Forecast Verification

Updated daily, last update 15:07 on Sunday 22/10/2017

Forecast vs. Observed Temperature Scatter Plots

5-Day Forecast Generated: 12:00 on Wednesday 18/10/2017


The scatter plots below compare the temperatures observed at midday against the predicted midday temperatures in the 5-day forecast for 121 Met Office observation sites. This 5-day forecast was produced by the Met Office and you can find a forecast for your site in the Simple 5-Day Forecast section.


The correlation co-efficient displayed is the Pearson Product Moment Correlcation Co-efficient (PMCC), which ranges between -1 and 1. A PMCC of -1 indicates strong negative linear association and a PMCC of 1 indicates strong positive linear association. This is a useful statistic to test a linear relationship, however it can be misleading for more complex relationships, look up Anscombe`s Quartet to see an example of this.

Temperature Scatter Plot for 12:00 on Thursday 19/10/2017 (day 1)

Forecast - Observed Temperature Correlation: 0.845

Temperature Observations at 12:00 - Minimum: 8.5°C Maximum: 17.3°C


Observed Temperature / °C

Forecast Temperature / °C

Temperature Scatter Plot for 12:00 on Friday 20/10/2017 (day 2)

Forecast - Observed Temperature Correlation: 0.723

Temperature Observations at 12:00 - Minimum: 9.5°C Maximum: 16.6°C


Observed Temperature / °C

Forecast Temperature / °C

Temperature Scatter Plot for 12:00 on Saturday 21/10/2017 (day 3)

Forecast - Observed Temperature Correlation: 0.803

Temperature Observations at 12:00 - Minimum: 7.9°C Maximum: 15.9°C


Observed Temperature / °C

Forecast Temperature / °C

Temperature Scatter Plot for 12:00 on Sunday 22/10/2017 (day 4)

Forecast - Observed Temperature Correlation: 0.724

Temperature Observations at 12:00 - Minimum: 7.3°C Maximum: 14.9°C


Observed Temperature / °C

Forecast Temperature / °C

Temperature Scatter Plot for 12:00 on Monday 23/10/2017 (day 5)

Forecast - Observed Temperature Correlation: 0.773

Temperature Observations at 12:00 - Minimum: 8.8°C Maximum: 17.6°C


Observed Temperature / °C

Forecast Temperature / °C

Correlation Co-efficients Summary

The table below displays the Pearson product moment correlation co-efficients for each day.

DateCorrelation
Thursday 19/10/20170.845
Friday 20/10/20170.723
Saturday 21/10/20170.803
Sunday 22/10/20170.724
Monday 23/10/20170.773




Data provided through the Met Office DataPoint Service.
Contains public sector information licensed under the Open Government Licence, available at:
http://www.nationalarchives.gov.uk/doc/open-government-licence/version/1/open-government-licence.htm

Alexander Todd & David Leppla-Weber (University of Exeter)
Supported by EPSRC and CliMathNet