Ag Weather Forum

El Nino Contributes to Warmth in Canada

Doug Webster
By  Doug Webster , DTN Senior Ag Meteorologist

There are several indicators across the Pacific and North America pointing to at least weak El Nino conditions at the current time. Ocean sea surface temperatures through the eastern Pacific are milder than average and near El Nino criteria and we are also seeing an active stream of weather systems moving into the U.S. West Coast where bouts of drought-relieving rains are likely for California during the next week.

Another signal that has arisen during the past several days as high latitude blocking fades from North America is the arrival of Pacific-origin air across much of the U.S. and across most of the southern half of Canada. Gone are the below-normal temperatures across the Prairies and during the past couple of days readings have jumped to above normal for many areas.

The main polar jet stream is crossing the Pacific and moving across Canada in a west-to-east fashion. This allows the modifying influence of the Pacific to reach far and wide across North America displacing arctic chill to the most northern latitudes of the nation.

P[L1] D[0x0] M[300x250] OOP[F] ADUNIT[] T[]

This is good news for those who could do without winter's icy chill but is this going to be a feature for the remainder of the winter or will we see cold air again grip western Canada before long? The answer is that we will most likely see a return of cold weather and that's probably the easy part of the question. The tough part is trying to figure out when cold weather makes a return.

For now the mild El Nino-like pattern is likely for another couple of weeks but there are some hints that by the time we get to Christmas and beyond that the Pacific flow may shut down and high latitude blocking could start to return to North America. Timing this change is nearly impossible at this time but the timeframe as it appears now is during the last week of December to the very beginning of January for the cold air return.

As we saw during early November the change from mild to cold can be impressive and quick. When the Pacific flow gets shut off, arctic air can build quickly across Canada sending temperatures crashing. It would not be surprising to see temperatures run above or well above normal for the next two weeks then fall to well-below normal quite quickly before New Year's arrives.

During the next two weeks, we are likely to see warmth most of the time but a couple of short periods of seasonably cool weather are likely, especially through eastern portions of the Prairies. Generally dry weather is also a typical theme of the current pattern with upslope snows probably holding off until the potential turn to cold weather late in the month.

Doug Webster can be reached at doug.webster@dtn.com

(ES)

P[] D[728x170] M[320x75] OOP[F] ADUNIT[] T[]
P[L2] D[728x90] M[320x50] OOP[F] ADUNIT[] T[]

Comments

To comment, please Log In or Join our Community .