Chapter 3a: Aviation Weather Sources  11. Zulu time—a term used in aviation for UTC, which places the entire world on one time  standard. 12. Remarks—the remarks section always begins with the letters “RMK.” Comments may or may  not appear in this section of the METAR. The information contained in this section may  include wind data, variable visibility, beginning and ending times of particular phenomenon,  pressure information, and various other information deemed necessary. An example of a  remark regarding weather phenomenon that does not fit in any other category would be:  OCNL LTGICCG. This translates as occasional lightning in the clouds and from cloud to ground.  Automated stations also use the remarks section to indicate the equipment needs  maintenance. Example: METAR KGGG 161753Z AUTO 14021G26KT 3/4SM +TSRA BR BKN008 OVC012CB  18/17 A2970 RMK PRESFR  Explanation: Routine METAR for Gregg County Airport for the 16th day of the month at 1753Z  automated source. Winds are 140 at 21 knots gusting to 26. Visibility is ¾ statute  mile. Thunderstorms with heavy rain and mist. Ceiling is broken at 800 feet, overcast  at 1,200 feet with cumulonimbus clouds. Temperature 18 °C and dew point 17 °C.  Barometric pressure is 29.70 "Hg and falling rapidly.  1. Type of report—a TAF can be either a routine forecast (TAF) or an amended forecast (TAF  AMD). 2. ICAO station identifier—the station identifier is the same as that used in a METAR. 3. Date and time of origin—time and date (081125Z) of TAF origination is given in the six- number code with the first two being the date, the last four being the time. Time is always  given in UTC as denoted by the Z following the time block. 4. Valid period dates and times—The TAF valid period (0812/0912) follows the date/time of  forecast origin group. Scheduled 24 and 30 hour TAFs are issued four times per day, at 0000,  0600, 1200, and 1800Z. The first two digits (08) are the day of the month for the start of the  TAF. The next two digits (12) are the starting hour (UTC). 09 is the day of the month for the  end of the TAF, and the last two digits (12) are the ending hour (UTC) of the valid period. A  forecast period that begins at midnight UTC is annotated as 00. If the end time of a valid  Remote Pilot – Small Unmanned Aircraft Systems Study Guide  18  Observed weather condition reports are often used in the creation of forecasts for the same area. A  variety of different forecast products are produced and designed to be used in the preflight planning  stage. The printed forecasts that pilots need to be familiar with are the terminal aerodrome forecast  (TAF), aviation area forecast (FA), inflight weather advisories (Significant Meteorological Information  (SIGMET), Airman’s Meteorological Information (AIRMET)), and the winds and temperatures aloft  forecast (FB). A TAF is a report established for the five statute mile radius around an airport. TAF reports are  usually given for larger airports. Each TAF is valid for a 24 or 30-hour time period and is updated four  times a day at 0000Z, 0600Z, 1200Z, and 1800Z. The TAF utilizes the same descriptors and  abbreviations as used in the METAR report. These weather reports can be beneficial to the remote  pilot for flight planning purposes. The TAF includes the following information in sequential order: Terminal Aerodrome Forecasts (TAF) Aviation Forecasts