Chapter 3, Overview of Aviation Weather Information 3-9
Product T-
Storm Wind Wind
Shear Visibility Precip Fog In-Flight
Icing
Freezing
Level Turb Ash TC SS/
DS
Mtn
Obsc
HI FA X X X X X X
GTG X
Gulf of
America and
Caribbean FA
X X X X X X X X X
Low-Level
SIGWX X X X
Med-Level
SIGWX X X X X X X
High-Level
SIGWX X X X X X
AK SIGWX X X X
AK Surface
Chart X X X
AK
Convective
Outlook
Surface Prog
Charts X X X
WAFS X X X X
Upper Air
Forecasts X X
FIP X
Cloud Top
Convective
Outlook X
TCF X
ECFP X
SAW X
AFD X X X X X X X X X X
MIS X X X X X X X X
NDFD X X X X X
Tools
GFA Tool X X X X X X X X X X X X X
Flight Service
Interactive
Map
X X X X X X X X X X X X X
Table 3-2. Continuation of Table 3-1 (See Table 3-3 for acronyms and abbreviations.)
An ‘X’ indicates that the weather product contains information pertaining to the weather element or phenomenon.
Product IFR MVFR Cloud
Cover
Cloud
Base
Cloud
Tops
Cloud
Layers Pressure Fronts Temp
Aloft
Space
Weather
Density
Altitude
Observations
METAR, SPECI
(ASOS, AWOS,
ATIS)
X X X X X X X X X
PIREP/AIREP X X X X X
Radar
Lightning Data
Satellite X
Weather Camera X X
Analysis
Surface Analysis
Charts X X X X X
Upper Air
Analysis X
Chapter 3, Overview of Aviation Weather Information 3-10
Product IFR MVFR Cloud
Cover
Cloud
Base
Cloud
Tops
Cloud
Layers Pressure Fronts Temp
Aloft
Space
Weather
Density
Altitude
Freezing Level
Analysis X
CIP
GTG
RTMA X
Advisories
Convective
SIGMET X
SIGMET X
CWA X X
VAA
TCA
Space Weather
Advisory X
LLWAS X
AWW
Forecasts
Wind and Temp
Aloft X
TAF X X X X X X
Aviation Surface
Forecast X
Aviation Clouds
Forecast X X X X
AK FA X X X X X X X
HI FA X X X X X X X
Gulf of America
and Caribbean
FA
X X X X X X X
Low-Level
SIGWX X X X X X
Med-Level
SIGWX
High-Level
SIGWX
AK SIGWX X X X X X
AK Surface
Chart X
Surface Prog
Charts X X
WAFS X
Upper Air
Forecasts X
FIP
GTG
Cloud Top X X
Convective
Outlook
TCF X
ECFP
SAW
AFD X X X X X
MIS X X
NDFD X X X X
Tools x
GFA Tool X X X X X X
Flight Service
Interactive Map X X X X X
Chapter 3, Overview of Aviation Weather Information 3-11
Table 3-3. Acronyms and Abbreviations Used in Product/Element/Phenomenon Tables
Acronym/Abbreviation Definition
AFD Aviation Forecast Discussion
AGL Above Ground Level
AIREP Aircraft Report
AIRMET Airmen’s Meteorological Information
AK Alaska
ARTCC Air Route Traffic Control Center
Ash Volcanic Ash
ASOS Automated Surface Observing System
ATIS Automatic Terminal Information Service
AWOS Automated Weather Observing System
AWW Airport Weather Warning
BCFG Patchy Fog
BKN Broken
BLDU Blowing Dust
BLSA Blowing Sand
BR Mist
CB Cumulonimbus
CIP Current Icing Product
CONUS Contiguous United States
CWA Center Weather Advisory
DRDU Drifting Dust
DRSA Drifting Sand
DS Dust Storm
ECFP Extended Convective Forecast Product
FA Area Forecast
FG Fog
FIP Forecast Icing Product
FL Flight Level
FROPA Frontal Passage
ft Feet
FZFG Freezing Fog
GFA Graphical Forecasts for Aviation
GTG Graphical Turbulence Guidance
Chapter 3, Overview of Aviation Weather Information 3-12
Acronym/Abbreviation Definition
HI Hawaii
HZ Haze
ICAO International Civil Aviation Organization
IFR Instrument Flight Rules
kt knot
LIFR Low Instrument Flight Rules
LLWAS Low-Level Wind Shear Alert System
LLWS Low-Level Wind Shear
METAR Aviation Routine Weather Report
MIFG Shallow Fog
MIS Meteorological Impact Statement
MSL Mean Sea Level
Mtn Obsc Mountain Obscuration
MVFR Marginal Visual Flight Rules
NIL SIG No Significant
NOAA National Oceanic and Atmospheric Administration
Obsc Obscuration
OVC Overcast
PIREP Pilot Weather Report
Precip Precipitation
PRFG Partial Fog
Prog Prognostic
RMK Remarks
RTMA Real-Time Mesoscale Analysis
SAW Aviation Watch Notification Message
SIGMET Significant Meteorological Information
SIGWX Significant Weather
SLD Supercooled Large Drop
SM statute mile
SPECI Aviation Selected Special Weather Report
SS Sandstorm
TAF Terminal Aerodrome Forecast
TC Tropical Cyclone
TCA Tropical Cyclone Advisory
Chapter 3, Overview of Aviation Weather Information 3-13
Acronym/Abbreviation Definition
TCF Traffic Flow Management Convective Forecast
Temp Temperature
TS Thunderstorm
TSRA Thunderstorm with Rain
T-Storm Thunderstorm
Turb Turbulence
VA Volcanic Ash
VAA Volcanic Ash Advisory
VAR Volcanic Activity Report
VC Vicinity
VCFG Fog in the Vicinity
VCTS Thunderstorm in the Vicinity
VFR Visual Flight Rules
WAFS World Area Forecast System
WDSPR DS Widespread Dust Storms
WDSPR SS Widespread Sandstorms
Wx or WX Weather
Z Zulu
3.4.2 Summaries of Specific Weather Information Contained in Various Weather
Products
The following set of tables identify specific weather elements (e.g., thunderstorms, turbulence) and list the
products that contain information relating to those elements. A brief summary description is also provided.
These summaries are not intended to provide all of the details. More detailed information can be found in
Chapters 24, 25, 26, 27, and 28.
3.4.2.1 Products with Thunderstorm Information
Table 3-4. Weather Element: Thunderstorm
Type: text (T), graphic (G), image (I), voice (V)
Thunderstorm
Information
Contained In:
Type Summary
Observations
METAR and SPECI
(ASOS, AWOS,
ATIS)
T, G,
Thunderstorms are reported in the body section of the METAR/SPECI when
observed or detected by lightning networks or observers. Lightning information
is provided in the RMK section of the METAR/SPECI.
PIREP T, G,
V Included when reported.
Chapter 3, Overview of Aviation Weather Information 3-14
Thunderstorm
Information
Contained In:
Type Summary
Radar I
Radar provides intensity levels of precipitation. Thunderstorms can typically be
distinguished based on intensity, but not always. Certain radar limitations can
be misleading.
Lightning data G Used in the METAR, SPECI, ASOS, AWOS, ATIS, as well as incorporated into
other product overlays (e.g., satellite pictures, radar display).
Satellite I Thunderstorms can be inferred by a meteorologist or trained specialist, unless
they are embedded in other cloud layers.
Weather Camera I CB clouds may be seen on the camera.
Analysis
Advisories
Convective
SIGMET T, G Active area of thunderstorms. Only issued for the CONUS instead of a SIGMET
for thunderstorms.
SIGMET T, G Active area of thunderstorms. Issued for areas outside the CONUS.
CWA T, G Active area of thunderstorms. Issued as a supplement to a Convective SIGMET
or when Convective SIGMET criteria have not been met.
AWW T
Intended for ground operations at select airports. Criteria may vary depending
on user needs. For example, it can be issued for cloud to ground lightning within
5 miles of the airport.
Forecasts
TAF T, G
Thunderstorm included using various descriptors. For example:
- TS: thunderstorm without precipitation (means dry thunderstorms).
- TSRA: thunderstorm with precipitation (in this case, rain).
- VCTS: thunderstorms in the vicinity (i.e., within 5–10 SM of the center of
the airport).
Aviation Surface
Forecast G Derived from the GFA and includes forecasts of areas of thunderstorms at
specified valid times.
Alaska Area
Forecast T A description of significant clouds and weather including thunderstorms and
CB clouds.
Hawaii Area
Forecast T A description of significant clouds and weather including thunderstorms and
CB clouds.
Gulf of America and
Caribbean Area
Forecast
T A description of significant clouds and weather including thunderstorms and
CB clouds.
Med-Level SIGWX G Forecast of significant weather including areas of CB clouds at specified valid
times for limited geographic areas around the globe.
High-Level SIGWX G Global forecast of significant weather including areas of CB clouds at specified
valid times.
Alaska SIGWX
Chart G Forecast of significant weather including areas of thunderstorms at specified
valid times.
Alaska Surface
Chart G Forecast of surface weather features including areas of thunderstorms at
specified valid times.
Alaska Convective
Outlook G Seasonal product that provides forecasts that indicate where conditions are
favorable for towering cumulus and thunderstorms at specified valid times.
Surface Prog Charts G CONUS forecast that includes areas of thunderstorms at specified valid times.
WAFS G Global forecasts that include areas of CB clouds.
Chapter 3, Overview of Aviation Weather Information 3-15
Thunderstorm
Information
Contained In:
Type Summary
TCF G The TCF depicts areas of convection meeting select criteria.
ECFP G The ECFP is a planning forecast mainly intended for air traffic managers.
Convective Outlook T, G
Convective Outlooks provide the potential for severe (tornado, wind gusts
50 knots or greater, or hail 1-in diameter or greater) and non-severe (general)
convection and specific severe weather threats during the following 8 days.
SAW T, G Formerly known as the AWW, the SAW provides an approximation of the area
covered by a Severe Thunderstorm Watch or Tornado Watch.
Severe
Thunderstorm
Watch
T, G
A watch is when conditions are favorable for severe thunderstorms, which is hail
1-in diameter or greater and/or damaging winds of 50 knots or greater. Not to be
confused with a Severe Thunderstorm Warning, which is issued when severe
thunderstorms are occurring.
Tornado Watch T, G A watch is when conditions are favorable for tornadoes. Not to be confused with
a Tornado Warning, which is issued when tornadoes are occurring.
AFD T
Describes the weather conditions as they relate to a specific TAF or group of
TAFs and may provide additional aviation weather-related issues that cannot be
encoded into the TAF, such as the reasoning behind the forecast.
MIS T A discussion of meteorological events (including significant convection) causing
or expecting to impact the flow of air traffic across an ARTCC.
Tools
GFA Tool G
Interactive website that includes forecast thunderstorm areas with different
coverage levels. Also overlays radar Convective SIGMETs, CWAs for
thunderstorms and Severe Thunderstorm/Tornado Warnings.
Flight Service
Interactive Map G
Interactive website that includes overlays of radar, Convective SIGMETs,
CWAs for thunderstorms, and Severe Thunderstorms/Tornado Watches and
Warnings. Also includes an overlay for radar echo tops.
3.4.2.2 Products with Wind Information
Table 3-5. Weather Element: Wind
Type: text (T), graphic (G), image (I), voice (V)
Wind Information
Contained In: Type Summary
Observations
METAR and SPECI
(ASOS, AWOS,
ATIS)
T, G,
Surface wind speed and direction are included. Wind direction is reported
relative to magnetic north in ATIS as well as ASOS and AWOS radio (voice)
broadcasts. Otherwise reported relative to true north. Wind speed is reported
in knots.
PIREP/AIREP T, G,
Wind direction is reported in tens of degrees magnetic north and wind speed
in knots.
Analysis
Surface Analysis
Chart G Surface wind speed and direction (true north) are depicted with standard
symbols on station plot models.
Upper Air Analysis G At select pressure levels, the wind direction aloft is displayed in tens of degrees
true north and wind speed aloft is displayed in knots.
Chapter 3, Overview of Aviation Weather Information 3-16
Wind Information
Contained In: Type Summary
Advisories
AIRMET T, G AIRMET Tango issued when sustained surface winds greater than 30 knots are
occurring or expected to occur.
CWA T, G May be issued if surface wind gusts are at or above 30 knots.
TCA T Includes maximum sustained surface winds.
AWW T Intended for ground operations at select airports. Criteria may vary depending
on user needs.
Forecasts
Winds and
Temperature Aloft T, G
Wind direction aloft is indicated in text format as tens of degrees with reference
to true north, and wind speed aloft in knots. The graphical forecast uses standard
wind barb display for wind speed/direction (true north).
TAF T, G Surface wind forecasts of direction rounded to the nearest 10 degrees (true
north) and the surface mean wind speed in knots are included in the wind group.
Aviation Surface
Forecast G Derived from the GFA and includes forecasts of surface winds at specified valid
times. Also includes AIRMET for surface winds.
Alaska Area
Forecast T Surface winds greater than 20 knots are included in the description of significant
clouds and weather.
Hawaii Area
Forecast T Sustained surface winds of 20 knots or greater are included in the description of
significant clouds and weather.
Gulf of America and
Caribbean Area
Forecast
T Sustained surface winds greater than or equal to 20 knots are included in the
description of significant clouds and weather.
Medium-Level
SIGWX G A jet stream axis with a wind speed aloft of more than 80 knots is depicted with
double hatched lines identifying 20-knot speed changes.
High-Level SIGWX G
Global forecast of a jet stream axis with a wind speed aloft of more than
80 knots is depicted with double hatched lines identifying 20-knot speed
changes.
WAFS G Winds aloft are issued at select FLs and are provided in chart and grid point
formats. Wind speed and direction (true north) are displayed with wind barbs.
Upper Air Forecasts G Model outputs for winds aloft are shown at select pressure levels. Wind speed
and direction (true north) are displayed with wind barbs.
AFD T Describes the weather conditions as they relate to a specific TAF or group of
TAFs, including surface winds.
Tools
GFA Tool G Interactive website that includes surface winds (true north) and winds aloft at
select altitudes/FLs.
Flight Service
Interactive Map G Interactive website that includes overlap of AIRMET for surface winds and
winds aloft (true north) at select altitudes/FLs.