Pattern Change thread

[CoastalWx]

Yeah I think we see our first legit winter event in that 4-5 day period starting Thanksgiving...if the actual T-day event doesn't happen then I think the next impulse will produce something.

I think your first two inch call looks good. If not that day..probably within a couple of days..either side. I'm starting to like the last days of November into the beginning of December. Good pattern developing.

[ORH_wxman]

I think your first two inch call looks good. If not that day..probably within a couple of days..either side. I'm starting to like the last days of November into the beginning of December. Good pattern developing.

Yeah, I like that period too. The NAO block might be trying to break down then which might lead to a more substantial event. I'm a bit worried about a warmup in Mid-December...but hopefully the NAO can stay neutral to negative enough to help offset it and maybe we can get a friendly +EPO like in Dec 2007.

[Ginx snewx]

Yeah, I like that period too. The NAO block might be trying to break down then which might lead to a more substantial event. I'm a bit worried about a warmup in Mid-December...but hopefully the NAO can stay neutral to negative enough to help offset it and maybe we can get a friendly +EPO like in Dec 2007.

VAwxman, on 16 November 2010 - 02:20 PM, said:

LOL... if you insist.

My, my , my, my...

This trough hits, so hard

Makes me say, Oh my Lord!

Thank you, for blessing me

With a big cold high and dual blocking.

It feels good, when it all comes down,

A strong polar flow from Santa's hometown.

And you know, as such

That this is a trough, uhh, you can't touch!

[dryslot]

I think your first two inch call looks good. If not that day..probably within a couple of days..either side. I'm starting to like the last days of November into the beginning of December. Good pattern developing.

As we thought

[CoastalWx]

Yeah, I like that period too. The NAO block might be trying to break down then which might lead to a more substantial event. I'm a bit worried about a warmup in Mid-December...but hopefully the NAO can stay neutral to negative enough to help offset it and maybe we can get a friendly +EPO like in Dec 2007.

Yeah that's definitely on the table. Luckily the Pacific (well specifically west coast) doesn't go to crap right away and flood the country with Pac air, but I'm sure the pattern will relax some...hopefully not too much.

[ORH_wxman]

The 18z GFS ensembles are really ripping the NAO block back over Greenland and the Davis Straight after T-day....definitely more west based than the ECMWF ensembles.

That would increase our chances of a larger Miller B system as the flow gets more blocked up and buckled with a potent and dominant polar jet coming out of the west.

[Ginx snewx]

The 18z GFS ensembles are really ripping the NAO block back over Greenland and the Davis Straight after T-day....definitely more west based than the ECMWF ensembles.

That would increase our chances of a larger Miller B system as the flow gets more blocked up and buckled with a potent and dominant polar jets coming out of the west.

Posted the other day about Tday being an anafront, saw HM posted the same thing today. Windex event Tday night?

[Damage In Tolland]

JB ripping shots.

The period starting the middle of next week through around Christmas is liable to be the highlight of the winter for much of the eastern part of the United States. I am getting fired up for the threat of a blockbuster storm sometime in early or mid December near the east coast, perhaps the only true monster of the winter in areas that were hammered last year south of I-80. However the problem is that its so early in the year, that this could be, like the great early season storms of 1992 or 1950, mainly rain in the coastal plain. Why am I saying this so early.. The kind of monster block that is evolving in this pattern, with the cold air that is going to be coming later next week an the week after, usually produces some kind of major buckling near the east coast that gets trapped. This is still 10-30 days away, but its on the table, given the pattern.

[ORH_wxman]

JB ripping shots.

The period starting the middle of next week through around Christmas is liable to be the highlight of the winter for much of the eastern part of the United States. I am getting fired up for the threat of a blockbuster storm sometime in early or mid December near the east coast, perhaps the only true monster of the winter in areas that were hammered last year south of I-80. However the problem is that its so early in the year, that this could be, like the great early season storms of 1992 or 1950, mainly rain in the coastal plain. Why am I saying this so early.. The kind of monster block that is evolving in this pattern, with the cold air that is going to be coming later next week an the week after, usually produces some kind of major buckling near the east coast that gets trapped. This is still 10-30 days away, but its on the table, given the pattern.

Looks like he is buying the idea of a very big NAO block...similar to what I posted a couple posts up abotu the 18z GFS ensembles. That would definitely heighten the risk for a larger system.

[CoastalWx]

The 18z GFS ensembles are really ripping the NAO block back over Greenland and the Davis Straight after T-day....definitely more west based than the ECMWF ensembles.

That would increase our chances of a larger Miller B system as the flow gets more blocked up and buckled with a potent and dominant polar jet coming out of the west.

I wish we had that last year. No PV, and instead cold was forced into the Plains and then south. At least this is ripping the PV into se Canada.

[Damage In Tolland]

Looks like he is buying the idea of a very big NAO block...similar to what I posted a couple posts up abotu the 18z GFS ensembles. That would definitely heighten the risk for a larger system.

He shares our thoughts about possible coastal plain screwjob this winter. Hopefully not the case

[CoastalWx]

He shares our thoughts about possible coastal plain screwjob this winter. Hopefully not the case

Gonna need that polar high. If I have a 1040 high near the Lakes like the euro and gfs had....

[Ginx snewx]

He shares our thoughts about possible coastal plain screwjob this winter. Hopefully not the case

LOL

[Damage In Tolland]

I don't like all the talk from HM, Brian, Gibbs of a mid December torch for weeks. I was thinking Dec. would be cold and snowy all month before Jan got warm

[ORH_wxman]

I don't like all the talk from HM, Brian, Gibbs of a mid December torch for weeks. I was thinking Dec. would be cold and snowy all month before Jan got warm

It hard to get it cold the whole month. Even Dec 2007 torched the final 10 days of the month. The hope is that the torch isn't extreme...we can still get snow threats in an above normal pattern (esp interior) provided its not ridiculously warm.

I'm hoping its just a moderation more than a torch and then we reload before Christmas. But given the NAO uncertainty, we really have no idea how it will perform.

[Ginx snewx]

I don't like all the talk from HM, Brian, Gibbs of a mid December torch for weeks. I was thinking Dec. would be cold and snowy all month before Jan got warm

Reading comprehension FTL

HM

Yeah this is going to potentially set up a reverse warm anomaly for many in the northern 2/3s of the CONUS, outside of maybe the NW, for a 6-10 day period. As the MJO composites suggest, a phase 3-4-5 transition from where we are now would bring quite an impressive warm shot, outside of the southern states. Once the -NAO block is finished and the EPO goes significantly positive (as wavelengths become longer from both being a winter seasonal progression and the -NAO block going away), it is going to get ugly. At some point in late December, I expect a classic cold Northwest/North regime to return and the ridge to properly place over the Southeas

[CoastalWx]

It hard to get it cold the whole month. Even Dec 2007 torched the final 10 days of the month. The hope is that the torch isn't extreme...we can still get snow threats in an above normal pattern (esp interior) provided its not ridiculously warm.

I'm hoping its just a moderation more than a torch and then we reload before Christmas. But given the NAO uncertainty, we really have no idea how it will perform.

The euro MJO plots go to the circle of death, but hedge to Phase 4-5. That had me a little worried. I'm sure they see that too. Hopefully the GOA low doesn't return with vengeance, but who knows. I'm hoping the pattern returns later on.....if it does indeed leave.

[Damage In Tolland]

Reading comprehension FTL

HM

Yeah this is going to potentially set up a reverse warm anomaly for many in the northern 2/3s of the CONUS, outside of maybe the NW, for a 6-10 day period. As the MJO composites suggest, a phase 3-4-5 transition from where we are now would bring quite an impressive warm shot, outside of the southern states. Once the -NAO block is finished and the EPO goes significantly positive (as wavelengths become longer from both being a winter seasonal progression and the -NAO block going away), it is going to get ugly. At some point in late December, I expect a classic cold Northwest/North regime to return and the ridge to properly place over the Southeas

Yes apparently you do

[Ginx snewx]

Yes apparently you do

Personally I do not think it is out of the ordinary to have a 6-10 ten day warm up in Dec. I also see where all of them have NE in the ?? area, are we north of the gradient, they seem to think so. You hyped up what they were saying big time., but whatever, time will tell. No need to worry about a month from now.

[Logan11]

We just have to enjoy our periodic bouts of cold/snow amidst a sea of mild in the eastern Conus this winter. I don't think building a big snow pack etc. is in the cards this year. South of us there may be no winter at all so savor what we get I suppose. We may get a few periods of great winter wx even in an overall sub par pattern.

[MaineJayhawk]

We just have to enjoy our periodic bouts of cold/snow amidst a sea of mild in the eastern Conus this winter. I don't think building a big snow pack etc. is in the cards this year. South of us there may be no winter at all so savor what we get I suppose. We may get a few periods of great winter wx even in an overall sub par pattern.

Debbie's sister, Donna Downer.

[Logan11]

Lets face it ...probably 50% of the time Christmas is mild..as in 40F +. I have no facts to bear it out here, but just seems it. So if it should get mild in later Dec...no shock there. We only get idyllic Christmas seasons maybe half the time.

I was thinking about this earlier and I think we have the later Nineteenth Century Little Ice Age period to thank for most of our snow/cold related Xmas traditions that are so deeply ingrained. So many of our traditions evolved during that time period.

Personally I do not think it is out of the ordinary to have a 6-10 ten day warm up in Dec. I also see where all of them have NE in the ?? area, are we north of the gradient, they seem to think so. You hyped up what they were saying big time., but whatever, time will tell. No need to worry about a month from now.

[Logan11]

Well now you are north of SNE More reason for optimism I'd say.

Debbie's sister, Donna Downer.

[Baroclinic Zone]

http://www.meteo.psu.edu/~gadomski/NARR/2003/us1205.php

Bring it on!

[CoastalWx]

Personally I do not think it is out of the ordinary to have a 6-10 ten day warm up in Dec. I also see where all of them have NE in the ?? area, are we north of the gradient, they seem to think so. You hyped up what they were saying big time., but whatever, time will tell. No need to worry about a month from now.

Even the weeklies relaxed the pattern before bring it back towards mid month. Not that it will happen that way, but these wild pattern changes early in the season don't always lock for weeks on end. Also, maybe heights stay weakly positive to our northeast and the North Pac ridge holds in place. It still may imply a gradient in our favor...we just don't know. Nevertheless, we should just worry about the next 2-3 weeks. Certainly the potential is there. I'm looking forward to it.

[ORH_wxman]

Looking at the CPC analogs rolled forward 3 weeks, the pattern may be tough to break quickly. This is what the pattern should look like in mid December if there is any truth to this

[ORH_wxman]

I screwed up with the first image...the correct one should be there now.

[Ginx snewx]

Even the weeklies relaxed the pattern before bring it back towards mid month. Not that it will happen that way, but these wild pattern changes early in the season don't always lock for weeks on end. Also, maybe heights stay weakly positive to our northeast and the North Pac ridge holds in place. It still may imply a gradient in our favor...we just don't know. Nevertheless, we should just worry about the next 2-3 weeks. Certainly the potential is there. I'm looking forward to it.

Me too, how one even worries about after that when we are looking at a possibly ideal pattern coming soon IDK

[weatherwiz]

I'm going to start basically blogging some thoughts (just posting them on facebook) and use this as a way to begin documenting some thoughts/forecasts so I can go back and read them and use it as a way to become better at forecasting and such. Every once in a while I'll just post it here as well so if anyone wants to give me any feedback (both good and bad) I could use that to help me out as well.

The next few weeks will be rather interesting wise as we now enter a more active weather pattern and we also begin to see a trend towards more below-average temperatures as colder temperatures try to work in from Canada. However, before we get to this point we have to deal with the short-term.

Currently an area of low pressure is working up from the southwest and is centered around the state of KY. As this deepening area of low pressure works to the north, passing well to the west of us here in southern New England warmer and more moist air will continue to be transported northward into the region as a warm front is propelled northward.

Over the next 12-18 hours the will be on and off periods of showers with isolated thunderstorms possible as well as the warmer air in the lower-levels of the atmosphere lifting northward coincides with much cooler and cooling temperatures in the mid levels of the atmosphere creating some elevated instability. Some of the showers will be quite heavy at times and the best chance to see heavier rainfall will be during the overnight and early morning hours. Not only will we have showers/isolated thunderstorms to contend with tonight and the first half of tomorrow but there will be potential for some strong winds as well, especially in the higher elevations. Associated with the warm front is an area of very strong low-level winds and with warm air advection occurring at the surface and in the low-levels of the atmosphere this will tend to weaken any inversion in place and allow for the potential for some of these stronger winds aloft to be transported down to the surface. Winds could occasionally gust to as high as 40-50 mph at times across portions of the region tomorrow.

As the system continues to lift northward into Canada a cold front will be approaching us from the west, eventually passing through the region sometime during the day on Thursday, once the front clears the region colder air that is built up in Canada will be transported into the Northeast and we will see cooler temperatures for the end of the work week and for the weekend as well.

This weekend will feature much cooler temperatures and it will also be rather breezy at times, making it feel colder than it actually is. There may also be several periods this weekend where some locations could see on and off snow showers as weak disturbances pass through the region in the fast flow aloft, the best chance for this to occur right now appears to be in northern New England.

As we move into the early part of next week the Southeast ridge begins to flex it's muscles again and starts to build northward again, as this occurs we will start to see the wind direction change to a more southwesterly and southerly direction. This will begin to transport warmer air into the region.

As we move towards mid-week yet another storm system begins to take shape across the Plains and begins to move eastward. As this occurs this will further build up heights across the east and allow for warm air to really be transported northward. While this warmth will be rather brief, lasting only two days (Tuesday and Wednesday) it may be rather warm as temperatures possibly near or perhaps exceed the 60F mark. By Thanksgiving Day the storm system will have moved closer to the region and this is when we begin to see drastic changes.

The system should have cleared the region by Friday and once the system passes the potential exists for much colder air to work into the region, while the coldest of the air may stay off to our north and west we should still end up in a below-average pattern, although there are some fairly large differences between two of the long-range models as to how cold it exactly gets.

The pattern that looks to set up post-Thanksgiving also appears to be rather favorable for a rather stormy and active weather pattern, and this is where we may indeed see our first potential for a widespread snow event.

This is still well over a week away, however, so the trends will continued to be monitored.

[Logan11]

Some kind of Thanksgiving overunning event is back on the 18Z GFS I see. It gets the colder air in here now by Tuesday night/early Wednesday.