Campbell Scientific PWS100 Present Weather Sensor - Manual (Page 112)

Appendix A. PWS100 Output Codes
Snow showers,
moderate
1
86 SHSN S S 1.0≤i<5.0 >0.5 mm
Snow showers, heavy 1 87 +SHSN S+ S+ i≥5.0 >0.5 mm
Reserved 88 - - - - -
Showers of hail, with
or without rain or rain
and snow mixed, not
associated with
thunder
1, 5
89 SHGR A A No Limit >0.5 mm
THUNDERSTORM 90 TS - - - -
Thunderstorm, slight
or moderate, with no
precipitation 91 -TS / TS - - - -
Thunderstorm, slight
or moderate, with rain
showers and/or snow
showers 92 -TS SHRA /
TS SHRA /
-TS SHSN /
TS SHSN /
-TS
SHSNRA /
TS
SHSNRA
- - - -
Thunderstorm, slight
or moderate, with hail 93 -TSGR /
TSGR
- - - >0.5 mm
Thunderstorm, heavy,
with no precipitation 94 +TS - - - -
Thunderstorm, heavy,
with rain showers
and/or snow showers 95 +TS SHRA
/ +TS
SHSN /
+TS
SHSNRA
- - - -
Thunderstorm, heavy,
with hail 96 +TSGR - - - >0.5 mm
Reserved 97-98 - - - - -
Tornado 99 FC - - - -
1 Reporting showers: The PWS100 does not presently report showers though this is due to be added to a future operating system once a
standard for reporting showers using automated instrumentation has been properly defined by the WMO.
2 The PWS100 uses the separated definitions for these outputs (see the bold entries directly below the entry identified). The same WMO code
will be output but a variation for the METAR and NWS codes may be observed.
3 These values are not from WMO documents.
4 Values for these events, where there are a mixture of particle types, are ill defined in WMO documents. The details from the WMO
documents and the implementation in the PWS100 is described further below.
5 WMO code 89 is used to indicate a hail event as there is no other WMO code of automatic stations that indicates hail. Like other present
weather sensors, this code is output when hail is detected, but there is no determination of whether this is a true shower event or not.
The WMO Guide to Meteorological Instruments and Methods of Observation
(WMO No. 8, 7
th Edition) gives the following information in the Annex to
Chapter 14 – ‘Present and Past Weather; State of the Ground’ regarding the
criteria for light, moderate and heavy precipitation intensity which was
recommended by the WMO Expert Meeting on Automation of Visual and
A-6