Medium Range Discussion Winter 2011-12

[phil882]

Yeah, big differences, but looks like the GEFS has better continuity between verified and forecasted...ie. look at ~160E

Precisely. The GFS looks overdone with the +OLR anomalies, but its like night and day between the GFS and ECMWF. This strongly supports that the GFS has the right idea with the initial propagating of the MJO into phase 7 as opposed to the ECMWF which hangs the MJO back a few days. This has pretty large implications on how quickly the PNA block might form.

[am19psu]

I think the bigger difference is at 90-120E. If the Euro is right with the convection there, even if we do get a PNA ridge, it'll most likely get undercut by a ripping Pac jet.

[wxmx]

I think the bigger difference is at 90-120E. If the Euro is right with the convection there, even if we do get a PNA ridge, it'll most likely get undercut by a ripping Pac jet.

Agree, though my comment was directed towards the assumption that the GEFS has better initialization (probably more recent data or more recent runs). Even with the superiority of the Euro vs the GFS, a +1 day advantage of data would even things out, IMO.

[Rainshadow]

I think the bigger difference is at 90-120E. If the Euro is right with the convection there, even if we do get a PNA ridge, it'll most likely get undercut by a ripping Pac jet.

Those are two very strange looking outlooks. The GFS continuity near the date line looks better, but then it has a total dearth of convection outlooked anywhere around it.

[phil882]

I think the bigger difference is at 90-120E. If the Euro is right with the convection there, even if we do get a PNA ridge, it'll most likely get undercut by a ripping Pac jet.

I see your point. The fun thing is that we can actually watch in real time to see which model is preforming better in terms of convective output. I've circled the two areas of interest on global satellite to show where the ECWMF and GFS have decided to center the convection over the next 5 days or so. Both areas are convectively active currently. In my mind, the key is how far eastward does the convection extend. The convection over Indonesia doesn't matter as long as the central pacific remains more convectively active. This allows the apex of the subtropical ridge to be located further east, which is an important concept in allowing the jet streak of the polar jet to be centered across the central pacific instead of the west pacific. The end result is that you get cyclogenesis in the east Pacific that supports Western North America ridging.

[Met1985]

Wow thanks guys for the class room teachings about the MJO. Really neat stuff.

[donsutherland1]

Verification:

In #548 in this thread on January 13, I wrote:

The Non-Winter of 2011-12 for the Eastern U.S. Continues...

With the exception of Alaska, western Canada, and perhaps the westernmost United States (especially Pacific Northwest) and portions of the Northern Plains near the Canadian border, the January 24-31 period looks to wind up on the mild side of normal. The EPO+/PNA-/neutral AO pattern is likely to continue to banish any prolonged stretches of wintry weather from much of the U.S. Cold shots in the eastern half of the U.S., as well as southern Ontario and Quebec are likely to remain transient. Some of the guidance, including the objective analogs, hint at a full-fledged torch.

I also included the following chart:

The January 24-31, 2012 temperature anomalies and a photo of Japanese Apricot blossoms that burst into bloom during the warmth are below.

Overall, the non-winter of 2011-12 maintained an iron grip on much of North America. Alaska, was brutally cold, as had anticipated.

[Qaanaaq]

Thanks Don. Might as well embrace the truth. The frogs are chirping here and daffodils are in bloom along with the forsythia.

[Snowstorms]

My initial thinking is that there will be colder than normal weather in much of Canada, including southern Ontario and southern Quebec (Toronto, Ottawa, and Montreal included). Parts of eastern Canada might be warm if there is a lot of blocking. Much will depend on the evolution of the ongoing La Niña, which could be fading fairly quickly in March.

Based on statistics and development, I think this year has great similarties to 1974-75.

Anomaly map below for 74-75 (Dec-Jan)

NAO was positive for Dec-Jan but was negative for Feb-March but the AO remained positive for DJF including March along with a dominant -PNA pattern. 1974-75 did feature a Weak -ENSO anomaly as well.

Though the MJO was quite different than this year. For a good part of December and January it was circulating between Phases 7,8,1 and the circle but it seems as though the Atlantic overwhelmed the Pacific Signal that year.

Again I'd rather wait till Week 3 before discussing about anomalies in March.

[NJwinter23]

I think the bigger difference is at 90-120E. If the Euro is right with the convection there, even if we do get a PNA ridge, it'll most likely get undercut by a ripping Pac jet.

That 8-10 day time frame is looking like a very crucial period that may make or break this pattern chance. Even the more favorable gefs show the pna ridge weakening (probably as a result of the Pac jet you mentioned here undercutting on some members) with the + anomalies bubbling north to the pole. If we don't see the +PNA ridge bounce back though, then our brief Hudson Bay-ish Polar vortex will probably slide under the block and back towards Alaska. I say this confidently because not only would that follow the seasonal trend of murdering alaska with cold, but because this is also looking eerily similar to what we just went through in early January leading up to that "pattern change".

Of course, their is at least reason for hope this go around because we have a chance with the MJO wave if it can propogate.

[The_Global_Warmer]

Checking the Weather for the arctic sea ice I noticed the GFS and Euro torch the arctic and dump the cold out.

Litterally every last drop of premium cold being built up right now:

That is the coldest it has been up there this winter.

That is terrible that it is mostly going to Asia and Canada.

It's not in the cards but apparently futility is.

[bluewave]

Big warm up on tap for Alaska from the record cold that they experienced in January.

[Ji]

NAO to be tanking?

http://policlimate.com/weather/oscillation.html

[Ji]

If this is right...we could be seeing some more winter in the 16-25 day period(look at 384--all the warm building in Alaska

http://policlimate.com/weather/current/gfs_t850a_plan_ext.html

[okie333]

The GEFS is right... in fact it may even be a little too weak and slow. The ECMWF ENS should be discarded as it got the 24-hour forecast horribly wrong.

[wxmx]

I would think that with this pattern...

...a big arctic outbreak would be on tap for the plains, MX and east, but...

...measly run of the mill cool down... it doesn't look right to me, unless the arctic is spent off cold big time.

[keggwx]

Whats that around 60-90 E in the IO boys?.....GFS epic faceplant.

[Gibbsfreeenergy]

^{Holla ALL! Been a while. I have tried to do my best to stay away so I didnt get death threats given the winter pattern.}

^{Note the key image here:}

^{What you notice is that the strong ridge over the pole is a floating ridge, as the H5 falls in western canada undercut the ridge near the pole and this is the game changer. The same evolution occurred back in January when the WPO ridge went ballistic and the Polar Pig dumping into Calgary ended up being a torch fest.}

^{In this pattern, we are seeing 2 ways to chop the H5 ridge up western Canada. One is with energy attacking from the East (block to the north gets so strong it forces energy into the H5 ridge in western Canada from the East). The other, and more important IMO, is Pacific wave train energy attacking from the West. This is where the mis representation of the tropical forcing is biting the GFS in the arse. It is not resolving the IO forcing well at all, and actually thinks there is subsidence and no convection at all. Meanwhile, its ripping convection off the chart amplitude in p7-8. The heat release in the mid-lats promotes a persistent +PNA ridge bias in GOA/AK/Western Canada and this allows the PV to shift too far south. The PV shifting south is also important for actually tring to get a real NAO signal. If the PV does not shift south, then it heads toward the DS and keeps the 582 dam ridge in the N. Atlantic, rooted in the N. Atlantic instead of drifting northward into Greenalnd and potentially allowing undercutting of energy. So you see, this OLR difference in the trop Pac can be a huge error.}

^{And it is no shock, that the GEFS is the biggest outlier here:}

[wxmx]

^{Holla ALL! Been a while. I have tried to do my best to stay away so I didnt get death threats given the winter pattern.}

^{Note the key image here:}

^{What you notice is that the strong ridge over the pole is a floating ridge, as the H5 falls in western canada undercut the ridge near the pole and this is the game changer. The same evolution occurred back in January when the WPO ridge went ballistic and the Polar Pig dumping into Calgary ended up being a torch fest.}

^{In this pattern, we are seeing 2 ways to chop the H5 ridge up western Canada. One is with energy attacking from the East (block to the north gets so strong it forces energy into the H5 ridge in western Canada from the East). The other, and more important IMO, is Pacific wave train energy attacking from the West. This is where the mis representation of the tropical forcing is biting the GFS in the arse. It is not resolving the IO forcing well at all, and actually thinks there is subsidence and no convection at all. Meanwhile, its ripping convection off the chart amplitude in p7-8. The heat release in the mid-lats promotes a persistent +PNA ridge bias in GOA/AK/Western Canada and this allows the PV to shift too far south. The PV shifting south is also important for actually tring to get a real NAO signal. If the PV does not shift south, then it heads toward the DS and keeps the 582 dam ridge in the N. Atlantic, rooted in the N. Atlantic instead of drifting northward into Greenalnd and potentially allowing undercutting of energy. So you see, this OLR difference in the trop Pac can be a huge error.}

^{And it is no shock, that the GEFS is the biggest outlier here:}

I agree, although the GFS pattern isn't ideal either in that map...it also torches the CONUS for the most part.

[CoastalWx]

There continues to be huge differences, relating to what kegg and Gibbs are saying. The EC is still a little suspect with the analysis, but I mean the difference in the IO is astounding. Looks like some other models are also putting convection in the IO as well. Clearly the GFS is going balls to the wall with the convection and potential TC developing east of the Indo. I would guess both models may be going to hard in either direction, but who will be right? Right now, there are two massive clusters of convection, like Phil pointed out. EC is loving the IO and GFS is loving the area near Coral Sea into Fiji. I think evidence right now points in the EC direction, but both clusters of convection are pretty solid right now.

[CoastalWx]

I also wonder if the latitude of that convection is a little too far south of optimal, for the GFS.

[CoastalWx]

And actually, the GFS has the same analysis problem in the IO where it just suppresses the convection as well. Weird stuff.

[bluewave]

Impressive suppression of convection over the Central Pacific.

...RECORD LOW PRECIPITATION AT KAHULUI HI...

A RECORD LOW PRECIPITATION OF 0.00 INCHES AT KAHULUI HI FOR THE

MONTH OF JANUARY BREAKS THE PREVIOUS RECORD OF 0.02 INCHES SET IN

2001.

http://cimss.ssec.wisc.edu/goes/blog/

[Ginx snewx]

Recurve us a typhoon please, Murphys Law winter.

[Gibbsfreeenergy]

Euro Op says Polar Pig epic dump!!! What an epic change. If thats correct, would be one of the biggest forecast busts from all weather vendors I have ever seen

[wxmx]

Euro Op says Polar Pig epic dump!!! What an epic change. If thats correct, would be one of the biggest forecast busts from all weather vendors I have ever seen

Stronger -EPO ridge (>558dm N of AK), something that the 12z GFS also shows...the main difference is that it progresses east, towards the Davis strait (instead of cutting off and drifting north), so all the cold tapped by the -EPO ridge is now blocked by a strong west based -NAO.

[Ottawa Blizzard]

Euro Op says Polar Pig epic dump!!! What an epic change. If thats correct, would be one of the biggest forecast busts from all weather vendors I have ever seen

Brett Anderson of accuweather has posted that the Euro weeklies imply that spring is just around the corner for the east. Is this true?

[HM]

You can analyze every cluster of thunderstorms all you like in the Tropics and talk about what happened in January, but the simple truth is that the regime has shifted. Now I am not suggesting an epic cold pattern is coming or that blizzard after blizzard is on the way, but this is NOT the same setup. This is the furthest east the forcing has gotten all winter, the NH AAM anomalies have reversed and the solar parameters continue to decline toward a probable min later this month during the next IMF dip. Our issue is not going to be the PV retreating to Alaska as much as it will be the tight / fast nature to the vortex (since the center of the stratospheric vortex will be essentially over the PV).

[wxmx]

You can analyze every cluster of thunderstorms all you like in the Tropics and talk about what happened in January, but the simple truth is that the regime has shifted. Now I am not suggesting an epic cold pattern is coming or that blizzard after blizzard is on the way, but this is NOT the same setup. This is the furthest east the forcing has gotten all winter, the NH AAM anomalies have reversed and the solar parameters continue to decline toward a probable min later this month during the next IMF dip. Our issue is not going to be the PV retreating to Alaska as much as it will be the tight / fast nature to the vortex (since the center of the stratospheric vortex will be essentially over the PV).

That makes a lot of sense, and I agree. Actually that answers my question of why cold doesn't seem to pour south on a seemingly favorable pattern...the PV is super tight, and unless ridging displaces it south (like the ECMWF), cold air would have a tough time advecting south.

[HM]

That makes a lot of sense, and I agree. Actually that answers my question of why cold doesn't seem to pour south on a seemingly favorable pattern...the PV is super tight, and unless ridging displaces it south (like the ECMWF), cold air would have a tough time advecting south.

Yeah exactly. When people imagine this whole thing in their heads, they should think of a giant conical tornado and at its base are multiple vortices. These multiple vortices are the tropospheric circulations which are more chaotic / fast. The stratospheric tornado with descending mesospheric NOx etc will be over our polar vortex, enhancing the u-component at most layers.

This is why our vortex isn't modeled to be lobed etc. like the rest in the NH. At least not yet anyway....