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2 Aviation Weather Service Program
2.1 Introduction
The aviation weather service program is a joint effort of the National Oceanic and Atmospheric
Administration (NOAA), the Federal Aviation Administration (FAA), the Department of Defense (DOD),
NASA, and commercial aviation weather providers.
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2.2 National Oceanic and Atmospheric Administration (NOAA)
NOAA is an agency of the Department of Commerce (DOC). NOAA conducts research and gathers data
about the global oceans, atmosphere, space, and Sun, and applies this knowledge to science and service,
which touches the lives of all Americans. Among its six major divisions are the National Environmental
Satellite, Data, and Information Service (NESDIS) and the NWS.
2.2.1 National Environmental Satellite, Data, and Information Service (NESDIS)
NESDIS manages the U.S. civil operational remote -sensing satellite systems, as well as other global
information for meteorology, oceanography, solid-earth geophysics, and solar-terrestrial sciences. NESDIS
provides this data to NWS meteorologists and a wide range of other users for operational weather
forecasting.
2.2.1.1 Satellite Analysis Branch (SAB)
NESDIS’ Satellite Analysis Branch ( SAB) serves as the operational focal point for real -time imagery
products and multidisciplinary environmental analyses. The SAB ’s primary mission is to support disaster
mitigation and warning services for the U.S. Federal agencies and the international community. Routine
environmental analyses are provided to forecasters and other environmental users and are used in the
numerical models of the NWS. The SAB schedules and distributes real-time satellite imagery products from
global geostationary and polar-orbiting satellites to environmental users.
The SAB coordinates the satellite and other information for the NOAA Volcanic Hazards Alert Program,
under an agreement with the FAA, and works with the NWS as part of the Washington, DC, Volcanic Ash
Advisory Center (VAAC). The Washington, DC, VAAC area of responsibility stretches from 40 ° W
to 130° E and includes the areas of the contiguous United States (CONUS), New York and Oakland
Oceanic flight information regions (FIR), and southward through Central America and the Caribbean to
10° S in South America.
2.2.2 National Weather Service (NWS)
The NWS provides weather data, forecasts, and warnings for the United States, its territories, adjacent
waters, and ocean areas for the protection of life and property and the enhancement of the national economy.
NWS data and products form a national informati on database and infrastructure that can be used by other
government agencies, the private sector, the public, and the g lobal community. The following sections
provide a description of NWS offices associated with aviation weather.
2.2.2.1 National Centers for Environmental Prediction (NCEP)
The National Centers for Environmental Prediction ( NCEP) is where virtually all global meteorological
data is collected and analyzed for the United States. The NCEP then provides a wide variety of national and
international weather guidance products to NWS field offices, government agencies, emergency managers,
and private sector meteorologists. The NCEP is a critical resource in national and global weather prediction
and is the starting point for nearly all-weather forecasts in the United States.
The NCEP is comprised of nine distinct centers and the Office of the Director. Each center has its own
specific mission. The following NCEP centers provide aviation weather products and services.
2.2.2.1.1 NCEP Central Operations (NCO)
The NCEP Central Operations (NCO) in College Park, MD, sustains and executes the operational suite of
the numerical analysis and forecast models and prepares NCEP products for dissemination. It also links all
nine of the national centers together via computer and communications-related services.
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2.2.2.1.2 Aviation Weather Center (AWC)
The Aviation Weather Center ( AWC) in Kansas City, MO, issues a suite of aviation weather forecasts in
support of the National Airspace System (NAS) that are described in this handbook , including Airmen’s
Meteorological Information (AIRMET), significant meteorological information (SIGMET), Convective
SIGMETs, and various icing, turbulence, and convective forecast products. The AWC is a Meteorological
Watch Office (MWO) for the International Civil Aviation Organization (ICAO). The AWC, in conjunction
with the NCO, also serves as one of two ICAO World Area Forecast Centers (WAFC), known as WAFC
Washington, issuing flight planning data (winds and temperatures) and Significant Weather (SIGWX)
forecasts.
The AWC ’s website provides the aviation community with textual, digital, and graphical forecasts,
analyses, and observations of aviation -related weather variables. Additionally, the website provides
information for international flights through the World Area Forecast System (WAFS) grids which are used
to support the Internet File Service (WIFS), which is a separate system.
2.2.2.1.3 Weather Prediction Center (WPC)
The Weather Prediction Center ( WPC) in College Park, MD, provides analysis and forecast products
specializing in multiday, quantitative precipitation forecasts and weather forecast guidance, weather model
diagnostics discussions, and surface pressure and frontal analyses.
2.2.2.1.4 Storm Prediction Center (SPC)
The Storm Prediction Center (SPC) in Norman, OK, provides tornado and severe weather watches for the
CONUS along with a suite of hazardous weather forecasts.
2.2.2.1.5 National Hurricane Center (NHC)
The National Hurricane Center (NHC) in Miami, FL, provides official NWS forecasts of the movement and
strength of tropical weather systems and issues the appropriate watches and warnings for the CONUS and
surrounding areas. It also issues a suite of marine products covering the tropical Atl antic, Caribbean, Gulf
of America, and tropical eastern Pacific. In support of ICAO, the NHC is also referred to as a Tropical
Cyclone Advisory Center (TCAC).
2.2.2.1.6 Space Weather Prediction Center (SWPC)
The Space Weather Prediction Center ( SWPC) in Boulder, CO, provides space weat her information
(e.g., current activity and forecasts) to a wide variety of users. The SWPC is also an ICAO Space Weather
Center and is responsible for issuing global advisories for space weather events affecting communication
and navigation systems as well as events that pose a potential health hazard to passengers and crew.
2.2.2.1.7 Alaska Aviation Weather Unit (AAWU)
The Alaska Aviation Weather Unit ( AAWU), located in Anchorage, AK, is an MWO for ICAO. The
AAWU is responsible for the entire Anchorage FIR. They issue a suite of aviation weather products for the
airspace over Alaska and adjacent coastal waters, including AIRMETs, SIGMETs, FAs, and SIGWX
Prognostic Charts.
The AAWU is also designated as the Anchorage VAAC. The VAAC area of responsibility includes the
Anchorage FIR and Far Eastern Russia and is responsible for the issuance of Volcanic Ash Advisories
(VAA).
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2.2.2.1.8 Center Weather Service Unit (CWSU)
Center Weather Service Units (CWSU) are units of NWS meteorologists under contract with the FAA that
are stationed at, and support, the FAA’s air route traffic control center (ARTCC).
CWSUs provide timely weather consultation, forecasts, and advice to managers within ARTCCs and to
other supported FAA facilities.
Special emphasis is given to those weather conditions that are hazardous to aviation or that could impede
the flow of air traffic within the NAS. CWSU meteorologists issue the following products in support of
their respective ARTCC: Center Weather Advisories (CWA) and Meteorological Impact Statements (MIS).
2.2.2.1.9 Weather Forecast Office (WFO)
The NWS has 122 Weather Forecast Offices (WFO) across the United States and select territories. An NWS
WFO is a multipurpose, local weather forecast center that produces, among its suite of services,
aviation-related products. In support of aviation, WFOs issue Terminal Aerodrome Forecasts ( TAF) and
Aviation Forecast Discussions (AFD), with some offices issuing Airport Weather Warnings (AWW),
Soaring Forecasts, and Balloon Forecasts . The WFO also issues weather warnings such as tornado and
severe thunderstorm warnings.
The Honolulu WFO is unique among NWS WFOs in that it provides multiple services beyond the typical
WFO. WFO Honolulu is also designated as an MWO for ICAO. As a result of this unique designation,
WFO Honolulu is the only WFO to issue the following text pro ducts: AIRMETs and SIGMETs. WFO
Honolulu is co -located with the Central Pacific Hurricane Center (CPHC). The CPHC provides official
NWS forecast of the movement and strength of tropical weather systems and issues the appropriate watches
and warnings for th e central Pacific, including the State of Hawaii. WFO Honolulu also issues a suite of
marine products covering a large portion of the Pacific Ocean. In support of ICAO, the CPHC is also
referred to as a TCAC.
2.3 Federal Aviation Administration (FAA)
The FAA, a part of the Department of Transportation (DOT), provides a safe, secure, and efficient airspace
system for the promotion of U.S. aerospace safety.
Per Title 49 of the United States Code (49 U.S.C.) § 44720, Meteorological Services , the FAA establishes
all requirements for aviation weather reports and forecasts.
The FAA provides a wide range of services to the aviation community. The following s ections provide a
description of those FAA facilities that are involved with aviation weather and pilot services.
2.3.1 Air Traffic Control Systems Command Center (ATCSCC)
The air traffic control systems command center (ATCSCC) has the mission of balancing air traffic demand
with system capacity. This ensures maximum safety and efficiency for the NAS, while minimizing delays.
The ATCSCC utilizes the Traffic Management System (TMS), aircraft situation display s, monitor alert,
follow-on functions, and direct contact with ARTCC and Terminal Radar Approach Control (TRACON)
facility Traffic Management Units (TMU) to manage flow on a national level.
Because weather is the most common reason for air traffic delays and rerouting, NWS meteorologists
support the ATCSCC. These meteorologists, called National Aviation Meteorologists, coordinate NWS
operations in support of traffic flow management within the NAS.
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2.3.2 Air Route Traffic Control Center (ARTCC)
An ARTCC is a facility established to provide air traffic control (ATC) service to pilots operating on
instrument flight rules (IFR) flight plans within controlled airspace, principally during the en route phase
of flight. When equipment capabilities and controller workload permit, certain advisory/assistance services
may be provided to pilots operating under visual flight rules (VFR).
En route controllers become familiar with pertinent weather information and stay aware of current weather
information needed to perform ATC duties. En route controllers advise pilots of hazardous weather that
may impact operations within 150 nautical miles (NM) of the controller ’s assigned sector or jurisdiction
and may solicit Pilot Weather Reports (PIREP) from pilots.
2.3.3 Airport Traffic Control Tower (ATCT) and Terminal Radar Approach Control
(TRACON), Central Radar Approach (CERAP)
An airport traffic control tower (ATCT) is a terminal facility that uses air-to-ground communications, visual
signaling, and other devices to provide ATC services to aircraft operating in the vicinity of an airport or on
the movement area.
Terminal controllers become familiar with pertinent weather information and stay aware of current weather
information needed to perform ATC duties. Terminal controllers advise pilots of hazardous weather that
may impact operations within 150 NM of the cont roller’s assigned sector or area of jurisdiction and may
solicit PIREPs from pilots. ATCTs and TRACONs may opt to broadcast hazardous weather information
alerts only when any part of the area described is within 50 NM of the airspace under the ATCT ’s
jurisdiction.
2.3.4 Flight Service
The FAA delivers flight services to pilots in the CONUS, Alaska, Hawaii, and Puerto Rico. For pilots in
the CONUS, services are available by phone at 1-800-WX-BRIEF (1-800-992-7433). For pilots in Alaska
call 1 -833-AK-BRIEF (1 -833-252-7433). Services include, but are not limited to , pre-flight weather
briefings, flight planning, and in-flight advisory services.
2.3.4.1 FAA Weather Camera Program
Flight Service also delivers the FAA ’s Aviation Weather Camera Network. It features an expanding
network of camera sites in Alaska , Hawaii, and the CONUS. Weather cameras provide pilots in certain
areas with snapshots of current conditions at a specific location, enabling pilots to have additional
information for improved decision making. Services may be obtained by visiting the Aviation Weather
Cameras website (found in Appendix G). See Section 3.3.3.2 and Section 24.9 for additional information.
2.4 Department of Defense (DOD)
The DOD is a key partner with the FAA and NWS in the Next Generation Weather Radar (NEXRAD)
program. Various branches of the DOD provide their own weather support, but this is beyond the scope of
this handbook.
2.5 Commercial Weather Information Providers
Commercial weather information providers are a major source of weather products for the aviation
community. In general, they produce proprietary weather products based on NWS information with
formatting and layout modifications but no material changes to the weather information itself. This is also
referred to as “repackaging.”
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Commercial providers also produce forecasts, analyses, and other proprietary weather products that may
substantially differ from the information contained in NWS -produced products. Operators who desire to
use products prepared by a commercial weather provider should consult the Aeronautical Information
Manual (AIM), Chapter 7, Section 1, Paragraph 7-1-3, Use of Aviation Weather Products, which provides
additional information pertaining to commercial providers , including the Enhanced Weather Information
System (EWINS).