A summary of
the main units and codes
used in the registers and weather reports
released by Pitsford Hall weather station.
Standard units
Temperatures:
ºC
Rainfall: mm
Duration of rain: hrs
Rainfall acidity: pH
Pressure: mb
Winds: knots* (Run of wind: miles)
Cloud cover: oktas
Duration of sunshine:hrs
Relative Humidity: %
*Given as mph in data before 1 July 2000.
Standard cloud types
Cirrus Ci
Cirrocumulus Cc
Cirrostratus Cs
Altocumulus Ac
Altostratus As
Nimbostratus Ns
Stratocumulus Sc
Stratus St
Cumulus Cu
Cumulonimbus Cb
Cloud types
only appear in datasets prior to
1 July 2000. This information has since been
discontinued.
Visibility codes
X Dense Fog
<20m
E Dense Fog 20m
0 Thick Fog up to 40m
1 Thick Fog up to 100m
2 Fog up to 200m
3 Moderate Fog up to 400m
4 Very poor visibility up to 1000m
5 Poor visibility up to 2km
6 Moderate visibility up to 7km
7 Good visibility up to 20km
8 Very good visibility up to 30km
9 Excellent visibility 40km
State
of the Ground
Not observerd between June and December 2007.
(Relating to the bare patch in the
agro-met and/or climatological enclosures
and the representative
area*)
Without
snow
0
Surface dry (without cracks)
1 Surface moist
2 Surface wet (with puddles)
3 Surface flooded
4 Surface frozen
5* Glaze on ground
6* Surface partly covered in dry dust
7* Surface covered in dry dust
8* Thick covering of dry dust
9* Surface very dry with cracks
With
snow
0*
Ground mostly ice covered
1* Wet/compact snow covering < half
2* Wet/compact snow covering half
3* Ground evenly covered by wet/compact snow
4* Ground unevenly covered by wet/compact snow
5* Dry/loose snow covering < half
6* Dry/loose snow covering half
7* Ground evenly covered by dry/loose snow
8* Ground unevenly covered by dry/loose snow
9* Complete snow cover, drifting
State
of the Concrete Slab
0 Dry
1 Moist
2 Wet
3 Icy
State of the Grass
Discontinued
June 2007
(Meaden's code, 1996)
0 Dry with no deposits
1 Wet with dew only
2 Wet from fog (some dew present)
3 Wet from falling rain or drizzle
4 Wet from the melting of frozen
deposits listed as codes 5-9, or from sleet
5 Ice resulting from the freezing of 1-3 or the
refreezing of 4
6 Ice of glaze resulting from freezing of rain or
drizzle on cold surface or ice from hail
7 Hoar frost - direct deposition of crystals from air
8 Rime - direct deposition of crystals from supercooled
freezing fog or falling ice prisms or fall ice crystals
9 Snow 9
Present Weather
00 -- clear skies
01 -- clouds dissolving
02 -- state of sky unchanged
03 -- clouds developing
Haze, smoke, dust or sand
04 -- visibility reduced by smoke
05 -- haze
06 -- widespread dust in suspension not raised by wind
07 -- dust or sand raised by wind
08 -- well developed dust or sand whirls
09 -- dust or sand storm within sight but not at station
Non-precipitation events
10 -- mist
11 -- patches of shallow fog
12 -- continuous shallow fog
13 -- lightning visible, no thunder heard
14 -- precipitation within sight but not hitting ground
15 -- distant precipitation but not falling at station
16 -- nearby precipitation but not falling at station
17 -- thunderstorm but no precipitation falling at station
18 -- squalls within sight but no precipitation falling at
station
19 -- funnel clouds within sight
Precipitation within past hour but not at observation time
20 -- drizzle
21 -- rain
22 -- snow
23 -- rain and snow
24 -- freezing rain
25 -- rain showers
26 -- snow showers
27 -- hail showers
28 -- fog
29 -- thunderstorms
Duststorm, sandstorm, drifting or blowing snow
30 -- slight to moderate duststorm, decreasing in intensity
31 -- slight to moderate duststorm, no change
32 -- slight to moderate duststorm, increasing in intensity
33 -- severe duststorm, decreasing in intensity
34 -- severe duststorm, no change
35 -- severe duststorm, increasing in intensity
36 -- slight to moderate drifting snow, below eye level
37 -- heavy drifting snow, below eye level
38 -- slight to moderate drifting snow, above eye level
39 -- heavy drifting snow, above eye level
Fog or ice fog
40 -- Fog at a distance
41 -- patches of fog
42 -- fog, sky visible, thinning
43 -- fog, sky not visible, thinning
44 -- fog, sky visible, no change
45 -- fog, sky not visible, no change
46 -- fog, sky visible, becoming thicker
47 -- fog, sky not visible, becoming thicker
48 -- fog, depositing rime, sky visible
49 -- fog, depositing rime, sky not visible
Drizzle
50 -- intermittent light drizzle
51 -- continuous light drizzle
52 -- intermittent moderate drizzle
53 -- continuous moderate drizzle
54 -- intermittent heavy drizzle
55 -- continuous heavy drizzle
56 -- light freezing drizzle
57 -- moderate to heavy freezing drizzle
58 -- light drizzle and rain
59 -- moderate to heavy drizzle and rain
Rain
60 -- intermittent light rain
61 -- continuous light rain
62 -- intermittent moderate rain
63 -- continuous moderate rain
64 -- intermittent heavy rain
65 -- continuous heavy rain
66 -- light freezing rain
67 -- moderate to heavy freezing rain
68 -- light rain and snow
69 -- moderate to heavy rain and snow
Snow
70 -- intermittent light snow
71 -- continuous light snow
72 -- intermittent moderate snow
73 -- continuous moderate snow
74 -- intermittent heavy snow
75 -- continuous heavy snow
76 -- diamond dust
77 -- snow grains
78 -- snow crystals
79 -- ice pellets
Showers
80 -- light rain showers
81 -- moderate to heavy rain showers
82 -- violent rain showers
83 -- light rain and snow showers
84 -- moderate to heavy rain and snow showers
85 -- light snow showers
86 -- moderate to heavy snow showers
87 -- light snow/ice pellet showers
88 -- moderate to heavy snow/ice pellet showers
89 -- light hail showers
90 -- moderate to heavy hail showers
Thunderstorms
91 -- thunderstorm in past hour, currently only light rain
92 -- thunderstorm in past hour, currently only moderate to heavy
rain
93 -- thunderstorm in past hour, currently only light snow or
rain/snow mix
94 -- thunderstorm in past hour, currently only moderate to heavy
snow or rain/snow mix
95 -- light to moderate thunderstorm
96 -- light to moderate thunderstorm with hail
97 -- heavy thunderstorm
98 -- heavy thunderstorm with duststorm
99 -- heavy thunderstorm with hail
Weather Diary - Past Weather
(Beaufort Letters)
Other Codes
SYNOP Code
(no longer in use by
this station)
The coding system in use at
Pitsford Hall
weather station is that detailed in the
Observer's Handbook (1982) and
Metform3100A, supplement to the daily
register. State of the Grass observations
are non-standard & are attributed to
Meaden (1996); this record commenced
at Pitsford Hall during September 2001.