Jump to content
  • Member Statistics

    17,502
    Total Members
    7,904
    Most Online
    Weathernoob335
    Newest Member
    Weathernoob335
    Joined

Next week's storm, Changes, Snow threats beyond (Part 2)


OKpowdah

Recommended Posts

Figured we should get a new thread going during the evening model lull.

So, very much to discuss:

1) Thursday 1/12 (one year anniversary of much rejoicing)

-- Significant trough diving into the Northern Plains, while a cutoff low lifts northeastwards toward the region.

Pretty big differences remain in model guidance with respect to the amplitude of the diving trough and the track of the cutoff.

Regardless: Big precipitation and wind event for New England.

Some question remains re: wintry potential for interior CNE and NNE ... a couple opportunities: first in advance of the cutoff low, and next with a s/w embedded in the large trough ... as the Euro alluded to, maybe a late blooming Miller B that throws some moisture back into the cold airmass blasting into the region (read on).

2) CAA behind the storm

Decent blast of cold air, as the trough digs into the Great Lakes and swings through New England.

Again, much disagreement with that trough, which just amplify through the end of the week.

3) Storm threat next weekend circa 1/14

-- Model differences ... to break it down simply ... three disturbances:

...1. the big trough moving through the region, and lifting northward

...2. model guidance has trended toward cutting off a piece of energy diving south with the big trough next week. So that should be fun to resolve.

Normal biases apply ... the Euro cuts it off west of southern California; the GFS further east, and the Canadian never cuts it off as it is overwhelmed by the bowling ball that it makes of the trough next week.

...3. incoming northern stream s/w behind the big trough.

So questions as to phasing of the northern s/w and the new cutoff, as well as the evolution of the big trough, which seems to pose huge questions for the end of next week.

4) Pattern change? Storm threats?

-- Signs that ridging building from the Aleutians northward definitely breaking up the polar vortex fairly efficiently.

Still looks like a fairly classic gradient pattern unfolding, with the states of the PNA and NAO affecting the orientation of the gradient and storm tracks.

Questions to the legitimacy of the pattern change, and will it hold?...Closely watching heights over Alaska...

At the very least, we're definitely taking care of the AO domain fairly well.

Also, watching for a possible major stratospheric warming in the next 10 days.

Link to comment
Share on other sites

  • Replies 1.1k
  • Created
  • Last Reply

Figured we should get a new thread going during the evening model lull.

So, very much to discuss:

1) Thursday 1/12 (one year anniversary of much rejoicing)

-- Significant trough diving into the Northern Plains, while a cutoff low lifts northeastwards toward the region.

Pretty big differences remain in model guidance with respect to the amplitude of the diving trough and the track of the cutoff.

Regardless: Big precipitation and wind event for New England.

Some question remains re: wintry potential for interior CNE and NNE ... a couple opportunities: first in advance of the cutoff low, and next with a s/w embedded in the large trough ... as the Euro alluded to, maybe a late blooming Miller B that throws some moisture back into the cold airmass blasting into the region (read on).

2) CAA behind the storm

Decent blast of cold air, as the trough digs into the Great Lakes and swings through New England.

Again, much disagreement with that trough, which just amplify through the end of the week.

3) Storm threat next weekend circa 1/14

-- Model differences ... to break it down simply ... three disturbances:

...1. the big trough moving through the region, and lifting northward

...2. model guidance has trended toward cutting off a piece of energy diving south with the big trough next week. So that should be fun to resolve. Normal biases apply ... the Euro cuts it off west of southern California; the GFS further east, and the Canadian never cuts it off as it is overwhelmed by the bowling ball that it makes of the trough next week.

...3. incoming northern stream s/w behind the big trough.

So questions as to phasing of the northern s/w and the new cutoff, as well as the evolution of the big trough, which seems to pose huge questions for the end of next week.

4) Pattern change? Storm threats?

-- Signs that ridging building from the Aleutians northward definitely breaking up the polar vortex fairly efficiently.

Still looks like a fairly classic gradient pattern unfolding, with the states of the PNA and NAO affecting the orientation of the gradient and storm tracks.

Questions to the legitimacy of the pattern change, and will it hold?...Closely watching heights over Alaska...

At the very least, we're definitely taking care of the AO domain fairly well.

Also, watching for a possible major stratospheric warming in the next 10 days.

Good post. I think with this major ridging/blocking over the Bering Strait wer'e finally able to get rid of the +AO. With strong stratospheric warming that is probably a good sign that the +AO regime won't come back.

I do think the retrograding Aleutian ridge/block is going to cause some problems for most of CONUS with the +EPO returning. I'm fairly confident that happens.

With a +EPO/-AO (or AO neutral) pattern we'll definitely have some chances. What's intriguing to me is that even looking at the op GFS run through D16 southern stream energy is basically non-existent. Not a classic "gradient" pattern in that sense with shortwaves ejecting from 4 corners region.

Thoughts?

Link to comment
Share on other sites

Good post. I think with this major ridging/blocking over the Bering Strait wer'e finally able to get rid of the +AO. With strong stratospheric warming that is probably a good sign that the +AO regime won't come back.

I do think the retrograding Aleutian ridge/block is going to cause some problems for most of CONUS with the +EPO returning. I'm fairly confident that happens.

With a +EPO/-AO (or AO neutral) pattern we'll definitely have some chances. What's intriguing to me is that even looking at the op GFS run through D16 southern stream energy is basically non-existent. Not a classic "gradient" pattern in that sense with shortwaves ejecting from 4 corners region.

Thoughts?

Relating to the patterns in 2007-9 ... an active southern stream depended on split flow downstream of a -EPO ridge, diving into a -PNA trough (with the northern stream directed southeast into the Northern Plains)... I think it might have been you who mentioned the attractiveness of some degree of -PNA for storm opportunities here in a gradient pattern like this ... classic SWFE set ups in that situation. Otherwise, the La Nina doesn't support much southern stream activity when it sits alone.

One thing that's nice to see with some of the recent GFS runs is that even with a re-emerging +EPO, the flow remains amplified, attributable to the falling AO ... so we're at least not stuck back in this raging zonal jet unimpeded across a full latitude circle.

Link to comment
Share on other sites

Good post. I think with this major ridging/blocking over the Bering Strait wer'e finally able to get rid of the +AO. With strong stratospheric warming that is probably a good sign that the +AO regime won't come back.

I do think the retrograding Aleutian ridge/block is going to cause some problems for most of CONUS with the +EPO returning. I'm fairly confident that happens.

With a +EPO/-AO (or AO neutral) pattern we'll definitely have some chances. What's intriguing to me is that even looking at the op GFS run through D16 southern stream energy is basically non-existent. Not a classic "gradient" pattern in that sense with shortwaves ejecting from 4 corners region.

Thoughts?

Ryan, would that be a general retrogressive pattern with other features doing same? i.e. the natl ridge and the greenland vortex?

Link to comment
Share on other sites

Relating to the patterns in 2007-9 ... an active southern stream depended on split flow downstream of a -EPO ridge, diving into a -PNA trough (with the northern stream directed southeast into the Northern Plains)... I think it might have been you who mentioned the attractiveness of some degree of -PNA for storm opportunities here in a gradient pattern likPe this ... classic SWFE set ups in that situation. Otherwise, the La Nina doesn't support much southern stream activity when it sits alone.

One thing that's nice to see with some of the recent GFS runs is that even with a re-emerging +EPO, the flow remains amplified, attributable to the falling AO ... so we're at least not stuck back in this raging zonal jet unimpeded across a full latitude circle.

If we can get that cut off block to hang near AK that could be good despite the +EPO. That EPO is my worry but that will be block dependent. It could also cause a lot of angst within a short distance around these parts lol, in terms of latitude.

Link to comment
Share on other sites

Relating to the patterns in 2007-9 ... an active southern stream depended on split flow downstream of a -EPO ridge, diving into a -PNA trough (with the northern stream directed southeast into the Northern Plains)... I think it might have been you who mentioned the attractiveness of some degree of -PNA for storm opportunities here in a gradient pattern like this ... classic SWFE set ups in that situation. Otherwise, the La Nina doesn't support much southern stream activity when it sits alone.

One thing that's nice to see with some of the recent GFS runs is that even with a re-emerging +EPO, the flow remains amplified, attributable to the falling AO ... so we're at least not stuck back in this raging zonal jet unimpeded across a full latitude circle.

Yes, that is a very good sign.

I think the -PNA pattern is going to be important for us to get some storminess. But as modeled the southern stream appears nearly dormant. May allow for some interesting redeveloping clippers but in general I think it's a relatively dry pattern.

Link to comment
Share on other sites

Yes, that is a very good sign.

I think the -PNA pattern is going to be important for us to get some storminess. But as modeled the southern stream appears nearly dormant. May allow for some interesting redeveloping clippers but in general I think it's a relatively dry pattern.

ryan - are you writing these two thoughts exclusive from one another?

Link to comment
Share on other sites

ryan - are you writing these two thoughts exclusive from one another?

Yeah... sorry didn't make much sense the way I wrote it.

I think the -PNA pattern is a plus in making sure we can ride the gradient and have some fun with storminess. However, as modeled, the southern stream looks pretty dull.

Link to comment
Share on other sites

Yes, that is a very good sign.

I think the -PNA pattern is going to be important for us to get some storminess. But as modeled the southern stream appears nearly dormant. May allow for some interesting redeveloping clippers but in general I think it's a relatively dry pattern.

Yeah, and what I was saying is I think that's due to the rise in the EPO domain. We don't have that split flow in the west to deliver disturbances to the southern stream

Link to comment
Share on other sites

Northern stream action is usually modeled pretty poorly out in the long range. We won't really know if anything comes from them...sometimes when it looks totally boring, we get a northern stream wave look better in the short range.

Link to comment
Share on other sites

Northern stream action is usually modeled pretty poorly out in the long range. We won't really know if anything comes from them...sometimes when it looks totally boring, we get a northern stream wave look better in the short range.

I think we're going to have to rely on the northern stream for fun in the D10-D15 range but it will be hard to pin down specifics as you said.

Link to comment
Share on other sites

Disturbances running (hopefully) under us creating several inches every few days works for me. It worked 18 winters ago with a couple f embedded over performers.

My first winter in Boston... set a very high standard, followed soon after by the epic 95-96... man were we spoiled!

What a difference a 12Z suite makes... strongest evidence yet that the AO is gonna take a hit... increasingly appears that the top of the order is up Jan 20-31 to challenge this shutout, and I'm still not clear on what pattern takes hold thereafter. We'll see!

Link to comment
Share on other sites

The interesting question down the line is how much impact the stratospheric warming will have up in the Arctic.

Will we see a sustained -AO?

We're already seeing the PV disrupted thanks to that big ridge north of the Caspian Sea and then the monster Bering Strait block that develops next week finished it off. But beyond D10 does the warming downwell to the tropopause...

I have a feeling if we are able to get the AO to dip that may save us from a relatively unfavorable Pacific and renewed ugly Indonesian MJO convection by 2/1.

Link to comment
Share on other sites

yup... that should get the weenies excited

Does it in a totally different manner than the Euro...but both have shown potential for something in that same time frame. At least its something to keep one eye on until it inevitably turns into flurries or just some high clouds by the time we get inside 4 days.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Guest
This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...