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83-834: The Storm Prediction Center ( SPC ) is a US government agency that is part of the National Centers for Environmental Prediction (NCEP), operating under the control of the National Weather Service (NWS), which in turn is part of the National Oceanic and Atmospheric Administration (NOAA) of the United States Department of Commerce (DoC). Headquartered at the National Weather Center in Norman , Oklahoma ,

166-730: A "Critical Fire Weather Area for Dry Thunderstorms". The outlook type depends on the forecast weather conditions, severity of the predicted threat, and local climatology of a forecast region. "See Text" is a map label used for outlining areas where fire potential is great enough to pose a limited threat, but not enough to warrant a critical area, similar to areas using the same notation title that were formerly outlined in convective outlooks. Critical Fire Weather Areas for Wind and Relative Humidity are typically issued when strong winds ( > 20 mph (32 km/h); 15 mph (24 km/h) for Florida ) and low relative humidity (usually < 20%) are expected to occur where dried fuels exist, similar to

249-552: A bicameral legislature. The term "government agency" or "administrative agency" usually applies to one of the independent agencies of the United States government , which exercise some degree of independence from the President's control. Although the heads of independent agencies are often appointed by the government, they can usually be removed only for cause. The heads of independent agencies work together in groups, such as

332-529: A commission, board or council. Independent agencies often function as miniature versions of the tripartite federal government with the authority to legislate (through the issuing or promulgation of regulations), to adjudicate disputes, and to enforce agency regulations. Examples of independent agencies include the Federal Communications Commission (FCC), Federal Reserve Board , U.S. Securities and Exchange Commission (SEC),

415-452: A few nights each summer when the low temperature exceeds 80 °F (27 °C). Summer daytime temperatures frequently exceed 100 °F (38 °C). Air conditioners are recommended for maximum comfort indoors and while traveling via automobile. Throughout the year, rainfall occurs more frequently during the night. Usually, periods of rainy weather last for only a day or two, and are followed by several days with fair skies. A large part of

498-806: A few situations that previously warranted a moderate risk were reclassified as enhanced (i.e. 45% wind or 15% tornado with no significant area). A moderate risk day indicates that more widespread and/or more dangerous severe weather is possible (sometimes with major hurricanes ), with significant severe weather often more likely. Numerous tornadoes (some of which may be strong and potentially long-track), more widespread or severe wind damage and/or very large/destructive hail (up to or exceeding 2 inches (5.1 cm) in diameter) could occur. Major events, such as large tornado outbreaks or widespread straight-line wind events, are sometimes also possible on moderate risk days, but with greater uncertainty. Moderate risk days are not terribly uncommon, and typically occur several times

581-719: A government agency include the British Navy Board , responsible for ships and supplies, which was established in 1546 by King Henry VIII and the British Commissioners of Bankruptcy established in 1570. From 1933, the New Deal saw growth in U.S. federal agencies, the " alphabet agencies " as they were used to deliver new programs created by legislation, such as the Federal Emergency Relief Administration . From

664-464: A high risk is typically issued (at the most) only a few times each year (see List of Storm Prediction Center high risk days ). High risk areas are usually surrounded by a larger moderate risk area, where uncertainty is greater or the threat is somewhat lower. The Storm Prediction Center began asking for public comment on proposed categorical additions to the Day 1-3 Convective Outlooks on April 21, 2014, for

747-591: A high-impact and high-confidence strong tornadoes (EF2+) or winds greater than 100 miles per hour (160 km/h) are called meso-gamma mesoscale discussions. Meso-gamma mesoscale discussions are rarely issued by the SPC. As of May 2024, the Storm Prediction Center has issued 42 meso-gamma mesoscale discussions. Watches (WWs) issued by the SPC are generally less than 20,000–50,000 square miles (52,000–129,000 km) in area and are normally preceded by

830-635: A marginal risk; depending on the sufficient wind shear, a tornado – usually of weak (EF0 to EF1) intensity and short duration – may be possible. This category replaced the "SEE TEXT" category on October 22, 2014. A slight risk day typically will indicate that the threat exists for scattered severe weather, including scattered wind damage (produced by straight-line sustained winds and/or gusts of 60 to 70 mph), scattered severe hail (varying in size from 0.25 inches (0.64 cm) to 1.75 inches (4.4 cm)) and/or isolated tornadoes (often of shorter duration and varying weak to moderate intensity, depending on

913-513: A mesoscale discussion. Watches are intended to be issued preceding the arrival of severe weather by one to six hours. They indicate that conditions are favorable for thunderstorms capable of producing various modes of severe weather, including large hail, damaging straight-line winds and/or tornadoes. In the case of severe thunderstorm watches organized severe thunderstorms are expected but conditions are not thought to be especially favorable for tornadoes (although they can occur in such areas where one

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996-401: A month during the peak of the severe weather season, and occasionally at other times of the year. Slight and enhanced risk areas typically surround areas under a moderate risk, where the threat is lower. A high risk day indicates a considerable likelihood of significant to extreme severe weather, generally a major tornado outbreak or (much less often) an extreme derecho event. On these days,

1079-514: A red line – indicating a moderate risk of severe weather); and "HIGH" (pink shaded area – previously a rendered as a fuchsia line – indicating a high risk of severe weather). Significant severe areas (referred to as " hatched areas " because of their representation on outlook maps) refer to a threat of increased storm intensity that is of "significant severe" levels (F2/ EF2 or stronger tornado, 2 inches (5.1 cm) or larger hail, or 75 miles per hour (121 km/h) winds or greater). In April 2011,

1162-466: A rg ina l : darker green shaded area, indicating a very low but present risk of severe weather); "SLGT" (for Sl i g h t : yellow shaded area – previously rendered as a green line – indicating a slight risk of severe weather); "ENH" (for Enh anced: orange shaded area, which replaced the upper end of the SLGT category on October 22, 2014); "MDT" (for M o d era t e: red shaded area – previously rendered as

1245-422: A slight risk, but conditions are not adequate for the development of widespread significant severe weather to necessitate a moderate category. Severe storms are expected to be more concentrated and of varying intensities. These days are quite frequent in the peak severe weather season and occur occasionally at other times of year. This risk category replaced the upper end of "slight" on October 22, 2014, although

1328-562: A slight, enhanced, or moderate risk of severe weather. Critical Fire Weather Areas for Dry Thunderstorms are typically issued when widespread or numerous thunderstorms producing rainfall of little accumulation to provide sufficient ground wetting ( < 0.10 inches (2.5 mm)) are expected to occur where dried fuels exist. Extremely Critical Fire Weather Areas for Wind and Relative Humidity are issued when very strong winds and very low humidity are expected to occur with very dry fuels. Extremely Critical areas are issued relatively rarely, similar to

1411-428: A textual forecast, map of categories and probabilities, and chart of probabilities. Prior to January 28, 2020, the Day 1 was currently the only outlook to issue specific probabilities for tornadoes, hail or wind. It is the most descriptive and highest accuracy outlook, and typically has the highest probability levels. Day 2 outlooks, issued twice daily at 0600Z and 1730Z, refer to predicted risks of convective weather for

1494-624: A total of 43 personnel, including five lead forecasters, ten mesoscale/outlook forecasters, and seven assistant mesoscale forecasters. Many SPC forecasters and support staff are heavily involved in scientific research into severe and hazardous weather. This involves conducting applied research and writing technical papers, developing training materials, giving seminars and other presentations locally and nationwide, attending scientific conferences, and participating in weather experiments. The Storm Prediction Center issues convective outlooks (AC), consisting of categorical and probabilistic forecasts describing

1577-470: A two-month period. The Storm Prediction Center broadened this system beginning on October 22, 2014 by adding two new risk categories to the three used originally. The new categories that were added are a "marginal risk" (replacing the "SEE TEXT" contours, see below) and an "enhanced risk". The latter is used to delineate areas where severe weather will occur that would fall under the previous probability criteria of an upper-end slight risk, but do not warrant

1660-464: A visual map depiction of the issued watch; the SPC typically delineates watches within this product in the form of "boxes," which technically are represented as either squares , rectangles (horizontal or vertical) or parallelograms depending on the area it covers. Jurisdictions outlined by the county-based watch product as being included in the watch area may differ from the actual watch box; as such, certain counties, parishes or boroughs not covered by

1743-513: A watch is likely and details thereof, particularly concerning conditions conducive for the development of severe thunderstorms in the short term, as well as situations of isolated severe weather when watches are not necessary. Watches are issued when forecasters are confident that severe weather will occur, and usually precede the onset of severe weather by one hour, although this sometimes varies depending on certain atmospheric conditions that may inhibit or accelerate convective development. The agency

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1826-434: A watch with special enhanced wording, " Particularly Dangerous Situation " (PDS), is subjectively issued. It is occasionally issued with tornado watches, normally for the potential of major tornado outbreaks, especially those with a significant threat of multiple tornadoes capable of producing F4/EF4 and F5/EF5 damage and/or staying on the ground for long-duration – sometimes uninterrupted – paths. A PDS severe thunderstorm watch

1909-458: Is a term used primarily by residents of the Dallas–Fort Worth metroplex to refer to a geographic area of Texas, generally considered to include the area south of Oklahoma , east of Abilene , west of Paris , and north of Waco . Definitions of the region usually don't include the sparsely populated Panhandle of Texas , which is the northernmost region of Texas bordered by New Mexico to

1992-417: Is a three-stage process in which the area, time period, and details of a severe weather forecast are refined from a broad-scale forecast of potential hazards to a more specific and detailed forecast of what hazards are expected, and where and in what time frame they are expected to occur. If warranted, forecasts will also increase in severity through this three-stage process. The Storm Prediction Center employs

2075-497: Is also responsible for forecasting fire weather (indicating conditions that are favorable for wildfires) in the contiguous U.S., issuing fire weather outlooks for Days 1, 2, and 3–8, which detail areas with various levels of risk for fire conditions (such as fire levels and fire alerts). The Storm Prediction Center began in 1952 as SELS ( Se vere L ocal S torms Unit), the U.S. Weather Bureau in Washington, D.C. In 1954,

2158-413: Is followed by the local NWS office issuing a specific county-based watch product. The latter product is responsible for triggering public alert messages via television, radio stations and NOAA Weather Radio. The watch approximation product outlines specific regions covered by the watch (including the approximate outlined area in statute miles ) and its time of expiration (based on the local time zone (s) of

2241-405: Is happening and what is expected to occur in the next few hours, and forecast reasoning in regard to weather watches. Mesoscale discussions are often issued to update information on watches already in effect, and sometimes when one is to be canceled. Mesoscale discussions are occasionally used as advance notice of a categorical upgrade of a scheduled convective outlook. SPC mesoscale discussions for

2324-442: Is in effect, and some severe thunderstorm watch statements issued by the SPC may note a threat of isolated tornadic activity if conditions are of modest favorability for storm rotation capable of inducing them), whereas for tornado watches conditions are thought to be favorable for severe thunderstorms to produce tornadoes. In situations where a forecaster expects a significant threat of extremely severe and life-threatening weather,

2407-547: Is not fully resolute on how severe weather will evolve more than three days out, the Day 4–8 outlook only outlines the areas in which severe thunderstorms are forecast to occur during the period at the 15% and 30% likelihood, and does not utilize other categorical risk areas or outline where general (non-severe) thunderstorm activity will occur. Local forecast offices of the National Weather Service, radio and television stations, and emergency planners often use

2490-470: Is responsible for forecasting the risk of severe weather caused by severe thunderstorms, specifically those producing tornadoes, hail of one inch (2.5 cm) in diameter or larger, and/or winds of 58 miles per hour (93 km/h) [50 knots] or greater. The agency also forecasts hazardous winter and fire weather conditions. It does so primarily by issuing convective outlooks , severe thunderstorm watches , tornado watches and mesoscale discussions. There

2573-419: Is responsible for issuing fire weather outlooks (FWD) for the continental United States. These outlooks are a guidance product for local, state and federal government agencies, including local National Weather Service offices, in forecasting the potential for wildfires . The outlooks issued are for Day 1, Day 2, and Days 3–8. The Day 1 product is issued at 4:00 a.m. Central Time and is updated at 1700Z, and

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2656-556: Is uncommon. The average length of the warm season (freeze-free period) is about 249 days. The average last occurrence of 32 °F (0 °C) or below is mid March and the average first occurrence of 32 °F or below is in late November. Although the terms "Northeastern Texas" or "North Texas" are not official state designations, the Texas State Data Center and Office of the State Demographer lists

2739-534: Is valid from 1200Z to 1200Z the following day. The Day 2 outlook is issued at 1000Z and is updated at 2000Z for the forecast period of 1200Z to 1200Z the following day. The Day 3–8 outlook is issued at 2200Z, and is valid from 1200Z two days after the current calendar date to 1200Z seven days after the current calendar date. There are four types of Fire Weather Outlook areas: "See Text", a "Critical Fire Weather Area for Wind and Relative Humidity", an "Extremely Critical Fire Weather Area for Wind and Relative Humidity", and

2822-523: Is very rare and is typically reserved for derecho events impacting densely populated areas. Watches are not "warnings", where there is an immediate severe weather threat to life and property. Although severe thunderstorm and tornado warnings are ideally the next step after watches, watches cover a threat of organized severe thunderstorms over a larger area and may not always precede a warning; watch "busts" do sometimes occur should thunderstorm activity not occur at all or that which does develop never reaches

2905-607: The Department of the Treasury . Most federal agencies are created by Congress through statutes called " enabling acts ", which define the scope of an agency's authority. Because the Constitution does not expressly mention federal agencies (as it does the three branches), some commentators have called agencies the "headless fourth branch" of the federal government. However, most independent agencies are technically part of

2988-750: The NITI Aayog , which is chaired ex officio by the Prime Minister. Russia has had many government agencies throughout its history. The USSR had the secretive KGB . Today, Russian government agencies such as the FSB , FSO , and the GRU use Spetsnaz or other masked operators for any missions. Other organizations include Kremlin and presidential security. The Government agencies in Sweden are State controlled organizations who act independently to carry out

3071-699: The National Labor Relations Board (NLRB) and the Federal Trade Commission (FTC). A broader definition of the term "government agency" also means the United States federal executive departments that include the President's cabinet-level departments and their sub-units. Examples of these include the Department of Energy (DOE) and the Internal Revenue Service (IRS), which is a bureau of

3154-616: The Parliament of the United Kingdom , Scottish Parliament or the Welsh Parliament . The Congress and President of the United States delegate specific authority to government agencies to regulate the complex facets of the modern American federal state . Also, most of the 50 U.S. states have created similar government agencies. Each state government is similar to the national government, with all but one having

3237-630: The Red River of the South border. Indigenous tribes in North Texas included the Caddo , Tawakoni , Wichita , Kickapoo , and Comanche . With European colonization, Mexican independence , and Texan independence and annexation to the United States , many of these tribes experienced demographic decline through relocation, slavery, etc. Since European colonization and the independence movements,

3320-800: The Texas Rangers , named after the statewide law enforcement agency . The National Basketball Association expanded into North Texas in 1980 when the Dallas Mavericks were added to the league. The fourth sport was added in 1993 when the Minnesota North Stars of the National Hockey League moved to Dallas, becoming the Dallas Stars . The Major League Soccer team FC Dallas is based in Frisco, and

3403-540: The 1980s, as part of New Public Management , several countries including Australia and the United Kingdom developed the use of agencies to improve efficiency in public services. Administrative law in France refers to autorité administrative indépendante (AAI) or Independent Administrative Authorities. They tend to be prominent in the following areas of public policy; Independent Administrative Authorities in France may not be instructed or ordered to take specific actions by

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3486-442: The Day 1 Convective Outlook were incorporated into the Day 2 Convective Outlook on January 28, 2020, citing research to SPC operations and improvements in numerical forecast guidance that have increased forecaster confidence in risk estimation for those hazards in that timeframe. The individual hazard probabilistic forecasts replaced the existing "total severe" probability graph for general severe convective storms that had been used for

3569-598: The Day 2 Convective Outlook (which include probabilistic forecasts for outlined areas of thunderstorm risk for the following day) and the Mesoscale Discussion (a short-term forecast outlining specific areas under threat for severe thunderstorm development). In October 1995, the National Severe Storms Forecast Center relocated its operations to Norman, Oklahoma, and was rechristened the Storm Prediction Center. At that time,

3652-487: The Day 2 outlook beforehand. Day 3 outlooks refer to the day after tomorrow, and include the same products (categorical outline, text description, and probability graph) as the Day 2 outlook. As of June 2012, the SPC forecasts general thunderstorm risk areas. Higher probability forecasts are less and less likely as the forecast period increases due to lessening forecast ability farther in advance. Day 3 moderate risks are quite rare; these have been issued only twenty times since

3735-456: The National Severe Storms Forecast Center began issuing status reports on weather watches; the agency then made its first computerized data transmission in 1971. On April 2, 1982, the agency issued the first " Particularly Dangerous Situation " watch, which indicates the imminent threat of a major severe weather event over the watch's timespan. In 1986, the NSSFC introduced two new forecast products:

3818-547: The Norman office). In 1998, the center began issuing the National Fire Weather Outlook to provide forecasts for areas potentially susceptible to the development and spread of wildfires based on certain meteorological factors. The Day 3 Convective Outlook (which is similar in format to the Day 2 forecast) was first issued on an experimental basis in 2000, and was made an official product in 2001. In 2006,

3901-417: The North Texas area was settled and most notably developed the cities of Dallas and Fort Worth. The North Texas climate is subtropical with hot summers. It is also continental , characterized by a wide annual temperature range. Average annual precipitation also varies considerably, ranging from less than 28 to more than 48 inches (700–1200 mm). Severe storms are frequent in the spring and summer, as

3984-531: The SPC incorporated a small table under the Convective Outlook's risk category map that indicates the total coverage area by square miles , the total estimated population affected and major cities included within a severe weather risk area. Public severe weather outlooks (PWO) are issued when a significant or widespread outbreak is expected, especially for tornadoes. From November to March, it can also be issued for any threat of significant tornadoes in

4067-421: The SPC introduced a new graphical format for its categorical and probability outlooks, which included the shading of risk areas (with the colors corresponding to each category, as mentioned above, being changed as well) and population , county / parish / borough and interstate overlays. The new shaded maps also incorporated a revised color palette for the shaded probability categories in each outlook. In 2013,

4150-438: The Storm Prediction Center is tasked with forecasting the risk of severe thunderstorms and tornadoes in the contiguous United States . It issues convective outlooks , mesoscale discussions , and watches as a part of this process. Convective outlooks are issued for the following eight days (issued separately for Day 1, Day 2, Day 3, and Days 4–8), and detail the risk of severe thunderstorms and tornadoes during

4233-407: The Storm Prediction Center, National Severe Storms Laboratory and National Weather Service Norman Forecast Office moved their respective operations into the newly constructed National Weather Center, near Westheimer Airport. Since the agency's relocation to Norman, the 557th Weather Wing at Offutt Air Force Base would assume control of issuing the Storm Prediction Center's severe weather products in

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4316-495: The United States coastline. This indicates that the risk for severe weather is also valid in that general area of the other side of the border or oceanic boundary. SPC mesoscale discussions (MDs) once covered convection (mesoscale convective discussions [MCDs]) and precipitation (mesoscale precipitation discussions [MPDs]); MPDs are now issued by the Weather Prediction Center (WPC). MCDs generally precede

4399-406: The annual precipitation results from thunderstorm activity, with occasional heavy rainfall over brief periods of time. Thunderstorms occur throughout the year, but are most frequent in the spring and early summer months. Hail falls on about two or three days a year, ordinarily with only slight and scattered damage. Windstorms occurring during thunderstorm activity are sometimes destructive. Snowfall

4482-904: The area lies in the southern section of " tornado alley ". South is the prevailing wind direction, and southerly winds are frequently high and persist for several days. Strong northerly winds often occur during the passage of cold fronts. Winters can be mild, but northers occur about three times each month, and often are accompanied by sudden drops in temperature. In Dallas, a record-setting 12.8 inches of snow fell in February 2010. Periods of extreme cold that occasionally occur are short-lived, so that even in January mild weather occurs frequently. The highest temperatures of summer are associated with fair skies, and moderate to high humidities. Characteristically, hot spells in summer are broken into three- to five-day periods by thunderstorm activity. There are only

4565-427: The areas under the watch), associated potential threats, a meteorological synopsis of atmospheric conditions favorable for severe thunderstorm development, forecasted aviation conditions, and a pre-determined message informing the public of the meaning behind the watch and to be vigilant of any warnings or weather statements that may be issued by their local National Weather Service office. Watch outline products provide

4648-403: The available wind shear and other sufficient atmospheric parameters). During the peak severe weather season, most days will have a slight risk somewhere in the United States. Isolated significant severe events are possible in some circumstances, but are generally not widespread. An enhanced risk day indicates that there is a greater threat for severe weather than that which would be indicated by

4731-402: The current system have chosen not to outline marginal risk areas. Generally, the convective outlook boundaries or lines – general thunderstorms (light green), marginal (dark green), slight (yellow), enhanced (orange), moderate (red) and high (purple) – will be continued as an arrow or line not filled with color if the risk area enters another country ( Canada or Mexico ) or across waters beyond

4814-425: The delineated region, as described in the previous section. The Day 1 Convective Outlook, issued five times per day at 0600Z (valid from 1200Z of the current day until 1200Z the following day), 1300Z and 1630Z (the "morning updates," valid until 1200Z the following day), 2000Z (the "afternoon update," valid until 1200Z the following day), and the 0100Z (the "evening update," valid until 1200Z the following day), provides

4897-489: The event that the SPC is no longer able to issue them in the event of an outage (such as a computer system failure or building-wide power disruption ) or emergency (such as an approaching strong tornadic circulation or tornado on the ground) affecting the Norman campus; on April 1, 2009, the SPC reassigned responsibilities for issuing the center's products in such situations to the 15th Operational Weather Squadron based out of Scott Air Force Base . The Storm Prediction Center

4980-539: The executive branch, with a few located in the legislative branch of government. By enacting the Administrative Procedure Act (APA) in 1946, Congress established some means to oversee government agency action. The APA established uniform administrative law procedures for a federal agency's promulgation of rules and adjudication of claims. The APA also sets forth the process for judicial review of agency action. North Texas North Texas

5063-581: The following counties as belonging to the North Central Texas Council of Governments (NCTCOG): The Texas State Demographer also lists the following regional county groupings, some or all of which are often included in the informal meaning of the terms "North Texas" or "North Central Texas". Nortex Regional Planning Commission : Texoma Council of Governments : Additionally, some other Texas counties contiguous with those named above are sometimes included in

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5146-490: The following day (1200Z to 1200Z of the next calendar day; for example, a Day 2 outlook issued on April 12, 2100, would be valid from 1200Z on April 13, 2100, through 1200Z on April 14, 2100) and include only a categorical outline, textual description, and a map of categories and probabilities. Day 2 moderate risks are fairly uncommon, and a Day 2 high risk has only been issued twice (for April 7, 2006 and for April 14, 2012 ). Probabilities for tornadoes, hail and wind applying to

5229-514: The forecasts to gauge the potential severe weather threats to their areas. Even after the marginal and enhanced risk categories were added in October 2014, some television stations have continued to use the original three-category system to outline forecasted severe weather risks (though stations that do this may utilize in-house severe weather outlooks that vary to some degree from the SPC convective outlooks), while certain others that have switched to

5312-735: The four major professional sports leagues. Major professional sports first came to the area in 1960, when the Dallas Cowboys began competing in the National Football League and the Dallas Texans began competing in the American Football League . (The Texans later relocated to Kansas City and became the Chiefs ). In 1972, Major League Baseball's Washington Senators moved to Arlington to become

5395-461: The fringes of the watch box may actually be included in the watch and vice versa. Watches can be expanded, contracted (by removing jurisdictions where SPC and NWS forecasters no longer consider there to be a viable threat of severe weather, in which case, the watch box may take on a trapezoidal representation in map-based watch products) or canceled before their set time of expiration by local NWS offices. Source: The Storm Prediction Center also

5478-534: The general meaning of "North Texas". In the North Texas region there is one combined statistical area , three metropolitan areas , and seven micropolitan areas . Metropolitan statistical areas (MSAs) Micropolitan statistical areas (μSAs) Metropolitan statistical areas (MSAs) Micropolitan statistical areas (μSAs) Micropolitan statistical Areas (μSAs) Dallas–Fort Worth metroplex Wichita Falls metropolitan area Sherman–Denison metropolitan area The North Texas region has teams from

5561-423: The general threat of severe convective storms over the contiguous United States for the next six to 192 hours (Day 1 through Day 8). These outlooks are labeled and issued by day, and are issued up to five times per day. The categorical levels of risks are TSTM (for T hunder St or m : light green shaded area – rendered as a brown line prior to April 2011 – indicating a risk for general thunderstorms), "MRGL" (for M

5644-416: The given forecast period, although tornado, hail and wind details are only available for Days 1 and 2. Day 3, as well as 4–8 use a probabilistic scale, determining the probability for a severe weather event in percentage categories (15%/yellow and 30%/orange). Mesoscale discussions are issued to provide information on certain individual regions where severe weather is becoming a threat and states whether

5727-630: The government. The General Secretariat for Macedonia and Thrace ( Greek : Γενική Γραμματεία Μακεδονίας-Θράκης), previously Ministry for Macedonia and Thrace ( Greek : Υπουργείο Μακεδονίας-Θράκης) is a government agency of the Hellenic Republic that is responsible for the Greek regions of Macedonia and Thrace . The term agency in India has several meanings; for example, the Cabinet and

5810-716: The guidance center was housed at Max Westheimer Airport (now the University of Oklahoma Westheimer Airport ), co-located in the same building as the National Severe Storms Laboratory and the local National Weather Service Weather Forecast Office (the latter of which, in addition to disseminating forecasts, oversees the issuance of weather warnings and advisories for the western two-thirds of Oklahoma and western portions of North Texas , and issues outline and status updates for SPC-issued severe thunderstorm and tornado watches that include areas served by

5893-477: The issuance of a moderate risk. In order from least to greatest threat, these categories are ranked as: marginal, slight, enhanced, moderate, and high. Convective outlooks are issued by the Storm Prediction Center in Zulu time (also known as Universal Coordinated Time or UTC). The categories at right refer to the risk levels for the specific severe weather event occurring within 25 miles (40 km) of any point in

5976-414: The issuance of a tornado or severe thunderstorm watch, by one to three hours when possible. Mesoscale discussions are designed to give local forecasters an update on a region where a severe weather threat is emerging and an indication of whether a watch is likely and details thereof, as well as situations of isolated severe weather when watches are not necessary. MCDs contain meteorological information on what

6059-465: The longest-term official SPC Forecast Product, and often change significantly from day to day. This extended forecast for severe weather was an experimental product until March 22, 2007, when the Storm Prediction Center incorporated it as an official product. Areas are delineated in this forecast that have least a 15% or 30% chance of severe weather in the Day 4–8 period (equivalent to a slight risk and an enhanced risk, respectively); as forecaster confidence

6142-464: The nighttime hours, noting the lower awareness and greater danger of tornadoes at that time of year. A marginal risk day indicates storms of only limited organization, longevity, coverage and/or intensity, typically isolated severe or near-severe storms with limited wind damage, large hail and perhaps a tornado. Wind gusts of at least 60 miles per hour (97 km/h) and hailstones of around 1 inch (2.5 cm) in diameter are common storm threats within

6225-407: The originally forecast level of severity. Warnings are issued by local National Weather Service offices, not the Storm Prediction Center, which is a national guidance center. The process of issuing a convective watch begins with a conference call from SPC to local NWS offices. If after collaboration a watch is deemed necessary, the Storm Prediction Center will issue a watch approximation product which

6308-565: The outcome in individual cases as well. In addition to the State and its agencies, there are also local government agencies, which are extensions of municipalities and county councils . Agencies in the United Kingdom are either executive agencies answerable to government ministers or non-departmental public bodies answerable directly to parliament or the devolved assemblies of the United Kingdom. They are also commonly known as Quangos . Agencies can be created by enabling legislation by

6391-771: The parliament Secretariat describes itself as a " nodal agency for coordination amongst the ministries of the Govt. of India". Most notably as an international feature, what appear to be independent agencies ( or apex agencies ) include some that have active roles for Ministers: such as, the National Security Council , the Medical Council of India , the Pharmacy Council of India (PCI), the Indian Council of Agricultural Research , and

6474-533: The policies of the Government of Sweden . The Ministries are relatively small and merely policy-making organizations, allowed to control agencies by policy decisions but not by direct orders. This means that while the agencies are subject to decisions made by the Government, Ministers are explicitly prohibited (so-called ban on ministerstyre ) from interfering with the day-to-day operation in an agency or

6557-459: The potential exists for extremely severe and life-threatening weather. This includes widespread strong or violent tornadoes which may be on the ground for a half-hour or longer, or very destructive straight-line winds. Hail cannot verify or produce a high risk on its own, although such a day usually involves a threat for widespread very large and damaging hail as well. Many of the most prolific severe weather days were high risk days. Such days are rare;

6640-507: The product became operational (most recently for March 22, 2022 ). Day 3 high risks are never issued and the operational standards do not allow for such. This is most likely because it would require both a very high degree of certainty (60%) for an event which was still at least 48 hours away and a reasonable level of confidence that said severe thunderstorm outbreak would include significant severe weather (EF2+ tornadoes, hurricane-force winds , and/or egg-sized hail ). Day 4–8 outlooks are

6723-580: The unit moved its forecast operations to Kansas City , Missouri . SELS began issuing convective outlooks for predicted thunderstorm activity in 1955, and began issuing radar summaries in three-hour intervals in 1960; with the increased duties of compiling and disseminating radar summaries, this unit became the National Severe Storms Forecast Center (NSSFC) in 1966, remaining headquartered in Kansas City. In 1968,

6806-605: The very low frequency of high risk areas in convective outlooks (see List of Storm Prediction Center extremely critical days ). 35°10′53″N 97°26′25″W  /  35.18139°N 97.44028°W  / 35.18139; -97.44028 Government agency A government agency may be established by either a national government or a state government within a federal system. Agencies can be established by legislation or by executive powers. The autonomy, independence, and accountability of government agencies also vary widely. Early examples of organizations that would now be termed

6889-647: The west and Oklahoma to the north and east. North Texas is centered upon the Dallas–Fort Worth metroplex, the largest metropolitan area in Texas and the Southern United States . People in the Dallas and Fort Worth areas sometimes use the terms Metroplex , DFW , and North Texas interchangeably. However, North Texas refers to a much larger area that includes many northern rural counties along

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