Submitted to: American Meteorological Society
Publication Type: Abstract Only
Publication Acceptance Date: May 8, 2000
Publication Date: May 8, 2000
Technical Abstract: Monthly and seasonal precipitation values for selected climate divisions in the Great Plains are compared with global atmospheric and oceanic circulation indices. The results of this analysis confirm findings of earlier studies that showed that the tropical Pacific Sea Surface Temperature (SST) is one of the indices that is better correlated to the climate in the Great Plains. Despite this higher correlation of the SST index compared to other global indices, its ability to explain monthly and seasonal variations in precipitation in the Great Plains remains weak with less than 50%, and in most of the case less than 30%, of the precipitation variance explained by the index. Decade scale variations of precipitation in the Great Plains and their relationship to tropical Pacific SST are also investigated. Three regions within the Great Plains that have similar patterns in their precipitation variation have been identified. These regions show a pronounced wet period during the last two decades. The increased precipitation parallels a warming trend of the tropical Pacific SST over the last decades (r**2 = 60% to 80%). This study suggests that the tropical Pacific SST and precipitation in the Great Plains are linked in some indirect fashion. The correlation is strong at a temporal scale of decades, and it is weak at an annual time scale. This suggests that the tropical Pacific SST and precipitation in the Great Plains are linked, but that on an annual time scale other factors obscure and weaken the relationship.