Weather Conditions Explained
DISCLAIMER:
The METARs are parsed and interpreted by a computer program. The program can be wrong. If a METAR is written by hand, or contains rarely used codes, the program can misinterpret the conditions. The Pilot in Command is ultimately responsible for determining if existing conditions meet a particular legal flight category.
Colors Indicate Flight Category
| VFR
| The color green indicates Visual Flight Rules.
Visibility is greater than 5 miles and
The lowest overcast or broken ceiling is greater than 3,000 feet AGL |
| MVFR
| The color blue indicates Marginal Visual Flight Rules.
Visibility is 3 to 5 miles and/or
The lowest overcast or broken ceiling is from 1,000 to 3,000 feet AGL |
| IFR
| The color red indicates Instrument Flight Rules.
Visibility is 1 mile to less than 3 miles and/or
The lowest overcast or broken ceiling is from 500 to below 1,000 feet AGL |
| LIFR
| The color magenta indicates Low Instrument Flight Rules.
Visibility is less than 1 mile and/or
The lowest overcast or broken ceiling is below 500 feet AGL |
Shapes Indicate Cloud Coverage
| An open circle indicates No Clouds
CLR, SKC, or no cloud information reported. |
| A circle with a dot indicates Few Clouds
Clouds reported as FEW
Cloud coverage greater than 0/8ths but not greater than 2/8ths of the sky. |
| A circle with 1/4 pie filled indicates Scattered Clouds
Clouds reported as SCT
Cloud coverage between 3/8ths and 4/8ths of the sky. |
| A circle with 3/4 pie filled indicates Broken Clouds
Clouds reported as BKN
Cloud coverage between 5/8ths and 7/8ths of the sky. |
| A filled circle indicates Overcast
Clouds reported as OVC/OVX/VV
Cloud coverage is complete or obscured with Vertical Visibility reported. |
How to read the Weather
The following is NOAA's "Quick Reference Guide" to reading weather.
Much more can be found at metar.noaa.gov.
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TAF KPIT 091730Z 091818 15005KT 5SM HZ FEW020 WS010/31022KT FM1930 30015G25KT 3SM SHRA OVC015 TEMPO 2022 1/2SM +TSRA OVC008CB FM0100 27008KT 5SM SHRA BKN020 0VC040 PROB40 0407 1SM -RA BR FM1015 18005KT 6SM -SHRA OVC020 BECMG 1315 P6SM NSW SKC
METAR KPIT 091955Z COR 22015G25KT 3/4SM R28L/2600FT TSRA OVC010CB
18/16 A2992 RMK SLP045 T01820159
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Forecast
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Explanation
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Report
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TAF
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Message type: TAF-routine or TAF AMD-amended forecast, METAR-hourly, SPECI-special or TESTM-non-commissioned ASOS report
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METAR
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KPIT
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ICAO location indicator
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KPIT
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091730Z
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Issuance time: ALL times in UTC "Z", 2-digit date, 4-digit time
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091955Z
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091818
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Valid period: 2-digit date, 2-digit beginning, 2-digit ending times
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In U.S. METAR: CORrected ob; or AUTOmated ob for automated report with no human intervention; omitted when observer logs on |
COR
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15005KT
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Wind: 3 digit true-north direction, nearest 10 degrees (or VaRiaBle); next 2-3 digits for speed and unit, KT (KMH or MPS); as needed, Gust and maximum speed; 00000KT for calm; for METAR, if direction varies 60 degrees or more, Variability appended, e.g. 180V260 |
22015G25KT
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5SM
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Prevailing visibility: in U.S., Statute Miles & fractions; above 6 miles in TAF Plus6SM. (Or, 4-digit minimum visibility in meters and as required, lowest value with direction) |
3/4SM
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Runway Visual Range: R; 2-digit runway designator Left, Center, or Right as needed; "/"; Minus or Plus in U.S, 4-digit value, FeeT in U.S. (usually meters elsewhere); 4-digit value Varialbility 4-digit value (and tendency Down, Up or No change)
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R28L/2600FT
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HZ
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Significant present, forecast and recent weather: see table (below)
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TSRA
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FEW020
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Cloud amount, height and type: SKy Clear 0/8, FEW >0/8-2/8, SCaTtered 3/8-4/8, BroKeN 5/8-7/8, OVerCast 8/8; 3-digit height in hundreds of ft; Towering CUmulus or CumulonimBus in
METAR; in TAF, only CB. Vertical Visibility for obscured sky and
height "VV004". More than 1 layer may be reported or forecast. In automated METAR reports only, CLeaR for "clear below 12,000 feet"
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OVC010CB |
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Temperature: degrees Celsius; first 2 digits, temperature "/" last 2 digits, dew-point temperature; Minus for below zero, e.g., M06
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18/16
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Altimeter setting: indicator and 4 digits; in U.S., A-inches and hundredths; (Q-hectoPascals, e.g. Q1013) |
A2992
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WS010/31022KT
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In U.S. TAF, non-convective low-level (<=2,000 ft)Wind Shear; 3-digit height (hundreds of ft); "/", 3-digit wind direction and 2-3 digit wind speed above the indicated height, and unit, KT
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In METAR, ReMarK indicator
& remarks. For example:Sea-Level Pressure in hectoPascals & tenths, as shown: 1004.5 hPa; Temp/dew-point in tenths °C, as shown: temp 18.2°C, dew-point 15.9°C
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RMK SLP045 T01820159
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FM1930
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FroM and 2-digit hour and 2-digit minute beginning time: indicates significant change. Each FM starts on a new line, indented 5 spaces.
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TEMPO 2022
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TEMPOrary: changes expected for < 1 hour and in total, < half of 2-digit hour beginning and 2-digit hour ending time period
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PROB40 0407
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PROBability and 2-digit percent (30 or 40): probable condition during 2-digit hour beginning and 2-digit hour ending time period
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BECMG 1315
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BECoMinG: change expected during 2-digit hour beginning and 2-digit hour ending time period |
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Table of Significant Present, Forecast and Recent Weather - Grouped in categories
and used in the order listed below; or as needed in TAF,
No Significant Weather.
QUALIFIER
Intensity or Proximity
- Light "no sign" Moderate + Heavy
VC Vicinity: but not at aerodrome;
in U.S. METAR, between 5 and 10SM of the point(s) of observation;
in U.S. TAF, 5 to 10SM from center of runway complex
(elsewhere within 8000m)
Descriptor
MI Shallow BC Patches PR Partial TS Thunderstorm
BL Blowing SH Showers DR Drifting FZ Freezing
WEATHER PHENOMENA
Precipitation
DZ Drizzle RA Rain SN Snow SG Snow grains
IC Ice crystals PL Ice pellets GR Hail GS Small hail/snow pellets
UP Unknown precipitation in automated observations
Obscuration
BR Mist(>= 5/8SM) FG Fog(< 5/8SM) FU Smoke VA Volcanic Ash
SA Sand HZ Haze PY Spray DU Widespread dust
Other
SQ Squall SS Sandstorm DS Duststorm PO Well developed
FC Funnel cloud +FC tornado/waterspout dust/sand whirls
- Explanations in parentheses "( )" indicate different worldwide
practices.
- Ceiling is not specified; defined as the lowest broken or
overcast layer, or the vertical visibility.
- NWS TAFs exclude turbulence, icing & temperature
forecasts; NWS METARs exclude trend fcsts
- Although not used in US, Ceiling And Visibility OK
replaces visibility, weather and clouds if: visibility >=10km;
no cloud below 5000 ft (1500m) or below the highest minimum sector
altitude, whichever is greater and no CB; and no precipitation,
TS, DS, SS, MIFG, DRDU, DRSA, or DRSN.
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