AIM
5/19/22
FIG 7
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1
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5
Hawaii Area Forecast Locations
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.
(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.
EXAMPLE
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Example of SIGMET Outside the U.S.:
WSNT06 KKCI 022014
SIGA0F
KZMA KZNY TJZS SIGMET FOXTROT 3 VALID
022015/030015 KKCI
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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
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AIRMET). Both formats meet
the criteria of paragraph 7
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1
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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
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Meteorology