In the paper the verification of precipitation condition forecasts are presented. The forecasts have been developed in the monitoring system of water deficiency and excess conducted by the Institute of Technology and Life Sciences. Analyses were performed for seven meteorological stations within Kujawy Region, south-eastern part of Pomerania and western Wielkopolska in the months of the growing season (April-September) in 2013-2014. Actual precipitation deficit and surplus and their 10-day and 20-day forecasts were determined every 10/11 days for the period of 30/31 days using the standardized precipitation index SPI. Two verification criteria were adopted: the difference between actual and predicted SPI cannot be greater than 0.5 and the agreement of the precipitation category classes. The verifiability is determined as the relative frequency of the forecasts meeting these criteria. It was found that the average verifiability of 10-day forecasts in the study area was high and equal to 80% for the assumed criteria. In the case of 20-day forecasts average verifiability was respectively 52%. ...
The aim of the undertaken research was an evaluation of the frequency of the dry and the wet months in the Opole Voivodeship in the months of May to September in1981-2010 years, in the view of the global warming. The dry and the wet months were characterized on the basis of hydrothermal index K, thermo-precipitation index A, standardized precipitation index SPI and the amount of the precipitation deficiencies and excesses of the late potato. The attempt of answering the question which of these indexes describe the moisture conditions of the vegetative season the best were undertaken.It was proved that the average frequency of months, in which the different level of draught's intensity was observed, was equal to 25% on the basis of the thermo-precipitation index A, 35% standardized precipitation index SPI, 36% hydrothermal index K, and 34% on the basis of the deficiencies precipitation amount. The average frequency of the wet months were counted to all four indexes and the values were: 23% on the basis of the thermo-precipitation index A, 23% standardized precipitation index SPI, 16% hydrothermal index K, and 29% on the basis of the deficiencies precipitation amount. The dependence between the four indexes and the yield of ...
