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Absolutely BRUTAL Cold Heading Our Way! When To Expect Wind Chills of 15 to 25 BELOW Zero!

We are heading into a pattern that will result is some absolutely brutal temperatures for our area in the next 8 days. We will see another "displacement of the polar vortex" that will result in wind chills in the 15 - 25 BELOW ZERO range and air temperatures could go BELOW zero twice in the next 7 days.


Another Displacement Of The Polar Vortex?


This weather pattern has been as consistent as anything you will ever see in winter. We have not deviated from this pattern virtually at all for the last month and the consistency of the pattern will lead do another breakdown of the polar vortex. Last time this happened, our wind chills went in the 15 - 25 BELOW ZERO range and it will get close to being that bad again. Notice by Thursday what has happened. You see a psuedo-displacement of the polar vortex by Thursday morning. The reason I say "psuedo" is because you see the low on the top of the map and one could argue that is the true polar vortex. Notice the jet stream is riding up into the north pole to yank that polar vortex southward.


Gfs 500 mb 1


By late this weekend, we see a true and full displacement of the polar vortex. You can see it has now taken up residence in the Great Lakes area ... again. You know this is not good news for our area.


Gfs 500 mb 2


I want to remind you why displacing the polar vortex is such a major problem for the US. The polar vortex resides over the North Pole and is obviously surrounded by the coldest air in the northern hemisphere. At times the polar vortex can get wobbled and if that occurs, it can move southward to the mid latitudes where we live in a process called a "displacement of the polar vortex". When the polar vortex is displaced, it drags the cold air from the North Pole where ever it goes. For us, this means brutal cold.



When It Will Get Cold And How Cold...


Let's look at these in two packages... first we look at Thursday through Friday then Monday through Tuesday of next week.


Thursday/Friday Cold...

The data suggests the first brutally cold surge from the first "psuedo" displacement of the polar vortex arrives Wednesday night. The data is showing absolutely brutal stuff by Thursday morning. The GFS computer model shows lows from 3F to 10F on Thursday morning.


GFS Temperatures Thursday Morning




While these temperatures are bad, the winds will be 20 - 30 mph and this means wind chill values will be dangerously cold on Thursday morning. Take a look at the NAM computer model showing wind chill values near 15F to 20F BELOW ZERO Thursday through Friday morning.


NAM Wind Chill Temperatures Thursday Noon




NAM Wind Chill Temperatures Friday 7 AM





Monday - Wednesday (Next Week) Cold...

The surge next week looks like it could be the real deal. It doesn't look quite as cold in the mid levels as what we saw earlier this month, but there is snow pack and this will have quite an impact. If we get more snow on Sunday (as I think we will in at least Southern Indiana), then these temperatures could be a touch generous. Let's start with the GFS temperatures starting Monday morning then move onto the EURO computer model.


GFS Temperatures Monday Morning

Notice the GFS shows another surge of arctic air on Monday morning. Air temperatures start off the day from Louisville north in the 5F to 10F degree range.




GFS Temperatures Tuesday Morning

Notice the GFS brings in full fledged arctic air from the north pole. The GFS shows widespread air temperatures BELOW ZERO north of the river and 0F to 5F north of the river.




GFS Temperatures Tuesday Afternoon

Notice the GFS highs on Tuesday are as bad as anything we have seen this season. This is absolutely BRUTAL cold.




GFS Temperatures Wednesday Morning

By Wednesday morning, the GFS takes nearly our entire area below zero. If this verified, then this would be the second time in a month that we have seen once in a decade cold.




The GFS is obviously throwing the farm at this cold. Now let's look at the EURO computer model.


EURO Temperatures Monday 5 PM

Notice the EURO is a touch slower with this arctic front. It still has very cold temperatures by Monday after, but not as cold as the GFS.




EURO Temperatures Tuesday Morning

Notice the EURO shows the northern 2/3rds of our area goes below zero again on Tuesday morning. Once again, this is decadal cold twice in a matter of a month.




EURO Temperatures Tuesday Morning

The EURO is not as aggressive as the GFS, but still has highs in the teens on Tuesday. I tend to think it is having an issue late Tuesday and Wednesday so I will disregard the Wednesday part at this point.





My Thoughts On Our Next Stretch Of Brutal Cold...


It was about 5 or 6 days ago that I told you a displacement of the polar vortex was likely on January 27-28. At the time, I argued that the pattern of a ridge of high pressure in the western US and dip of low pressure in the eastern US was so intense that it would wobble the polar vortex. That wobble means the polar vortex would eventually get pulled by the jet stream southward and draw air from the north pole into our area. It appears that forecast will verify... unfortunately. It could almost be argued that is the not on a displacement of the polar vortex, but it appears to almost take up residence in the Great Lakes for nearly 10 days which is absolutely remarkable!


The first dangerous cold will move in Wednesday night and Thursday morning. I see air temperatures approaching 5 to start on Thursday in Louisville with near or slightly below zero for some or our areas with the thicker snow pack. The wind chill values could be dangerously cold! I expect wind chills from Thursday morning to Friday morning to stay in the 15 to 20 BELOW ZERO range. This is absolutely brutal stuff.


The worst could come next week. Monday through Wednesday (next week) in my opinion could be the worst of these two cold air surges if we have get more snow on Sunday and I think at least southern Indiana will. The timing of the front on Monday is not 100% clear, but I do think it comes during the day. The second surge Monday night appears to be the worst. For now, I am going for a low of 5 degrees in Louisville on Tuesday and I think our northern counties are virtually assured of below zero. Wind chill values by Tuesday morning through Wednesday could be in the 15 to 25 BELOW ZERO range! This is not just cold, but quite frankly dangerous cold. I am not willing to go colder yet, but we I will dial it in over the next couple of days.


On an interesting note, the Climate Prediction Center has an 80% chance of below normal temperatures in their 6 - 10 day forecast.


CPC 6 - 10


On the Climate Prediction Centers 8 - 14 day forecast, they have a 60% chance of below normal temperatures. Think about how long this cold is forecast. WOW!


CPC 8 - 14




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Hi Marc,

Given how early our winter started and how intense it has been this season already, do you think February and March will stay below normal and ultimately lead us to a delayed Spring? I'm ready for some fairly consistent high 40s-50s. This cold is brutal!

Jason, it is the pattern that has not changed and in my opinion this is caused by the PDO created a west coast ridge. I just cannot see the cold season changing much.

I've always wondered this... Does a snowpack of 10" or 20" make a big difference in temperatures via nocturnal radiational cooling as 0" or 3" would make? It seems to me that once you get past 5 inches, a higher snowpack doesn't cool temps as much, or does it?

Israel, snowpack is remarkable effective at releasing heat. At some point there would be diminishing return, but I don't think research has been done on where that diminishing return would occur.

I'm seeing data that suggests it will be mid-Feb before we see much (if any) real change in this pattern.

Why do these patterns seem to be "camping out" for so long anymore. It happens in the Summers and lasts for months and it's happening again now with the Winter?

The last 10-12 years have just been brutal around here. Wind storms, ice storms, drought, record rainfall, record heat, tornadoes, etc. I've lived here 50 years and can't ever remember a time when we've had the amount of "once in 10 years" or "one in a lifetime" type of "events" with the frequency we do now. It's just one after another....

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