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Pattern change on our doorstep - will it deliver the goods? General Discussion/ banter

Baroclinic Zone

By Baroclinic Zone,
in New England

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QVectorman

QVectorman

Posted
Posted

For me it's more or less an attempt at bias correcting of the models as we step through the days to see if there's potential biases still existing in the long term.   I think it's been pretty clear that the GEFS is indeed running too cold (speaking across the board not IMBY), and even the Euro ENS has been favoring cold in the longer range and gradually backed off.  JMHO, we'll see in the days ahead.  The trend in general over the course of many runs has been for the GEFS to run cold, the EURO ENS to be not quite as cold, and the two gradually mild up as we get closer. Will it really matter if it's -15 vs -30 in the long term, not really, but it beats discussing whether this is a torch or not.

:)

 

What's tough....I think I was about as specific as possible with dates even 2 weeks ago which is going to turn out to be pretty good.  The change is coming, the differences are in how extreme the various people here think the change is going to be.

Ya definitely a cold bias in the models...I didn't expect anything less than for the models to temper the 15-23/24 temps. Even the last week of Jan I think we will end up with only -33c near the CA border. But I covered my thoughts back on Jan 5 on how the 850 temps would play out for this week and next so I wasn't really surprised to see them backing off...I was actually pleased much to the dismay of everyone here's hopes and aspirations for cold unfortunately.

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mitchnick

mitchnick

Posted
Posted

Right which is great news in 7 or so days as it dumps down...unless of course that too is a potential bias.  I didn't store the images back long enough to see if this current shot coming this weekend was over-forecast in terms of cold in Canada 3-4 days ago.  So...it beats me.

 

 

I'm curious to see if the reason this shot this weekend was muted somewhat is because we're now seeing a more robust second shot, or is it because we're going to see a back down process in the models as we get these cold shots inside of the 5 day range.   That's all, curiosity more than anything.

graphics ain't great, but the Euro site has a pull down menu under "Forecast Base Time" that go back 11 days

http://www.ecmwf.int/products/forecasts/d/charts/medium/deterministic/msl_uv850_z500!Wind%20850%20and%20mslp!0!North%20America!pop!od!oper!public_plots!2013011312!!/

 

also, Earl Barker has old GFS and NAM runs here:

GFS

http://charlie.wxcaster.com/cgi-bin/GFSModelArchive.cgi

NAM

http://charlie.wxcaster.com/cgi-bin/NAMModelArchive.cgi

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Clinch Leatherwood

Clinch Leatherwood

Posted
Posted

 

 

Ha cool I found the ecm int site didn't know about the GFS archive.

 

Here's what I find interesting to track absent staring at a sprinklestorm Tuesday:

 

Note the Friday EC ENS forecast for this coming Friday.  Now take a look at todays 48 hours later.  Particularly over the Midwest through to Chicago on the ENS...sure it's only 4 or 6c, but the entire angle of the cold intrusion has begun to change as well.  Doesn't mean much long as it doesn't deflect more, but note particularly the deterministic changes in those two days. Deep intrusion of cold versus not so much (-20 diving deep 2 days ago to just barely making the US this run).  Chicago as a point of reference, -12, -8, -6/7 this run.  Small changes, but in the long term day to day as things move from 180 to say 72...

 

QVector has talked extensively about why this would likely occur in terms of a slight deflection of the cold on push 1, for the latter cold shot after MLK I don't think anyone is anticipating that the cold shot will get blunted, just something to watch going forward.

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Clinch Leatherwood

Clinch Leatherwood

Posted
Posted

Not really making a point here....TBE on such a long range forecast but comparing several days ago to todays forecast for 12z Wednesday.  Obviously the ENS did better than the OP.  I look to the west towards the Dakotas thru Chicago because they are closer to the event (cold got there 2 days ahead of us so the lead isn't as long).

 

Even the Euro ENS was too aggressive with how far south, and how fast the cold would get.  Not huge, but just pointing it out.  I'm interested in the trajectory the cold takes in getting here just as much as anything else.

 

Nothing else going on, just figured i'd hard link.

 

 

 

 

 

 

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Ginx snewx

Ginx snewx

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Ya definitely a cold bias in the models...I didn't expect anything less than for the models to temper the 15-23/24 temps. Even the last week of Jan I think we will end up with only -33c near the CA border. But I covered my thoughts back on Jan 5 on how the 850 temps would play out for this week and next so I wasn't really surprised to see them backing off...I was actually pleased much to the dismay of everyone here's hopes and aspirations for cold unfortunately.

Actually most of us want the obscene cold to stay in Canada until we get some good snows, on track.
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CT Rain

CT Rain

Posted
Posted

5 more seconds it happens. Then again .5 colder would often bring me alt more snow...

Euro ensembles d10 look great.

Great pattern through D15. We lose the +PNA post-day 10 but the -PNA may mean a stormier pattern and with the cold/PV to the north of the border (AO stays quite negative) I think we'll have plenty of fun. 

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NorEaster27

NorEaster27

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Posted

Great pattern through D15. We lose the +PNA post-day 10 but the -PNA may mean a stormier pattern and with the cold/PV to the north of the border (AO stays quite negative) I think we'll have plenty of fun. 

I am not seeing it, I think the PV winds up 500 miles further north than where the ensembles are showing it.  They did the same thing last week for late this week.  If that is the case, the +NAO and loss of the PNA spells a fast zonal gradient pattern.

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CT Rain

CT Rain

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I am not seeing it, I think the PV winds up 500 miles further north than where the ensembles are showing it.  They did the same thing last week for late this week.  If that is the case, the +NAO and loss of the PNA spells a fast zonal gradient pattern.

 

Why do you see it 500 miles north? Do you have a reason or are you just trolling?

 

Seems like a pretty close match to 94-94 in the D11-D15 time frame. 

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NorEaster27

NorEaster27

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Posted

Why do you see it 500 miles north? Do you have a reason or are you just trolling?

 

Seems like a pretty close match to 94-94 in the D11-D15 time frame. 

Its the trend we are seeing, look where the PV was modeled for this friday a week ago.  You need a huge +PNA to get the amplification needed to move the PV as far south as modeled.  I do not see that happening, we may get a brief spike of a +PNA but I am not betting against the strong pac jet this winter.  I dont see SST in the north pacific that support a sustainted +PNA.

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CT Rain

CT Rain

Posted
Posted

Its the trend we are seeing, look where the PV was modeled for this friday a week ago.  You need a huge +PNA to get the amplification needed to move the PV as far south as modeled.  I do not see that happening, we may get a brief spike of a +PNA but I am not betting against the strong pac jet this winter.  I dont see SST in the north pacific that support a sustainted +PNA.

 

I don't think that's true. The height anomalies showing up over the North Pole are exceptionally impressive for a D16 ensemble mean on the GEFS. That alone will keep the PV dislodged. Even though the models lose the +PNA they don't go strongly negative with the PNA... more of a neutral setup. Very '93-'94 like.

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