In our winter outlook, we discussed the potential for a cold December. That would be much different than most Decembers over the past several years, especially last year.
This does not mean it will stay cold the entire month, however, the month as a whole may end up below average. Let me explain.
I like to look at 3 teleconnective indicies: EPO (Eastern Pacific Oscillation), AO (Arctic Oscillation), and the NAO (North Atlantic Oscillation). Knowing the state of these indices help predict weather patterns across the northern hemisphere. Generally, when they are negative, it indicates blocking over the higher latitudes. That blocking disrupts the pattern and sends the cold air south. Getting all 3 of these indices to turn negative during the same time period is a recipe for arctic intrusions.
Follow the green line which is the model ensemble mean. They are all going negative.
A birds eye view of the northern hemisphere shows the ridging in red and orange over the polar areas. Look at the blue showing up over Canada and the northern United States. That's a trough and it's filled with cold air pressing south.
IF this happens, expect the cold to dive south towards the end of the first week of December. How long will it last? Tough to say. Once these patterns break, they break big time and the warmth rushes back in. Let's just get the cold air in here first, then worry about that later.
By far, the coldest air of the season is on the way and it may stick around for awhile. This week will be mild, but the cold dives out of Canada Friday. Play the video below and watch it dive out of north and engulf much of the country.
Birdseye view of the northern hemisphere below. Strong ridging in Canada will set this up. The strongly negative Eastern Pacific Oscillation supports this. In it's positive phase, lower pressure off the west coast of Canada/U.S pushes Pacific air into the country and that's typically mild. In the negative phase, it opens up the arctic gates as ridging goes up in Alaska and the arctic.
GFS EPO is strongly negative= cold
Euro EPO is strongly negative = cold
Won't be perfect, but you can see where this is all going. Euro ensembles mild this week, then turning much colder
GFS ensemble has the same message.
What about snow? I would not be surprised to have some sleet and/or snow in the Ozarks at some point before the end of the month. That would not be all that unusual though. Get ready! Cold is coming.
Almost every county is under a burn ban until further notice, but what does it mean? These are issued by county judges and are lifted by those officials as conditions improve.
I have a feeling the restrictions could vary from county-to-county with some agricultural exemptions as well. I thought I would reach out to the Pulaski County Judges office to find out what you can and can't do. Thanks to Madeline Roberts for responding.
Any outdoor burning is restricted and banned to include, but not limited to:
Brush and Yard Waste
Trash and Garbage
Any other combustible materials.
Outdoor burning may be permitted under special circumstances, when the Court is assured that all necessary and proper precautions are being enforced to ensure that burning constitutes no hazard to life and property. No outdoor burning shall be permitted in the absence of a written permit from the Pulaski County Office of Emergency Management.
The use of charcoal and propane grills are allowed for cooking purposes during the burn ban.
As of Thursday afternoon, October 13th, here are the burn bans the wildfire danger according to the Arkansas Department of Agriculture.