b. The cause of LIFR, IFR, or MVFR is indicated by either ceiling or visibility restrictions or both. The contraction “CIG” and/or weather and obstruction to vision symbols are used. If winds or gusts of 25 knots or greater are forecast for the outlook period, the word “WIND” is also included for all categories including VFR. 

## EXAMPLE − 

1. LIFR CIG − low IFR due to low ceiling. 

2. IFR FG − IFR due to visibility restricted by fog. 

3. MVFR CIG HZ FU − marginal VFR due to both ceiling and visibility restricted by haze and smoke. 

4. IFR CIG RA WIND − IFR due to both low ceiling and visibility restricted by rain; wind expected to be 25 knots or greater. 

## 7 − 1 − 8. Inflight Weather Advisory Broadcasts 

a. ARTCCs broadcast a Severe Weather Forecast Alert (AWW), Convective SIGMET, SIGMET, AIRMET, Urgent Pilot Report, or CWA alert once on all frequencies, except emergency, when any part of the area described is within 150 miles of the airspace under their jurisdiction. These broadcasts advise 

pilots of the availability of hazardous weather advisories and to contact the nearest Flight Service facility for additional details. 

## EXAMPLE − 

1. Attention all aircraft, SIGMET Delta Three, from Myton to Tuba City to Milford, severe turbulence and severe clear icing below one zero thousand feet. Expected to continue beyond zero three zero zero zulu. 

2. Attention all aircraft, convective SIGMET Two Seven Eastern. From the vicinity of Elmira to Phillipsburg. Scattered embedded thunderstorms moving east at one zero knots. A few intense level five cells, maximum tops four five zero. 

3. Attention all aircraft, Kansas City Center weather advisory one zero three. Numerous reports of moderate to severe icing from eight to niner thousand feet in a three zero mile radius of St. Louis. Light or negative icing reported from four thousand to one two thousand feet remainder of Kansas City Center area. 

## NOTE − 

Terminal control facilities have the option to limit the AWW, convective SIGMET, SIGMET, or CWA broadcast as follows: local control and approach control positions may opt to broadcast SIGMET or CWA alerts only when any part of the area described is within 50 miles of the airspace under their jurisdiction. 

