Presentation on theme: "ATS/ESS 452: Synoptic Meteorology"— Presentation transcript:
1 ATS/ESS 452: Synoptic Meteorology METARThe Station Model
2 What is a METAR? Acronym for METeorological Aviation Report Generated at least once an hour (usually right prior to the end) or when a significant change in weather occursComposed of two parts: Body and RemarksInformation contained within is added in a specific order and format
3 ExampleKHSV Z 22010KT 3SM -RA BR OVC010 09/08 A2969 RMK AO2 RAB01E11B45 CIG 007V012 SLP053 P0000 TInformation ALWAYS given includes:Station IDDate/TimeWind Speed/DirectionVisibilityCurrent Observed WeatherSky conditionsTemperature/DewpointAltimeter Reading (Pressure)Any information given after RMK are referred to as remarks, and this information can vary
4 Web ResourcesStation ID Look-up: Federal Meteorological Handbook Chapter on METAR:
5 Station ID Example = KABC 4 character identifier for reporting stationsThe first letter identifies the country. All US stations begin with ‘K’, Canadian stations begin with ‘C’Next 3 characters identify the station.KJAN is Jackson, MS for example
6 Date/Time Example = 121553Z Given in Greenwich Mean Time, or Zulu First two numbers are the day of the month. Single dates are reported with a 0Next 4 numbers are the time.
7 Report Modifier Example = AUTO 3 possibilities: None, AUTO and COR AUTO means the observation was taken without human interaction or oversightCOR indicates a correction to a previous reportIf nothing, then a human took the observation
8 Wind Direction and Speed Example = 21016G24KT 180V240First three numbers denote the direction given in degrees.The next two numbers are speed in knotsIn this example, the G indicates that a gust occurred.The second group, 180V240, indicates a wind shift occurred or it is variableCalm winds are reported as 00000KT
9 Wind Direction/Speed Examples 27005KT indicates a wind that is blowing from 270 degrees (i.e. from the west) at a speed of 5 knots 16018G35KT indicates a wind that is blowing from 160 degrees (i.e. from the south-southeast) at a speed of 18 knots with gusts to 35 knots.
10 Visibility Example = 1SM ‘SM’ is Statute Miles 10SM would indicate a visibility of 10 statute miles2 1/2SM would indicate a visibility of 2.5 statute milesM at the beginning would mean less than the reported numberM1/4SM indicates a visibility of less than 0.25 statute miles
11 Runway Visual Range Example = R11/P6000FT The first number indicates the runwayRange is given, after the slash, in feet
12 Present Weather Example = -RA BR The weather occurring at, or in the vicinity of, the observation point at the time of reportingThere are 5 categories, constructed in sequences, to consider: Intensity, Descriptor, Precipitation, Obscuration, Other Weather
13 Present Weather - Intensity Example = -RA BRIntensity: -, +, VC- = Light (.10”/hour or .01” in 6 minutes)+ = Heavy (.30”/hour or .03” in 6 minutes)VC = in the vicinity of stationModerate precip has no symbol
17 Present Weather - Other SQ = SquallsFC = Funnel Cloud, Tornado or WaterspoutSS = SandstormDS = Duststorm
18 Present Weather Examples -TSRA indicates a thunderstorm with light rain. -RA FG indicates light rain and fog.
19 Sky Conditions Example = SCT060 First three letters represent the amount the sky is coveredNext three numbers are the height of the cloud base in hundreds of feetUp to 3 cloud layers may be reported to a height of 12,000 feet
21 Sky Conditions Example SCT060 indicates 3/8 to 4/8 sky (scattered) coverage by a layer of clouds at 6000 feet above the surface. BKN039 OVC100 indicates 5/8 to 7/8 (broken) sky coverage at 3900 feet and 8/8 (overcast) sky coverage at 10,000 feet.
22 Temperature/Dewpoint Example = 06/04Temperature is given first, followed by the dewpoint. Both are rounded to the nearest whole Celsius degreeNegative readings are coded with a ‘M.’ Example, 01/M01 is temp = 1C, dew = -1C
23 Altimeter Example = A2990 Always coded with an ‘A’ Given in inches of mercuryIt is the barometric pressure of the location if it were at sea levelA2990 = inches of mercury
24 The Remarks Section Added only when appropriate Up to 26 different items can be reported in this section‘RMK’ indicates the beginning of the Remarks section
25 Example Remarks TORNADO B13 6 NE PK WND 20032/25 Means a tornado began 13 minutes after the hour and was located 6 miles northeast of the stationPK WND 20032/25Indicates the strongest (peak) wind since the last observationDirection (200), speed of gust (32 knots) and time of gust (25)
26 Example Remarks Precip Start/Stop Times RAB07 Coded with type of precip, followed by a B for began or E for endedLast numbers indicate minute of the hour the precip began/endMay be coded together (RAB07E24) indicates rain began at 7 after and ended at 24 after the hour
27 Example Remarks Sea Level Pressure SLP125 Given in millibars SLP stands for sea-level pressure, followed by the last three digits of the readingA decimal point is placed between the last two digitsRule of thumb: If the number is less than 500, place a 10 in front. If more than 500, place a 9 in frontSLP125 mbSLP955 mb
28 Example Remarks Hourly Precip Amount 6-Hour Precip 24-Hour Precip Given in hundredths of an inch. Amount recorded since the last observationTrace of precip is reported as P00006-Hour PrecipSimilarly to hourly, but 6000924-Hour PrecipCoded with a 7 in front 70009Reported at 12Z, amount recorded in last 24 hours
29 Example Remarks Precise Temp/Dewpoint T00640036 Exact temperature and dewpoint reading to the tenth of a degreeBegins with a T followed by two 4 digits groups, the first is temp and the second is dewpointThe first digit is always the sign; if 0, then the reading is positive, if 1, then it is negativeIn the example, the exact temp = 6.4 degrees C and dewpoint = 3.6 degrees C