Ag Weather Forum
Doug Webster DTN Senior Ag Meteorologist

Thursday 12/19/13

Yo-Yo Temperature Pattern For The Rest of December

The persistent cold pattern that has covered much of Canada during the past few weeks is showing some signs of breaking down a bit. Temperatures are now moving into a pattern of variable if not highly variable readings as arctic air and Pacific air start to play tag across the region.

The reasons behind these changes are tied to a weakening of the polar vortex that has been across west-central Canada during recent weeks a shift of this feature to northeastern Canada. The strong ridge across the eastern Pacific northward to Alaska has also de-amplified to the west coast of Canada which allows for a better chance of some Pacific air making it into western Canada for brief periods.

When a milder day occurs don't get used to it because in a pattern like this above freezing temperatures one day can be followed by readings below -20C the next. Precipitation prospects for a pattern such as this are generally light with the greatest chances coming behind arctic fronts when upslope winds have a better chance of developing.

The best chance of mild weather at times will be across Alberta during the next week or two while Manitoba might be the region seeing more dominant arctic cold.

Some of the computer model output is showing a January featuring milder than normal for a large portion of central and western Canada. Confidence is this pattern is low since the overall ridge/trough pattern across North America has not changed much recently. It will take only a little strengthening of the polar vortex and ridge to again bring more persistent cold to the Prairies during the next few weeks. Only time will tell if bitter cold returns for January or if chinnook winds take the bite out of the arctic cold.

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

(AG/CZ)

Posted at 10:44AM CST 12/19/13 by Doug Webster
Post a Blog Comment:
Your Comment:
DTN reserves the right to delete comments posted to any of our blogs and forums, for reasons including profanity, libel, irrelevant personal attacks and advertisements.
Blog Home Pages
February  2016
S M T W T F S
   1 2 3 4 5 6
7 8 9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29               
Subscribe to Ag Weather Forum RSS
Recent Blog Posts
  • Lower Chance For La Nina
  • Different Seasons Across the Prairies
  • More On El Nino-La Nina Transition
  • Temperature Gyrations Ahead for W. Canada
  • El Nino Remains Strong
  • Major Change In Western U.S. Snow Cover
  • Roller Coaster Temperatures for W. Canada
  • Greater Chance For La Nina
  • Midsummer Crop Weather Projection
  • El Nino's Impact Returns to Western Canada
  • Possible Stress for South Brazil Soy
  • Arctic Cold to Ease for W. Canada Next Week
  • Brazil Rainfall Improves
  • High Latitude Blocking Brings the Big Chill to W. Canada
  • El Nino Looms Over 2016 Crop Season
  • El Nino Makes a Difference in West
  • El Nino Regains Control of W. Canada Weather
  • Nothing "Freakish" About Recent Storms
  • SW Plains Blizzard; Rain For Brazil
  • Major Winter Storm for Southern Plains, Flooding Threat in Southeast