Ag Weather Forum

The upper level ridge that has been over Western Canada much of the spring is showing signs of relocating farther from the area. This may allow for more and better chances for rainfall in some of the driest areas of the southwest Canadian Prairies during the next week to 10 days.

The longer range charts, verifying at eight to 10 days from now, show a mean upper level ridge located between western Alaska and far eastern Siberia. This opens the door for low pressure systems to come underneath this ridge into either Western Canada or the Pacific Northwest in the U.S. before moving eastward. This is a somewhat better pattern in terms of getting rainfall to become more widespread over Canada's Prairies.

However, we still note a split jet stream pattern over the North America region away from this high latitude blocking ridge. The northern branch of the jet stream features a trough over north-central to northeast Canada, along with the ridge that is over western Alaska and Siberia. The northwest flow around the back side of the trough is into northern Saskatchewan and northern Manitoba, possibly keeping these areas drier but cooler.

The southern branch of the jet stream features a trough over the western U.S. region and a ridge over the east, especially the southeast U.S. This represents a storm track that would bring systems into the West Coast of North America over the northern Rockies region of the U.S. and then near or just south of Manitoba, Canada.

Canada's Prairies are still between the northern and southern jet streams at that time. This is one aspect of the pattern that is still troublesome in terms of increasing the rainfall chances. However, with the ridge centered so far to the northwest it does allow for the rain shield associated with the southern storm track to come somewhat further north than has been the case during recent weeks. Also, this is an outlook at the eight-to-10-day period. Prior to this period the trough is in its developmental stages. This includes one trough moving over the area during the next one to three days and a second trough moving over the area during the early to middle portion of next week. The second of the troughs is the one that forces the southward shift to the southern jet stream and gets us to where we are at eight to 10 days out.

If the trends continue and the western ridge remains well away from the area, it may be only a matter of time before significant rains ease current dryness concerns through southwest growing areas. However, until the southern branch of the jet stream lifts northward into the area, the outlook of better rain chances is uncertain.

Joel Burgio can be reached at Joel.burgio@dtn.com

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