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Pattern December to Remember

Cold dump out west on latest GFS. Cad areas stay chilly though050324D2-F4A4-4336-8B36-80B3665763D7.png
 
Quite shocked cold lovers aren’t posting about the 0z GFS. I know it’s the long range gfs but after the warm up next week I barely got above 50 IMBY. Then the whole southeast got quite chilly leading right up to Christmas
 
Quite shocked cold lovers aren’t posting about the 0z GFS. I know it’s the long range gfs but after the warm up next week I barely got above 50 IMBY. Then the whole southeast got quite chilly leading right up to Christmas
I like the 1088 mb high over Greenland.
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I see nothing to lead me to believe there will be any pattern change between the 17th and 22nd. Doesn't matter how hard you look it's not there. If the MJO progression is actually correct then maybe by the 1st week in January.

I'm forecasting a colder pattern between those dates based from the evolution of the upper stratosphere PV and the nature/placements of areas of blocking across the high latitudes. The blocking over the North Pacific Ocean is influencing the upper PV currently (and will continue to do so) due to warm air extending into the upper stratosphere. As higher heights build over Russia at 10mb and at 500mb over the NAO region, and over Europe/extending over the Arctic ocean, (in the near future) the upper PV will begin to extend lower geopotential heights over the Central US/Eastern US within the suggested time frame. Basically, I think there would be a partial PV disruption, but not enough stratospheric warming across the pole to cause a full disruption. The warmer air within the higher heights over the NAO region and Europe may not extend into the upper stratosphere, but there would probably be enough influence to cause lower stratosphere mesoscale PVs to track into the mid-latitudes of the Continental US - east of the Rockies. If everything comes together as I think it will; I wouldn't be surprised to see models becoming colder within time of the suggested time frame.

I think he means there will be a brief shot of cold around or right before Christmas then another brief warm up before we go cold. Could be little lag time.

Correct, of course the pattern change will not be instant - colder periods at time before the colder pattern. I think the warm up and cold pattern would be before Christmas, (colder pattern by the 22nd.)

By "colder" you mean from mega torch to just kinda torchy.

Yes, it would be a gradual colder pattern, because there's going to be numerous of fronts sweeping through, and the coldest air mass would eventually translate to the Eastern US as the upper pattern across the higher latitudes evolve.
 
To add further to my post above - taking a look at the upper PV, you can see the evolution of the PV in the 17th - 22nd time frame. As mentioned higher heights build at 10mb over Russia and the 3100/3120 geopotential height meanders around the North Pacific causing the PV to elongate and the core shifting to the south and east a tad pushing lower heights into the Continental US at 10mb. Even though, the coldest layers wouldn't propagate downward to the surface (likely not) from the upper PV, but lower heights I think would still be east of the Rockies in the lower stratosphere at 500mb due to enhancement from the lower heights above the 500mb layer from the upper PV and blocking in NAO/AO regions. In my opinion, the ridge we've been seeing east of the Rockies will eventually no longer exist on upcoming model runs and or vorticites of air from the ridge may force into the higher latitudes across the NAO region.
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To add further to my post above - taking a look at the upper PV, you can see the evolution of the PV in the 17th - 22nd time frame. As mentioned higher heights build at 10mb over Russia and the 3100/3120 geopotential height meanders around the North Pacific causing the PV to elongate and the core shifting to the south and east a tad pushing lower heights into the Continental US at 10mb. Even though, the coldest layers wouldn't propagate downward to the surface (likely not) from the upper PV, but lower heights I think would still be east of the Rockies in the lower stratosphere at 500mb due to enhancement from the lower heights above the 500mb layer from the upper PV and blocking in NAO/AO regions. In my opinion, the ridge we've been seeing east of the Rockies will eventually no longer exist on upcoming model runs and or vorticites of air from the ridge may force into the higher latitudes across the NAO region.
420f461ec8a3986db49ffd847b7c127e.gif

That's definitely not how this works
 
Yeah that was a crazy run; especially the progression of the storm across the mid section of the county and then the development of the storm offshore. Most of the wintery precip stayed just to the north, but still out in la la land. So just seeing the cold at Christmas looks good right now. Who knows, we get this type of cold maybe a clipper will hit on Christmas.
 
Yeah that was a crazy run; especially the progression of the storm across the mid section of the county and then the development of the storm offshore. Most of the wintery precip stayed just to the north, but still out in la la land. So just seeing the cold at Christmas looks good right now. Who knows, we get this type of cold maybe a clipper will hit on Christmas.

Lol clipper…what are thoooose? That’s up there with anafrontal.


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Typically doesn’t get real cold until about 10 days after MJO phase 7 or roughly 20 after phase 6. Lagged pentad average (5-day) 850 temp anomalies composites wrt MJO phase are about right timing-wise with when I’ve been thinking the past few weeks it tries to get cold. We probably start to flip in early January, perhaps peaking mid January near our peak snow climo

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I’m still thinking January 15th or later for first chance of winter storm E of ?. Always lag or temporary air masses in the models during pattern changes to push out anything special by 2 weeks at least.
 
Everything way out can certainly change, but even though stuff may be changing up top, to me it looks the same for the SE as far as the eye can see. The Pacific ridge is still too far west and needs to scoot further east and poleward hopefully. Get the PNA at least neutral and stop the dump out west.

Good to see more red showing up on the top of the world, but hoping it gets in a better configuration for the SE the following week. Maybe this is the start. ??‍♂️

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Looking at the eps members has kind of the step down to cold look more than a single dump of cold. With the cold/trough loading in west Canada and the PNW it'll be hard to bodily spread that east through Christmas. That said it does seem like we can sneak in short periods of cold or almost a gradient type pattern with wedge leading into Christmas
 
Looking at the eps members has kind of the step down to cold look more than a single dump of cold. With the cold/trough loading in west Canada and the PNW it'll be hard to bodily spread that east through Christmas. That said it does seem like we can sneak in short periods of cold or almost a gradient type pattern with wedge leading into Christmas
I think our best hope for seasonal weather at Christmas is a wedge pattern, similar to what we just saw this week. I'm totally discounting a massive cold dump like the GFS operational is showing - it's 300+ hours out anyway, so why waste print on these solutions?
 
I think our best hope for seasonal weather at Christmas is a wedge pattern, similar to what we just saw this week. I'm totally discounting a massive cold dump like the GFS operational is showing - it's 300+ hours out anyway, so why waste print on these solutions?

Agree…slim likelihood of things playing out like that. Especially in modeling that far out


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