ARTCC
The ARTCC identifier shows the Air Route Traffic Control Center associated with the advisory. In the example below,ZDV is the ARTCC identifier.
CWA DECODER
Decode a Center Weather Advisory
Decode U.S. Center Weather Advisories into ARTCC, validity, affected area, movement, cloud tops, wind gusts and hail.
Try an example:
CENTER WEATHER ADVISORY
What is a CWA?
A Center Weather Advisory (CWA) is a U.S. aviation weather advisory issued for conditions affecting an Air Route Traffic Control Center area. A CWA identifies the issuing ARTCC, issuance and validity information, the affected area and the weather conditions described in the advisory.
The original advisory remains visible above the decoded fields, so each value can be checked directly against the issued CWA.
CWA FORMAT
How to read a CWA
The advisory begins with identification and time information, followed by the affected location and weather description. Reading these elements separately makes the validity period, affected area and reported weather easier to identify.
Issue time and valid until
The issue time shows when the CWA was issued. The valid-until time marks the end of the advisory period, with both times expressed by day, hour and minute.
Phenomenon and issuance numbers
The CWA header contains numeric identifiers for the phenomenon and issuance. They are displayed separately in the decoded report.
Affected area
The affected area is carried as a geographic description in the advisory. That description remains in its original form rather than being converted into coordinates or boundaries that are not stated in the message.
Movement
When movement is reported, the direction and speed are shown separately. Movement speed is given in knots.
Cloud tops
A CWA can report thunderstorm tops as a flight level. In the example below, TOP FL410 reports tops at flight level 410.
WEATHER DETAILS
Thunderstorms, gusts and hail
The example includes isolated severe thunderstorms together with wind-gust and hail information. These details are shown separately when they appear in this CWA format.
Hail information can include both the reported size and a location identifier. The original wording remains visible beside the decoded values.
EXAMPLE
Center Weather Advisory example
ZDV 2 CWA 032140
In this example, ZDV is the ARTCC identifier and the message carries separate issue and valid-until times. The advisory body defines the affected area and reports severe thunderstorms, movement, cloud tops, wind gusts and hail.
The decoded report also indicates when the advisory states that the weather is expected to continue beyond its stated valid-until time.
RELATED WEATHER PRODUCTS
CWA, SIGMET and AIRMET are separate products
Center Weather Advisories, SIGMETs and AIRMETs are separate aviation weather products. Decode SIGMET reports with the SIGMET Decoder. Alaska and Hawaii text AIRMETs can be read with the AIRMET Decoder.
Each tool follows the format and fields documented for that particular weather product.
DECODER COVERAGE
Current decoder coverage
The decoder covers the FAA CWA format represented in the documented example, including identification, validity, affected area, movement, cloud tops, wind gusts, hail and continuation beyond the valid time. CWA forms that use structures not established by the available documentation are left uninterpreted rather than assigned an assumed meaning.