{"id":15864,"date":"2026-06-13T05:33:58","date_gmt":"2026-06-13T00:03:58","guid":{"rendered":"https:\/\/ibexaviation.com\/pilot-training\/?p=15864"},"modified":"2026-07-26T10:56:44","modified_gmt":"2026-07-26T05:26:44","slug":"meteorological-forecast","status":"publish","type":"post","link":"https:\/\/ibexaviation.com\/pilot-training\/meteorological-forecast\/","title":{"rendered":"Meteorological Forecast"},"content":{"rendered":"<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aviation-meteorology\/m27-meteorological-forecast-1.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<h3>Aerodrome Forecast<\/h3>\n<h3>Aerodrome Weather Forecast<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aviation-meteorology\/m27-meteorological-forecast-2.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Aerodrome forecasts are classified into four types:\n<ul>\n<li><strong>Nowcasting:<\/strong> Valid for less than 24 hours.<\/li>\n<li><strong>Short-Range Forecast:<\/strong> Valid for 1\u20133 days.<\/li>\n<li><strong>Medium-Range Forecast:<\/strong> Valid for 4\u201310 days.<\/li>\n<li><strong>Long-Range Forecast:<\/strong> Valid for more than 10 days.<\/li>\n<\/ul>\n<\/li>\n<li><strong>Terminal Aerodrome Forecast (TAF):<\/strong>\n<ul>\n<li>9-hour validity TAF is issued every <strong>3 hours<\/strong> for domestic flights.<\/li>\n<li>12\u201330 hour validity TAF is issued every <strong>6 hours<\/strong> for international flights.<\/li>\n<li>9-hour TAF is broadcast on <strong>VOLMET<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<li><strong>Landing (Trend) Forecast:<\/strong> Appended to METAR or SPECI and valid for <strong>2 hours<\/strong>. <strong>NOSIG<\/strong> indicates no significant change is expected. Probability groups are not used in trend forecasts.<\/li>\n<li><strong>Take-off Forecast:<\/strong> Issued approximately <strong>3 hours before ETD<\/strong> and contains:\n<ul>\n<li>Surface wind averaged over 2 minutes.<\/li>\n<li>Temperature.<\/li>\n<li>QNH.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>TAF &#8211; Time, Wind and Visibility<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aviation-meteorology\/m27-meteorological-forecast-3.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li><strong>Report Type and Location:<\/strong> TAF followed by the ICAO aerodrome indicator (e.g., <strong>TAF VIDP<\/strong>).<\/li>\n<li><strong>Date and Time:<\/strong> UTC issue time and validity period (e.g., <strong>270630Z 2707\/2716<\/strong>).<\/li>\n<li><strong>Wind Direction:<\/strong> True direction expressed in three digits at 10\u00b0 intervals.<\/li>\n<li>Variable wind extremes may be reported (e.g., <strong>26005KT 220V360<\/strong>).<\/li>\n<li><strong>Wind Speed:<\/strong> Mean wind speed and gusts (when gusts exceed the mean by 10 kt or more) are reported in knots or metres per second.<\/li>\n<li><strong>P99<\/strong> indicates gusts greater than 99 knots.<\/li>\n<li><strong>Visibility:<\/strong> Prevailing visibility reported in metres.<\/li>\n<\/ul>\n<h3>TAF &#8211; Weather and Clouds<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aviation-meteorology\/m27-meteorological-forecast-4.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>The weather group contains a <strong>Qualifier<\/strong>, <strong>Descriptor<\/strong>, and <strong>Weather Phenomenon<\/strong>, similar to METAR (e.g., <strong>-SHRA<\/strong>).<\/li>\n<li>Clouds are reported as height above aerodrome level (QFE) in ascending order of cloud amount.<\/li>\n<li>High clouds are included only when covering a significant area. Only <strong>CB (Cumulonimbus)<\/strong> is specifically identified.<\/li>\n<li><strong>NSC (No Significant Clouds)<\/strong> means:\n<ul>\n<li>No cloud below <strong>5000 ft<\/strong> or the <strong>Minimum Sector Altitude (MSA)<\/strong>, whichever is higher.<\/li>\n<li>No Cumulonimbus (CB) clouds.<\/li>\n<\/ul>\n<\/li>\n<li>TAF does <strong>not<\/strong> include forecasts of:\n<ul>\n<li>Temperature.<\/li>\n<li>Dew Point.<\/li>\n<li>QNH.<\/li>\n<li>Recent Weather.<\/li>\n<li>Wind Shear.<\/li>\n<li>Runway State.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Temporary and Permanent Changes<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aviation-meteorology\/m27-meteorological-forecast-5.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li><strong>Permanent Change:<\/strong>\n<ul>\n<li><strong>FM (From):<\/strong> Indicates a permanent change from the specified date and time.<br \/>\n                Example: <code>FM271220 27010KT 4000 TSRA BKN010CB<\/code>\n            <\/li>\n<li><strong>BECMG (Becoming):<\/strong> Indicates gradual change during the specified validity period.<br \/>\n                Example: <code>BECMG 1309\/1311 4000 TSRA BKN010CB<\/code>\n            <\/li>\n<\/ul>\n<\/li>\n<li><strong>Temporary Change:<\/strong>\n<ul>\n<li><strong>TEMPO<\/strong> indicates temporary fluctuations that may occur at any time within the specified period.<\/li>\n<li>Each fluctuation lasts for less than one hour and occupies less than half of the forecast period.<\/li>\n<li>Example: <code>TEMPO 1312\/1314 TSRA BKN010CB<\/code><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Probability and Amended Forecast<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aviation-meteorology\/m27-meteorological-forecast-6.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li><strong>Probability Groups:<\/strong>\n<ul>\n<li>Probability is expressed as a percentage.<\/li>\n<li>Example: <strong>PROB40<\/strong> indicates a 40% probability.<\/li>\n<li>Probability groups may accompany either permanent or temporary changes.<\/li>\n<\/ul>\n<\/li>\n<li><strong>Amended Forecast:<\/strong> Forecast amendments are indicated using <strong>TAF AMD<\/strong>.<\/li>\n<\/ul>\n<h3>Aerodrome Warnings<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aviation-meteorology\/m27-meteorological-forecast-7.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Aerodrome warnings are issued for weather conditions likely to adversely affect aircraft on the ground.<\/li>\n<li>Warnings are generally valid for less than <strong>4 hours<\/strong>.<\/li>\n<li><strong>Wind Criteria:<\/strong>\n<ul>\n<li>Wind speed greater than <strong>30 kt<\/strong>.<\/li>\n<li>Wind speed greater than <strong>20 kt<\/strong> with a direction change of at least <strong>45\u00b0<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<li><strong>Weather Warnings:<\/strong> Squall, Tropical Cyclone (TC), Duststorm (DS), Sandstorm (SS), Thunderstorm (TS), Hail (GR), Frost, Snow (SN), Hoar Frost, Rime Ice, Freezing Rain, Sand or Dust Storm, Volcanic Ash (VA), and Tsunami.<\/li>\n<li>Warnings for gliders, helicopters and light aircraft are issued when surface wind is expected to reach <strong>17 kt<\/strong> or more.<\/li>\n<li>Wind shear warnings cover the area up to <strong>500 m (1600 ft)<\/strong> above the runway affecting aircraft during approach, take-off, circling approach or while on the runway.<\/li>\n<li>Wind shear information is also included in <strong>METAR<\/strong>, <strong>SPECI<\/strong>, and <strong>SPECIAL<\/strong>.<\/li>\n<\/ul>\n<h3>Types of Area Forecast<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aviation-meteorology\/m27-meteorological-forecast-8.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li><strong>ARFOR (Area Forecast):<\/strong> Coded or tabular forecast providing:\n<ul>\n<li>Upper winds.<\/li>\n<li>Upper-air temperatures.<\/li>\n<li>Significant weather.<\/li>\n<li>Clouds.<\/li>\n<li>Freezing level.<\/li>\n<li>Turbulence.<\/li>\n<li>Icing.<\/li>\n<li>Jet stream.<\/li>\n<li>Tropopause.<\/li>\n<li>Maximum wind.<\/li>\n<li>Wind shear.<\/li>\n<li>Airfield warnings.<\/li>\n<\/ul>\n<\/li>\n<li><strong>CODAR:<\/strong> Upper-air report from aircraft other than dedicated weather reconnaissance aircraft.<\/li>\n<li><strong>WINTEM:<\/strong> Forecast of upper-level wind and temperature.<\/li>\n<li><strong>ROFOR (Route Forecast):<\/strong> Coded route forecast including upper winds, upper-air temperature, significant weather, clouds, freezing level, turbulence, icing, jet stream, tropopause and maximum winds.<\/li>\n<li><strong>Local Area Forecast:<\/strong>\n<ul>\n<li>Covers a radius of <strong>100 NM<\/strong>.<\/li>\n<li>Valid for <strong>8 hours<\/strong>.<\/li>\n<li>Issued three times daily:\n<ul>\n<li>2130 UTC (Valid 2200\u20130600 UTC)<\/li>\n<li>0530 UTC (Valid 0600\u20131400 UTC)<\/li>\n<li>1330 UTC (Valid 1400\u20132200 UTC)<\/li>\n<\/ul>\n<\/li>\n<li>Includes surface wind, visibility, weather, clouds, upper winds, temperature, sunrise, sunset and warnings.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3>Example of Area and Route Forecast<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aviation-meteorology\/m27-meteorological-forecast-9.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<ul>\n<li>Area and Route Forecasts are designated as <strong>ARFOR<\/strong> and <strong>ROFOR<\/strong>.<\/li>\n<li><strong>ARFOR<\/strong> provides a complete forecast for a geographical area.<\/li>\n<li><strong>ROFOR<\/strong> provides a forecast for a specified route.<\/li>\n<li>The overall format of ARFOR and ROFOR is similar.<\/li>\n<\/ul>\n<h3>Comparison Between ARFOR and ROFOR<\/h3>\n<p>  <img decoding=\"async\" src=\"https:\/\/ibexaviation.com\/page-show\/aviation-meteorology\/m27-meteorological-forecast-10.jpg\" alt=\"\" loading=\"lazy\"\/><\/p>\n<h3>Area Forecast (ARFOR)<\/h3>\n<ul>\n<li>Issuing station.<\/li>\n<li>Date and time of issue.<\/li>\n<li>Applicable flight levels.<\/li>\n<li>Validity period (From \/ To).<\/li>\n<li>Wind speed units.<\/li>\n<li>Area description (coordinates or plain language).<\/li>\n<li>Visibility.<\/li>\n<li>Weather in code.<\/li>\n<li>Cloud layers (lowest to highest including CB).<\/li>\n<li>Cloud layer altitudes and freezing level.<\/li>\n<li>Icing type, altitude and thickness.<\/li>\n<li>Turbulence information.<\/li>\n<\/ul>\n<h3>Route Forecast (ROFOR)<\/h3>\n<ul>\n<li>Issuing station.<\/li>\n<li>Date and time of issue.<\/li>\n<li>Applicable flight levels.<\/li>\n<li>Validity period (From \/ To).<\/li>\n<li>Wind speed units.<\/li>\n<li>Route description divided into sectors.<\/li>\n<li>Upper wind and temperature.<\/li>\n<li>Tropopause pressure level and temperature.<\/li>\n<li>Jet stream location, altitude and wind speed.<\/li>\n<li>Maximum wind altitude, speed, direction and wind shear.<\/li>\n<li>Supplementary information such as lowest pressure, BECMG and TEMPO.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Aerodrome Forecast Aerodrome Weather Forecast Aerodrome forecasts are classified into four types: Nowcasting: Valid for less than 24 hours. Short-Range Forecast: Valid for 1\u20133 days. Medium-Range Forecast: Valid for 4\u201310 days. Long-Range Forecast: Valid for more than 10 days. Terminal Aerodrome Forecast (TAF): 9-hour validity TAF is issued every 3 hours for domestic flights. 12\u201330 hour validity TAF is issued every 6 hours for international flights. 9-hour TAF is broadcast on VOLMET. Landing (Trend) Forecast: Appended to METAR or SPECI and valid for 2 hours. NOSIG indicates no significant change&hellip;<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"disable_featured_image":false,"footnotes":""},"categories":[358],"tags":[],"class_list":["post-15864","post","type-post","status-publish","format-standard","hentry","category-aviation-meteorology"],"_links":{"self":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/15864","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/comments?post=15864"}],"version-history":[{"count":1,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/15864\/revisions"}],"predecessor-version":[{"id":16701,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/posts\/15864\/revisions\/16701"}],"wp:attachment":[{"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/media?parent=15864"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/categories?post=15864"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ibexaviation.com\/pilot-training\/wp-json\/wp\/v2\/tags?post=15864"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}