Long range model discussion

[Cpv17]

Source region being?

Western and central Canada.

[Cpv17]

If we want a big cold snap, then we’ll need our source region to load up with cold air. Love the blocking I’m seeing over the top. Helps build a continental trough over us in the long range on the ensembles. Looks promising.

[sambucol]

Something from Siberia would bring down plenty of cold

[Cpv17]

Step in the right direction on that 0z GFS run.

[sambucol]

Larry Cosgrove this morning:

Is the forecast for a switch to a much colder pattern for real?

Anyone watching the numerical model forecasts yesterday and this morning is probably doing a double-take. After all, the schemes and the respective ensemble members were showing what seemed like endless warmth across the entire continent. Media and official sources talked endlessly about a mild winter. But then chatter started popping up about the likely decline of El Nino and a major stratospheric warming event in the Northern Hemisphere. Which leads to this discussion.

Yes, I do believe that the rapid amplification of the upper air pattern is correct. It is almost a perfect match for the January analog sets, and if true will mean an expanded snow cover across the lower 48 states and a likely depression of the nocturnal freeze line into Mexico and the Gulf Coast. But I would be careful of the advance of the colder air at surface, as I do not believe that the East Coast will get into the cAk values until after the 15th of next month. Curiously, the southern branch storm track may enable some minor snow or sleet in Texas and parts of the Dixie states just before the plunge of cold readings into the U.S.

This is a pattern that allows for significant cold and storms. If the comparison test scenarios are right, the opportunity for wintry conditions will be to the right of the Continental Divide and mostly along and below the Interstate 90 corridor between January 15 and February 28. As 1973 is a heavy influence in the analog creation, I lean toward a rapid warming in March.

[Stratton20]

That 12z EPS is one of the coldest ensemble runs ive seen in quite some time, that US continental trough is really going to drag down some significant cold air, its still early in the game, but with great agreement in ensemble guidance, i cant help but get excited of what may come

[sambucol]

That 12z EPS is one of the coldest ensemble runs ive seen in quite some time, that US continental trough is really going to drag down some significant cold air, its still early in the game, but with great agreement in ensemble guidance, i cant help but get excited of what may come

Is it comparable to February 2021’s extreme cold for our area? And what is the timeframe the model is showing for our area? Thank you!

[Stratton20]

Sambucol not that cold, but definitely way colder than what we have experienced so far, and its a good pattern for potentially a southern snow storm/ winter storm, time frame looks to be the 12-th and beyond because this trough just sticks around, so the cold blast looks to be long lived, lots to watch, but ensembles are in excellent agreement with this US continental trough, so my confidence is higher

[Harp1]

Yes, the trend looks good at this time.

[sambucol]

Thanks. Larry Cosgrove said a couple of weeks ago SETX may have a couple of winter precip events. I had asked him if our area might get some.

[Cpv17]

https://x.com/judah47/status/1740801759 ... _m1NXPw4Cg

https://x.com/ryanmaue/status/174080362 ... _m1NXPw4Cg

Hmmm!!! I guess positive signs are back today regarding the SSWE.

[Stratton20]

Cpv17 I like Judah, ive read some of his work about the polar vortex, definitely a very credible and reliable source, a stretch would definitely do the trick

[Harp1]

If you go by the operational GFS, you’d never know that changes are supposed to happen…

[Stratton20]

Ensembles look amazing, I know its early, but I know I cant be the only one on this forum thats starting to get excited, and ensembles keep this pattern locked in place for quite an extended period, you love to see it

[snowman65]

Ensembles look amazing, I know its early, but I know I cant be the only one on this forum thats starting to get excited, and ensembles keep this pattern locked in place for quite an extended period, you love to see it

So things still seem to be on track for pv split or stretching in 2nd half of Jan?

[Stratton20]

All models and ensembles are in amazing agreement on some much colder air blasting its way all the way down here, could see some opportunities for wintry precip with this pattern, once that cold air gets here, it stays around for a long time, at least 7 days at a minimum

[Cpv17]

All models and ensembles are in amazing agreement on some much colder air blasting its way all the way down here, could see some opportunities for wintry precip with this pattern, once that cold air gets here, it stays around for a long time, at least 7 days at a minimum

I’m worried about the storm track staying north of us. The CPC forecast also has it mainly north of us.

[Harp1]

All models and ensembles are in amazing agreement on some much colder air blasting its way all the way down here, could see some opportunities for wintry precip with this pattern, once that cold air gets here, it stays around for a long time, at least 7 days at a minimum

I’m worried about the storm track staying north of us. The CPC forecast also has it mainly north of us.

That’s my concern as well. Those vorts are all crossing the country over the same path. Too far north for us.

[Stratton20]

Cpv17 Im not really that concerned about that, the initial storm that brings down the colder air will definitely be taking a northerly track, however ensemble’s and global guidance show a secondary dip behind this storm system, look at the 12z Euro 500 mb vort map, has a shortwave moving in from new mexico with the cold air in place, its not close enough yet to see if it generates any precip, but the euro does show what we would need to get any fun stuff down here

[Cpv17]

All models and ensembles are in amazing agreement on some much colder air blasting its way all the way down here, could see some opportunities for wintry precip with this pattern, once that cold air gets here, it stays around for a long time, at least 7 days at a minimum

I’m worried about the storm track staying north of us. The CPC forecast also has it mainly north of us.

That’s my concern as well. Those vorts are all crossing the country over the same path. Too far north for us.

For whatever reason, something isn’t allowing these troughs to dig down far enough south. Almost like there’s a SE ridge but there isn’t one so I don’t quite understand. It should lay down a good snow pack to our north though so that’s definitely a big positive.