Guest Post By Madhav Khandekar –
Summer 2010: Wettest on the Canadian Prairies in 60 years! A Preliminary Assessment by Ray Garnett and Madhav Khandekar
My article with Ray Garnett from CMOS Bulletin December 2010 is a preliminary analysis of extensive flooding on the Canadian Prairies (and to some extent on the US Prairies as well) this past summer 2010. In our assessment, the summer 2010 deluge on the Prairies was a result of a favourable combination of several large-scale forcing factors like SST in equatorial Pacific- El Nino phase since last December 2009 providing the primary forcing, NAO (North Atlantic Oscillation) phase during Spring & Summer 2010 which enabled moisture from the Gulf of Mexico to reach eastern Prairies and low sunspot activity for the past several months. The linkage between the Canadian/American Prairie drought and solar variability has been studied for the last 30 years or more and there is now a growing conviction that solar variability does indeed influence a Prairie drought (or flood). The precise mechanism for the sun/drought linkage is not well understood at this point, however a simple algorithm using sunspot activity can be used to foreshadow Prairie summer weather & climate and impact on grain yield. This simple algorithm has operational utility.
The abstract of the article reads
The May-July period over the Canadian Prairies in 2010 was the wettest in 60 years and possibly 100 years. in July the federal and three prairie provincial governments announced $450 million in funding to assist waterlogged farmers. Caual factors are considered to be El Niño conditions during the past winter and spring months, below normal North American snow cover in April and extremely low sunspot activity.