Natural siphon autographic raingauge

Llansadwrn (Anglesey) Weather

Observations from the observer's spreadsheet

FEBRUARY 2010

Logo: Llansadwrn Weather - Melin Llynnon, Ynys Môn.

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CLIMATOLOGICAL OBSERVATIONS AT LLANSADWRN, ANGLESEY, FOR FEBRUARY 2010
------09 GMT---> <-------Air temperature--------> <---Soil temp---> <---Earth temp---> <--State Grd.--> Rain Sol <-------Weather-------> Press Rain Fr. Pch
DD N dd ff V ww Temp Dpt RH Max Min Mean Gmin 5cm 10cm 20cm 30cm 50cm 100cm E C Gr SS mm MJ/m2 S L H T G F mb hrs hrs evap
1 6 NE 1 7 03 -0.3 -0.9 96 6.2 -1.0 2.6 -4.5 0.6 1.2 1.8 2.8 4.1 5.9 6 6 9 rem 6.8 3.08 1015 7.5 0.5 0.5
2 8 SW 4 5 61 6.2 6.0 98 7.4 -0.3 3.6 -2.6 4.0 3.8 2.6 3.2 4.0 5.8 2 3 3 0 3.0 0.76 1003 3.8 0.5 0.0
3 8 SE 1 7 03 1.2 0.4 94 5.8 0.2 3.0 -2.1 1.6 2.0 2.5 3.4 4.4 5.5 1 3 3 0 4.2 0.64 sl 1008 1.8 0.0 0.5
4 7 SE 1 8 25 4.7 4.0 95 9.7 1.2 5.5 -0.3 2.4 2.4 2.6 3.5 4.3 5.6 1 2 3 0 0.1 0.83 1001 0.0 0.0 1.7
5 7 S 3 7 02 6.5 4.4 87 10.4 4.8 7.6 3.8 4.2 4.4 4.0 4.3 4.5 5.7 1 2 3 0 0.0 4.62 996 0.0 0.0 0.8
6 6 NE 1 7 10 3.7 3.2 97 8.2 2.1 5.2 -1.2 2.0 2.3 3.1 4.1 4.8 5.5 1 1 5 0 tr fr 6.15 1014 0.0 0.0 0.5
7 6 SE 2 3 42 0.2 -0.4 96 7.5 -1.5 3.0 -4.5 1.0 1.6 2.8 3.8 4.8 5.9 3 4 5 0 0.1 6.90 1024 0.0 6.5 0.3
8 8 E 3 6 04 2.4 0.0 84 4.0 0.1 2.1 -1.7 2.6 3.0 3.0 3.9 4.6 5.6 1 1 3 0 0.2 3.07 s 3 1017 0.1 0.0 1.5
9 6 NE 4 8 01 2.9 -0.7 77 4.6 1.8 3.2 0.8 2.0 2.5 3.0 3.8 4.5 5.6 1 0 0 0 0.0 4.73 1017 0.0 0.0 1.6
10 6 NE 3 8 03 2.2 -0.6 82 4.6 1.1 2.9 -1.0 0.8 1.4 2.0 3.2 4.4 5.8 3 0 5 0 0.0 7.65 1020 0.0 0.0 2.0
11 1 NE 2 8 02 0.5 -3.1 76 4.6 -1.0 1.8 -3.8 0.3 1.0 1.5 2.8 4.1 5.5 3 0 5 0 tr 8.70 1026 0.0 6.5 1.1
12 6 NE 3 6 01 2.5 1.5 93 5.7 0.0 2.9 -2.8 1.0 1.5 1.5 2.8 3.9 5.4 1 1 4 0 tr 6.58 1027 0.0 0.0 1.1
13 7 NE 2 8 03 2.7 -2.2 70 5.5 0.6 3.1 -2.3 1.3 1.8 2.1 3.1 4.0 5.2 1 0 0 0 tr 7.15 1028 0.0 0.0 0.9
14 7 E 1 7 05 2.2 1.1 93 4.8 0.2 2.5 -3.5 1.5 2.0 2.5 3.2 4.3 5.4 1 2 4 0 8.4 2.36 1020 9.7 0.0 0.5
15 8 SW 1 3 47 4.7 4.5 98 6.4 2.1 4.3 1.9 3.9 3.8 3.2 3.9 4.3 5.5 1 2 3 0 6.4 2.18 sl 3 1 1006 9.5 0.0 0.0
16 6 SW 1 6 01 1.0 1.0 100 6.6 0.1 3.4 -2.2 1.7 2.3 2.9 3.8 4.6 5.4 1 2 5 0 2.0 5.25 s 3 990 2.0 0.0 0.3
17 1 NE 1 8 02 -0.5 -2.3 88 6.5 -1.7 2.4 -6.0 0.6 1.4 2.1 3.3 4.4 5.5 1 4 5 0 tr fr 10.43 990 0.0 11.8 0.5
18 7 NE 2 5 10 1.7 1.2 96 4.3 -0.5 1.9 -3.5 1.0 1.5 1.8 2.9 4.2 5.3 3 2 4 0 2.7 4.97 2 991 1.3 1.2 0.2
19 8 W 2 4 72 0.1 -0.2 98 3.8 -2.2 0.8 -5.4 0.8 1.5 2.1 2.9 3.8 5.2 6 7 9 1 4.6 4.14 s 1 3 994 5.0 10.5 0.6
20 5 SW 1 7 01 0.2 -1.9 86 6.9 -1.3 2.8 -6.0 0.6 1.0 1.2 2.4 3.6 5.2 8 9 9 2 3.0 7.32 s 1 996 3.8 10.5 0.6
21 6 W 2 6 01 0.5 0.2 98 4.3 -0.7 1.8 -4.3 1.0 1.5 1.3 2.5 3.5 5.1 6 7 9 2 0.1 4.62 s 1 2 988 0.0 2.0 0.7
22 6 E 4 7 04 0.3 -2.1 84 4.2 -1.6 1.3 -4.8 0.5 1.1 1.3 2.5 3.5 5.1 3 5 5 rem 0.0 9.05 987 0.0 13.0 1.0
23 6 E 2 7 04 0.4 -3.3 76 6.4 -1.3 2.6 -4.4 0.4 1.0 1.2 2.5 3.5 5.0 3 0 5 rem 3.7 5.82 s 2 991 4.2 11.3 0.9
24 2 SE 2 6 05 6.1 4.7 91 12.8 0.4 6.6 0.0 2.8 2.8 2.0 2.6 3.3 5.0 1 2 3 0 tr 9.35 sl 986 0.0 0.0 1.3
25 7 S 2 6 80 5.8 5.3 97 9.1 3.0 6.1 0.8 4.3 4.1 3.7 4.0 4.0 5.0 1 3 3 0 tr 6.76 sl 2 987 0.0 0.0 0.7
26 8 SW 2 7 05 3.5 1.4 86 6.2 2.8 4.5 0.9 4.1 4.3 4.2 4.5 4.6 5.0 1 0 1 0 0.9 4.63 4 987 1.0 0.0 0.5
27 7 NE 1 8 02 3.2 1.4 88 9.8 1.6 5.7 -1.2 2.5 3.0 3.5 4.3 4.8 5.2 1 1 4 0 tr 9.37 992 0.0 0.0 1.1
28 8 N 2 7 02 3.5 1.2 85 6.5 2.9 4.7 1.8 3.6 4.0 4.0 4.7 5.0 5.6 1 1 3 0 tr fr 7.00 990 0.0 0.0 0.6
N 78 %
Means----> 2.4 0.8 90 6.5 0.4 3.5 -2.1 1.9 2.3 2.5 3.4 4.2 5.4 5.5 1003
Totals-----> 46.2 154.1 10 3 8 0 0 2 49.7 74.3 22.0
MEANS AND AVERAGES AT LLANSADWRN, ANGLESEY FOR FEBUARY 2010
Differences from 2000-2009 average* as used by the Weather Observers Network & from 1971-2000 average**.
Air temperature * ** Weather (No. days occurrence) * Wind direction (days) Rainfall (mm) * **
Mean maximum 6.5 -2.0 -2.0 Sleet/ snow falling 10 6.4 N 1 Total 46.2 51 62 %
Mean minimum 0.4 -2.4 -1.7 Snow lying (at 09 GMT) 3 2.3 NE 10 Largest fall 8.4
Mean (max+min)/2 3.5 -2.2 -1.8 Hail <5 mm 8 2.5 E 4
Highest maximum 12.8 0.3 Hail >=5 mm 0 {All types} SE 4 Evaporation (mm)
Lowest maximum 3.8 -0.2 Thunder heard 0 -0.2 S 2 Lysimeter PE 3.3
Highest minimum 4.8 -3.2 Gales 0 n.a. SW 5 Monthly total PWB 42.9
Lowest minimum -2.2 -0.7 Fog (at 09 GMT) 0 n.a. W 2 PWS 44.8
No. days <0.0C 11 6.9 Rainfall (No. days occurrence) NW 0 PWD -1.9
Grass minimum mean -2.1 -2.3 No pptn 0.0 mm 4 -2.5 Calm 0
Lowest minimum -6.0 0.0 Dry < 0.2 mm 16 5.3 Piche (ml) 22.0
No. days <0.0C 21 5.9 Rain >= 0.2 mm 12 -5.6 Check days 28
Earth temperature 30cm 3.4 -2.3 Wet >= 1.0 mm 10 -2.8 This month 28
>= 5.0 mm 3 -2.6

Feb_temp.gif Feb_rain.gif Feb_msl.gif Feb_soil.gif Feb_sol.gif Feb_rh.gif Feb_wind.gif Feb_pe.gif

Note: Any peaks seen on the PE graph are due to recent rainfalls having not yet percolated through the soil. This method is not good for daily measurements, but good results are obtained over 3 days (allowing time for percolation) and on a monthly basis. The lysimeter also measures dew and depositions of frost, and is a better raingauge than one with a rim at 30 cm high. In winter, when evaporation from the ground is low, negative values are sometimes seen and indicate an accumulation of dew and frost, and more rain than measured by a standard raingauge. In summer, when evaporation is high and rainfall less, the lysimeter still measures dew and more rain than the standard gauge, but the effect is less noticeable. The daily graph is show here for it's interest and you can read more about this 'classic' method of measuring evaporation here

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KEY: OBSERVATIONS AT 09 GMT

  DD date; N cloud (oktas, 9=obscured); DD wind direction (8 sectors, 00=calm); ff wind speed (Beaufort scale);
  V visibility (0 dense fog, 1 thick fog, 2 fog, 3 moderate fog, 4 very poor, 5 poor, 6 moderate, 7 good, 8 very good);
  WW present weather SYNOP code (eg. 01 cloud decreasing, 02 sky not changing, 03 cloud increasing, 04 smoke haze, 05 haze)
  Temperatures (degC); Temp dry bulb temperature; Dpt dewpoint; RH relative humidity (%); soil temperatures are under bare
  soil and earth under grass; SS snow depth (cm), rem is remnant remaining; Press air pressure, aneroid (mb). 
  For state of the ground E, concrete C, and grass Gr codes consult the page on 'Recording Atmospheric Depositions on Grass'.

24 hour observations...

  Max maximum temperature (degC) beginning 09GMT; Min minimum temperature ending 09GMT;
  Gmin grass minimum temperature (degC) ending 09GMT; Pch Evap Piche evaporation (ml) beginning 09GMT;
  Rain rainfall beginning 09GMT (mm); Rain hrs hours of rainfall (>0.1mm/hr) 09-09GMT; trace <0.05 mm; tr trace of rain; tr dw trace of dew;
  tr fr trace of frost; Fr. hrs hours of frost (09-09GMT).
  Sol MJ/m2 Global Solar Radiation (MJ per m2) 21-21 GMT. 

Monthly observations...

  PE Potential evapotranspiration, PWB Potential water balance, PWS Potential water surplus, PWD Potential water deficit.

Weather: days with...

  s slight or S heavy snow/sleet falling; L >=50% snow cover at 09GMT; H categories of hail: 1 ice crystals, 2 snow grains,
  3 snow pellets, 4 ice pellets, 5 hail 5-9 mm, 6 hail 10-19 mm; t slight or T heavy thunder heard; G gale; Fog any hour 1, 09 GMT 9.

Monthly summary and annual statistics. Monthly summary and annual statistics

Go here for the latest diary. Latest diary

These pages are designed and written by Donald Perkins © 2010

http://www.llansadwrn-wx.co.uk

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