Section 4. Hazardous Inflight Weather Advisory Service (HIWAS)

2-4-1. GENERAL

a. Hazardous Inflight Weather Advisory Service (HIWAS) is a continuous broadcast of inflight weather advisories including summarized AWWs, SIGMETs, convective SIGMETs, CWAs, AIRMETs, and urgent PIREPs.

b. The HIWAS broadcast area is defined as that area within 150 NM of HIWAS outlets assigned to your facility.

2-4-2. PRIORITY

HIWAS broadcast shall not be interrupted/delayed except for emergency situations, when an aircraft requires immediate attention, or for reasonable use of the voice override capability on specific HIWAS outlets in order to use the limited RCO to maintain en route communications. The service shall be provided 24 hours a day.

a. Make the following announcement if there are no hazardous weather advisories in the HIWAS broadcast area.

PHRASEOLOGY-
THIS RECORDING PREPARED AT (time) ZULU. THERE ARE NO HAZARDOUS WEATHER ADVISORIES WITHIN A ONE-FIVE-ZERO NAUTICAL MILE RADIUS OF THIS HIWAS OUTLET.

b. The update recording shall be completed as soon as practicable, but not more than 15 minutes from time of receipt of new hazardous weather information.

2-4-3. CONTENT

Record hazardous weather information occurring within the HIWAS broadcast area. The broadcast shall include the following elements:

a. Statement of introduction including the appropriate area(s) and a recording time.

PHRASEOLOGY-
HIWAS WITHIN A ONE-FIVE-ZERO NAUTICAL MILE RADIUS OF (geographic area) RECORDED AT (time) ZULU (text).

NOTE-
Border facilities shall append "in domestic U.S. airspace" to the geographical area text in the introduction statement.

b. Statement of hazardous weather, including WSTs, WSs, WAs, UUAs, AWWs, and CWAs.

c. Request for PIREPs, if applicable. (See para 9-2-5.)

PHRASEOLOGY-
PILOT WEATHER REPORTS ARE REQUESTED.

d. Recommendation to contact AFSS/FSS/FLIGHT WATCH for additional details concerning hazardous weather.

PHRASEOLOGY-
CONTACT FLIGHT WATCH OR FLIGHT SERVICE, AS APPROPRIATE, FOR ADDITIONAL DETAILS.

2-4-4. BROADCAST PROCEDURES

a. Upon receipt of new hazardous weather information:

1. HIWAS facilities shall update the HIWAS broadcast.

2. Make a HIWAS update announcement once on all communications/NAVAID frequencies except on emergency, EFAS, and navigational frequencies already dedicated to continuous broadcast services. Delete reference to Flight Watch when those services are closed.

PHRASEOLOGY-
ATTENTION ALL AIRCRAFT, HAZARDOUS WEATHER ADVISORY UPDATE FOR (geographical area) IS AVAILABLE ON HIWAS, OR CONTACT FLIGHT WATCH, OR FLIGHT SERVICE.

b. In the event that a HIWAS broadcast area is out of service, make the following announcement on all communications/NAVAID frequencies except on emergency, EFAS, and navigational frequencies already dedicated to continuous broadcast services:

PHRASEOLOGY-
ATTENTION ALL AIRCRAFT, HAZARDOUS WEATHER ADVISORY UPDATE IS AVAILABLE FROM FLIGHT WATCH OR FLIGHT SERVICE.

NOTE-
Simultaneous announcements may cause heterodyne problems on multiple outlets having the same frequency and announcements may have to be rebroadcast to insure compliance.

2-4-5. SUSPENSION

HIWAS broadcasts shall not be suspended for routine maintenance during periods when weather advisories have been issued for the HIWAS outlet area.