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Feb 2016 Medium/Long Range Disco


Bob Chill

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I would say overall that the 12z eps was a marked improvement over 0z in general for the d6-15 period. Large increase in members with snow and a good bit colder @ 850. Mean 0c line is never north of us from thurs through the end of the run. Of course that doesn't mean the d8-10 thing is a snowstorm. Just that colder solutions increased in #. 

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Is a real clipper even a remote possibility any more?  I mean a little low pressure sliding from about Cincinnati to Roanoke to the Delmarva?

We don't really do that kind of clipper very often anyway.

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I would say overall that the 12z eps was a marked improvement over 0z in general for the d6-15 period. Large increase in members with snow and a good bit colder @ 850. Mean 0c line is never north of us from thurs through the end of the run. Of course that doesn't mean the d8-10 thing is a snowstorm. Just that colder solutions increased in #. 

Bob, I didn't look at individual members, but the mean is still under 2". So that tells me we may have gained "some" support with some of the members you mentioned but probably lost some in others since the mean snowfall for the 15 days hasn't budged from yesterday's 12z.

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I found an interesting link from CPC that shows all the mjo plume forecasts http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml#verif and the verifiable composites to go with it http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/Composites/Temperature/. Does anyone know if there has been any verification attempts among the individual models for the mjo? For some reason Joe Bastardi is concerned about the mjo signal taking over for much of February. What I don't understand is why he would be so concerned when the phases 4-5-6 crappy patterns seem to have lower verification/significance % among all models. Please only answer if you know what I'm asking.

 

Very interesting pattern on the table in terms of forecast challenges!

 

It is a fairly valid concern if the MJO eventually ends up in a higher amplitude phase 4-5 as the Euro and UK models have been especially suggesting on those MJO forecasts. The significance percentages are in fact the opposite of what you might think.. as in low significance percentage numbers indicate a high confidence in the associated anomalies. 

 

As noted from the info section of that website:

 

 

  • Left 8 panels: For each 3month season, 8 MJO phases are displayed showing the �raw anomalies� composites that are unmasked. The anomalies shown are not necessarily statistically significant or associated with MJO even though they are averaged according to the eight MJO phases. 
  • Right 8 panels: Displayed as in the left panel except showing the level of statistical significance. Purple/blue shaded areas (lower percentages) represent regions that have higher levels of statistical significance according to a Monte Carlo test (see details in methodology). In these plots, a significance level of 5% means that there is a 5% chance that the anomalies arise from random chance (also known as the 95% confidence level).

 

 

 

 

Phases 4-6 are very strongly associated with southeast ridging, and one could see the result of this just back in December when we took the full tour through 4-6. Now looking forward we have more mixed signals this time with an anticipated SSW event and splitting of the PV.. which would imply -AO and a consistent cold intrusion into the mid-latitudes. There's also the possibility that the forecasts for a stronger 4-5 phase don't occur... and these forecasts can be pretty inaccurate especially at longer range like anything else. But for now and the next several days or so, most of those models keep it in the circle or at a very low amplitude phase 4. Just another thing to keep an eye on as we watch how this pattern evolves this week and beyond following the lakes cutter. 

 

I'm not an MJO guru by any means and I'm sure there some other mets that could add some more details, but I figured I would at least point out what that significance percentage meant.

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It is a fairly valid concern if the MJO eventually ends up in a higher amplitude phase 4-5 as the Euro and UK models have been especially suggesting on those MJO forecasts. The significance percentages are in fact the opposite of what you might think.. as in low significance percentage numbers indicate a high confidence in the associated anomalies. 

 

As noted from the info section of that website:

 

 

Phases 4-6 are very strongly associated with southeast ridging, and one could see the result of this just back in December when we took the full tour through 4-6. Now looking forward we have more mixed signals this time with an anticipated SSW event and splitting of the PV.. which would imply -AO and a consistent cold intrusion into the mid-latitudes. There's also the possibility that the forecasts for a stronger 4-5 phase don't occur... and these forecasts can be pretty inaccurate especially at longer range like anything else. But for now and the next several days or so, most of those models keep it in the circle or at a very low amplitude phase 4. Just another thing to keep an eye on as we watch how this pattern evolves this week and beyond following the lakes cutter. 

 

I'm not an MJO guru by any means and I'm sure there some other mets that could add some more details, but I figured I would at least point out what that significance percentage meant.

Thx for your input. It helps.

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Bob, I didn't look at individual members, but the mean is still under 2". So that tells me we may have gained "some" support with some of the members you mentioned but probably lost some in others since the mean snowfall for the 15 days hasn't budged from yesterday's 12z.

 

If you flip the mean panels for the mid atlantic region between 0&12z you can see a significant move eastward and further south as well. The whole run was indicative of an overall colder look than the 0z run. The d8-10 thing will be fraught with peril no matter which way you slice it. Beyond that looked a good bit better for our chances. PV goes to SE canada for a time on the means. That's good for us in the MA. 

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If you flip the mean panels for the mid atlantic region between 0&12z you can see a significant move eastward and further south as well. The whole run was indicative of an overall colder look than the 0z run. The d8-10 thing will be fraught with peril no matter which way you slice it. Beyond that looked a good bit better for our chances. PV goes to SE canada for a time on the means. That's good for us in the MA. 

I never looked at the 0Z run so I was comparing it for our back yard to the 12Z run yesterday.

I wish I had gotten Wxbell before the bliz so I could see what real ensemble forecasts look like.  :cry:

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It is a fairly valid concern if the MJO eventually ends up in a higher amplitude phase 4-5 as the Euro and UK models have been especially suggesting on those MJO forecasts. The significance percentages are in fact the opposite of what you might think.. as in low significance percentage numbers indicate a high confidence in the associated anomalies. 

 

As noted from the info section of that website:

 

 

Phases 4-6 are very strongly associated with southeast ridging, and one could see the result of this just back in December when we took the full tour through 4-6. Now looking forward we have more mixed signals this time with an anticipated SSW event and splitting of the PV.. which would imply -AO and a consistent cold intrusion into the mid-latitudes. There's also the possibility that the forecasts for a stronger 4-5 phase don't occur... and these forecasts can be pretty inaccurate especially at longer range like anything else. But for now and the next several days or so, most of those models keep it in the circle or at a very low amplitude phase 4. Just another thing to keep an eye on as we watch how this pattern evolves this week and beyond following the lakes cutter. 

 

I'm not an MJO guru by any means and I'm sure there some other mets that could add some more details, but I figured I would at least point out what that significance percentage meant.

Thank you so much! That was enlightening to me. I should have realized the differences between the confidence and significance levels.

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I never looked at the 0Z run so I was comparing it for our back yard to the 12Z run yesterday.

I wish I had gotten Wxbell before the bliz so I could see what real ensemble forecasts look like.  :cry:

Weatheronline isn't so bad for comparing ensemble trends. http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=namk&MODELL=ecmwfens&MODELLTYP=2&BASE=201601240000&VAR=t85p&HH=120&ZOOM=0&WMO=&ARCHIV=0&RES=0

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I compared the last 4 GEFS runs and unsurprisingly the LR flip to AN temps keeps getting pushed back in time.

The GFS has been bad this winter as far as long range stuff. It did the same thing back in early January when we went into the normal to slightly below normal pattern. It continually tried breaking it down beyond day 12 and we ended up in it almost the whole month. The EURO however continually showed days 11-15 normal to below

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The GFS has been bad this winter as far as long range stuff. It did the same thing back in early January when we went into the normal to slightly below normal pattern. It continually tried breaking it down beyond day 12 and we ended up in it almost the whole month. The EURO however continually showed days 11-15 normal to below

This is very true with one exception. It locked on to the blizzard at about 156 hours iirc and never let go.

For that reason alone I'm curious to see what it does at 18z with the system about a week from today.

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The GFS has been bad this winter as far as long range stuff. It did the same thing back in early January when we went into the normal to slightly below normal pattern. It continually tried breaking it down beyond day 12 and we ended up in it almost the whole month. The EURO however continually showed days 11-15 normal to below

 

I've noticed it as well. I think I posted yesterday the same thing about January. I remembered worrying in early Jan about those GEFS runs. 

 

Both GEFS and Euro ens went colder in the LR with the 12z runs. I think were good for a while temp wise. Now combining that with precip could be challenging. I'm just going to hug the 12z para gfs for now until something better comes along. lol

 

gfs_namer_384_850_temp_mslp_precip.gif

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This is very true with one exception. It locked on to the blizzard at about 156 hours iirc and never let go.

For that reason alone I'm curious to see what it does at 18z with the system about a week from today.

 

He was talking about the GEFS in the d11-15 range.

 

GFS op inside of 7 days has been decent all year for the most part. It will struggle like any model at times but overall the GFS has proven to be a very useful mid range tool. The only weird thing it did (and will likely do again) is unusual precip distribution with a rapidly strengthening coastal storm. That's something to keep in the back of the mind next time one pops up.

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Ugh, snow on the doorstep at 165...totally different evolution with CAD and low running into it, but will likely ultimately fail.  GL low is still there but encouragingly farther north and west/slower.

 

That 1030hp leading in is starting to show up a lot more. The good euro ens members all had it. Hmmm.... Still a jacked up evolution but all hope is not lost. Plus I need the 10 grand from Mitch. 2 kids in college is killing me. 

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That 1030hp leading in is starting to show up a lot more. The good euro ens members all had it. Hmmm.... Still a jacked up evolution but all hope is not lost. Plus I need the 10 grand from Mitch. 2 kids in college is killing me. 

Mitch, I love you, but I hope you go down hard.  I'm actually encouraged because the GFS continues with that high showing up a lot more.  

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He was talking about the GEFS in the d11-15 range.

GFS op inside of 7 days has been decent all year for the most part. It will struggle like any model at times but overall the GFS has proven to be a very useful mid range tool. The only weird thing it did (and will likely do again) is unusual precip distribution with a rapidly strengthening coastal storm. That's something to keep in the back of the mind next time one pops up.

Not sure I agree here. It has had big shifts at days 6+ from time to time. I brought this up as far back as December. This latest 18 z run is a good example. Yesterday I made a post about big changes from the previous day.

As for this latest run, interesting that the gl low is much further north. There's cad like you were talking about on the euro.

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