(MI, PR, DR, BL, BC, SH, TS, or FZ), and a two-letter weather  descriptor.  When  more  than  one  type  of precipitation is falling at the same time, up to 3 two- letter precipitation descriptors may be combined in the same group. Obscurations are normally only reported when the prevailing visibility is less than 7 miles. Note that no intensity qualifier may be coded with VC. Table 3-2 provides a list of METAR/SPECI code weather phenomena type entries. Q10. REVIEW  QUESTIONS How many types of observations are in the METAR  code? Q11. Q12. What elements make up the identification section of a METAR observation? How should a wind direction of 183° a wind speed of 105 knots, and gusts at 120 knots be encoded? Q13.   How should a variable wind of 090° to 150° at 15 knots be encoded? Q14. Q15. What does the symbol VVVVVSM indicate? How should the RVR information "left runway 02, visibility 1,000 feet, varying 3,000 feet" be encoded? Q16. What does the symbol BR indicate? Q17. How should heavy showers in the vicinity be encoded? Q18. What does the symbol PO indicate? Sky  Coverage/Height  Group Either the group N_SN_Sh_Sh_Sh_S is used up to three times to report cloud layer coverage and height or the group VVhshshs is used to report conditions when the sky is obscured. The abbreviation "SKC" is used when the sky is clear. CLOUD  COVERAGE  /  HEIGHT.— N_SN_SN_Sh_Sh_Sh_S.  This  group  is  used  to  report  coverage  of cloud layers or cloud masses, not specifically for individual cloud types. The summation principle is used to evaluate sky coverage in ascending order, as discussed  in  chapter  1.  The  same  sky  coverage abbreviations for N_SN_SN_S are also used on the form; that is, FEW for 1/8 to 2/8 coverage, SCT for scattered (3/8 to 4/8), BKN for broken (5/8 to 7/8), and OVC for overcast  (8/8).  The  cloud  base  height,  h_Sh_Sh_S,  is encoded in hundreds of feet, as discussed in chapter 1. At mountain stations, if the layer is below station level, the height of the layer will be coded as ///. This group may be used six times for masses of clouds at six different levels. When CB or TCU clouds are observed, the cloud abbreviation is added to the end of the group, as in "BKN035CB." Stations overseas are Table 3-2.—METAR/SPECI Code Weather Phenomena Type Entries QUALIFIER WEATHER   PHENOMENA Intensity or Other Proximity 1 2 5 -  Light Moderate Dust/Sand + Heavy Whirls VC  Vicinity Descriptor MI  Shallow PR  Partial BC  Patches DR   Low Drifting SQ Squalls BL  Blowing SH  Shower(s) Tornado TS  Thunderstorm Waterspout FZ  Freezing Precipitation 3 DZ Drizzle RA Rain SN Snow SG   Snow Grains IC    Ice Crystals PE Ice Pellets GR Hail GS   Small Hail and/or Ice Pellets Obscuration 4 BR Mist FG Fog FU Smoke VA Volcanic Ash DU  Widespread Dust SA Sand HZ Haze PY  Spray PO  Well-dvlpd FC Funnel Cloud SS  Sandstorm DS  Duststorm NOTE: The weather groups are constructed by considering columns 1 to 5 in the table above in sequence, i.e., intensity followed by description, followed by weather phenomena. Example, heavy rainshower(s) is coded as +SHRA. 3-8