December 2025 Short/Medium Range Forecast Thread

[Carvers Gap]

1 hour ago, Jed33 said:

Yeah I saw that earlier. I don’t know about that. Seems a little strange for him to say that. I remember times in the 80’s and 90’s where Alaska hit -70 and lower. I remember one instance where it was even closer to -80! I can remember talk about how airplanes couldn’t function when the temp was lower than -70. So, -60F is not unprecedented at all. I’m not sure where he’s getting the 1000 yr event talk. To me if it was going to be 1000yr event we’d be talking -100 or more. Akin to the lowest temps ever observed on the planet, which happens to be on the other side of the globe in Antarctica. 

Nice post.  Interesting find by Golf.

I keep an off-and-on eye on the coldest modeled mins for North America during the winter.   I do that just to monitor how cold our cold source could be.  The coldest I can find right now is low -60s.  Now, that is pretty cold, but the record is -81 in the Yukon in 1947 according to a quick search.

This is not for you, Jed.  I know you know this.  I am just trying to save a second post.  Models have been having crazy amounts of feedback this winter.  I think they are vastly overdoing certain features(Baja, NW Pac lows on repeat, western Canada cold?) which causes wild feedback all over the Western Hemisphere.  I am not sure why this is happening.  I don't know if there is a data ingest problem or programming has been changed/updated across models.  Maybe they have a bug?  But I have observed some pretty big errors.  It reminds me of the 4' of snow forecast for Charlotte one year...and it never materialized.  It was feedback which sometimes occurs to the SE of the southern tip of the Apps.  Places on the map to watch for feedback...Baja, NW Pac, Aleutians(but not as bad as one would think IMHO), and Greenland.  Now, the fun thing about that area of South Carolina which tends to feedback....sometimes it actually has extreme precip events.  Think Helene.  All of those other places have had extreme events...sometimes I think models go to that extreme due to those data sets.

I would guess that Canada is going to be very, very cold this winter.  That is a pretty easy guess as it already has been there this season.  I think it finds its way south 1-2 times, and that will be plenty for most.  Like you, I don't see even 100 year cold up there right now.  But we'll see.  Not everything is feedback though. I guess maybe the thing that concerns me some is that many of these cold fronts are getting much colder as we get closer to the event - that is kind of unusual.  That might be a signal that the air mass up there is strong.  We have good snowpack for it to move quickly.

I would be more than thrilled to track an all-time great Arctic outbreak w/ lots of snow.  I just don't know that we are gonna get much lead time on that...

That said, I do think the strength of the cold is currently and is going to be in the future...a problem for modeling this winter.  We have had some winters where we get a trough in the East, and there is only Canadian or weak polar air to fill it.  This stuff is legit Arctic air.  

Let's not forget the SSW....we haven't had the cold dive to our side of the planet with that recently.  But Russia and/or China have been hammered when that occurs.  Sometimes, it does come to our side of the planet.  Is this one of our years?  Maybe, and there is some evidence to support that but just to early to know.

edit:  On an interesting note, my daytime highs for the past couple of months have sometimes been well under the point and click forecasts.  I am ready for a few days of warm air.  I keep waiting on some warm mornings!  It was not warm this morning.

[Carvers Gap]

I am gonna tag @John1122in this.  His records are easily the best and most uncorrupted that I know of.  They are rigorous and have good fidelity to boot(they are his family's for those who don't know).  He might be able to shed some light on Maue's thoughts and hopefully chip in some insight.  John, I am not asking you to support or criticize RM...just to add some context to the cold forecast in Alaska and in relation to our area.

[Carvers Gap]

I found this analog in the d6-10 analogs of CPC.  1-7-94.  I could see that being usable.  John always has to remind me of that winter.  I had to go back and look it up.  Sure enough, that winter I had to drive to campus on frozen interstates for about a week.  My apartment started leaking as water backed up under the ice.  It may be a reach on my part, but that analog makes some sense, and it has fit recent winters.  I don't know its ENSO state, but that might be one to think about.

[iluvsnow]

Here is a link to current coldest temperatures on the planet. I tried to copy and paste the top 15, but it didn't work....so go to the link and peruse for yourselves. Canada does have some of the top 15 low temps on earth for the date. We should also remember that its only December 22nd. The really bottom level stuff in the Northern Hemisphere doesn't occur until late January and February up top. This is pretty rare for Canada to have lows this cold, this early......the link:  https://eldoradoweather.com/climate/world-extremes2/world-temp-rainfall-extremes.php

[Carvers Gap]

Just now, iluvsnow said:

Here is a link to current coldest temperatures on the planet. I tried to copy and paste the top 15, but it didn't work....so go to the link and peruse for yourselves. Canada does have some of the top 15 low temps on earth for the date. We should also remember that its only December 22nd. The really bottom levels stuff in the Northern Hemisphere doesn't occur until late January and February up top. This is pretty rare for Canada to have lows this cold, this early......the link:  https://eldoradoweather.com/climate/world-extremes2/world-temp-rainfall-extremes.php

I will re-respond.  Mercy!

Cold source. Check.

[Matthew70]

And as I have been saying.  Top snows for TN is in February.  With the cold air source in Canada.  If we were to get one of the ole blue northern clippers.  The ratios of that snow with them would be plentiful. 

[Jed33]

I’ve been following the weather for many years. Most years during my childhood (80’s) the weather was oftentimes very cold during the winter and I took note of it. I didn’t write down the dates when the brutally cold air would build in Alaska and Canada,  but my dad and I watched it and we knew it would usually eventually be unleashed into the lower 48. I looked it up on google just now and found about 24 cases where the temps were between -70 to the record of -80. These were scattered from Jan 19-20 1952 to Jan 29 1999. The coldest being Jan 27 1989 at -76 and Jan 5 1997 at -77. The ultimate coldest Jan 23 1971 at -80. I don’t see any temps that cold though in the 2000’s. So, there is definitely precedent for it to be lower than -60 with 24 cases at or below-70 in Alaska.

[Daniel Boone]

5 minutes ago, Jed33 said:

I’ve been following the weather for many years. Most years during my childhood (80’s) the weather was oftentimes very cold during the winter and I took note of it. I didn’t write down the dates when the brutally cold air would build in Alaska and Canada,  but my dad and I watched it and we knew it would usually eventually be unleashed into the lower 48. I looked it up on google just now and found about 24 cases where the temps were between -70 to the record of -80. These were scattered from Jan 19-20 1952 to Jan 29 1999. The coldest being Jan 27 1989 at -76 and Jan 5 1997 at -77. The ultimate coldest Jan 23 1971 at -80. I don’t see any temps that cold though in the 2000’s. So, there is definitely precedent for it to be lower than -60 with 24 cases at or below-70 in Alaska.

-80 in Prospect Creek  Alaska Jan. 23 1971. It was coldest US Record. Coldest lower 48 is -70 Rogers Pass Montana in 1954. -83 NA Record in Snag. Yukon.

[Jed33]

This is the link I where I found the information on Alaska.
 

https://www.currentresults.com/Weather-Extremes/US/lowest-temperatures-alaska.php

[Daniel Boone]

My reply from earlier just posted. My phone really fouled up tonight. It's sticking and closing out on me. Tan cleaner and took some things off but still not up to par.

[Golf757075]

The ensembles are starting to somewhat extend the pacific jet in the extended. I believe that will be a game changer if it comes to fruition 

[John1122]

The Canadian is just full blown winter, snow, ice box cold before New Years and after. +PNA looks beginning to appear and downstream we win. Old fashioned clipper/Siberian express on there.

 

 

[John1122]

I think we'd all take this, with single digit cold pressing in behind the second clipper.

 

[Carvers Gap]

Some bitterly cold runs overnight for the end of the year and beginning of the New Year.  We are gonna get June and January within about 48 hours of each other.

LR ext (weeklies) modeling has started to pick up on an EPO ridge towards the end of January.  The CFSv2, Euro Weeklies, and CFSv2 seasonals have it.  My guess could be sometime around the last week of January.  

The current pattern appears to be classic "C-FYAO" pattern, otherwise knows as a chinook - then freeze your tail off.

[Carvers Gap]

Two, back-2-back cold fronts appear possible between Dec 28 and Jan4.  

If recent model history trends hold...that second front might be colder than what is modeled(well, except for the GDPS which brought it).  The Canadian is likely too cold, but it looks like it might be about to score the coup for the Dec 28th run - most models have trended colder and if memory serves me correctly...it caught that first cold front before any other model(maybe the Euro Weeklies as well).

Will models back off the intensity of the cold like they did in early December?  I keep asking myself that, and then I remember this is a late December and early January air mass which is BN over western Canada.  It is possible that the fronts are under modeled outside of seven days.

The Music City Bowl is trending colder....oof.

[Kentucky]

Eric has indeed backtracked today, Merry Christmas to all. 

https://x.com/i/status/2003487195450286581

[Carvers Gap]

The 12z suite looks reasonably consistent w/ the exception of the 12z GFS which for whatever reason sometimes completely loses the NAO on random runs.  The 12z AIGFS looks about right.  So, we are just gonna sub out the 12z GFS and grab the sixth guy off the bench.