AIM 8/15/19  e. SIGMET Outside the CONUS 1. Three NWS offices have been designated by ICAO as Meteorological Watch Offices (MWOs). These offices are responsible for issuing SIGMETs for designated areas outside the CONUS that include Alaska, Hawaii, portions of the Atlantic and Pacific Oceans, and the Gulf of Mexico. 2. The offices which issue international SIG- METs are: (a) The AWC in Kansas City, Missouri. (b) The AAWU in Anchorage, Alaska. (c) The WFO in Honolulu, Hawaii. 3. SIGMETs for outside the CONUS are issued for 6 hours for volcanic ash clouds, 6 hours for tropical cyclones (e.g. hurricanes and tropical storms), and 4 hours for all other events. Like the CONUS SIGMETs, SIGMETs for outside the CONUS are also identified by an alphabetic designator from Alpha through Mike and are numbered sequentially until that weather phenome- non ends. The criteria for an international SIGMET are: (a) Thunderstorms occurring in lines, embed- ded in clouds, or in large areas producing tornadoes or large hail. EXAMPLE − Example of SIGMET Outside the U.S.: WSNT06 KKCI 022014 SIGA0F KZMA KZNY TJZS SIGMET FOXTROT 3 VALID 022015/030015 KKCI −  MIAMI OCEANIC FIR NEW YORK OCEANIC FIR SAN JUAN FIR FRQ TS WI AREA BOUNDED BY 2711N6807W 2156N6654W 2220N7040W 2602N7208W 2711N6807W. TOPS TO FL470. MOV NE 15KT. WKN. BASED ON SAT AND LTG OBS. MOSHER f. AIRMET 1. AIRMETs (WAs) are advisories of signifi- cant weather phenomena but describe conditions at intensities lower than those which require the issuance of SIGMETs. AIRMETs are intended for dissemination to all pilots in the preflight and en route phase of flight to enhance safety. AIRMET information is available in two formats: text bulletins (WA) and graphics (G − AIRMET). Both formats meet the criteria of paragraph 7 − 1 − 3i and are issued on a scheduled basis every 6 hours beginning at 0245 UTC. Unscheduled updates and corrections are issued as necessary. AIRMETs contain details about IFR, extensive mountain obscuration, turbulence, strong surface winds, icing, and freezing levels. 2. There are three AIRMETs: Sierra, Tango, and Zulu. After the first issuance each day, scheduled or unscheduled bulletins are numbered sequentially for easier identification. (a) AIRMET Sierra describes IFR conditions and/or extensive mountain obscurations. (b) AIRMET Tango describes moderate turbulence, sustained surface winds of 30 knots or greater, and/or nonconvective low − level wind shear. (c) AIRMET Zulu describes moderate icing and provides freezing level heights. EXAMPLE − Example of AIRMET Sierra issued for the Chicago FA area: CHIS WA 131445 AIRMET SIERRA UPDT 2 FOR IFR AND MTN OBSCN VALID UNTIL 132100. AIRMET IFR...KY  FROM 20SSW HNN TO HMV TO 50ENE DYR TO20SSW HNN  CIG BLW 010/VIS BLW 3SM PCPN/BR/FG. CONDS ENDG BY 18Z.  . AIRMET IFR....MN LS FROM INL TO 70W YQT TO 40ENE DLH TO  30WNW DLH TO 50SE GFK TO 20 ENE GFK TO INL  CIG BLW 010/VIS BLW 3SM BR. CONDS ENDG 15 − 18Z.  . AIRMET IFR....KS FROM 30N SLN TO 60E ICT TO 40S ICT TO 50W LBL TO 30SSW GLD TO 30N SLN CIG BLW 010/VIS BLW 3SM PCPN/BR/FG. CONDS ENDG 15 − 18Z. . AIRMET MTN OBSCN...KY TN FROM HNN TO HMV TO GQO TO LOZ TO HNN MTN OBSC BY CLDS/PCPN/BR. CONDS CONTG 7 − 1 − 13 Meteorology (b) Tropical cyclones. (c) Severe icing. (d) Severe or extreme turbulence. (e) Dust storms and sandstorms lowering visibilities to less than 3 miles. (f) Volcanic ash.