that  may  require  an  amended  TAF.  Table  3-5  is  a summary  of  minimum  amendment  criteria.     More stringent   amendment   criteria   may   be   established locally.  The  actual  time  that  the  amendment  is completed for transmission is the last element encoded. For  example,  an  amendment  completed  at  2130  UTC would have as the last element "AMD 2130." Not   all,   but   most   aviation   weather   offices   are equipped  with  a  PMSV  voice  radio.  PMSV  radio  is used to pass updated weather observations and forecasts to aircraft in flight and to receive pilot-reported, flight- level, weather observations or pilot reports (PIREPs). The   duty   observer   is   normally   assigned   the responsibility  to  transmit  and  receive  traffic  over  the PMSV  radio.  In  the  next  section,  we  will  discuss  the PIREP code. Q1. Q2. Q3. Q4. Q5. REVIEW  QUESTIONS What instruction governs the use of the Terminal Aerodrome  Forecast  (TAF)  code  for  Navy  and Marine Corps activities? What  are  the  standard  synoptic  times  for  the transmission  of  TAFs  and  what  is  the  valid forecast period? What   cloud   genus   is   always   reported   as   a separate group for element N_sN_sN_sh_sh_sh_s of the TAF code? When is the abbreviation "WSCONDS" used in the TAF code? How should light icing from 6,000 to 10,000 feet be encoded in a TAF? Table 3-5.—Minimum Amendment Criteria Minimum  Amendment  Criteria Ceilings  and  Visibilities Whenever ceilings and/or visibilities are observed or are later forecast to increase to, equal or exceed, or decrease to less than any  of  the  following: Ceiling Visibility 3,000  ft 4,800  meters 1,000  ft 1,600  meters 200  ft 800   meters Surface   Winds Wind speed change of 10 knots or more. Directional change of 30° or more when mean wind or gusts are in excess of 15 knots. Winds  speed  or  directional  change  resulting  in  change  of active  runway. Thunderstorm  or  Tornadic  Activity Thunderstorm or tornadic activity was not forecast to occur, but later occurs or is expected to occur. Thunderstorm  or  tornadic  activity  was  forecast,  but  later  is  not expected. Precipitation Precipitation that will affect safety of flight, including runway braking  action,  is  occurring  or  is  forecast  to  occur,  of  if forecast, is no longer expected. Non-Convective,  Low-Level  Wind  Shear Low-Level Wind Shear is occurring or forecast to occur, or if forecast, is no longer expected. Q N H  Whenever the observed altimeter falls below, or is expected to fall  below  the  original  forecast. 3-4