tag:blogger.com,1999:blog-33386160.post116258332494957220..comments2024-02-25T19:29:38.176-06:00Comments on Rob's Blog: Warm up next week..Unknownnoreply@blogger.comBlogger1125tag:blogger.com,1999:blog-33386160.post-1162669647601384992006-11-04T13:47:00.000-06:002006-11-04T13:47:00.000-06:00"Zonal flow" refers to a prevailing westerly flow ..."Zonal flow" refers to a prevailing westerly flow of air in the upper atmosphere. This tends to bring milder air in from the Pacific over the Prairies, and often moderates the eastern Prairies from a period of cold weather. When the upper wind flow is from the north or northwest, then that usually means a period of cold weather for us.<BR/><BR/>As fas as the Arctic vortex is concerned.. yes, you're right.. it's a fancy term for a low pressure area in the upper atmosphere that tends to bring colder unsettled weather over an area. Often this Arctic vortex will become established over Hudson Bay bringing a counter clockwise circulation of cold air around it from the Arctic. Sometimes this feature can persist for weeks on end, giving a prolonged period of below normal temperatures over Manitoba. <BR/><BR/>the eatsrn Prairies.robhttps://www.blogger.com/profile/01577519556216420480noreply@blogger.com