UK Climate Projections - What is UKCP09: UKCIP02 & UKCP09 4.3 Mean winter precipitation

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You are here: Home What is UKCP09? Upgrading to UKCP09 Assessing the differences – UKCIP02 & UKCP09 4 Assessing the differences 4.3 Mean winter precipitation
	What is UKCP09? Upgrading to UKCP09 Assessing the differences – UKCIP02 & UKCP09 1 Background & purpose 2 Key differences 3 Do I need to update earlier assessments? 4 Assessing the differences 4.1 Mean winter temperature 4.2 Mean summer temperature 4.3 Mean winter precipitation 4.4 Mean summer precipitation Figure 27: Winter mean temperature Figure 28: Summer mean temperature Figure 29: Winter mean precipitation Figure 30: Summer mean precipitation Appendix	4.3 Mean winter precipitation Key Points: UKCIP02 values and UKCP09 central estimates are broadly similar with notable regional differences in North and West Scotland across all time periods (Figures 15–20). All UKCIP02 values are within the UKCP09 range. Projections of winter precipitation are generally similar between UKCP09 and UKCIP02 for the 2020s (Figures 19–20), with UKCP09 showing slightly greater increases in winter precipitation for the 2050s and 2080s (Figures 15–18). The notable exceptions to this are in Northern and Western Scotland and the Channel Islands. The largest differences are in Northern Scotland, where in all time periods and emission scenarios the UKCIP02 value is in the lowest part of the UKCP09 range, with the UKCP09 central estimate consistently +10% higher than the UKCIP02 value (Figures 15–20). There are also large differences in the UKCP09 central estimates and the UKCIP02 values for the Channel Islands for the 2020s and the 2050s (Low emissions scenario only) with the UKCP09 central estimate being over 10% greater than the UKCIP02 value. Western Scotland also has marked differences between the UKCP09 central estimate and the UKCIP02 value but in the 2080s only. The plot for the 2080s Low emissions scenario clearly illustrates the differences between the UKCP09 central estimate and the UKCIP02 value in the Northern and Western Scottish regions (Figures 15–20). For most of the UK there is little difference in winter mean precipitation between UKCP09 central estimates and UKCIP02 values. The exception being in Scotland, where by the 2080s there is difference of +10 to +40% on the western and northern coastal areas and –10 to –30% in the northeast (Cairngorm) (Figure 29). This is due to change from UKCIP02 which projected small (<10%) increases in winter precipitation in NW Scotland compared to UKCP09 projections of 20-50% increases. The northeast/cairngorm area goes from UKCIP02 projected increase of +10-30% to negligible increase or even drying in UKCP09 (±10% change) (Figure 29).

		Figure 15: Change in winter mean precipitation for the 2080s High emissions scenario



		Figure 16: Change in winter mean precipitation for the 2080s Low emissions scenario



		Figure 17: Change in winter mean precipitation for the 2050s High emissions scenario



		Figure 18: Change in winter mean precipitation for the 2050s Low emissions scenario



		Figure 19: Change in winter mean precipitation for the 2020s High emissions scenario



		Figure 20: Change in winter mean precipitation for the 2020s Low emissions scenario

Last Updated Wednesday, 20 July 2011