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Medium-long range thread


tombo82685

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Gfs showed some signs is ridding the PV /+epo in it's longer range tonight an showing a decent PNA spike. However, the ATL never looks great and we go more seasonal. Just when you think it's all clear is Alaska, the end of the gfs rebuilds the PV ...eghh beter hope that doesn't happen.

And just be because the pattern change I'm

Thinking happens around dec 15th-20th, doesn't mean it'll become more favorable for storms and

Cold. No signs of a -NAO in sight...

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both gfs and euro say 'not so fast, my friend' to the post Turkey Day cooloff...obviously one run but the cooloff has been delayed a bit more.

6z gfs does have a prolonged cool shot .

Starting around 240hrs, it starts pumping the PnA ridge. 6z gfs a bit more bullish and closer to the west coast than the 0z was. After a fropa around 286, a storm phases offshore and heads north and kinda becomes a PV. By the last 2 frames, the ridge is starting to slide east towards us.

Just showing what the long range gfs was showing. A step in the right direction from the torch pattern. Too bad there's not a half decent block with that PNA spike.

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6z gfs does have a prolonged cool shot .

Delayed til 12/1-2 tho...the Sat-Thu thinking that was getting kicked around by Adam and I doesn't look as likely as it did 24 hours ago.

The 0z GFS was delayed until 12/4 and the EC is delayed past Day 10.

Not being a debby downer but the pattern (right now) isn't supporting prolonged cooldowns for a few more weeks...there will certainly be cool shots in there (Thanksgiving is looking cool) but a locked pattern isn't supported at this point as long as the Pacific is sucking.

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Delayed til 12/1-2 tho...the Sat-Thu thinking that was getting kicked around by Adam and I doesn't look as likely as it did 24 hours ago.

The 0z GFS was delayed until 12/4 and the EC is delayed past Day 10.

Not being a debby downer but the pattern (right now) isn't supporting prolonged cooldowns for a few more weeks...there will certainly be cool shots in there (Thanksgiving is looking cool) but a locked pattern isn't supported at this point as long as the Pacific is sucking.

I hear ya. Textbook "Nina" in play right now,

Initially I was thinking dec 15th-20th for a pattern change , but I'm starting to get a bit nervous that just because a "pattern change" is coming, it might necessarily last . The way patterns have locked in over the past year, the rule of thumb on the 45 day pattern lock might turn into a 90 day lock instead. Not gonna pull the trigger on the unfavorable pattern setting back up mid December, but te long range op and ensembles of the gfs rebuilding the PV over Alaska is alarming. Still waitin to see what the MJO does.

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I hear ya. Textbook "Nina" in play right now,

Initially I was thinking dec 15th-20th for a pattern change , but I'm starting to get a bit nervous that just because a "pattern change" is coming, it might necessarily last . The way patterns have locked in over the past year, the rule of thumb on the 45 day pattern lock might turn into a 90 day lock instead. Not gonna pull the trigger on the unfavorable pattern setting back up mid December, but te long range op and ensembles of the gfs rebuilding the PV over Alaska is alarming. Still waitin to see what the MJO does.

Yeah I originally thought that cfp on Thanksgiving Eve was going to be the MJO pattern changer a couple of weeks ago, but its not been the force to reckon with, the non-tropics laughed and carried on. Never been a big fan of patterns lasting longer than six weeks. Granted the "change" may really be a short lived "reload", December will tell.

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I'll put my foot in my mouth too and say it may avg negative, but weakly so. Again, I'm not a long range guru, but just my guess. I'm hoping in a few weeks we'll see some signs of it, or at the very least...get that dam AK trough out of there and have the EPO tank.

It was interesting that last autumn there was a NAO graph that showed there have never been two consecutive deeply negative NAO winters in a row. I remember Brian (Vawxman) telling me it depends on how these sites are defining winter, some include March, some don't in those graphs. I don't know if we include or exclude March, then there have been deeeply negative couplets in the past. Of course now we'd be banking on a triplet which would seem pretty hard to do. I did notice that (RIP) Jack's NF pool SSTA was implying a near zero NAO for this upcoming winter, but it did the same last winter. The only thing is that the ssta gradient is flipped (w to e) from the 2010 spring/early summer. I'm guessing that the UKMET stopped with NAO winter outlooks (or are they not public domain anymore?). Either way NE can get away with +NAO winters, we start losing chances here, although there have been exceptions.

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Delayed til 12/1-2 tho...the Sat-Thu thinking that was getting kicked around by Adam and I doesn't look as likely as it did 24 hours ago.

The 0z GFS was delayed until 12/4 and the EC is delayed past Day 10.

Not being a debby downer but the pattern (right now) isn't supporting prolonged cooldowns for a few more weeks...there will certainly be cool shots in there (Thanksgiving is looking cool) but a locked pattern isn't supported at this point as long as the Pacific is sucking.

I am starting to get that "pot of gold is always at the end of the rainbow" feeling that was around in I believe the 2006 winter.

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The idea of a SSW this January has been something I have liked for a while now. All the years with a setup similar to 2011-12 had a substantial SSW/MMW and some of my favorite years had it in January. It is quite possible that a majority of January and February come in cooler than normal across the eastern US, but it depends on how fast this all occurs.

Some of you are arguing for a late January response, which is perfectly reasonable. However, if the MJO continues to remain faster than normal, you are going to get a tropical boost much sooner than that in the month, possibly jump-starting the SSW.

Whenever this period occurs, it will have significant cold / snow and be similar to the last couple of years' outcomes in terms of wintry extremes. The potential exists for historic snow / cold with this particular round of -AO and the timing of it couldn't be better (or worse) for significant cold.

I took this from Wes's NAO thread in the general weather forum.

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Not really buying any of the model solutions after D7-8. Lots of scatter on the ensembles in the out periods, but all of the MJO teleconnections suggest ridging to be centered over the Great Lakes or East Coast. We're going to have to wait for P6 before the tropics help us out and that doesn't appear likely until Dec 15 or so.

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Sun-Tue, I would think, but not buying the D8-10 part of the Euro. Doesn't fit with the tropical stuff.

I assume your alluding to the MJO?

If so, I have a question. When looking at the circle diagram , does the amplitude of the phase have different affects in the forcing?

Let's say, the end of October, the wave pulsed pretty big into phase 8-1. Would that same phase be as "far reaching" if it were a weaker pulse ( say hovering around the COD) ? Hopefully this makes sense.

If not, I apologize . Its a Monday morning after

A Sunday night eagles game ;-)

And i would think the cool shot has some creedance with the way the PNA is suppose spike a bit. I did see the 12z euro and gfs yesterday had a cut off low over the area. Was originally a bowling ball system, the the PNA spike kept feeding vorts into the system cutting it off. But cut offs are always a Mehh forecast, especially day 6-7.

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I assume your alluding to the MJO?

If so, I have a question. When looking at the circle diagram , does the amplitude of the phase have different affects in the forcing?

Let's say, the end of October, the wave pulsed pretty big into phase 8-1. Would that same phase be as "far reaching" if it were a weaker pulse ( say hovering around the COD) ? Hopefully this makes sense.

If not, I apologize . Its a Monday morning after

A Sunday night eagles game ;-)

And i would think the cool shot has some creedance with the way the PNA is suppose spike a bit. I did see the 12z euro and gfs yesterday had a cut off low over the area. Was originally a bowling ball system, the the PNA spike kept feeding vorts into the system cutting it off. But cut offs are always a Mehh forecast, especially day 6-7.

I'm not Adam, but I would agree with this, the COD must be there for a reason and this MJO wave through colder phases hardly produced a ripple here.

The Euro has had some squirrelly over closed solutions lately beyond day 5, i.e. the rain/snow around NYC on Thanksgiving, but the running theme that the PNA is the first to fall off the bus seems to be holding. The problem may be if the amplitude is not high enough, it would still be pacific air, granted coming from a colder direction.

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I assume your alluding to the MJO?

If so, I have a question. When looking at the circle diagram , does the amplitude of the phase have different affects in the forcing?

Let's say, the end of October, the wave pulsed pretty big into phase 8-1. Would that same phase be as "far reaching" if it were a weaker pulse ( say hovering around the COD) ? Hopefully this makes sense.

If not, I apologize . Its a Monday morning after

A Sunday night eagles game ;-)

And i would think the cool shot has some creedance with the way the PNA is suppose spike a bit. I did see the 12z euro and gfs yesterday had a cut off low over the area. Was originally a bowling ball system, the the PNA spike kept feeding vorts into the system cutting it off. But cut offs are always a Mehh forecast, especially day 6-7.

In general, yes, the higher the amplitude of the MJO in the phases, the stronger the mid-latitude response. But keep in mind, the response changes by months and seasons due to the changing wavelengths of mid-lat Rossby waves. In late Oct-early Nov, P8-P1 are warm for the East, but in DJF, they are cold and snowy.

I'm not Adam, but I would agree with this, the COD must be there for a reason and this MJO wave through colder phases hardly produced a ripple here.

The Euro has had some squirrelly over closed solutions lately beyond day 5, i.e. the rain/snow around NYC on Thanksgiving, but the running theme that the PNA is the first to fall off the bus seems to be holding. The problem may be if the amplitude is not high enough, it would still be pacific air, granted coming from a colder direction.

The "cold" phases aren't that cold here in November. But yeah, overall, I agree with what you are saying. The huge -PNA seems to be breaking a bit, but I don't think we're going to break the "more warm than cold" pattern until mid-month. Phases 3-4-5 are coming up and they are generally warm phases in the December. When it gets to P6, we'll see ridging along the West Coast and the chance to tap into some truly cold air (though that pattern is colder for the N Plains/Western Lakes than us).

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For those interested and who don't pay for JB....he sees a below normal but nothing extreme December. Seems in line with most of the professionals on here

"I have been trying to get across, that in analog years like this, changes to an eastern trough come late in November and generally last through much of December. Still missing though is the block. It looks like we are going into a broad 3 wave pattern. The fact its occurring, like last year, about 10 days after a temp rise in the mid trop is interesting, but the fact another rapid fall is developing means that there is not likely to be blocking in the near future"

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12z

Gfs has a pretty big cut off develop over the great lakes for the mid-long range.

Just some quick notes on the 12z gfs:

Big cut off low to our west.

Cut off lows are difficult to forecast. If it's as wrapped up and that far west, I'm sure the 850's could look cold, but the surface could become quite "warm" being as you get a sw flow.

2. Looks like the NAO doesn't become to positive or negative. In line with MJO and strat forecasts.

3. The biggest thing I'll focus on for now. The PV does not try and become re established over ALaska. Instead, it splits and starts shifting towards the Hudson bay. Take with a grain of salt, but it's encouraging to see.

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the 12z euro is taking a step in the right direction if you want colder weather. Lost the huge AK vortex, which gets replaced by a nice ridge extending into the alaska. Also, trying to pop a -nao but its more or a north atlantic ridge at that point. Only downfall is it has the beginning of a trof on the west coast which is trying to rise the se ridge.

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the 12z euro is taking a step in the right direction if you want colder weather. Lost the huge AK vortex, which gets replaced by a nice ridge extending into the alaska. Also, trying to pop a -nao but its more or a north atlantic ridge at that point. Only downfall is it has the beginning of a trof on the west coast which is trying to rise the se ridge.

Its been kind of holding of a cool down relative to normal once December starts, but the $$$ question is whether this is a pause and what happens next. I get the feeling with where the mjo is going and the lack of any ssw showing we snap back milder (given my wag normally fail, you should be happy with this post). The real test comes in the latter half of December.

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Its been kind of holding of a cool down relative to normal once December starts, but the $ question is whether this is a pause and what happens next. I get the feeling with where the mjo is going and the lack of any ssw showing we snap back milder (given my wag normally fail, you should be happy with this post). The real test comes in the latter half of December.

saving grace is, normal temps can atleast yield some snow in december...i think in this kind of pattern only shot of snow we have is from a clipper or lake affect snow showers...any disturbance that is some what strong is just going to cut west with the lack of blocking and semi trof on the west coast will flex the se ridge

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Its been kind of holding of a cool down relative to normal once December starts, but the $$$ question is whether this is a pause and what happens next. I get the feeling with where the mjo is going and the lack of any ssw showing we snap back milder (given my wag normally fail, you should be happy with this post). The real test comes in the latter half of December.

Yep.

saving grace is, normal temps can atleast yield some snow in december...i think in this kind of pattern only shot of snow we have is from a clipper or lake affect snow showers...any disturbance that is some what strong is just going to cut west with the lack of blocking and semi trof on the west coast will flex the se ridge

Yep.

I'll be surprised at this point if we see accumulating snow >1" through Dec 15 (at least I-95 and east).

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you look at this setup shown by the euro at day 10, not saying its right but, its not a horrid situation if we had atleast a somewhat neutral or slightly negative ao. The +ao is really hurting this setup with bottling all the cold air up, allowing no real driving force to pull that cold air down. I don't even think having a a severely -nao right now would do much. Just not much cold air up in canada. Granted its cold enough for snow up there, but as it comes down here that would moderate.

12zeuro500mbHGHTNA240.gif

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That cut off low in the SWUS is Helping pump up eights along the east coast. Still, not

Too bad. Could be worse right?!

that storm would cut big time...i was merely just posting that the bigger features wern't horrible. The nao is probably around neutral...no ak vortex, with a ridge poking in...somewhat of a quasi trof on the west coast. If the ao wasnt so flipping positive, this would be a good bit colder look.

which is shown in the euro ens at day 9, but its again trying to build the ak vortex back in, rinse and repeat?

12zecmwfens500mbHGHTNH216.gif

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