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Medium Range Discussion Winter 2011-12


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What mess out W for the Cental/Southen Rockies into TX. Winter Storm chances appear on the increase with several days of snow for the higher elevations and freezing rain/snow for W TX into the Panhandle and even as far S as the Permian Basin/Abilene. The Euro continies to advertise a very cold surge of Arctic Air S into the Plains in the longer range. I love Adam's new avatar, by the way... :lol:

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What mess out W for the Cental/Southen Rockies into TX. Winter Storm chances appear on the increase with several days of snow for the higher elevations and freezing rain/snow for W TX into the Panhandle and even as far S as the Permian Basin/Abilene. The Euro continies to advertise a very cold surge of Arctic Air S into the Plains in the longer range. I love Adam's new avatar, by the way... :lol:

Yeah, looks like a one-two punch for the center part of the country next week. There might even be a flake or two on the EC, but it's definitely a Lakes/Plains preferred pattern. Once the Pac flattens out, it's going to get ugly in the East again (see Don S' posts on the previous page)

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The GFS really struggled with the cutoff low in the East. That's a really wide lead the Euro had over the GFS at 120 hrs.

The Euro definitely kept the cut-off low idea for much of the forecast period but BOTH models had it 6/7 plus days out... I distinctly remember the GFS having it, taking it away around day 3,4,5 and bringing it back towards day two or so... The GFS has become better in the longer range, compared to before the upgrade. I'm not saying it's GREAT, just better.... If you're forecasting around 5 days out, I'd definitely take the Euro right now...

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FWIW, we are seeing some warming at 10mb due to a wave 1 response from an East Asian MT. However, that timed "perfectly" with the recent proton flux from the sun, so I doubt this wave will be able to do anything noteworthy down the road. Meanwhile, the lower stratospheric levels are quite cold (historic cold actually at some levels).

The GWO sequence into early December and long range ensembles do develop a growing positive height anomaly across Siberia in the media range. That is certainly something to take note of for down the road, in terms of the state of the AO.

We need a lot more Wave 1/2 action, we are lacking this year.

For illustrative purposes

Last season:

time_pres_WAVE1_MEAN_OND_NH_2010.gif

time_pres_WAVE1_MEAN_JFM_NH_2011.gif

So far this year:

time_pres_WAVE1_MEAN_OND_NH_2011.gif

Those kept the PV on check for most of the winter.

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The Euro definitely kept the cut-off low idea for much of the forecast period but BOTH models had it 6/7 plus days out... I distinctly remember the GFS having it, taking it away around day 3,4,5 and bringing it back towards day two or so... The GFS has become better in the longer range, compared to before the upgrade. I'm not saying it's GREAT, just better.... If you're forecasting around 5 days out, I'd definitely take the Euro right now...

Right, the GFS lost the cutoff and found it again. The Euro really seems to shine at 120 hours with the GFS usually catching on by 96 or so.

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The Euro definitely kept the cut-off low idea for much of the forecast period but BOTH models had it 6/7 plus days out... I distinctly remember the GFS having it, taking it away around day 3,4,5 and bringing it back towards day two or so... The GFS has become better in the longer range, compared to before the upgrade. I'm not saying it's GREAT, just better.... If you're forecasting around 5 days out, I'd definitely take the Euro right now...

Oh, this was an EPIC bust for the GFS, and I'm sure we have a few folks already looking into it. I guess the silver lining is at least I have a good case study for our hybrid variational/ensemble and 4D assimilation work.

Speaking of medium range, both the EC and GFS have had mean AC skill at 500 hPa above 0.6 (generally considered the demarcation for "usefull" forecasts) out past day 8 or so for a while now....but beyond that, ensembles are still the way to go.

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Right, the GFS lost the cutoff and found it again. The Euro really seems to shine at 120 hours with the GFS usually catching on by 96 or so.

Bluewave, where did you find that graphic? I'd love to have that just to compare how well the models are doing in more extreme scenarios, like longwave troughs, cut-offs, PVs, etc...

Oh, this was an EPIC bust for the GFS, and I'm sure we have a few folks already looking into it. I guess the silver lining is at least I have a good case study for our hybrid variational/ensemble and 4D assimilation work.

Speaking of medium range, both the EC and GFS have had mean AC skill at 500 hPa above 0.6 (generally considered the demarcation for "usefull" forecasts) out past day 8 or so for a while now....but beyond that, ensembles are still the way to go.

Were you running this work during this event? I vaguely remember you saying something about it a few months ago but can't remember (too lazy) where it was, or which thread.

That and I'm looking forward to another BRIEF shot of cold air in the southeast next week... Those in the Great Lakes Region and Upper Plains are going to cash in for the next week or so. As long as the Pacific Ridge retrogrades back into the northern Pacific, then the East Coast will continue to see transient cold shots... At least there might some lake effect snow to talk about next week arrowheadsmiley.png

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I'm almost ready to forecast CLIMO across the CONUS for December. MJO continues to skirt through the warm East Coast phases 3-6 before going back into the CoD. Models are still consistently too slow with propagating the MJO (along with keeping its amplitude past week one), so one could assume that we'll eventually hit the colder phases of 7-2 starting around mid-December.

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Bluewave, where did you find that graphic? I'd love to have that just to compare how well the models are doing in more extreme scenarios, like longwave troughs, cut-offs, PVs, etc...

Were you running this work during this event? I vaguely remember you saying something about it a few months ago but can't remember (too lazy) where it was, or which thread.

That and I'm looking forward to another BRIEF shot of cold air in the southeast next week... Those in the Great Lakes Region and Upper Plains are going to cash in for the next week or so. As long as the Pacific Ridge retrogrades back into the northern Pacific, then the East Coast will continue to see transient cold shots... At least there might some lake effect snow to talk about next week arrowheadsmiley.png

We are actually in the processing of running a retrospective experiment (to simulate from June 01 2011 up to real time for eventual hand-off to NCO). Unfortunately, it is only processing some dates in early October and is not yet caught. We'll get a good look in a few weeks at the new system once it finally runs through the end of November dates.

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I'm almost ready to forecast CLIMO across the CONUS for December. MJO continues to skirt through the warm East Coast phases 3-6 before going back into the CoD. Models are still consistently too slow with propagating the MJO (along with keeping its amplitude past week one), so one could assume that we'll eventually hit the colder phases of 7-2 starting around mid-December.

What, are areas west of the Mississippi not part of the CONUS? ;)

Sure looks like a cold first 7-10 days of the month for the plains and much of the west.

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Wouldn't be so sure given the equatorial ENSO signal in the Pacific right now.

That was also my thought, those raging east winds should reinforce the nina.

I'm starting to think you guys just keep pulling new signals out of your asses. Every new thread seems to spawn a different signal (and all of them are warm :P) I don't know how you people have the time to look at all of these different signals and combine them into the big picture every day.

What, are areas west of the Mississippi not part of the CONUS? ;)

Sure looks like a cold first 7-10 days of the month for the plains and much of the west.

I'm talking the whole friggen CONUS for the full month.

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I'm starting to think you guys just keep pulling new signals out of your asses. Every new thread seems to spawn a different signal (and all of them are warm :P) I don't know how you people have the time to look at all of these different signals and combine them into the big picture every day.

I'm talking the whole friggen CONUS for the full month.

All my long range forecast ideas come out of my ass, if I was smart, I'd stick to what I know and not make wild guesses.

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I'm starting to think you guys just keep pulling new signals out of your asses. Every new thread seems to spawn a different signal (and all of them are warm :P) I don't know how you people have the time to look at all of these different signals and combine them into the big picture every day.

I know you're joking, but if forecasting the MJO were THAT easy, the AR algorithm would beat the op models. Jorge made a good post about the easterlies in the Central Pacific in the ENSO/Stratosphere thread... those easterlies are what will keep the MJO from completing a full loop. ENSO > MJO in this case (or at least, it appears to be right now)

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I know you're joking, but if forecasting the MJO were THAT easy, the AR algorithm would beat the op models. Jorge made a good post about the easterlies in the Central Pacific in the ENSO/Stratosphere thread... those easterlies are what will keep the MJO from completing a full loop. ENSO > MJO in this case (or at least, it appears to be right now)

Thanks for pointing that post out to me... I somehow missed it. Any idea as to what caused the easterlies to surge over the past few days and why we should expect them to continue (versus persistence)?

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Thanks for pointing that post out to me... I somehow missed it. Any idea as to what caused the easterlies to surge over the past few days and why we should expect them to continue (versus persistence)?

I have some ideas, but they are probably wrong.

You've got a ripping East Asian jet (helped out by the +MT event last week?), so you're getting increased subsidence on the anticyclonic side, increasing the strength of the subtropical high in the WPAC and therefore stronger than normal easterlies at the equator.

*Cue HM coming in with something about the strength of the Hadley Cell reinforcing the Brewer-Dobson circulation or something :P *

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Bluewave, where did you find that graphic? I'd love to have that just to compare how well the models are doing in more extreme scenarios, like longwave troughs, cut-offs, PVs, etc...

The EMC keeps a great page with the model verification maps and old GFS/AVN/MRF model runs going back to 1999.

http://www.emc.ncep.noaa.gov/gmb/STATS/animatey/hpc5n_animatee.html

http://www.emc.ncep....STATS/MAPS.html

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I have some ideas, but they are probably wrong.

You've got a ripping East Asian jet (helped out by the +MT event last week?), so you're getting increased subsidence on the anticyclonic side, increasing the strength of the subtropical high in the WPAC and therefore stronger than normal easterlies at the equator.

*Cue HM coming in with something about the strength of the Hadley Cell reinforcing the Brewer-Dobson circulation or something :P *

I agree with what your saying as well, but that might not mean much either. :lol:

I have noticed some slight + temp anomalies at 10mb and 50mb over the past couple of says, that might play along to what HM alluded to.

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It looks like the GFS has been too quick to retrograde the ridge near the West Coast beyond the 240hr mark.

As we are getting closer, more ridging is showing up in the forecast.

Still no help with the ao and nao, they are locked in and with them being locked in it's probably only a matter of time before the pac ridge does retrograde a little west to better fit the tropical forcing/nina.

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