SIGMET These messages are intended to provide short term warnings of certain potentially hazardous weather phenomena. These messages are intended to provide.

SIGMETSIGMET• These messages are intended to provide These messages are intended to provide

short term warnings of certain potentially short term warnings of certain potentially hazardous weather phenomena. hazardous weather phenomena.

• Warnings are issued for:Warnings are issued for:– active thunderstorm areas, active thunderstorm areas, – lines of thunderstorms, lines of thunderstorms, – heavy hail, heavy hail, – severe turbulence or icing, severe turbulence or icing, – marked mountain waves, marked mountain waves, – hurricanes, hurricanes, – widespread sand or dust storms, widespread sand or dust storms, – volcanic ash, volcanic ash, – and low level windshear. and low level windshear.

SIGMETSIGMET

• Sigmets are meant especially to Sigmets are meant especially to warn pilots who are already flying warn pilots who are already flying about severe weatherabout severe weather

• Sigmets are broadcast by VFR and Sigmets are broadcast by VFR and IFR air traffic control units, FSS, and IFR air traffic control units, FSS, and are available on the Navcanada are available on the Navcanada weather website.weather website.

SIGMETSIGMET

WSCN31 CWTO 250430WSCN31 CWTO 250430SIGMET A1 VALID 250430/250830SIGMET A1 VALID 250430/250830LN TSTMS 30NM WIDE MAX TOPS 400 OBSRVD AT 0400Z FROM LN TSTMS 30NM WIDE MAX TOPS 400 OBSRVD AT 0400Z FROM LONDON-TORONTO-PETERBOROUGH. LN MOVG SWD ABT 20 LONDON-TORONTO-PETERBOROUGH. LN MOVG SWD ABT 20 KTS AND INTSFYG. TSTMS MOVG OUT OF AREA BY 0730Z.KTS AND INTSFYG. TSTMS MOVG OUT OF AREA BY 0730Z.

Significant Meteorological Report

Severe Icing or Turbulence not associated with convective cloudsLarge area for dust storm or sandstorm (most likely in the Prairies)Possible volcanic ash clouds, hurricanes and tropical storms (uncommon in Canada)

SIGMETLine of thunderstorms or active area of thunderstorms

Severe Squall LineMountain Waves (mostly Rockies)

Heavy hail (rarely)Tornado or Water Spout

Low level wind shear

PIREPs (PIlot REPorts) PIREPs (PIlot REPorts)

• PIREPs are reports of weather PIREPs are reports of weather conditions encountered by aircraft conditions encountered by aircraft during flight. during flight.

• Pilots are encouraged to file brief Pilots are encouraged to file brief reports of weather conditions especially reports of weather conditions especially reports of any significant atmospheric reports of any significant atmospheric phenomena that differ from forecast. phenomena that differ from forecast.

• PIREPs are usually reported to Flight PIREPs are usually reported to Flight Service Stations but can be passed Service Stations but can be passed along to Air Traffic Control as well.along to Air Traffic Control as well.

PIREP (AIM MET 2-0)PIREP (AIM MET 2-0)

UACN10 CYXU 032133 YZ UA /OV YXU 090010 /TM 2120 /FL080 UACN10 CYXU 032133 YZ UA /OV YXU 090010 /TM 2120 /FL080 /TP PA31 /SK 020BKN040 110OVC /TA 12 /WV 030045 /TB MDT /TP PA31 /SK 020BKN040 110OVC /TA 12 /WV 030045 /TB MDT BLO 040 /IC LGT RIME 020040 /RM NIL TURB CYYZ CYHM BLO 040 /IC LGT RIME 020040 /RM NIL TURB CYYZ CYHM

TRY TO DECIPHER THIS FOR YOURSELF

Go to: http://www.tc.gc.ca/civilaviation/publications/tp14371/met/3-0.htm#3-17to see how you did!

PIREPSPIREPS

• Significant weather that can be Significant weather that can be reported by PIREP includes, but is not reported by PIREP includes, but is not limited to:limited to:– Clear Air TurbulenceClear Air Turbulence– Wind ShearWind Shear– Airframe IcingAirframe Icing– Volcanic AshVolcanic Ash– Pilot Estimation of Surface WindPilot Estimation of Surface Wind

Levels of Turbulence (AIM-MET Levels of Turbulence (AIM-MET 3.7)3.7)

INTENSITY AIRCRAFT REACTION REACTION INSIDE AIRCRAFT

LIGHT

Turbulence that momentarily causes slight, erratic changes in altitude and/or attitude (pitch, roll, yaw).Report as “Light Turbulence”.

OR Turbulence that causes slight, rapid and somewhat rhythmic bumpiness without appreciable changes in altitude or attitude.Report as “Light Chop”.

Occupants may feel a slight strain against seat belts or shoulder straps. Unsecured objects may be displaced slightly. Food service may be conducted and little or no difficulty is encountered in walking.

Levels of Turbulence (AIM-MET Levels of Turbulence (AIM-MET 3.7)3.7)

INTENSITY AIRCRAFT REACTION REACTION INSIDE AIRCRAFT

MODERATE

Turbulence that is similar to Light Turbulence but of greater intensity. Changes in altitude and/or attitude occur but the aircraft remains in positive control at all times. It usually causes variations in indicated airspeed. Report as “Moderate Turbulence”.OR Turbulence that is similar to Light Chop but of greater intensity. It causes rapid bumps or jolts without appreciable changes in aircraft altitude or attitude. Report as “Moderate Chop”.

Occupants may feel a slight strain against seat belts or shoulder straps. Unsecured objects may be displaced slightly. Food service may be conducted and little or no difficulty is encountered in walking.

Levels of Turbulence (AIM-MET Levels of Turbulence (AIM-MET 3.7)3.7)INTENSITY AIRCRAFT REACTION REACTION INSIDE AIRCRAFT

SEVERE

Turbulence that causes large, abrupt changes in altitude and/or attitude. It usually causes large variations in indicated airspeed. Aircraft may be momentarily out of control.Report as “Severe Turbulence”.

Occupants are forced violently against seat belts or shoulder straps. Unsecured objects are tossed about. Food service and walking impossible.

NOTES 1: Occasional: Less than 1/3 of the time. Intermittent: 1/3 to 2/3. Continuous: More than 2/3.

Icing Types and IntensitiesIcing Types and IntensitiesINTENSITY ICE ACCUMULATION

Trace

Ice becomes perceptible. The rate of accumulation is slightly greater than the rate of sublimation. It is not hazardous, even though de-icing or anti-icing equipment is not used, unless encountered for

an extended period of time (over 1 hour).

LightThe rate of accumulation may create a problem if flight is prolonged in this environment (over 1 hour).

ModerateThe rate of accumulation is such that even short encounters become

potentially hazardous, and use of de-icing or anti-icing equipment or diversion is necessary.

Severe The rate of accumulation is such that de-icing or anti-icing equipment fails to reduce or control the hazard. Immediate

diversion is necessary.

*Rime ice:Rough, milky, opaque ice formed by the instantaneous freezing of

small supercooled water droplets.

*Clear ice:Glossy, clear, or translucent ice formed by the relatively slow freezing of large supercooled water droplets.

Icing typesIcing types

Clear Ice Clear Ice (there is a bit of (there is a bit of

mixed here too)mixed here too)Rime Ice

PIREP report Mixed IcingPIREP report Mixed Icing