Precipitation related variables

Maximum five-day precipitation total

 
 

Figure 38 - Maximum five-day precipitation total (in millimetres) each year for Scottish regions,
from 1961 to 2004, with smoothed curves showing a running average.

Table 20 - Changes in maximum five-day precipitation amount (as a percentage), from 1961 to 2004. Values in bold show that we are 95% confident (statistically) that the change is part of a measurable trend.

 

North Scotland East Scotland West Scotland Scotland
Rainfall intensity (%) 16.8 25.2 24.5 21.3

 

Regional trends

 

  • The average increase since 1961 is over 20%. We can clearly see an increasing trend.
  • The value of this measure varies greatly from year to year, and, apart from a few years, there is little agreement between the regional average values in any one year.
  • Values of the index are very similar in North and West Scotland, although a steadily increasing trend is clear in all regions.
  • The lower rainfall totals of East Scotland are reflected in lower maximum five-day averages.

Spatial trends

 

  • As with rainfall intensity there is an increase for most of Scotland, although there is a reduction for some northern and coastal areas, including the Outer Hebrides, Orkney and Shetland Islands.

Future trends

 

  • The UKCIP02 report does not provide estimates for this measure.

 

Figure 39 - Pattern of change (as a percentage) in maximum five-day precipitation amount each year, from 1961 to 2004.