Abbreviations, Acronyms, and Initialisms

14 CFR — Title 14 of the Code of Federal Regulations

3D — Three Dimensional

A — Arctic

AAG — Alaska Aviation Guidance

AAWU — Alaska Aviation Weather Unit

AC — Advisory Circular

AC — Convective Outlook

ACARS — Aircraft Communications Addressing and Reporting System

ACFJ — Australia, Canada, France, and Japan

ACSL — Altocumulus Standing Lenticular

ADS-B — Automatic Dependent Surveillance-Broadcast

AFD — Aviation Forecast Discussion

AFIS — Automatic Flight Information Service

AGL — Above Ground Level

AIM — Aeronautical Information Manual

AIREP — Aircraft Report

AIRMET — Airmen’s Meteorological Information

ALP — Airport Location Point

AMDAR — Aircraft Meteorological Data Relay

AP — Anomalous Propagation

app — Application

ARTCC — Air Route Traffic Control Center

ASI-AD — Aviation Safety Inspector—Aircraft Dispatch

ASOS — Automated Surface Observing System

ATC — Air Traffic Control

ATCSCC — Air Traffic Control Systems Command Center

ATCT — Airport Traffic Control Tower

ATIS — Automatic Terminal Information Service

AWC — Aviation Weather Center

AWIPS — Advanced Weather Interactive Processing System

AWOS — Automated Weather Observing System

AWRP — Aviation Weather Research Program

AWW — Airport Weather Warning

Note: AWW formerly stood for the Alert Severe Weather Watch Bulletin as well as the Severe Weather Forecast Alert.

°C or C — degrees Celsius or Celsius

c — Continental

cA — Continental Arctic

CAPE — Convective Available Potential Energy

CAT — Clear-Air Turbulence

Cb — Cumulonimbus

CCSL — Cirrocumulus Standing Lenticular

CERAP — Central Radar Approach

CH — Certificate Holder

CIP — Current Icing Product

CIT — Convectively Induced Turbulence

CIWS — Corridor Integrated Weather System

cm — centimeter

C-MAN — Coastal-Marine Automated Network

CME — Coronal Mass Ejection

CMO — Certificate Management Office

CONUS — Contiguous United States

CoSPA — Consolidated Storm Prediction for Aviation

cP — Continental Polar

CPHC — Central Pacific Hurricane Center

CRC — China-Russian Federation Consortium

cT — Continental Tropical

CWA — Center Weather Advisory

CWSU — Center Weather Service Unit

dBZ — decibels of Z

DH — Decision Height

DO — Director of Operations

DOC — Department of Commerce

DOD — Department of Defense

DOT — Department of Transportation

E — East

ECFP — Extended Convective Forecast Product

EDR — Eddy Dissipation Rate

EF — Enhanced Fujita

EFB — Electronic Flight Bag

ENE — East-Northeast

ESE — East-Southeast

ETA — Estimated Time of Arrival

EUV — Extreme Ultraviolet

EWINS — Enhanced Weather Information System

°F or F — degrees Fahrenheit or Fahrenheit

FA — Area Forecast

FAA — Federal Aviation Administration

FACA — Area Forecast for Caribbean

FAGX — Area Forecast for Gulf of America

FB — Wind and Temperature Aloft Forecast

FIP — Forecast Icing Product

FIR — Flight Information Region

FIS — Flight Information Services

FIS-B — Flight Information Service-Broadcast

FL — Flight Level

FOC — Flight Operations Center

fpm — feet per minute

FSS — Flight Service Station

ft — foot

g — gram

GA — General Aviation

GCR — Galactic Cosmic Rays

GFA — Graphical Forecasts for Aviation

GFS — Global Forecast System

GNSS — Global Navigation Satellite System

GOES — Geostationary Operational Environmental Satellites

GPS — Global Positioning System

GTG — Graphical Turbulence Guidance

GTG-N — Graphical Turbulence Guidance Nowcast

HEMS — Helicopter Emergency Medical Services

HF — High Frequency

HF COM — High Frequency Communications

Hg — Mercury

HIWC — High Ice Water Content

hPa — hectopascal

hr — hour

HRRR — High Resolution Rapid Refresh

IAP — Instrument Approach Procedure

IATA — International Air Transport Association

ICAO — International Civil Aviation Organization

IFR — Instrument Flight Rules

IMC — Instrument Meteorological Conditions

in — inch

inHg — inches of mercury

IR — Infrared

ITCZ — Intertropical Convergence Zone

ITWS — Integrated Terminal Weather System

J — joule

J/g — joules per gram

J g⁻¹ K⁻¹ — joules per gram Kelvin

J/kg — joules per kilogram

K — Kelvin

kg — kilogram

kg/m — kilogram per meter

kg/m³ — kilogram per cubic meter

K-H — Kelvin-Helmholtz

km — kilometer

km/h — kilometers per hour

kt — knot

kW — kilowatt

LAA — Local Airport Advisory

LAMP — Localized Aviation MOS Program

lb — pound

LCL — Lifted Condensation Level

LFC — Level of Free Convection

LI — Lifted Index

LIFR — Low Instrument Flight Rules

LLWAS — Low-Level Wind Shear Alert System

LLWS — Low-Level Wind Shear

LRNS — Long-Range Navigation System

m — Maritime

m — meter

m³ — cubic meter

mA — Maritime Arctic

mb or mbar — millibar

MCS — Mesoscale Convective System

MDA — Minimum Descent Altitude

MEL — Minimum Equipment List

METAR — Aviation Routine Weather Report

mg/m³ — milligrams per cubic meter

MHz — megahertz

mi — mile

min — minute

MIS — Meteorological Impact Statement

MOS — Model Output Statistics

mP — Maritime Polar

mph — miles per hour

m/s — meters per second

MSL — Mean Sea Level

mT — Maritime Tropical

MVFR — Marginal Visual Flight Rules

MWO — Meteorological Watch Office

MWT — Mountain Wave Turbulence

N — North

N/A — Not Applicable

NAM — North American Model

NAS — National Airspace System

NASA — National Aeronautics and Space Administration

NAVAID — Navigational Aid

NCEP — National Centers for Environmental Prediction

NCO — NCEP Central Operations

NCWF — National Convective Weather Forecast

NDFD — National Digital Forecast Database

NE — Northeast

NESDIS — National Environmental Satellite, Data, and Information Service

NEXRAD — Next Generation Weather Radar

NextGen — Next Generation Air Transportation System

NHC — National Hurricane Center

nm — nanometer

NM — nautical mile

NNE — North-Northeast

NNW — North-Northwest

NOAA — National Oceanic and Atmospheric Administration

NOTAM — Notice to Airmen

NW — Northwest

NWP — Numerical Weather Prediction

NWS — National Weather Service

OAT — Outside Air Temperature

ODP — Obstacle Departure Procedure

OMO — One-Minute Observation

OPC — Ocean Prediction Center

OPMET — Operational Meteorological

P — Polar

PECASUS — Pan-European Consortium for Aviation Space Weather User Services

PGF — Pressure Gradient Force

PIC — Pilot in Command

PIREP — Pilot Weather Report

POES — Polar Operational Environment Satellite

POI — Principal Operations Inspector

Prog — Prognostic

psi — pounds per square inch

QA — Quality Assurance

radar — Radio Detection and Ranging

RCM — Radar Coded Message

RCO — Remote Communications Outlet

RH — Relative Humidity

ROFOR — Route Forecast

RTMA — Real-Time Mesoscale Analysis

RVR — Runway Visual Range

S — South

s or sec — second

SAA — Special Activity Airspace

SAB — Satellite Analysis Branch

SAS — Safety Assurance System

SATCOM — Satellite Communications

SAW — Aviation Watch Notification Message

SE — Southeast

SFRA — Special Flight Rules Area

SI — International System of Units

SIC — Second in Command

SID — Standard Instrument Departure

SIGMET — Significant Meteorological Information

SIGWX — Significant Weather

SLD — Supercooled Large Drop

SLWC — Supercooled Liquid Water Content

SM — statute mile

SMS — Safety Management System

SO₂ — Sulfur Dioxide

SPC — Storm Prediction Center

SPECI — Aviation Selected Special Weather Report

SRM — Safety Risk Management

SSE — South-Southeast

SSW — South-Southwest

STOP — Special Terminal Operation Procedures

SUA — Special Use Airspace

SW — Southwest

SWPC — Space Weather Prediction Center

T — Tropical

TAF — Terminal Aerodrome Forecast

TCA — Tropical Cyclone Advisory

TCAC — Tropical Cyclone Advisory Center

TCF — TFM Convective Forecast

TCu — Towering Cumulus

TDWR — Terminal Doppler Weather Radar

TDZ — Touchdown Zone

TFM — Traffic Flow Management

TFR — Temporary Flight Restriction

TMS — Traffic Management System

TMU — Traffic Management Unit

TRACON — Terminal Radar Approach Control

TUTT — Tropical Upper Tropospheric Trough

U.S. — United States

UAT — Universal Access Transceiver

UCAR — University Corporation for Atmospheric Research

UTC — Coordinated Universal Time

VAA — Volcanic Ash Advisory

VAAC — Volcanic Ash Advisory Center

VAD — Velocity Azimuth Display

VAG — Graphical Version of the Volcanic Ash Advisory

VAR — Volcanic Activity Report

VCP — Volume Coverage Pattern

VEIA — Visibility Estimation through Image Analytics

VFR — Visual Flight Rules

VHF — Very High Frequency

VMC — Visual Meteorological Conditions

VNR — VFR Flight Not Recommended

VOR — Very High Frequency Omni-Directional Range Station

VR — Rotation Speed

W — watt

W — West

W m⁻¹ K⁻¹ — watt per meter-Kelvin

WADL — West African Disturbance Line

WAFC — World Area Forecast Center

WAFS — World Area Forecast System

WARP — Weather and Radar Processor

WFO — Weather Forecast Office

WIFS — WAFS Internet File Service

WMO — World Meteorological Organization

WNW — West-Northwest

WPC — Weather Prediction Center

WSP — Weather Systems Processor

WSR-88D — Weather Surveillance Radar—1988 Doppler

WSW — West-Southwest

Wx — Weather

yd — yard

Z or z — Zulu