Decoding Guide

Aerodrome Forecast (TAF) and Aviation Routine Weather Report (METAR)

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

Forecast Explanation Report
TAF Message type: TAF-routine or TAF AMD-amended forecast, METAR-hourly, SPECI-special or TESTM-non-commissioned ASOS report METAR
KPIT ICAO location indicator KPIT
091730Z Issuance time: ALL times in UTC "Z", 2-digit date, 4-digit time 091955Z
091818 Valid period: 2-digit date, 2-digit beginning, 2-digit ending times  
  In U.S. METAR: CORrected ob; or AUTOmated ob for automated report with no human intervention; omitted when observer logs on COR
15005KT 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
5SM 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
  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 Variability 4-digit value (and tendency Down, Up or No change) R28L/2600FT
HZ Significant present, forecast and recent weather: see table (below) TSRA
FEW020 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" OVC010CB
  Temperature: degrees Celsius; first 2 digits, temperature "/" last 2 digits, dew-point temperature; Minus for below zero, e.g., M06 18/16
  Altimeter setting: indicator and 4 digits; in U.S., A-inches and hundredths; (Q-hectoPascals, e.g. Q1013) A2992
WS010/31022KT 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  
  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 RMK SLP045 T01820159
FM1930 FroM and 2-digit hour and 2-digit minute beginning time: indicates significant change. Each FM starts on a new line, indented 5 spaces.  
TEMPO 2022 TEMPOrary: changes expected for < 1 hour and in total, < half of 2-digit hour beginning and 2-digit hour ending time period  
PROB40 0407 PROBability and 2-digit percent (30 or 40): probable condition during 2-digit hour beginning and 2-digit hour ending time period  
BECMG 1315 BECoMinG: change expected during 2-digit hour beginning and 2-digit hour ending time period  

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.


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)


MI - Shallow
BC - Patches
PR - Partial
TS - Thunderstorm
BL - Blowing
SH - Showers
DR - Drifting
FZ - Freezing



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


BR Mist ( >= 5/8 SM )
FG Fog ( < 5/8 SM )
FU Smoke
VA Volcanic Ash
SA Sand
HZ Haze
PY Spray
DU Widespread dust


SQ Squall
SS Sandstorm
DS Dust storm
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.