December 2025 Short/Medium Range Forecast Thread

[Holston_River_Rambler]

Just now, Golf757075 said:

Do you think it will?

The mountain torquers seem rather excited. Got to have a big old HP slam down from Siberia into east Asia. Of course we have to hope some hitherto little known index does not screw it up. 
 

 

[Golf757075]

1 minute ago, Holston_River_Rambler said:

The mountain torquers seem rather excited. Got to have a big old HP slam down from Siberia into east Asia. Of course we have to hope some hitherto little known index does not screw it up. 
 

 

Would be nice to get a few weeks sustainable cold pattern and take our chances

[Matthew70]

47 minutes ago, Carvers Gap said:

I have been wanting to post that GEM map all day.  We were doing Christmas with some of my family...I definitely was sneaking a peak at models.  But my 12z model deep dive...just now happening.  

There is an interesting demarcation point after the 5th...does it warm up and we get a heavy rain event as Holston posted?  Or does end up frozen(not at those levels)???  I tend to think the cold hangs around, but that is an educated guess and by no means fact.

I’m sneaking looks hoping I see the HOT sign on!!!

[Golf757075]

1 minute ago, Matthew70 said:

I’m sneaking looks hoping I see the HOT sign on!!!

CMC has always been a cold biased model. Sometimes it's right, especially with freezing rain and ice

[*Flash*]

Seeing the 12z EPS/GEFS agree on week 2 cold and a +PNA emerge on modeling today felt like a Christmas present from Mother Nature. How quickly things can change in our field of interest. 

[Carvers Gap]

54 minutes ago, Holston_River_Rambler said:

The mountain torquers seem rather excited. Got to have a big old HP slam down from Siberia into east Asia. Of course we have to hope some hitherto little known index does not screw it up. 
 

 

LOL.  That is a great line.  I always forget about mountain torque events in Asia.  I am assuming this is good or us?

[*Flash*]

58 minutes ago, Holston_River_Rambler said:

The mountain torquers seem rather excited. Got to have a big old HP slam down from Siberia into east Asia. Of course, we have to hope some hitherto little-known index does not screw it up. 
 

 

Why do I feel dirty reading this? Probably just the mountain. 

[Holston_River_Rambler]

25 minutes ago, Carvers Gap said:

 I am assuming this is good or us?

The idea seems to be a jet extension caused by a +east Asian mountain torque will help dislodge the Aleutian high. 

Here it is on the 18z GFS:

Big high drops down into east Asia:

 

Momentum gets added to the pac jet:

 

Aleutian high dies:

20 minutes ago, *Flash* said:

Why do I feel dirty reading this? Probably just the mountain. 

I almost wrote the "mountain twerkers" lol. 

 

Hope that jet extension doesn't go too far. That's burned us in the past. 

[John1122]

Mammoth got over a foot of snow in a couple of hours overnight. Up to 100 inches expected in the area. I like to watch it, but when they're getting buried, we usually are waiting on the pattern to change. 

[John1122]

Mammoth has gotten 28 inches as of 4pm local time.  The forecast through Friday. 

"Tonight

Snow. Steady temperature around 20. Wind chill values as low as -1. Windy, with a south southwest wind 30 to 35 mph, with gusts as high as 55 mph. Chance of precipitation is 100%. Total nighttime snow accumulation of 26 to 32 inches possible.

Christmas Day

Snow. High near 20. Wind chill values as low as -3. Windy, with a south southwest wind around 30 mph, with gusts as high as 60 mph. Chance of precipitation is 100%. New snow accumulation of 33 to 39 inches possible.

Thursday Night

Snow showers. The snow could be heavy at times. Some thunder is also possible. Steady temperature around 20. Wind chill values as low as -1. Windy, with a south southwest wind around 35 mph, with gusts as high as 60 mph. Chance of precipitation is 100%. New snow accumulation of 23 to 29 inches possible.

Friday

Snow showers before 1pm, then snow, mainly after 1pm. The snow could be heavy at times. Some thunder is also possible. High near 18. Wind chill values as low as -4. Windy, with a southwest wind 25 to 30 mph decreasing to 20 to 25 mph in the afternoon. Winds could gust as high as 55 mph. Chance of precipitation is 100%. New snow accumulation of 9 to 13 inches possible."

[John1122]

The Canadian keeps the subzero cold. The GFS lays down some anafrontal snow on Monday now with that cold front passage. 

[John1122]

The GFS is mostly ugly with a capital UGH in the long range. +NAO/-PNA/Aleutian Ridge rock solid. Who knows if it verifies, as it's been flopping back and forth so much lately.