete understanding of atmospheric processes mean that forecasts become less accurate as the difference in time between the present moment and the time for which the forecast is being made (the range of the forecast) increases. Image File history File links Download high resolution version (895x716, 27 KB) Summary Three-day cone of uncertainty for the path of Hurricane Rita as of 10 PM CDT, September 22, 2005. ... Image File history File links Download high resolution version (895x716, 27 KB) Summary Three-day cone of uncertainty for the path of Hurricane Rita as of 10 PM CDT, September 22, 2005. ... For other uses, see Data (disambiguation). ... // Meteorology (from Greek: μετέωρον, meteoron, high in the sky; and λόγος, logos, knowledge) is the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting. ... For other uses, see Chaos Theory (disambiguation). ...

History of weather forecasting

See also: Weather lore

Weather map of Europe, 10 December 1887

Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location. Cumulus humilis indicates a good day ahead. ... Image File history File links Download high resolution version (800x1275, 376 KB) Weather map for Europe (09. ... Image File history File links Download high resolution version (800x1275, 376 KB) Weather map for Europe (09. ... For other uses, see Europe (disambiguation). ... is the 344th day of the year (345th in leap years) in the Gregorian calendar. ... 1887 (MDCCCLXXXVII) is a common year starting on Saturday (click on link for calendar) of the Gregorian calendar or a common year starting on Monday of the Julian calendar. ... For the geological process, see Weathering or Erosion. ... Air redirects here. ...

For millennia people have tried to forecast the weather. In 650 BC, the Babylonians predicted the weather from cloud patterns. In about 340 BC, Aristotle described weather patterns in Meteorologica. Chinese weather prediction lore extends at least as far back as 300 BC. For other uses, see Aristotle (disambiguation). ... Meteorology (or Meteorologica) is a text by Aristotle which contains his theories about the earth sciences. ...

Ancient weather forecasting methods usually relied on observed patterns of events. For example, it might be observed that if the sunset was particularly red, the following day often brought fair weather. This experience accumulated over the generations to produce weather lore. However, not all of these predictions prove reliable and many of them have since been found not to stand up to rigorous statistical testing.^[1] Cumulus humilis indicates a good day ahead. ...

It was not until the invention of the telegraph in 1837 that the modern age of weather forecasting began. Before this time, it had not been possible to transport information about the current state of the weather any faster than a steam train. The telegraph allowed reports of weather conditions from a wide area to be received almost instantaneously by the late 1840's.^[2] This allowed forecasts to be made by knowing what the weather conditions were like further upwind. The two men most credited with the birth of forecasting as a science were Francis Beaufort (remembered chiefly for the Beaufort scale) and his protégé Robert Fitzroy (developer of the Fitzroy barometer). Both were influential men in British Naval and Governmental circles, and though ridiculed in the press at the time, their work gained scientific credence, was accepted by the British Navy and formed the basis for all of today's weather forecasting knowledge.^[3] Telegraph and Telegram redirect here. ... Events and Trends Technology First use of anaesthesia in an operation, by Crawford Long War, peace and politics First signing of the Treaty of Waitangi (Te Tiriti o Waitangi) on February 6, 1840 at Waitangi New Zealand. ... Rear-Admiral Sir Francis Beaufort, FRS, FRGS (7 May 1774 – 17 December 1857) was an Irish hydrographer and officer in the British Royal Navy. ... The Beaufort scale is an empirical measure for describing wind intensity based mainly on observed sea conditions. ... Vice-Admiral Robert FitzRoy (5 July 1805 – 30 April 1865) achieved lasting fame as the captain of HMS Beagle during Charles Darwins famous voyage, and as a pioneering meteorologist who made accurate weather forecasting a reality. ... A barometer is an instrument used to measure atmospheric pressure. ...

Great progress was made in the science of meteorology during the 20th century. The possibility of numerical weather prediction was proposed by Lewis Fry Richardson in 1922, though computers fast enough to complete the vast number of calculations required to produce a forecast before the event had occurred did not exist at that time. Practical use of numerical weather prediction began in 1955,^[4] spurred by the development of programmable electronic computers. Bob Ryan is the Prophet of the Golden Sun, fortold by the Sage Zarmatha in the year 1230 in the Emerald Palace, it was there that Zarmatha gazed into the sphere of Oberona and exclaimed to the Council of 9, Behold, in the year 2010 the chosen meteorologist, Bob Ryan... The American Meteorological Society (AMS) promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. ... // Meteorology (from Greek: μετέωρον, meteoron, high in the sky; and λόγος, logos, knowledge) is the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting. ... (19th century - 20th century - 21st century - more centuries) Decades: 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s As a means of recording the passage of time, the 20th century was that century which lasted from 1901–2000 in the sense of the Gregorian calendar (1900–1999... An example of 500 mb geopotential height prediction from a numerical weather prediction model Numerical weather prediction is the science of predicting the weather using mathematical models of the atmosphere. ... For the Hollyoaks character, see Lewis Richardson (Hollyoaks) Lewis Fry Richardson (October 11, 1881 - September 30, 1953) was an innovative mathematician, physicist and psychologist. ... This article is about the machine. ...

Modern day weather forecasting system

Components of a modern weather forecasting system include:

• Data collection
• Data assimilation
• Numerical weather prediction
• Model output post-processing
• Forecast presentation to end-user

Data collection

Observations of atmospheric pressure, temperature, wind speed, wind direction, humidity, precipitation are made near the earth's surface by trained observers, automatic weather stations or buoys. The World Meteorological Organization acts to standardize the instrumentation, observing practices and timing of these observations worldwide. Stations either report hourly in METAR reports, or every six hours in SYNOP reports. Diurnal (daily) rhythm of air pressure in northern Germany (black curve is air pressure) Atmospheric pressure is the pressure at any point in the Earths atmosphere. ... For other uses, see Temperature (disambiguation). ... An AWS in Antarctica An automatic weather station (AWS) is an automated version of the traditional weather station, either to save human labour or to enable measurements from remote areas. ... Weather buoys are instruments which collect weather and ocean data within the worlds oceans. ... WMO flag The World Meteorological Organization (WMO, French: , OMM) is an intergovernmental organization with a membership of 188 Member States and Territories. ... METAR (for METeorological Aerodrome Report) is a format for reporting weather information. ... SYNOP (surface synoptic observations) is a numerical code (called FM-12 by WMO) used for reporting marine weather observations made by manned and automated weather stations. ...

Measurements of temperature, humidity and wind above the surface are found by launching radiosondes (weather balloon). Data are usually obtained from near the surface to the middle of the stratosphere, about 30,000 m (100,000 ft). In recent years, data transmitted from commercial airplanes through the AMDAR system has also been incorporated into upper air observation, primarily in numerical models. radiosonde with measuring instruments A radiosonde (Sonde is German for probe) is a unit for use in weather balloons that measures various atmospheric parameters and transmits them to a fixed receiver. ... Rawinsonde weather balloon just after launch. ... Atmosphere diagram showing stratosphere. ... Aircraft Meteorological Data Relay (AMDAR) is a program initiated by the World Meteorological Organization. ...

Increasingly, data from weather satellites are being used due to their (almost) global coverage. Although their visible light images are very useful for forecasters to see development of clouds, little of this information can be used by numerical weather prediction models. The infra-red (IR) data however can be used as it gives information on the temperature at the surface and cloud tops. Individual clouds can also be tracked from one time to the next to provide information on wind direction and strength at the clouds steering level. Polar orbiting satellites provide soundings of temperature and moisture throughout the depth of the atmosphere. Compared with similar data from radiosondes, the satellite data has the advantage that coverage is global, however the accuracy and resolution is not as good. A weather satellite is a type of artificial satellite that is primarily used to monitor the weather and/or climate of the Earth. ... Sounding - The historical nautical term for measuring depth. ...

Meteorological radar provide information on precipitation location and intensity. Additionally, if doppler radar are used then wind speed and direction can be determined.^[5] Weather radar in Norman, Oklahoma with rainshaft (Source: NOAA) Environment Canada King City (CWKR) weather radar station. ... Doppler Effect Doppler radar uses the Doppler effect to measure the radial velocity of targets in the antennas directional beam. ...

Data assimilation

Main article: Data assimilation

During the data assimilation process, information gained from the observations is used in conjunction with a numerical model's most recent forecast for the time that observations were made (since this contains information from previous observations) to produce the meteorological analysis. This is the best estimate of the current state of the atmosphere. It is a three dimensional representation of the distribution of temperature, moisture and wind. Data assimilation (DA) is a method used in the weather forecasting process in which observations of the current (and possibly, past) weather are combined with a previous forecast for that time to produce the meteorological `analysis; the best estimate of the current state of the atmosphere. ...

Numerical weather prediction (NWP)

Main article: Numerical weather prediction

Numerical weather prediction models are computer simulations of the atmosphere. They take the analysis as the starting point and evolve the state of the atmosphere forward in time using understanding of physics and fluid dynamics. The complicated equations which govern how the state of a fluid changes with time require supercomputers to solve them. The output from the model provides the basis of the weather forecast.^[6] An example of 500 mb geopotential height prediction from a numerical weather prediction model Numerical weather prediction is the science of predicting the weather using mathematical models of the atmosphere. ... An example of 500 mb geopotential height prediction from a numerical weather prediction model Numerical weather prediction is the science of predicting the weather using mathematical models of the atmosphere. ... A computer simulation or a computer model is a computer program which attempts to simulate an abstract model of a particular system. ... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... Fluid dynamics is the sub-discipline of fluid mechanics dealing with fluids (liquids and gases) in motion. ... A fluid is defined as a substance that continually deforms (flows) under an applied shear stress regardless of the magnitude of the applied stress. ... A supercomputer is a device for turning compute-bound problems into I/O-bound problems. ...

Model output post processing

The raw output is often modified before being presented as the forecast. This can be in the form of statistical techniques to remove known biases in the model, or of adjustment to take into account consensus among other numerical weather forecasts. For other senses of this word, see bias (disambiguation). ...

In the past, the human forecaster used to be responsible for generating the entire weather forecast from the observations. However today, for forecasts beyond 24hrs human input is generally confined to post-processing of model data to add value to the forecast. Humans are required to interpret the model data into weather forecasts that are understandable to the end user. Additionally, humans can use knowledge of local effects which may be too small in size to be resolved by the model to add information to the forecast. Increasing accuracy of forecast models continues to decrease the need for post-processing and human input, mostly in areas with a low variation in terrain.

Presentation of weather forecasts

An example of a two-day weather forecast in the visual style that an American newspaper might use.

The final stage in the forecasting process is perhaps the most important. Knowledge of what the end user needs from a weather forecast must be taken into account to present the information in a useful and understandable way. Image File history File links This is a lossless scalable vector image. ... When you create an image to communicate an idea, you are using visual language. ...

Public information

Most end users of forecasts are members of the general public, who have interest in such information for several reasons. Thunderstorms can create strong winds and dangerous lightning strikes that can lead to deaths, power outages,^[7] and widespread hail damage. Heavy snow or rain can bring transportation and commerce to a stand-still, as well as cause flooding in low-lying areas. Excessive heat or cold waves can sicken or kill those with inadequate utilities, and droughts can impact water usage and destroy vegetation. Many use forecasts simply to schedule outdoor recreation or to assist in determining daily attire. A rolling thundercloud over Enschede, The Netherlands. ... Not to be confused with lighting. ... Snow is a type of precipitation in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. ... A flood (in Old English flod, a word common to Teutonic languages; compare German Flut, Dutch vloed from the same root as is seen in flow, float) is an overflow of water, an expanse of water submerging land, a deluge. ... Fields outside Benambra, Victoria, Australia suffering from drought conditions A drought is an extended period of months or years when a region notes a deficiency in its water supply. ...

Several countries employ government agencies to provide forecasts and watches/warnings/advisories to the public in order to protect life and property and maintain commercial interests. Examples include the United States' National Weather Service (NWS)^[8] and Canada's Meteorological Service of Canada (MSC).^[9] Traditionally, newspaper, television, and radio have been the primary outlets for presenting weather forecast information to the public. Increasingly, however, the internet is being used due to the vast amount of specific information that can be found. In all cases, these outlets update their forecasts on a regular basis, in accordance with their respective publication schedules. The National Weather Service (NWS) is one of the six scientific agencies that make up the National Oceanic and Atmospheric Administration (NOAA) of the United States government. ... The Meteorological Service of Canada (MSC) is a Canadian government agency which provides meteorological information. ...

Air traffic

The aviation industry is especially sensitive to the weather. Fog and/or exceptionally low ceilings can prevent many aircraft landing and taking off. Similarly, turbulence and icing can be hazards whilst in flight. Thunderstorms are a problem for all aircraft, due to severe turbulence and icing, as well as large hail, strong winds, and lightning, all of which can cause fatal damage to an aircraft in flight. On a day to day basis airliners are routed to take advantage of the jet stream tailwind to improve fuel efficiency. Aircrews are briefed prior to take off on the conditions to expect en route and at their destination. Additionally, runway orientation is often changed to take advantage of a headwind to generate lift for takeoff. For other uses, see Fog (disambiguation). ... In fluid dynamics, turbulence or turbulent flow is a flow regime characterized by chaotic, stochastic property changes. ... The effect of atmospheric icing on a tree. ... This article is about the precipitation. ... Not to be confused with lighting. ... Jet streams are fast flowing, relatively narrow air currents found in the atmosphere at around 12 km above the surface of the Earth, just under the tropopause. ... A Ryanair Boeing 737 takes off from Bristol International Airport, England Take off is the phase of flight where an aircraft transitions from moving along the ground (taxiing) to flying in the air (see flight), usually from a runway. ... This article or section does not adequately cite its references or sources. ... The wind that hits an aircraft in the front. ...

Marine

Commercial and recreational use of waterways can be limited significantly by weather in that wind direction and speed, wave periodicity and heights, tides, and precipitation can each influence the safety of marine transit. Consequently, a variety of codes have been established to efficiently transmit detailed marine weather forecasts to vessel pilots via radio, for example the MAFOR (marine forecast). MAFOR, an abbreviation of MArine FORcast, is a code used in the transmission of marine weather forecasts to compresses a volume of meteorological and marine information into shorter code for convenience during radio broadcasting. ...

Agriculture

Farmers rely on weather forecasts to decide what work to do. For example, cutting hay is only feasible in dry weather. For other uses, see Farmer (disambiguation). ... For other uses, see Hay (disambiguation). ...

Utility companies

Electricity and gas companies rely on weather forecasts to anticipate demand which can be strongly affected by the weather. In winter, severe cold weather can cause a surge in demand as people turn up their heating. Similarly, in summer a surge in demand can be linked with the increased use of air conditioning systems in hot weather. By anticipating a surge in demand, utility companies can purchase additional supplies of power or natural gas before the price increases, or in some circumstances, supplies are restricted. Note: in the broadest sense, air conditioning can refer to any form of heating, ventilation, and air-conditioning. ...

Private sector

Increasingly, private companies pay for weather forecasts tailored to their needs so that they can increase their profits or avoid large losses. For example, supermarket chains may change the stocks on their shelves in anticipation of different consumer spending habits in different weather conditions. State Departments of Transportation and private road maintenance companies also use their forecasts to demonstrate a 'best effort' in defending against lawsuits as a result of traffic accidents.

Military applications

Similarly to the private sector, military weather forecasters present weather conditions to the war fighter community. They provide pre-flight weather briefs and flight weather briefs from take off to terminal location, including updates throughout the flight path. Also, military weather forecasters provide real time resource protection services for military installations. Four branches of the armed forces have independent weather forecasting techniques tailored for their specific needs: Naval forecasters cover the waters and ship weather forecasts; Air Force forecasters cover air operations in both wartime and peacetime operations and provide Army support; Coast Guard forecasters provide ship forecasts for ice breakers and other various operations within their realm; and Marine forecasters provide support for ground- and air-based Marine Corps operations. All four military branches take their initial meteorology training at Keesler AFB, MS. Military and civilian forecasters actively cooperate in analyzing, creating and critiquing weather forecast products.

Persistence forecasting

The simplest method of forecasting the weather, persistence relies upon today's conditions to forecast the conditions tomorrow. This can be a valid way of forecasting the weather when it is steady state, such as during the summer season in the tropics. This method of forecasting strongly depends upon the presence of a stagnant weather pattern. It can be useful in both short range forecasts and long range forecasts.^[10]

Nowcasting

The forecasting of the weather in the 0-12 hour timeframe is often referred to as nowcasting. It is in this range that the human forecaster still has an advantage over computer NWP models. In this time range it is possible to forecast smaller features such as individual shower clouds with reasonable accuracy, however these are often too small to be resolved by a computer model. A human given the latest radar, satellite and observational data will be able to make a better analysis of the small scale features present and so will be able to make a more accurate forecast for the following few hours.^[11]

Below is a sample nowcast, issued by the National Weather Service in Mount Holly, New Jersey: The National Weather Service (NWS) is one of the six scientific agencies that make up the National Oceanic and Atmospheric Administration (NOAA) of the United States government. ... Mount Holly Township highlighted in Burlington County. ...

 000 FPUS71 KPHI 240805 NOWPHI 

 SHORT TERM FORECAST NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 405 AM EDT FRI JUN 24 2005 DEZ002>004-MDZ015-019-020-NJZ013-014-020-022>027-241200- ATLANTIC NJ-ATLANTIC COASTAL CAPE MAY NJ-CAPE MAY NJ-CAROLINE MD- COASTAL ATLANTIC NJ-COASTAL OCEAN NJ-DELAWARE BEACHES DE- EASTERN MONMOUTH NJ-INLAND SUSSEX DE-KENT DE-OCEAN NJ- QUEEN ANNE'S MD-SOUTHEASTERN BURLINGTON NJ-TALBOT MD- WESTERN MONMOUTH NJ- INCLUDING THE CITIES OF...ATLANTIC CITY AND DOVER 405 AM EDT FRI JUN 24 2005 

 .NOW... 

 AREAS OF FOG AND LOW CLOUDS WILL BE OVER SOUTHERN DELAWARE AND PORTIONS OF THE NORTHEASTERN MARYLAND SHORE EARLY THIS MORNING, AS WELL AS ALONG THE NEW JERSEY COAST. THE PATCHY DENSE FOG MAY REDUCE THE VISIBILITY TO A QUARTER MILE OR LESS AT TIMES. IF YOU WILL BE DRIVING THIS MORNING, BE SURE TO LEAVE PLENTY OF ROOM BETWEEN YOUR VEHICLE AND THE ONE AHEAD OF YOU. YOUR VISIBILITY COULD DROP QUICKLY IF YOU DRIVE INTO A DENSE PATCH OF FOG. WATCH ESPECIALLY FOR PEDESTRIANS. THE FOG SHOULD DISSIPATE AN HOUR OR TWO AFTER SUNRISE. $$ 

Medium Range Forecasting

Analog technique

A more complicated way of making a forecast, it requires remembering a previous weather event which is expected to be mimicked by an upcoming event. What makes it a difficult technique to use is that there is rarely a perfect analog for an event in the future.^[12] Some call this type of forecasting pattern recognition, which remains a useful method of observing rainfall over data voids such as oceans,^[13] as well as the forecasting of precipitation amounts and distribution in the future. A variation on this theme is used in Medium Range forecasting, which is known as teleconnections, when you use systems in other locations to help pin down the location of another system within the surrounding regime.^[14] One method of using teleconnections are by using ENSO-related phenomena.^[15]

Ensemble forecasting

Although a forecast model will predict realistic looking weather features evolving realistically into the distant future, the errors in a forecast will inevitably grow with time due to the chaotic nature of the atmosphere. The detail that can be given in a forecast therefore decreases with time as these errors increase. There becomes a point when the errors are so large that the forecast is completely wrong and the forecast atmospheric state has no correlation with the actual state of the atmosphere. For other uses, see Chaos Theory (disambiguation). ... Positive linear correlations between 1000 pairs of numbers. ...

However, looking at a single forecast gives no indication of how likely that forecast is to be correct. Ensemble forecasting uses lots of forecasts produced to reflect the uncertainty in the initial state of the atmosphere (due to errors in the observations and insufficient sampling). The uncertainty in the forecast can then be assessed by the range of different forecasts produced. They have been shown to be better at detecting the possibility of extreme events at long range. Ensemble forecasting is a method used by modern operational forecast centers to account for sensitive dependency on initial conditions. ...

Ensemble forecasts are increasingly being used for operational weather forecasting (for example at ECMWF, NCEP, and the Canadian forecasting center). ^[16] The European Centre for Medium-Range Weather Forecasts (ECMWF) is an international intergovernmental organization based at Reading, England that was founded in 1975. ... The National Cholesterol Education Program is a program managed by the National Heart, Lung and Blood Institute, a division of the NIH. Its goal is to reduce increased cardiovascular disease rates due to hypercholesterolemia (evelated cholesterol levels) in the United States of America. ...

See also

• Citizens weather observer program
• Downscaling
• Environment Canada
• Forecasting
• geodesic grid
• National Collegiate Weather Forecasting Competition
• National Weather Service
• Trend estimation
• Tropical cyclone forecasting
• Weather control
• Weather wars
• WxChallenge

The Citizens Weather Observer Program (CWOP)is a program to collect weather observations from thousands of privately operated weather stations, into the FindU database, and forward it to the Meteorological Assimilation Data Ingest System (MADIS), operated by the National Oceanic and Atmospheric Administration (NOAA). ... There are very few or no other articles that link to this one. ... Environment Canada is the department of the government of Canada with responsibility for coordinating environmental policies and programs as well as preserving and enhancing the natural environment and conservation of wildlife. ... Look up forecast in Wiktionary, the free dictionary. ... A geodesic grid as a technique primarily used in climate modelling to model the surface of a sphere (Earth). ... The National Collegiate Weather Forecasting Competition or NCWFC is a yearly competition between colleges in the US. The competition is run by Penn State. ... The National Weather Service (NWS) is one of the six scientific agencies that make up the National Oceanic and Atmospheric Administration (NOAA) of the United States government. ... A series of measurements of a process may be treated as a time series, and then trend estimation is the application of statistical techniques to make and justify statements about trends in the data. ... Tropical cyclone forecasting is the science and art of forecasting where a tropical cyclones center, and its effects, are expected to be at some point in the future. ... A tornado in central Oklahoma. ... This article may contain original research or unverified claims. ... The WxChallenge is a weather forecasting competition between colleges in North America. ...

References

Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 105th day of the year (106th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 125th day of the year (126th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 105th day of the year (106th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 47th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 105th day of the year (106th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 47th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 47th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 47th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 47th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 47th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 47th day of the year in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 47th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 47th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 47th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 47th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 47th day of the year in the Gregorian calendar. ...

Websites providing forecasts

Meteorological agencies

These are academic or governmental meteorology organizations. Most provide at least a limited forecast for their area of interest on their website.

• The World Meteorological Organization
• NOAA weather page

  NOAA satellite images

  National Weather Service

  Current meteorology forecast of Air Resources Laboratory

• Met Éireann (Ireland)
• The Met Office of the UK
• European Centre for Medium Range Weather Forecasting (ECMWF)
• Environment Canada Weather Office
• Australian Bureau of Meteorology
• New Zealand MetService
• Meteo Suisse (Swiss Weather Agency, in English
• Finnish Meteorological Institute
• Royal Meteorological Institute of Belgium
• Korea Meteorological Administration
• Hong Kong Observatory
• Italian Air Force (Aeronautica Militare) Meteorological Service
• South African Weather Service

Commercial organizations

These are high profile commercial sites.

• Foreca World Weather — Detailed weather forecast for all the countries in the world (except some microstates). In English.
• Freese-Notis Weather Site — Meteorologists with doppler radar images, data analysis, forensics and a wide variety industry specific US and international weather forecasts, agriculture and energy being strong areas of performance plus supplies advanced web site content with an emphasis upon long range weather forecasts
• Weather Underground — Provides a wide variety of US and international weather information
• Unisys Weather Site — Provides meteorological data, analysis, and forecasts for the US along with ancillary information for aircraft or flight systems related information domestically and overseas particular skills in software for commercial applications
• Verizon's Weather Forecasts - Provides weather briefs & extended outlook for the U.S. Also powers weather on 20,000 other websites
• Meteo Webcam - A Italian language site displaying all webcam live from all the world and other utility resources.
• MeteoGroup[1] Europe's largest independent weather forecasting company. Provides weather for Transport, Energy, Agriculture, Maritime, Media, Leisure, Health & Environment, Insurance and Water Management.
• Accuweather — Weather forecasts and weather-related news (US and international) known for television grade services
• WEATHER365 - Detaiiled weather charts and weather forecasts
• The Weather Channel — Weather forecasts and weather-related news mainly for the US, but also has world forecasts. Also provides services to media organizations.
• TheWeatherOutlook — Weather forecasts for the UK.
• BBC Weather — Weather forecasts for the UK and climate overviews for the whole world. Links to contemporary climate change news for astute observers of the controversial topic
• GMTV Weather Centre — Weathergirls Clare Nasir and Andrea McLean with the latest weather forecasts from the UK and around the world.
• Wetterzentrale - A German language site displaying a large range of high quality weather charts.
• The Weather Network - Canadian weather and forecasts.
• seabreeze.com.au - Australian wide weather forecasts.
• Weatherzone - Provides a wide variety of Australian weather information.
• Weather.com.au - Australian weather forecasts.
• Weatheronline - Meteorological data, analysis, and forecasts for the UK and the whole world. Provides radar images, climate data and weather-related news.
• MSN Weather (Data provided by FORECA) - Worldwide Weather Forecasts (Hourly, Extended Ten-day and Historical Averages)
• ClearPoint Weather - World-Wide, Location-Specific, Weather Forecasts and Information - Including High Definition Weather For Today's Global Mariner.

Wikipedia does not yet have an article with this exact name. ... Weather Underground is a commercial weather service which provides free, real-time weather information via the Internet. ... AccuWeather is a large American company that provides weather forecasting services. ... The Weather Channel (TWC) is a cable and satellite television network that broadcasts weather and weather-related news 24 hours a day. ... Variations in CO2, temperature and dust from the Vostok ice core over the last 450,000 years For current global climate change, see Global warming. ...

Severe Weather alerts and advisories

A major part of modern weather forecasting is the severe weather alerts and advisories which the National Weather Services issues in the case that severe or hazardous weather is expected. Some of the most commonly known of the long list of severe weather advisories is the Severe thunderstorm and tornado warning, as well as the severe weather or the tornado watch. Other forms of these advisories include winter weather, high wind, flood, tropical storm, hurricane, fog and more. Severe weather advisories and alerts are sometimes broadcast through the NOAA weather radio.

Other external links

• Economic history and impact of weather forecasting from EH.NET
• About Live Weather Report Do yourself Weather Forecast