December Obs/Disco

[Isopycnic]

Another storm then warm again next weekend?

[FoothillsNC]

Extremely tall western Ridge showing up on a few runs of both GFS and Euro lately. I still don't trust either with details but the next storm coming out of the southwest might be able to catch a ride with a s/w riding down from Canada and then form a major storm near the Miss. River and pull down the first real widespread Arctic blast.

This pattern being shown on the GFS continues to fit the pattern overall of going to extremes, and another massive cutoff is possible if the +PNA goes to extremes (near the Pole!) , somewhere generally in the South central to Southeast quadrant of the US.

[BullCityWx]

It's too bad the AO and NAO arent cooperating if that PNA ridge plays out like that.

[FoothillsNC]

It's too bad the AO and NAO arent cooperating if that PNA ridge plays out like that.

It would be quite a cold wave if it did! I am a little skeptical right now of the really tall ridge, too often the models overbuild it, but if it keeps showing up it's probably legit. Some areas are probably going to have a major widespread winter storm within the next 10 days, but the placement could be anywhere from Tx to Carolinas to the Lakes. Huge area LOL.

[burgertime]

If the 18z came to fruition the western half of NC and the northern half of GA would be flooded. It just has a direct line from the GOM which is pretty neat to see on the map. It just keeps pumping and pumping.

[burgertime]

It would be quite a cold wave if it did! I am a little skeptical right now of the really tall ridge, too often the models overbuild it, but if it keeps showing up it's probably legit. Some areas are probably going to have a major widespread winter storm within the next 10 days, but the placement could be anywhere from Tx to Carolinas to the Lakes. Huge area LOL.

What's the old saying? If DFW gets snow then ATL or CLT more than likely will to? It's interesting how on the 18z that cold front just stalls and stalls.

[FoothillsNC]

What's the old saying? If DFW gets snow then ATL or CLT more than likely will to? It's interesting how on the 18z that cold front just stalls and stalls.

Yeah thats the old rule of thumb for nino years mostly (split flow). Right now we're in such an amplified pattern the storms can drop snow in Jackson, Ms and rain in DC. I think we will still have a few majors where we get rain and the deep south to our west gets snow from a cutoff or strong wrap around. I'd love to see the extreme ridging verify, as that could send development down into the Gulf then go up the east coast if things are right. Even with no -NAO.

[NavarreDon]

Yeah thats the old rule of thumb for nino years mostly (split flow). Right now we're in such an amplified pattern the storms can drop snow in Jackson, Ms and rain in DC. I think we will still have a few majors where we get rain and the deep south to our west gets snow from a cutoff or strong wrap around. I'd love to see the extreme ridging verify, as that could send development down into the Gulf then go up the east coast if things are right. Even with no -NAO.

Would like to see some of that action!

[griteater]

Looking at tonight's GFS / UKMET / GGEM through the next 7 days, after our current system, the ridge is too far off the west coast, leading to trough out west and mild in the SE.

This matches up well with HPC's discussion this aftn...

BEYOND DAY 5...THE MAIN ISSUE IS RESOLVING THE EVOLVING PATTERN

DOWNSTREAM OF THE AMPLIFYING RIDGE OVER THE NORTHERN PACIFIC.

GENERALLY SPEAKING...AN AMPLIFYING RIDGE IN THIS PROXIMITY FAVORS

THE POTENTIAL FOR CONSIDERABLE DIGGING OF DOWNSTREAM PERTURBATIONS

INTO TROUGHS OR POSSIBLY CLOSED LOWS ALONG WITH INTRUSIONS OF

POLAR OR ARCTIC AIRMASSES INTO THE ROCKIES OR NORTHERN PLAINS.

TOTAL SOLUTION SPREAD IS QUITE LARGE BEYOND DAY 5...BUT GIVEN THE

ANTICIPATED LARGE-SCALE RIDGE A SOLUTION SIMILAR OR BETWEEN THE

00Z ECMWF/12Z GFS IS EXPECTED ALBEIT WITH UNCERTAIN DETAILS.

IN ADDITION TO BELOW NORMAL TEMPERATURES FOR MUCH OF THE

ROCKIES/PLAINS THROUGH THE PERIOD... CORRESPONDINGLY WARM AREAS

ARE ANTICIPATED OVER PARTS OF THE PACIFIC NORTHWEST BENEATH THE

EASTERN EDGE OF THE LONGWAVE RIDGE...AND ACROSS MUCH OF THE

EAST/SOUTHEAST WHICH WILL REMAIN BENEATH A BROAD BUT WEAKER RIDGE

THAN OVER THE PACIFIC. FINALLY...SIGNIFICANT SNOWS ARE EXPECTED

ACROSS THE CENTRAL/SOUTHERN ROCKIES DAYS 3/4 DUE TO THE UPPER

LOW...WITH A LARGER SHIELD OF PRECIPITATION DEVELOPING ACROSS

PARTS OF THE PLAINS/MISSISSIPPI VALLEY DAY 5 AND BEYOND AS MORE

ABUNDANT MOISTURE INTERACTS WITH THE EJECTING LOW.

[Gastonwxman]

The Euro says a pretty dang good cold shot comes during the mid period of next week:

[burgertime]

The Euro says a pretty dang good cold shot comes during the mid period of next week:

Per the euro sfc temps it would appear that it's only going to get cold in the morning hours next week if you took it verbatim. They jump up by 18z above freezing..probably more seasonal in the low 50's.

[Poimen]

some hint at some high latitude blocking/-NAO developing on the 10 day EC and the longer range panels of the GFS on the overnight runs. Who knows if it will verify, but It would be nice to transition to a -NAO regime by mid Dec.

[burgertime]

12z GFS has seasonal temps in the short range and medium range. It then has some cold air in the LR with a possible storm at 288 but it's fantasy land.

[Jon]

12z GFS has seasonal temps in the short range and medium range. It then has some cold air in the LR with a possible storm at 288 but it's fantasy land.

288-300 woohoooo now lets start the west trend! ....

It's funny every time I come here to post something about a model run, even in fantasy land, someone beats me to it...it's sad when we are discussing the long range gfs.

[franklin NCwx]

Not much else to do in Nov. We would really be in trouble if it was March.

288-300 woohoooo now lets start the west trend! ....

It's funny every time I come here to post something about a model run, even in fantasy land, someone beats me to it...it's sad when we are discussing the long range gfs.

[BullCityWx]

The euro ensembles show at or above normal temps for most of it's run at 0z. We're going to lose almost all of December if this keeps up.

[burgertime]

Euro doesn't have the cold really coming till 240 and even then it hasn't reached TN....it does however have a storm popping off early next week with some cold around but it quickly chases the cold off . So next week still looks like something to watch.

[burgertime]

The euro ensembles show at or above normal temps for most of it's run at 0z. We're going to lose almost all of December if this keeps up.

Yep it seems every day the carrot gets dangled as the real cold we need is at least a week away. If the switch never really occurs hopefully we have a good Jan.

[BullCityWx]

In contrast to my previous post, there is some hope shown by the 0z Euro OP.

[BullCityWx]

Yep it seems every day the carrot gets dangled as the real cold we need is at least a week away. If the switch never really occurs hopefully we have a good Jan.

We need that NAO and AO to cooperate.

[burgertime]

In contrast to my previous post, there is some hope shown by the 0z Euro OP.

Hasn't it been showing that in the LR though simply for it not to come to fruition? It may not have been the Euro showing and only the GFS if so at least it's showing the NAO in the right direction. PNA is going bonkers too next week which as Robert has been touting might give us some hope.

[BullCityWx]

Hasn't it been showing that in the LR though simply for it not to come to fruition? It may not have been the Euro showing and only the GFS if so at least it's showing the NAO in the right direction. PNA is going bonkers too next week which as Robert has been touting might give us some hope.

I cant remember the Euro giving any hope regarding the AO or NAO up until this point.

[WeatherNC]

Hasn't it been showing that in the LR though simply for it not to come to fruition? It may not have been the Euro showing and only the GFS if so at least it's showing the NAO in the right direction. PNA is going bonkers too next week which as Robert has been touting might give us some hope.

Next solid RN chances are about a week out, Weds, looks like a frontal passage, although a couple of the GFS members have been hinting at a surface wave developing over the Gulf Coast and traversing the front. Behind it is likely the coldest air we have seen thus far, with areas in NC especially, struggling into the 40's. Pretty good agreement between the Euro and GFS considering a 7 day, Euro wants to close off a upper level to our north, which helps to lock in the cold longer, and to a more extreme degree... GFS keeps it open and more progressive, so just a glancing transient shot, compared to one that may stick around for a couple days.

12z GFS mems, above avg agreement in terms of frontal passage, and cold behind it.

12z EC 850T anomalies @ 192, similar to the last run

[Wow]

I cant remember the Euro giving any hope regarding the AO or NAO up until this point.

I don't think so either. The 240 hr Euro begins introducing some blocking over the N Atlantic and E Canada. Give that a few days to work itself into the Arctic and then the fun begins hopefully by mid December. Meanwhile, temps will be around average with progressive cold shots for the most part.

[BullCityWx]

I don't think so either. The 240 hr Euro begins introducing some blocking over the N Atlantic and E Canada. Give that a few days to work itself into the Arctic and then the fun begins hopefully by mid December. Meanwhile, temps will be around average for the most part.

Definitely the best -NAO look we've had in sometime. How was the drive home? I saw your post yesterday.

[burgertime]

I cant remember the Euro giving any hope regarding the AO or NAO up until this point.

I don't think so either. The 240 hr Euro begins introducing some blocking over the N Atlantic and E Canada. Give that a few days to work itself into the Arctic and then the fun begins hopefully by mid December. Meanwhile, temps will be around average with progressive cold shots for the most part.

Awesome thanks for the info!

[Wow]

Definitely the best -NAO look we've had in sometime. How was the drive home? I saw your post yesterday.

Heavy rain up to the border. Pretty crappy driving wx to say the least.

[HKY_WX]

10 day euro looking sexy!

[WeatherNC]

10 day euro looking sexy!

Agree, sig + anomalies south of Greenland, somewhat favorable Pac, no more GoA vortex , Russia and Siberia look cutoff from the real cold for awhile, and a source of Arctic air, which should be funneling into central Canada @ day 10, flirting with the Great Lakes, maybe a PV setting up shop in SE Canada with time if the blocking can retrograde NW some.

[Wow]

Ahh, so the 12z Euro continues from the 0z with a possible N Atlantic block setting up. This looks to pull the PV into SE Canada and build that ridge back into Greenland. This helps my idea of a mid-December pattern change.