2000 For an explanation of _how_ it got there see the Phlog entry 11-15-2004 METAR HELP _________________________________________________________________ The following is an example of a METAR, a surface observation, from Oshkosh Wittman Regional Airport. ID TIME WIND VIS WX SKY T/TD ALT REMARK KOSH 141253Z 19004KT 6SM BR CLR M03 M04 A3016 RMK AO2 _________________________________________________________________ METAR-TYPE METAR is the scheduled observation taken at the end of each hour. SPECI is an observation taken at an unscheduled time due to certain criteria that is met such as low visibility, low clouds, frozen precipitation, or thunderstorms. _________________________________________________________________ KOSH-Station ID In this example, K refers to a North American Station and OSH is the three letter id for Oshkosh. Other examples are KRFD (Rockford Il), KAMA (Amarillo, TX) and KDEN (Denver, Co). _________________________________________________________________ 141253Z-Time and Date The 14 represents the day of the month The 1253 represents the time at which the observation went out The Z represents that the time is in ZULU or UTC (Universal Time Code). _________________________________________________________________ 19004KT-Winds The 190 (the first three numbers) is the direction of the winds in degrees from 0 to 360 degrees (although you will never see 360 because after 350, it goes back to 0). The 04 (next two numbers) is the speed of the winds in knots. G** represents the wind gusts. Gust will not always be on here... there is criteria which must be met in order to have a gust. Simply, unless it's windy, you are not going to see gusts in the obsevation. the KT simply means knots. It will always be at the end. For winds speeds below 7 knots, you might see VRB005KT which means the wind direction is variable. This is the idea of "light and variable" that you might see in a forecast. For winds greater than 6 knots you might see 18015KT 150V210. The winds are from 180 degrees at 15 knots, but the direction is actually variable between 150 degrees and 210 degrees. In order to be variable above 6 knots, the winds must have at least a 60 degree variation. _________________________________________________________________ 4SM-Visibility The 4SM simply means 4 Statute Miles. Occasionally you might see visibility up to 20 or 30 SM but for the most part it will go from < 1/4 (vis below 1/4 SM) up to 10 SM. _________________________________________________________________ (BR)-Present Weather and Obscurations (-) is the designator for light. Precipitation will either be light (-), moderate ( ), or heavy (+) based on certain criteria that must be met. For more info on that criteria, please see the FMH-1 link at the bottom of this page. For now, just understand that it is simply the intensity of the snow, rain, hail, sleet, or freezing rain. The following is from the FMH-1 HANDBOOK. QUALIFIER WEATHER PHENOMENA INTENSITY OR PROXIMITY 1 DESCRIPTOR 2 PRECIPITATION 3 OBSCURATION 4 OTHER 5 - Light Moderate (see note 2) + Heavy VC In the Vicinity (see note 3) MI Shallow PR Partial BC Patches DR Low Drifting BL Blowing SH Shower(s) TS Thunderstorm FZ Freezing DZ Drizzle RA Rain SN Snow SG Snow Grains IC Ice Crystals PL Ice Pellets GR Hail GS Small Hail and/or Snow Pellets UP Unknown Precipitation BR Mist FG Fog FU Smoke VA Volcanic Ash DU Widespread Dust SA Sand HZ Haze PY Spray PO Well- Developed Dust/Sand Whirls SQ Squalls FC Funnel Cloud Tornado Waterspout (see note 3) SS Sandstorm SS Duststorm 1. The weather groups shall be constructed by considering columns 1 to 5 in the table above in sequence, i.e. intensity, followed by description, followed by weather phenomena, e.g. heavy rain shower(s) is coded as +SHRA 2. To denote moderate intensity no entry or symbol is used. 3. Tornados and waterspouts shall be coded as +FC. _________________________________________________________________ CLR-Sky Condition BKN represents a broken sky. (The clouds cover 5/8 to 7/8 of the sky) 110 represents the clouds are at 11,000 feet (simply add 2 zeroes to get the height) The cloud cover will either be FEW (1/8 TO 2/8 cloud coverage), SCT (SCATTERED, 3/8 TO 4/8 cloud coverage, BKN (5/8-7/8 coverage), and OVC (OVERCAST, 8/8 Coverage). You will often have more than 1 designator (i.e. SCT035 BKN090 OVC140) An indefinate ceiling caused by fog, rain, snow, etc., will require a designator as VV (Vertical Visibility). VV is the how high you can see vertically into the indefinate ceiling. Significant Clouds such as TCU (Towering Cumulus), CB, (Cumulonimbus, or a shower/thunderstorm), or ACC (Altocumulus Castellanus) will be found on the en of a category (i.e. SCT035TCU) _________________________________________________________________ M03/M04-Temperature and Dewpoint 03represents the temperature in Celcius 04represents the dewpoint in Celcius If the temperature or dewpoint falls below 0 there will be an "M" before it (i.e. 03/M02). "M" means minus. _________________________________________________________________ 30.74-Altimeter/Pressure A simply stands for Altimeter 3074 means 30.74 inches of mercury for the pressure. _________________________________________________________________ RMK AO2-REMARKS RMK simply means REMARKS and marks the end of the standard metar observation and the beginning of the remarks that are put in as necessay. A02 means that the site is automated and HAS a precipitation sensor. If it were AO1, there would be no precip sensor. This does not mean the site is un-manned. If there is an AUTO after the ID in the metar ob, then there is no observer. There are many remarks, and the FMH-1 (Federal Meteorological Handbook-1) at the bottom will give you a full listing of them. Here are only a few of the important and common remarks: Volcanic Eruptions are in plain english TORNADO, FUNNEL CLOUD, or WATERSPOUT Peak Wind (PK_WND) Wind Shift (WSHFT_time) BINOVC (Breaks in Overcast) BINOVC denotes a few, small clear patches in the overcast sky Tower or Surface Visibility (TWR_VIS SFC_VIS) CIG (Ceiling=Lowest BKN/OVC layer or height of VV) V (Variable) i.e. BKN V SCT, VIS 2V3 [2 variable 3 miles], CIG 025V030 [2500 ft-3000ft]) Lightning (Frequency_LTG-type) CG: Cloud to ground IC: Intracloud CC: Cloud to Cloud CA: Cloud to Air OCNL: Occasional FRQ: Frequent CONS: Continuous Beginning/Ending of Thunderstorms/Rain/Snow (TSB, SNE, RAB, etc) Thunderstorm Location (TS_LOC_(MOV_DIR) LOC=Location (N, NE, S, VC, OHD [Overhead], ALQDS [All Quadrants]) DIR=Direction (N, NE, S, etc) Hailstone Size (GR_[size]) Virga (VIRGA_[ DIR]) Cumulonimbus or Cumulonimbus Mammatus (CB or CBMAM_LOC_(MOV_DIR). Towering cumulus (TCU_[DIR]) Altocumulus castellanus (ACC_[DIR]) Standing lenticular or Rotor clouds (CLD_[DIR]) Pressure Rising or Falling Rapidly (PRESRR/PRESFR) Sea-Level Pressure (SLP###) Aircraft Mishap (ACFT_MSHP) Snow Increasing Rapidly (SNINCR_amount this hour/total) Hourly Precipitation Amount (P####). 3- and 6-Hour Precipitation Amount (6####) 24-Hour Precipitation Amount (7####). Snow Depth on Ground (4/###) Water Equivalent of Snow on Ground (9####) Hourly Temperature and Dewpoint (Tsn###sn###) T=Temp sn=Type (0=above zero celcius, 1=below zero celcius) ###=celcius temperature to nearest tenth of a degree 6-Hourly Maximum Temperature (1sn###) 6-Hourly Minimum Temperature (2sn###) 24-Hour Maximum and Minimum Temperature (4sn######) First three numbers=maximum temp to nearest tenth of a degree ce 5b9 lcius Last three numbers=mimimum temp to nearest tenth of a degree celcius -Hourly Pressure Tendency (5a###)--see table 12-7 at the bottom for a (type) RVR (Runway Visual Range, Rrrr/####ft)--will eventually be in the body! R=RVR r=runway, i.e. 31C, 21L, etc. ####ft=Distance of visual range (i.e. 6000ft, P6000ft [plus], m600ft [minus]) Primary Requirement Description Code Figure Atmospheric pressure now higher than 3 hours ago. Increasing, then decreasing. 0 Increasing, then steady, or increasing then increasing more slowly. 1 Increasing steadily or unsteadily. 2 Decreasing or steady, then increasing; or increasing then increasing more rapidly. 3 Atmospheric pressure now same as 3 hours ago. Increasing, then decreasing. 0 Steady 4 Decreasing then increasing. 5 Atmospheric pressure now lower than 3 hours ago. Decreasing, then increasing. 5 Decreasing, then steady, or decreasing then decreasing more slowly. 6 Decreasing steadily or unsteadily. 7 Steady or increasing, then decreasing; or decreasing then decreasing more rapidly. 8 _________________________________________________________________ For the ultimate guide to METAR and observations, please see the The Federal Meteorological Handbook No. 1 from the National Weather Service _________________________________________________________________ 0