The descriptors low drifting (DR) and blowing (BL) will only be coded with dust (DU), sand (SA), and snow (SN) (e.g., BLSN or DRSN). DR is coded with DU, SA, or SN for raised particles drifting less than 6 ft above the ground.

When blowing snow is observed with snow falling from clouds, both phenomena are reported (e.g., SN BLSN). If blowing snow is occurring and the observer cannot determine whether or not snow is also falling, then BLSN is reported. Spray (PY) is coded only with blowing (BL).

The descriptor for showery-type precipitation (SH) is coded only with one or more of the precipitation qualifiers for rain (RA), snow (SN), ice pellets (PL), or hail (GR). When any type of precipitation is coded with VC, the intensity and type of precipitation is not coded.

The descriptor for thunderstorm (TS) may be coded by itself when the thunderstorm is without associated precipitation. A thunderstorm may also be coded with the precipitation types of rain (RA), snow (SN), ice pellets (PL), snow pellets (GS), or hail (GR). TS is not coded with SH.

The descriptor freezing (FZ) is only coded in combination with fog (FG), drizzle (DZ), or rain (RA) (e.g., FZRA). FZ is not coded with SH.

Precipitation is any form of water particle, whether liquid or solid, that falls from the atmosphere and reaches the ground. The precipitation types are drizzle (DZ), rain (RA), snow (SN), snow grains (SG), ice crystals (IC), ice pellets (PL), hail (GR), snow pellets (GS), and unknown precipitation (UP). UP is reported if an automated station detects the occurrence of precipitation, but the precipitation sensor cannot recognize the type.

Up to three types of precipitation may be coded in a single present weather group. They are coded in order of decreasing dominance based on intensity.

Obscurations are any phenomenon in the atmosphere, other than precipitation, that reduces the horizontal visibility in the atmosphere. The obscuration types are mist (BR), fog (FG), smoke (FU), volcanic ash (VC), widespread dust (DU), sand (SA), haze (HZ), and spray (PY). Spray (PY) is coded only as BLPY.

With the exception of volcanic ash, low drifting dust, low drifting sand, low drifting snow, shallow fog, partial fog, and patches (of) fog, an obscuration is coded in the body of the report if the surface visibility is less than seven miles or if the obscuration is considered operationally significant. Volcanic ash is always reported when observed.

Other weather phenomenon types include well-developed dust/sand whirls (PO), sandstorms (SS), dust storms (DS), squalls (SQ), funnel clouds (FC), and tornados and waterspouts (+FC).

Examples:

-DZ Light drizzle.

-RASN Light rain and (light) snow.

SN BR (Moderate) snow, mist.

-FZRA FG Light freezing rain, fog.

SHRA (Moderate) rain shower.

VCBLSA Blowing sand in the vicinity.