Central/Western Summer Medium/Long Range Discussions

[Quixotic1]

Looks like a potential mess developing next week from NM and CO into Kansas/Southern Plains.  Individual members of the GFS Ensembles have varying solutions but this is something that has been showing up for awhile.   

[Srain]

The overnight guidance continues to advertise a synoptic pattern change from that of a Western Ridge/Eastern trough to a pattern that becomes more zonal with a split flow developing across the Western half of the Lower 48. Changes begin to lurk near the Day 4-5 time frame as differences are seen via the operation GFS and Euro. The guidance generally agree that a upper air disturbance drops S into Northern Mexico as the 500MB trough pattern shifts back to the W and a positive trough regime develops from the Desert SW on NE across New Mexico into the Upper Mid West. The Global models suggest a upper low will drop S into Mexico, but the GFS shears out this feature while the Euro suggests a stronger more closed core low.

 

It does appear that a weak cold front will push S and stall near the Coast increasing our rain chances by Friday. As the front stalls, a Coastal wave develops allowing over running light to moderate rain to spread N into Central and SE Texas and Louisiana. The SPC does mention the potential for stronger storms to develop across the NW Gulf Region as lee side  cyclogenesis becomes possible as that upper low ejects from Mexico into the Southern Plains around a week from today or next Tuesday. As is typical with any synoptic large scale pattern change, there tends to be a great deal of run to run volatility but it does appear we are transitioning to a pattern that will increase our rain chances across Central/N/ SE Texas and on E where dry conditions have plagued our Region since the pesky NW flow aloft developed. As the pattern further changes to that of a trough across the West and a SE Ridge, additional storminess is suggested as very cold air pools across Western Canada into the Inter Mountain West and Plains as Pacific storms drop S into California and the Baja Region of NW Mexico  and tap Eastern Pacific moisture. This type of pattern in early February tends to suggest a very unsettled weather pattern with cold air intrusions into our Region as Winter Storms wrap up across the Southern Plains and pull much colder air S from Western Canada. The storm track also tends to favor dropping heavy snow across the Plains that has been lacking and adding to less air mass modification as the very cold air pushes S. Time will tell, but the pattern suggests we have not seen the last of wintry mischief across our Region extending back into New Mexico, Colorado, The Panhandle/Central/N and Eastern Texas as well as Oklahoma, Arkansas and Missouri .

[brettjrob]

Looks like a potential mess developing next week from NM and CO into Kansas/Southern Plains.  Individual members of the GFS Ensembles have varying solutions but this is something that has been showing up for awhile.   

 

Thank goodness, after NW flow hell for the past 40 days. We can only hope the solution trends deeper and slower with high QPF across the whole region, particularly western TX/OK.

[Quixotic1]

Thank goodness, after NW flow hell for the past 40 days. We can only hope the solution trends deeper and slower with high QPF across the whole region, particularly western TX/OK.

California getting wet gives us hope.

[baroclinic_instability]

Thank goodness, after NW flow hell for the past 40 days. We can only hope the solution trends deeper and slower with high QPF across the whole region, particularly western TX/OK.

 

 

California getting wet gives us hope.

early next week looks interesting as that mobile wave ejects the Rockies. A few of the 18z GEFS members as well as the 12z ECMWF hit parts of the plains hard. We will have to see as the neutral wave tilt can be boom or bust either way depending on the timing/strength of that basal shortwave.

 

And you guys think it has been bad in the plains. It has been worse in AK, and it will continue to suck for another 2 weeks at least.

[Srain]

The overnight guidance continues to advertise a rather deep Western Trough transitioning E into the Plains in the mid to late next week timeframe. While it is too soon to know the 'finer details', there are indications that rather potent Winter Storm will move inland along the Pacific Coast and a robust 5H cold core low will trek E across the Great Basin and leeside cyclogensis may develop across the Southern and Central Plains as the storm system heads NE toward the Mid West/Great Lakes Region.

[1900hurricane]

Guidance (particularly Euro) is starting to look a bit McFarlandy (yup, made that one up) in the 8-10 day range. Too long to say much of anything yet, but it does appear winter will be back in a week or so.

 

 

[ZackH]

Honestly surprised no one has mentioned the large scale troughing that the GFS has been consistently showing for next weekend (3/21-3/23).  Obviously way too far out for details and there are certain factors that will have to ironed out (will there be enough moisture, how organized will the trough be, how far east will the surface low setup, etc...) but it looks like there will be something in the pattern that could make things interesting severe wise if everything shapes up.  

 

Now, the 12z runs kind of killed it today (the Euro now has nothing even resembling a trough in the same time frame, but it had been showing it in previous runs) but it also seems as if there may have been model initialization errors today... at least that's how I'm reading it.  From WPC:

 

12Z MODEL EVALUATION WITH PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT
RANGE FORECASTS.

 

So, while they may not have degraded the short range, they definitely could have degraded the long range.  That doesn't really explain what happened with the drastically different Euro, but I suppose it could have ingested some of the same errors.  It will be interesting to see if the 18z and 00z runs move back towards the previous trend.  It will also be interesting to see how the GFS treats this feature once it moves into the pre-truncation time period.  That extra resolution could really help the setup or kill it.

 

(I know this isn't a Winter long range discussion, so if it needs to be moved into a new long range discussion topic based on Spring, that's fine)

[andyhb]

Honestly surprised no one has mentioned the large scale troughing that the GFS has been consistently showing for next weekend (3/21-3/23).  Obviously way too far out for details and there are certain factors that will have to ironed out (will there be enough moisture, how organized will the trough be, how far east will the surface low setup, etc...) but it looks like there will be something in the pattern that could make things interesting severe wise if everything shapes up.  

 

Now, the 12z runs kind of killed it today (the Euro now has nothing even resembling a trough in the same time frame, but it had been showing it in previous runs) but it also seems as if there may have been model initialization errors today... at least that's how I'm reading it.

 

Been watching this for some time now, most of the ensembles have the teleconnections (-PNA, positive-spiking AO, +NAO etc.) becoming more favorable towards this timeframe for western troughing, although the 12z runs today were not as enthusiastic. The Euro continues to blow up the system around 120-168 hrs and then flips back to the typical trend this year of going back to eastern troughing with frustrating results.

 

I mean this crappy pattern has to break eventually, right?   

[brettjrob]

Honestly surprised no one has mentioned the large scale troughing that the GFS has been consistently showing for next weekend (3/21-3/23).  Obviously way too far out for details and there are certain factors that will have to ironed out (will there be enough moisture, how organized will the trough be, how far east will the surface low setup, etc...) but it looks like there will be something in the pattern that could make things interesting severe wise if everything shapes up.  

 

Now, the 12z runs kind of killed it today (the Euro now has nothing even resembling a trough in the same time frame, but it had been showing it in previous runs) but it also seems as if there may have been model initialization errors today... at least that's how I'm reading it.  From WPC:

 

12Z MODEL EVALUATION WITH PREFERENCES

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT

RANGE FORECASTS.

 

So, while they may not have degraded the short range, they definitely could have degraded the long range.  That doesn't really explain what happened with the drastically different Euro, but I suppose it could have ingested some of the same errors.  It will be interesting to see if the 18z and 00z runs move back towards the previous trend.  It will also be interesting to see how the GFS treats this feature once it moves into the pre-truncation time period.  That extra resolution could really help the setup or kill it.

 

(I know this isn't a Winter long range discussion, so if it needs to be moved into a new long range discussion topic based on Spring, that's fine)

 

I've been watching it for several days but was afraid to say anything. The 12z runs today confirm my fear. Unfortunately, I'm inclined to think it's a real trend, as the 00z ECMWF had already reneged on the pattern shift last night.

 

Anything but another March-April 2013. Anything. That 1040mb high settling into the Plains at the end of the 12z EC run makes me want to look for razor blades.

[andyhb]

I've been watching it for several days but was afraid to say anything. The 12z runs today confirm my fear. Unfortunately, I'm inclined to think it's a real trend, as the 00z ECMWF had already reneged on the pattern shift last night.

 

Anything but another March-April 2013. Anything. That 1040mb high settling into the Plains at the end of the 12z EC run makes me want to look for razor blades.

 

Considering March has had a whopping 1 tornado confirmed so far, you'd have to think that at least one of April, May or June is going to need to be at least significantly above normal/borderline hyperactive to get numbers back on track.

 

I'm really hoping that ENSO really starts to kick into higher gear so we can at least have a potential catalyst for a significant pattern change since this was got old about three months ago.

[brettjrob]

Considering March has had a whopping 1 tornado confirmed so far, you'd have to think that at least one of April, May or June is going to need to be at least significantly above normal/borderline hyperactive to get numbers back on track.

 

Yeah. The season isn't even really underway yet out here, but I guess the Southeast hasn't contributed anything of substance all winter, so we're running a real deficit already. If the latest trends in the medium range are any indication and we see little for the rest of March, we'd be down almost 200 going into April.

 

I don't mind waiting a bit, but more dry and cold isn't the way to do it.

[andyhb]

Yeah. The season isn't even really underway yet out here, but I guess the Southeast hasn't contributed anything of substance all winter, so we're running a real deficit already. If the latest trends in the medium range are any indication and we see little for the rest of March, we'd be down almost 200 going into April.

 

I don't mind waiting a bit, but more dry and cold isn't the way to do it.

 

I do like what I'm seeing on the mid/long range composites with retrogression of the ridge that has been rather firm on the West Coast for what has seemed like an eternity. It would only be a matter of time after that happens for some type of western troughing to establish itself in all likelihood.

 

It is common for models to flip things too quickly in the mid/long range, which is what we might be seeing with the less aggressive recent runs for the 3/21-23 period.

[heavy_wx]

I do like what I'm seeing on the mid/long range composites with retrogression of the ridge that has been rather firm on the West Coast for what has seemed like an eternity. It would only be a matter of time after that happens for some type of western troughing to establish itself in all likelihood.

 

It is common for models to flip things too quickly in the mid/long range, which is what we might be seeing with the less aggressive recent runs for the 3/21-23 period.

 

Part of the problem is that the MJO has been in phase 7/8 for the past three weeks, only within the last week has it begun to propagate more eastward. That has likely been exciting Rossby waves that propagate with a trajectory that helps build the ridge over the NPAC.

 

However, there is currently some convection over equatorial Africa which could move into the Indian Ocean in the next week or so. The GFS wants to develop some convection (on-going at the moment as well) just east of the Maritime Continent and essentially retrograde the MJO back into phase 7/8. The Euro ensembles are more bullish on bringing the convection over Africa eastward and developing an MJO in phase 1/2 by the end of the week two period. One thing that gives me pause about the Euro ensemble forecast is that the NPAC ridge has tended to persist longer than guidance has suggested this winter.

 

That would be a more favorable forcing for severe weather in the central US. Thompson and Roundy showed this in a paper where there was statistical significant enhanced probability of a severe weather outbreak in phase 2 of the MJO.

[ZackH]

I've been watching it for several days but was afraid to say anything. The 12z runs today confirm my fear. Unfortunately, I'm inclined to think it's a real trend, as the 00z ECMWF had already reneged on the pattern shift last night.

 

Anything but another March-April 2013. Anything. That 1040mb high settling into the Plains at the end of the 12z EC run makes me want to look for razor blades.

 

You are probably right.  I'm just still holding out hope because of how consistent the pattern was.  The 18z GFS is still holding onto the general pattern at that time.  While I'm a realist, I'm holding out hope for a bit longer as the timing would ideal (which obviously means it won't happen).

[ZackH]

And then there goes the 00z GFS starting to basically conform to the Euro, although not quite as drastic.  Still a lot of moisture and decent instability showing up with interesting looking soundings on 3/22, but with that amount of instability the wind fields would need to be a whole lot more impressive.  If that is even a setup still, it looks very suspect.

[brettjrob]

Things could not possibly look bleaker at this stage. No indication whatsoever that our fortunes will change before the end of the month. Hard to believe we're really going through this for a second consecutive year.

 

 

Some runs of the ECMWF/GFS indicate hope well beyond D10, but that's been true for weeks now, and it never comes to fruition. Absolutely no reason to forecast anything but persistence beyond the window of reasonable predictability, which currently seems to be only 6-7 days.

 

heavy_wx, thanks for your input and for pointing out that Thompson and Roundy paper. What's interesting is that they find an extremely heightened incidence of outbreaks during Phase 2, but as they admit in the conclusion, any direct MJO effects upon the extratropical pattern in this part of the world would have their roots days to weeks earlier. I'd be more interested to see which, if any, antecedent phase (5? 6? 7?) is most associated with outbreaks 1-3 weeks later.

 

Also, just an observation: they list all of the Phase 2 outbreaks in a table, and a large majority occurred east of the Plains. I'm wondering if Phase 2 is most strongly associated with troughing slightly too far east for most in this subforum, and for chasers. The composite H3 height anomalies are plotted too small to tell for sure, but it kind of looks that way. Caveat to my observation: population density increases to the east of the Plains, and therefore the likelihood of a tornado receiving EF4-5 and qualifying for their criteria.

[Stebo]

I think it is a bit premature to say which way this year will go, especially considering it is only Mid March and things usually don't get going in the plains until mid to especially late April.

[andyhb]

[brettjrob]

I think it is a bit premature to say which way this year will go, especially considering it is only Mid March and things usually don't get going in the plains until mid to especially late April.

 

Agreed regarding the Plains season. I think all of us complaining are just antsy for a pattern change bringing an end to crashing cold fronts, like the one we just experienced last night, and the lack of consistent precipitation-bearing systems. While the clock is beginning to tick for the Gulf Coast and Southeast season, we're still several weeks away from the real uptick in Plains severe climatology. It is a bit unusual to get through March without a few mediocre Plains severe setups, though.

[Hoosier]

 

 

Still very early but might be another year where you have to throw numbers out the window and just hope for some good days. 

[Stebo]

Agreed regarding the Plains season. I think all of us complaining are just antsy for a pattern change bringing an end to crashing cold fronts, like the one we just experienced last night, and the lack of consistent precipitation-bearing systems. While the clock is beginning to tick for the Gulf Coast and Southeast season, we're still several weeks away from the real uptick in Plains severe climatology. It is a bit unusual to get through March without a few mediocre Plains severe setups, though.

 

GFS has a few of those mediocre potentials on them. I wouldn't ride just the Euro especially considering its fall from grace compared to how it was before. The fact there is little consistency in the models would lead me to not get too concerned about a day 10 projection.

[andyhb]

I mean it's not like late bloomers can't reach average or even above average numbers, case in point 1992 and 2003, although this year doesn't really match them ENSO wise. I'm sure there are others but those are the two examples that immediately came to mind. 1982 is a decent analog to this year in many categories and really didn't have much at all in Jan, Feb or March and then there was a major outbreak to begin April followed by the most active May on record up until that point.

[ZackH]

I still think Friday will hold some severe storms in TX/OK, but probably very similar to the kind of storms we saw yesterday with very little tornado threat.

[brettjrob]

With all the talk of Nino conditions developing in the coming months, I thought I'd cheer everyone up even more by listing the last four years in which a Nino developed during the spring or summer: 1997, 2002, 2006, 2009. All terribly quiet severe weather seasons for the Plains, with '97 and '06 being in the "holy crap, how is this possible?" category.

 

Mitigating factors:

 

- The H5 anomalies look substantially different between each of those springs, so the "failure mode" is not really consistent.

- The preceding winters were generally warm across the eastern half of the CONUS, except for 2009. This winter was brutal.

- Going back as far as the 1950s, one can find a few examples of active years with the Nina-Nino switch: 1957, 1965, and 1982.

 

Overall, I don't consider this to be a big red flag in itself, but it's just another slightly-noteworthy piece of bad news for Spring 2014 in my opinion.

 

I still think Friday will hold some severe storms in TX/OK, but probably very similar to the kind of storms we saw yesterday with very little tornado threat.

 

Still keeping an eye on this. Would be nice to get some marginal supercells nearby, but we'll have to see whether storms initiate before sunset and how much of a limiting role moisture/instability play.

[andyhb]

I'd throw 1982 in there as well, since it has also mirrored some of the Winter patterns this year nicely in addition to being similar in ENSO status and possible progression.

[brettjrob]

I'd throw 1982 in there as well, since it has also mirrored some of the Winter patterns this year nicely in addition to being similar in ENSO status and possible progression.

 

Good catch! Will edit my post above to reflect this.

 

I missed '82 because there was never technically a Nina during that whole '79-81 period, but it was in fact weakly negative most of the preceding year, much like we've seen this past year. In terms of the winter pattern and anomalies, while it wasn't a perfect match, it's probably better than any of the others I looked at. Encouraging, since that was a fantastic season for the S Plains, as I'm sure you know.

 

As always, speculating more than a month out based on analogs is 90% fun and games, given our limited dataset. The pattern the next 10-15 days definitely lends itself to said speculation, though.

[andyhb]

Good catch! Will edit my post above to reflect this.

 

I missed '82 because there was never technically a Nina during that whole '79-81 period, but it was in fact weakly negative most of the preceding year, much like we've seen this past year. In terms of the winter pattern and anomalies, while it wasn't a perfect match, it's probably better than any of the others I looked at. Encouraging, since that was a fantastic season for the S Plains, as I'm sure you know.

 

As always, speculating more than a month out based on analogs is 90% fun and games, given our limited dataset. The pattern the next 10-15 days definitely lends itself to said speculation, though.

 

May that year was the most active on record up until that point, and there was also a major event and a handful of other notable ones in April.

[andyhb]

Hopefully these aren't famous last words (again), but there does appear to be a bit of a light at the end of the tunnel looking at the 8-10 day mean from the ensemble suites.

 

[Chicago Storm]

Hopefully these aren't famous last words (again), but there does appear to be a bit of a light at the end of the tunnel looking at the 8-10 day mean from the ensemble suites.

Don't waste your time...