NWS Code Lists
These pages support the exchange of US products encoded in XML and other encoding schemes.
The World Meteorological Organization (WMO) maintains a WMO Codes Registry where many other useful codes are documented.
The NWS code list pages will only document local use information that is not available in the WMO registry.
The links in the following table provide access to the code lists developed to support not only the US extensions to the ICAO Meteorological Information Exchange Model (IWXXM; IWXXM-US) but products unique to the United States Meteorological Services. The top level of organization reflects the documents that regulate the Traditional Alphanumeric Code (TAC) versions of these products.
| FMH-1 | Federal Meteorological Handbook Number 1, Surface Weather Observations is maintained by the United States Office of the Federal Coordinator for Meteorology. The code lists documented here also include Air Force Manual 15-111, Surface Weather Observations. |
| FMH-12 | Federal Meteorological Handbook Number 12, United States Meteorological Codes and Coding Practices, is maintained by the United States Office of the Federal Coordinator for Meteorology. The code lists documented here also include codes from FAA Flight Services Chapter 7, International Operations, Section 1, Messages and Formats. The code lists documented on these web pages are designed to support the encoding of AIREP and PIREP reports. |
| NWSI 10-503 | National Weather Service Instruction (NWSI) 10-503, WFO Public Weather Forecast Products Specifications, is maintained by the United States National Weather Service. The code lists documented on these web pages are designed to support the encoding of US Weather Discussions and Forecasts. |
| NWSI 10-511 | National Weather Service Instruction (NWSI) 10-511, WFO Severe Weather Products Specifications, is maintained by the United States National Weather Service. The code lists documented on these web pages are designed to support the encoding of US Warnings, Advisories and Statements. |
| NWSI 10-512 | National Weather Service Instruction (NWSI) 10-512, National Severe Weather Products Specifications, is maintained by the United States National Weather Service. The code lists documented on these web pages are designed to support the encoding of US Watches and Outlooks. |
| NWSI 10-803 | National Weather Service Instruction (NWSI) 10-803, Support to Air Traffic Control Facilities, is maintained by the United States National Weather Service. The code lists documented on these web pages are designed to support the encoding of Meteorologicall Impact Statements and Center Weather Advisories. |
| NWSI 10-811 | National Weather Service Instruction (NWSI) 10-811, Enroute Forecasts and Advisories is maintained by the United States National Weather Service. The code lists documented on these web pages are designed to support the encoding of US SIGMETs and AIRMETs. |
| NWSI 10-813 | National Weather Service Instruction (NWSI) 10-813, Terminal Aerodrome Forecasts is maintained by the United States National Weather Service. The code lists documented on these web pages are designed to support the encoding of US TAFs. |
| MADIS | Meteorological Assimilation Data Ingest System (MADIS) is a meteorological observational database and data delivery system that provides observations that cover the globe. The code lists documented on these web pages are specific to MADIS data assimilation and quality control processes and procedures. |
| Severe Weather Phenomena | A list of meterological and hydrological phenomena which present threats to human life and property. |
